Contact Lenses and Eyeglasses

Number: 0126

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

---

Policy

Scope of Policy

This Clinical Policy Bulletin addresses contact lenses and eyeglasses.

1. Medical Necessity

   Note: Many Aetna medical plans exclude coverage of contact lenses or eyeglasses.  Under medical plans with this exclusion, contact lenses are only covered under medical plans for a narrow set of therapeutic indications, as outlined below.  Additional coverage of contact lenses and eyeglasses may be provided under the member's vision care plan, if any.  Please check benefit plan descriptions for details.

   1. Replacement Eyeglasses Under Plans With a Pediatric Vision Benefit

      Some plans include a pediatric vision benefit. Please check benefit plan descriptions. Under these plans, replacement lenses are considered medically necessary for children and adolescents when one or more of the following criteria are met:

      1. There is a change in refractive error; or
      2. With regular use, the previous eyeglasses were broken or marred to a degree significantly interfering with vision or eye safety; or
      3. The eyeglasses are replaced because a different frame size or shape is necessary due to the child's growth, metal allergy or other justifiable medical reasons.

   2. Prosthetic Contact Lenses and Eyeglasses for Aphakia

      1. Medicare plans and HMO plans (HMO, QPOS)

         For Aetna Medicare plans and Aetna HMO plans, Aetna follows Medicare's rules for prosthetic lenses.

         For Aetna Medicare members and HMO members, Aetna considers external lenses (contacts or spectacles) and intraocular lenses medically necessary after cataract surgery.  Centers for Medicare and Medicaid Services (CMS) defines both types of lenses as “prostheses” replacing the lens of the eye.  This includes post-surgical external lenses that are customarily used during convalescence from cataract removal surgery.  In addition, an intraocular lens is considered a medically necessary prosthetic for individuals lacking an organic lens because of surgical removal (e.g., cataract surgery) or congenital absence (congenital aphakia).  Note: Aetna covers medically necessary external and internal lenses as prosthetics for aphakic members even if the surgical removal of the member's lens occurred before the member enrolled in Aetna's medical plan.

         For Medicare and HMO members, Aetna considers lenses or combinations of lenses medically necessary following cataract surgery to essentially restore the vision provided by the crystalline lens of the eye, including:

         • Bifocal spectacles; or
         • Spectacles for far vision or for near vision; or
         • Aetna considers contact lenses for far vision (including cases of binocular and monocular aphakia) medically necessary, including both the contact lens(es) and spectacles for near vision that are worn either simultaneously with the contact lenses or when the contact lenses have been removed.

         For Medicare members and HMO members, Aetna medical plans consider lenses with ultraviolet (UV) protection medically necessary in lieu of regular (untinted) lenses for aphakia.  UV coating is considered medically necessary when applied to a glass lens material.

         Anti-reflective coating, tints, or oversize lenses are not generally considered medically necessary; the medical necessity of such features must be documented by the treating physician.

         Aetna considers cataract sunglasses (i.e., tinted lenses, including photochromatic lenses (lenses in which the tint changes in response to light)) that are prescribed in addition to regular (untinted) lenses for aphakia medically necessary because the sunglasses duplicate the restoration of vision function performed by the regular lenses.

         Aetna considers contact lenses (including colored, painted, and tinted contact lenses) medically necessary as a prosthetic to reduce glare and light sensitivity / photophobia, and optimize visual acuity in members with aniridia.

         Aetna considers the following features not medically necessary:

         • Eyeglass cases;
         • Mirror coating (colored, highly-reflective lens treatments);
         • Polarization;
         • Progressive lenses (i.e., multifocal lens that gradually changes in lens power from the top to the bottom of the lens, eliminating the lines that would otherwise be seen in a bifocal or trifocal lens);
         • Scratch resistant coating.

         Lenses made of polycarbonate or other impact-resistant materials (e.g., Trivex) are considered medically necessary for members with functional vision in only one eye.  Use of polycarbonate or similar material or high index glass or plastic for indications such as light weight or thinness is considered not medically necessary.

         Standard eyeglass frames are considered medically necessary for persons who meet criteria for refractive lenses.  Deluxe frames are considered convenience items.

         Under Medicare and HMO plans, Aetna considers eyewear a medically necessary prosthetic for aphakic members who have not had an intraocular lens replacement. Additionally, Aetna considers aphakic contact lenses medically necessary under Medicare and HMO plans as prosthetics for infants with aphakia after congenital cataract surgery and who have not had intraocular lens implantation. Aphakic members lack an internal lens where their contact lenses or eyeglasses are considered to be prosthetics.  For Medicare and HMO plans, Aetna medical plans consider medically necessary the first pair of glasses or aphakia contact lenses after cataract surgery and an additional pair of lens(es) each time the member's prescription changes.  Requests for replacement of lost or broken glasses or lenses will be reviewed on an individual basis. (There is a CMS requirement for consideration of replacement of lost or broken contact lenses or eyeglasses for Medicare members who have had cataract surgery.)

         Note: For Medicare and HMO members who have had cataract surgery with insertion of an intraocular lens (IOL), Aetna Medicare and HMO plans, by administration, will cover no more than 1 pair of eyeglasses or contact lenses after each cataract surgery.  Replacements of conventional eyeglasses or contact lenses are not covered under these medical plans.  The member may have additional eyewear coverage through a vision care rider.

      2. Traditional (non-HMO) plans (Indemnity, PPO and MC POS plans)

         While contact lenses and eyeglasses are rarely used in place of intraocular lenses in aphakia, contact lenses and eyeglasses are considered medically necessary under traditional medical plans as a prosthetic device following cataract surgery in lieu of intraocular lenses. Additionally, Aetna considers aphakic contact lenses medically necessary under traditional plans as prosthetics for infants with aphakia after congenital cataract surgery and who have not had intraocular lens implantation. Aphakic members lack an internal lens where their contact lenses or eyeglasses are considered to be prosthetics. For traditional plans, Aetna medical plans consider medically necessary the first pair of glasses or aphakia contact lenses after cataract surgery and an additional pair of lens(es) each time the member's prescription changes. Note: Most Aetna plans exclude coverage of contact lenses and spectacles.  Under these plans, eyeglasses and contact lenses in non-aphakic members, including those who have had intraocular lenses implanted after cataract surgery, are not covered under medical plans.  Contact lenses and eyeglasses may be covered under the member's vision care plan.

   3. Therapeutic Hydrophilic Contact Lenses (Corneal Bandage)

      Therapeutic soft (hydrophilic) contact lenses or gas-permeable fluid ventilated scleral lenses (e.g., Boston Scleral Lens and PVR PROSE Scleral Lens) are considered medically necessary prosthetics under medical plans where used as moist corneal bandages for the treatment of severe ocular surface diseases, including

      1. Corneal stem cell deficiency (Stevens-Johnson syndrome/TEN, chemical and thermal injuries to the eye including surgical procedures, aniridia, idiopathic corneal stem cell deficiency and ocular pemphigoid); or
      2. Neurotrophic (anesthetic) corneas, such as may result from:
         
         
         1. Acquired etiologies, such as may result from acoustic neuroma surgery, trigeminal ganglionectomy, trigeminal rhyzotomy, herpes simplex/zoster of the cornea, diabetes; or
         2. Congenital etiologies, such as congenital corneal anesthesia (familial dysautonomia), Seckle's syndrome; or
      3. Severe dry eyes (keratoconjunctivitis sicca) (such as from Sjogren's syndrome, chronic graft versus host disease, radiation, surgery, meibomian gland deficiency); or
      4. Corneal disorders associated with systemic autoimmune diseases (rheumatoid arthritis, dermatological disorders such as atopic, epidermolysis bullosa, epidermal dysplasia); or
      5. Epidermal ocular disorders (atopy, ectodermal dysplasia, epidermolysis bullosa); or
      6. Corneal exposure (e.g., anatomic, paralytic).

      Note: Liquid bandage scleral lenses are covered under plans that exclude coverage of contact lenses, as these lenses are not primarily for correction of refractive errors.

      Note: For scleral lenses for masking irregular astigmatism, see section below. 

      Replacement lenses are considered medically necessary under medical plans if required because of a change in the patient's physical condition (not including refractive changes). Note: Charges to replace contact lenses that are lost, damaged, or required solely due to refractive changes are not covered under medical plans.

   4. Scleral Shells

      Scleral shells are considered medically necessary under medical plans when prescribed to support orbital tissue (such as where an eye has been rendered sightless and shrunken by inflammatory disease).

   5. Replacement Lenses

      Replacement lenses are considered medically necessary under medical plans if required because of a change in the member's physical condition (not including refractive changes). 

      Note: Charges to replace contact lenses that are lost, damaged, or required solely due to refractive changes are not covered under medical plans.

      Note: Scleral shell lenses are covered under plans that exclude coverage of contact lenses, as scleral shell lenses are not primarily for correction of refractive errors.

   6. Contact Lenses and Eyeglasses for Accidental Injury

      An initial pair of contact lenses or eyeglasses is considered medically necessary under medical plans when they are prescribed by a physician to correct a change in vision directly resulting from an accidental bodily injury.  Note: Charges to replace such contact lenses or eyeglasses are not covered under medical plans.

   7. Contact Lenses for Masking Irregular Astigmatism Associated with Keratoconus and Other Corneal Disorders

      Aetna considers services that are part of an evaluation of keratoconus or other corneal disorders associated with irregular astigmatism (e.g., keratoglobus, pellucid corneal degeneration, Terrien's marginal degeneration, post-LASIK ectasia, corneal scarring) medically necessary.  This includes the general examination, advanced corneal topographic modeling, and fitting of contact lenses or scleral lenses.

      Note: Most Aetna medical benefit plans exclude coverage of contact lenses and other vision aids.  Please check benefit plan descriptions for details.  These benefit plans do not cover contact lenses or scleral lenses for correcting astigmatism associated with keratoconus or other corneal disorders under medical plans that exclude coverage of contact lenses and eyeglasses.  This includes corneal contact lenses and scleral lenses that may be prescribed for masking irregular astigmatism associated with corneal ectasia (e.g., keratoconus, keratoglobus, pellucid corneal degeneration, Terriens marginal degeneration, post-LASIK ectasia), post-operative astigmatism (e.g., following refractive surgery or corneal transplant), corneal scarring (e.g., from trauma, infection, or Hydrops), and anterior corneal dystrophies (e.g. Meesman's, Cogan's).  Contact lenses and scleral lenses provided to members with keratoconus and other corneal disorders associated with irregular astigmatism are covered under the provisions of the member's vision care plan only.

   8. Contact Lenses for Myopia Management

      Aetna considers the following contact lenses for myopia management medically necessary when criteria are met. Note: Aetna standard medical benefit plans exclude coverage of vision aids, contact lenses and eyeglasses, and surgery to correct refractive errors; the following would be excluded from coverage under those plans. Please check benefit plan descriptions for details.
      

      1. Acuvue Abiliti Overnight Therapeutic Lenses 

         For correction of myopia in persons with myopia of up to 4 diopters (D) and no more than 1.5 D of astigmatism. 

      2. MiSight 1 Day Soft Contact Lenses 

         For correction of myopic ametropia and for slowing the progression of myopia in children with non-diseased eyes, who at the initiation of treatment, are 8 to 12 years of age and have a refraction of -0.75 to -4.00 D (spherical equivalent) with less than or equal to 0.75 D of astigmatism.

   9. Echo Frames/Smart Audio Glasses

      Aetna considers Echo Frames/smart audio glasses not medically necessary.

   Note: Some HMO plans cover only an initial prosthetic, and exclude coverage of replacements of prosthetics regardless of medical necessity.  Under these plans, only an initial set of glasses or contact lenses are covered under the medical plan.  Please check benefit plan descriptions for details.

2. Experimental, Investigational, or Unproven

   The following procedures are considered experimental, investigational, or unproven because the effectiveness of these approaches has not been established:

   1. Blue light filtering contact lenses for improvement of sleep, and use of electronic devices
   2. Corneal bandages for all other indications (except for the ones listed above)
   3. Hydrogel-embedded contact lens for ocular drug delivery 
   4. MiSight 1 Day Soft Contact Lenses for all other indications (except for the ones listed above)
   5. Orthokeratology lenses for correction of myopia and for all other indications (except for Acuvue Abiliti overnight therapeutic lenses; see above).

3. Policy Limitations and Exclusions

   Note: Many Aetna medical plans exclude coverage of contact lenses or eyeglasses.  Under medical plans with this exclusion, contact lenses are only covered under medical plans for a narrow set of therapeutic indications, as outlined below.  Additional coverage of contact lenses and eyeglasses may be provided under the member's vision care plan, if any.  Please check benefit plan descriptions for details.

4. Related Policies

   1. CPB 0023 - Corneal Remodeling
   2. CPB 0508 - Cataract Surgery

---

Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
Prosthetic Contact Lenses and Eyeglasses for Aphakia:
CPT codes covered if selection criteria are met:
92311	Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneal lens for aphakia, 1 eye
92312	corneal lens for aphakia, both eyes
92315	Prescription of optical and physical characteristics of contact lens, with medical supervision of adaptation and direction of fitting by independent technician; corneal lens for aphakia, 1 eye
92316	corneal lens for aphakia, both eyes
92326	Replacement of contact lens
92352 - 92353	Fitting of spectacle prosthesis for aphakia
92358	Prosthesis service for aphakia, temporary (disposable or loan, including materials)
CPT codes not covered for indications listed in the CPB:
92371	Repair and refitting spectacles; spectacle prosthesis for aphakia
HCPCS codes covered if selection criteria are met:
S0592	Comprehensive contact lens evaluation
V2020	Frames, purchases
V2100 - V2499	Eyeglasses
V2500 – V2525, V2530 - V2599	Contact lens [except V2526]
V2630 - V2632	Intraocular lenses
V2782	Lens, index 1.54 to 1.65 plastic or 1.60 to 1.79 glass, excludes polycarbonate, per lens
V2783	Lens, index greater than or equal to 1.66 plastic or greater than or equal to 1.80 glass, excludes polycarbonate, per lens
V2784	Lens, polycarbonate or equal, any index, per lens
HCPCS codes not covered for indications listed in the CPB:
S0504	Single vision prescription lens (safety, athletic, or sunglass), per lens
S0506	Bifocal vision prescription lens (safety, athletic, or sunglass), per lens
S0508	Trifocal vision prescription lens (safety, athletic, or sunglass), per lens
S0510	Non-prescription lens (safety, athletic, or sunglass), per lens
S0514	Color contact lens, per lens
S0516	Safety eyeglass frames
S0518	Sunglasses frames
S0580	Polycarbonate lens (list this code in addition to the basic code for the lens)
S0581	Nonstandard lens (list this code in addition to the basic code for the lens)
S0590	Integral lens service, miscellaneous services reported separately
S0595	Dispensing new spectacle lenses for patient supplied frame
V2025	Deluxe frame
V2526	Contact lens, hydrophilic, spherical, photochromic additive, per lens
V2702	Deluxe lens feature
V2744	Tint, photochromatic, per lens
V2745	Addition to lens; tint, any color, solid, gradient or equal, excludes photochromatic, any lens material, per lens
V2750	Antireflective coating, per lens
V2756	Eye glass case
V2760	Scratch resistant coating, per lens
V2761	Mirror coating, any type, solid, gradient or equal, any lens material, per lens
V2762	Polarization, any lens material, per lens
V2780	Oversize lens, per lens
V2781	Progressive lens, per lens
V2786	Specialty occupational multifocal lens, per lens
ICD-10 codes covered if selection criteria are met:
H25.011 - H26.9	Cataract
H27.00 - H27.03	Aphakia
Q12.0	Congenital cataract
Q12.3	Congenital aphakia
Z96.1	Presence of intraocular lens
Z98.41 - Z98.49	Cataract extraction status
Contact lenses (including colored, painted and tinted contact lenses) for aniridia:
CPT codes covered if selection criteria are met::
92310	Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneal lens, both eyes, except for aphakia
HCPCS codes covered if selection criteria are met:
S0500	Disposable contact lens, per lens
S0512	Daily wear specialty contact lens, per lens
S0514	Color contact lens, per lens
S0592	Comprehensive contact lens evaluation
V2500 – V2525, V2530 - V2599	Contact lenses
V2744	Tint, photochromatic, per lens
V2745	Addition to lens; tint, any color, solid, gradient or equal, excludes photochromatic, any lens material, per lens
ICD-10 codes covered if selection criteria are met:
Q13.1	Absence of iris
Therapeutic Hydrophilic Contact Lenses (Corneal Bandage):
CPT codes covered if selection criteria are met:
92071	Fitting of contact lens for treatment of ocular surface disease
92072	Fitting of contact lens for management of keratoconus, initial fitting
HCPCS codes covered if selection criteria are met:
S0515	Scleral lens, liquid bandage device, per lens
V2520 - V2523	Contact lens, hydrophilic
V2530	Contact lens, scleral, gas impermeable, per lens
V2531	Contact lens, scleral, gas permeable, per lens
ICD-10 codes covered if selection criteria are met:
B02.30 - B02.39	Zoster ocular disease
D89.811	Chronic graft-versus-host disease
G90.1	Familial dysautonomia [Riley-Day]
H02.881 - H02.88B	Meibomian gland dysfunction of eyelid
H04.121 - H04.129	Dry eye syndrome of lacrimal gland
H16.211 - H16.219	Exposure keratoconjunctivitis
H16.221 - H16.229	Keratoconjunctivitis sicca, not specified as Sjogren's
H16.231 - H16.239	Neutrophic keratoconjunctivitis
H18.811 - H18.819	Anesthesia and hypoesthesia of cornea
L12.1	Cicatricial pemphigoid
L20.0 - L20.9	Atopic dermatitis
L51.1	Stevens-Johnson syndrome
L51.2	Toxic epidermal necrolysis [Lyell]
L51.3	Stevens-Johnson syndrome-toxic epidermal necrolysis overlap syndrome
M05.00 - M06.9	Rheumatoid arthritis
M35.00 - M35.09	Sicca syndrome
Q13.1	Absence of iris
Q81.0 - Q81.9	Epidermolysis bullosa
Q82.4	Ectodermal dysplasia (anhidrotic)
Q87.89	Other specified congenital malformation syndromes, not elsewhere classified [Seckle's syndrome]
T26.00XA – T26.92XS	Burn and corrosion confined to eye and adnexa
T66.XXXA – T66.XXXS	Radiation sickness, unspecified [dry eyes due to radiation]
Scleral Shell Contact Lenses:
CPT codes covered if selection criteria are met:
92313	Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneoscleral lens
92317	Prescription of optical and physical characteristics of contact lens, with medical supervision of adaptation and direction of fitting by independent technician; corneoscleral lens
HCPCS codes covered if selection criteria are met:
V2627	Scleral cover shell
ICD-10 codes covered if selection criteria are met:
H05.10	Unspecified chronic inflammatory disorders of orbit
H05.30 - H05.359	Deformity of orbit
H44.521-H44.529	Atrophy of globe
Contact Lenses and Eyeglasses for Accidental Injury:
CPT codes covered if selection criteria are met:
92310	Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneal lens, both eyes, except for aphakia [initial]
92314	Prescription of optical and physical characteristics of contact lens, with medical supervision of adaptation and direction of fitting by independent technician; corneal lens, both eyes except for aphakia [initial]
CPT codes not covered for indications listed in the CPB:
92326	Replacement of contact lens
ICD-10 codes covered if selection criteria are met:
H44.601 - H44.799	Retained (old) intraocular foreign body
S00.10XA – S00.12XS	Contusion of eyelid and periocular area
S00.201A – S00.279S	Superficial injuries of eyelid and periocular area
S01.101A – S01.159S	Open wound of eyelid and periocular area
T15.00XA – T15.92XS	Foreign body on external eye
Z87.821	Personal history of retained foreign body fully removed
Numerous options	Burn of eye, face, head, and neck, sequela [Codes not listed due to expanded specificity]
Numerous options	Open wound of head, neck, and trunk, sequela [Codes not listed due to expanded specificity]
Contact Lenses for Masking Irregular Astigmatism Associated with Keratoconus and Other Corneal Disorders:
CPT codes covered if selection criteria are met:
92025	Computerized corneal topography, unilateral or bilateral, with interpretation and report
92071	Fitting of contact lens for treatment of ocular surface disease
92072	Fitting of contact lens for management of keratoconus, initial fitting
HCPCS codes covered if selection criteria are met:
S0592	Comprehensive contact lens evaluation
V2500 – V2513	Contact lens
ICD-10 codes covered if selection criteria are met:
H17.00 - H17.9	Corneal scars and opacities
H18.40 - H18.9	Corneal degeneration
H18.601 - H18.629	Keratoconus
H18.711 - H18.719	Corneal ectasia [post-LASIK]
Q13.4	Other congenital corneal malformations
Q15.0	Congenital glaucoma [keratoglobus]
Contacts for Myopia Management:
CPT codes covered if selection criteria are met:
92310	Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneal lens, both eyes, except for aphakia [initial]
92314	Prescription of optical and physical characteristics of contact lens, with medical supervision of adaptation and direction of fitting by independent technician; corneal lens, both eyes except for aphakia [initial]
HCPCS codes covered if selection criteria are met:
Acuvue Abiliti Overnight Therapeutic Lenses -no specific code
S0592	Comprehensive contact lens evaluation
V2525	Contact lens, hydrophilis, dual focus, per lens [MiSight 1 Day]
ICD-10 codes covered if selection criteria are met::
H52.10 – H52.13	Myopia
Echo Frames/smart audio glasses:
HCPCS codes not covered for indications listed in the CPB:
Echo Frames/smart audio glasses – no specific code
Hydrogel-embedded contact lens for ocular drug delivery:
HCPCS codes not covered for indications listed in the CPB:
Hydrogel-embedded contact lens for ocular drug delivery - no specific code

---

Background

Therapeutic soft hydrophilic contact lenses are made of poly-2-hydroxyethyl methacrylate and other flexible plastics. They are about 13 to 15 mm in diameter and cover the entire cornea. Hydrophilic contact lenses may be prescribed for the treatment of bullous keratopathy and other corneal disorders (bandage lenses). Prophylactic antibiotic eye-drops may be used with a bandage lens. Most therapeutic eye-drops can be used with hydrophilic lenses.

The Boston Scleral Lens is a fluid-ventilated scleral lens designed to enclose aqueous fluid over the corneal surface. The scleral lens acts as a corneal bandage, and can mask irregular astigmatism.  The scleral lens rests entirely on the sclera and avoids all contact with the cornea.  Thus, the scleral lens can be used by persons who are intolerant to standard (hard) contact lenses, which rest on the sensitive cornea. The Boston Scleral lens has a series of channels that aspirate tears into the fluid reservoir while preventing the formation of air bubbles in the reservoir.

Scleral shell (or shield) is a catchall term for different types of hard scleral contact lenses. A scleral shell fits over the entire exposed surface of the eye as opposed to a corneal contact lens that covers only the central nonwhite area encompassing the pupil and iris.

When an eye has been rendered sightless and shrunken by inflammatory disease, a scleral shell may, among other things, obviate the need for surgical enucleation and prosthetic implant and act to support the surrounding tissue. In such a case, the device serves essentially as an artificial eye.

Scleral shells are occasionally used in connection with artificial tears in the treatment of "dry eye" of diverse etiology. Tears ordinarily dry at a rapid rate, and are continually replaced by the lacrimal gland. When the lacrimal gland fails, the half-life of artificial tears may be greatly prolonged by the use of the scleral shell contact lens as a protective barrier against the drying action of the atmosphere. Thus, the difficult and sometimes hazardous process of frequent instillation of artificial tears may be avoided. The lens acts in this instance to substitute, in part, for the functioning of the diseased lacrimal glands and would be considered a prosthetic device in the rare case when it is used in the treatment of dry eye.

Aphakic Contact Lenses for Infants with Aphakia

Lambert and colleagues (2014) conducted the Infant Aphakia Treatment Study, a multi-center, randomized clinical trial (RCT), comparing the visual outcomes of patients optically corrected with contact lenses versus intraocular lens (IOL) implantation following unilateral cataract surgery in early infancy. This RCT consisted of 114 infants with unilateral congenital cataracts with 5 years of follow-up and visual acuity assessment at 4.5 years of age. The median logMAR visual acuity was not significantly different between the treated eyes in the 2 treatment groups (both, 0.90 (20/159); p=0.54). About 50% of treated eyes in both groups had visual acuity ≤20/200. Significantly more patients in the IOL group had at least 1 adverse event after cataract surgery (contact lens, 56%; IOL, 81%; p=.016). The most common adverse events in the IOL group included lens reproliferation into the visual axis, pupillary membranes and corectopia. Glaucoma/glaucoma suspect occurred in 35% of treated eyes in the contact lens group vs. 28% of eyes in the IOL group (p=.55). Since the initial cataract surgery, significantly more patients in the IOL group have had at least 1 additional intraocular surgery (contact lens, 21%; IOL, 72%; p<.0001). No significant difference was observed between the medial visual acuity of operated eyes in children who underwent primary IOL implantation and those left aphakic. However, the IOL group had significantly more adverse events and additional intraoperative procedures. The investigators recommended leaving the eye aphakic and focusing the eye with a contact lens when operating on an infant with a unilateral cataract < 7 months of age. Furthermore, primary IOL implantation should be reserved for infants the surgeon believes that the burden of cost and handling of a contact lens may result in significant periods of uncorrected aphakia.

VanderVeen and colleagues (2021) reported outcomes of secondary intraocular lens (IOL) implantation in the Infant Aphakia Treatment Study (IATS), a multicenter, randomized clinical trial. The investigators evaluated visual outcomes, refractive outcomes, and adverse events at age 10 1/2 years. Eyes that remained aphakic eyes were compared to eyes randomized to primary IOL placement. Fifty-five out of fifty-seven patients randomized to aphakia with contact lens correction were seen for the 10 ½ year study visit; 24/55 eyes (44%) had secondary IOL surgery. Median age at IOL surgery was 5.4 years (range 1.7 to 10.3 years). Mean absolute prediction error was 1.0 ± 0.7D. At age 10 ½ years, the median log MAR VA was 0.9 (range 0.2 to 1.7), similar to VA in the 31 eyes still aphakic (0.8, range 0.1 to 2.9); the number of eyes with stable or improved VA scores between the 4 ½ and 10 ½ year study visits was also similar (78% secondary IOL eyes, 84% aphakic eyes). For eyes undergoing IOL implantation after the 4.5 year study visit (n=22), the mean refraction at age 10 ½ years was −3.2 ±2.7D (range −9.9D to 1.1D), compared to −5.5 ±6.6 D (n=53, range −26.5 to 3.0D) in eyes with primary IOL (p=0.03). The investigators concluded that delayed IOL implantation provides a more predictable refractive outcome at age 10 1/2 years, though the range of refractive error is still large.

Contact Lenses for Myopia Management

Acuvue Abiliti Overnight Therapeutic Lenses

Acuvue Abiliti Overnight Therapeutic Lenses (Johnson & Johnson Vision Care, Inc) were U.S. FDA-approved in May 2021 for the management of nearsightedness (myopia) in non-diseased eyes when prescribed and managed by a qualified eye professional. The lenses are indicated for overnight wear for the temporary reduction of myopia up to 4.00 diopters (D) with eyes having astigmatism up to 1.50 D, and subject to the eye care professional’s myopia management plan, may eliminate the need to wear contact lenses or glasses throughout the waking hours after lenses are removed. The lenses are manufactured from Menicon Z (tisilfocon A) (Johnson & Johnson, 2021a).

Acuvue Abiliti Overnight are orthokeratology (ortho-k) contact lenses that are specifically designed and fitted to match a patient’s eye based on its unique corneal shape to temporarily reshape the cornea during sleep with the goal of correcting myopia during the day without correction. The lenses produce a temporary reduction of myopia by changing the shape (flattening) of the cornea. Flattening the cornea reduces the focusing power of the eye, and if the amount of corneal flattening is properly controlled, it is possible to bring the eye into correct focus and completely compensate for myopia. Thus, these lenses are designed to purposely flatten the shape of the cornea by applying slight pressure to the center of the cornea when the patient is asleep. After the lens is removed, the cornea retains its altered shape for all or part of the remainder of the day. The lenses are to be worn overnight with removal during the following day. The lenses must be worn at night on a regular schedule to maintain the orthokeratology effect, or the myopia will revert to the pre-treatment level (Johnson & Johnson, 2021a, 2021b). 

Acuvue Abiliti Overnight lenses are optimized by the use of corneal topography, refractive error and other measurements connected to an experiential fitting software, FitAbiliti. The FitAbiliti software guides the eye care professional through the fitting process and recommends a lens. Abiliti Overnight lenses will be available in two different contact lens designs: Acuvue Abiliti Overnight Therapeutic Lenses for Myopia Management, and Acuvue Abiliti Overnight Therapeutic Lenses for Myopia Management for Astigmatism (Johnson & Johnson, 2021b).

FDA approval was based on a study that evaluated a total of 300 eyes (150 patients) with 274 eyes (137 patients) completing a minimum of 12 months of contact lens wear. Data on 252 eyes were analyzed after 12 months of wear. A total of 251 eyes showed some reduction in myopic refractive error. The average reduction was -2.48 diopters with a range from -0.25 to -4.00 diopters. The amount of myopia reduction varied between patients and could not be predicted prior to treatment. The Acuvue Abiliti Overnight provided a temporary full reduction in some patients with up to -4.00 diopters of myopia. A total of 185 (73%) eyes achieved a visual acuity of 20/20 or better and 242 (96%) eyes achieved 20/40 or better. For the 252 eyes analyzed after 12 months of wear, 55% had no change in or improved best spectacle-corrected visual acuity (BSCVA), while 38% had a loss of 1 line in BSCVA compared to baseline. Four eyes (2 patients) showed a constant reduction of greater than or equal to 2 lines of BSCVA from initial visit to 12-month visit. Reasons of the vision loss were not accurately determined in these cases; however, no significant ocular abnormalities were observed in these eyes at the time of study exit. Of the 252 eyes with initial cylinder power ranging from 0 to 1.50 D, changes in astigmatism after 12 months of wear found decrease from 0.25 to 0.50 D on 85 eyes (34%); decrease from 0.75 to 1.00 D on 71 (28%) of eyes; and decrease greater than or equal to 1.25 D on 14 (6%) of eyes. No astigmatism change was found in 81 (32%) of eyes (Johnson & Johnson, 2021a).

Labeled contraindications include the following:

• Acute and sub-acute inflammation or infection of the anterior chamber of the eye
• Any eye disease, injury, or abnormality that affects the cornea, conjunctiva or eyelids
• Dry eyes
• Reduced corneal sensitivity
• Any systemic disease which may affect the eye or be exacerbated by wearing contact lenses
• Allergic reactions of ocular surfaces or adnexa which may be induced or exaggerated by wearing contact lenses or use of contact lens solutions
• Allergy to any ingredient, such as mercury or thimerosal, in a solution which is to be used to care for the Acuvue Abiliti Overnight
• Any active corneal infection (bacterial, fungal or viral)
• If eyes are red or irritated.

Per the label, it is not expected that the lenses will provide a risk that is greater than other overnight wear rigid gas permeable contact lenses. The most common side effects which occur in general rigid contact lens wearers are corneal edema and corneal staining. It is anticipated that these two side effects can also occur in some wearers of Acuvue Abiliti Overnight. Other side effects, which may occur, include pain, redness, tearing, irritation, discharge, or abrasion of the eye. When overnight orthokeratology lenses dislocate during sleep, transient distorted vision may occur the following morning after removal of the lenses. This distortion may not be corrected with spectacle lenses. The duration of the distorted vision would rarely be greater than the duration of the daily visual improvement normally achieved with the lenses (Johnson & Johnson, 2021a).

MiSight 1 Day Soft Contact Lenses

MiSight 1 Day soft contact lenses for daily wear (Cooper Vision, Inc.) were FDA-approved in 2019 for the correction of myopic ametropia and for slowing the progression of myopia in children with non-diseased eyes, who at the initiation of treatment are 8 to 12 years of age and have a refraction of -0.75 to -4.00 diopters (spherical equivalent) with ≤ 0.75 diopters of astigmatism. The MiSight soft contact lenses are meant to be worn daily to correct nearsightedness and slow the progression of myopia in children with healthy eyes. When placed on the eye, one part of the MiSight contact lens corrects the refractive error to improve distance vision in nearsighted eyes, similar to a standard corrective lens. In addition, concentric peripheral rings in the lens focus part of the light in front of the retina (the back of the eye). This is believed to reduce the stimulus causing the progression of myopia. MiSight contact lenses are made from a material containing 60% water and 40% omafilcon A. They are intended for single use, are disposable, and should be discarded at the end of each day, not worn overnight (FDA, 2019).

FDA approval was based on data obtained from a prospective clinical trial at four clinical sites and real-world evidence. The safety and effectiveness of MiSight was studied in a three-year randomized, controlled clinical trial by Chamberlain et al (2019) which showed that for the full three-year period, the progression in myopia of those wearing MiSight lenses was less than those wearing conventional soft contact lenses. In addition, subjects who used MiSight had less change in the axial length of the eyeball at each annual checkup. Over the course of the trial, there were no serious ocular adverse events in either arm of the study. Additionally, to estimate the rate of vision-threatening corneal infections (i.e., corneal ulcers) among children and adolescents who wear soft contact lenses daily, the FDA reviewed real world data from a retrospective analysis of medical records of 782 children ages 8 to 12 years old from seven community eye care clinics. The results showed a rate comparable to the rate of ulcer cases among adults who wear contact lenses daily (FDA, 2019).

Chamberlain et al (2019) conducted a 3-year parallel-group, randomized, controlled, double-masked clinical trial to evaluate the effectiveness of the MiSight daily disposable soft contact lens in slowing the progression of juvenile-onset myopia. One-hundred-forty-four (144) myopic children (spherical equivalent refraction, -0.75 to -4.00 D; astigmatism, <1.00 D) aged 8 to 12 years with no prior contact lens experience were enrolled in this multicenter study. Subjects in each group were matched for age, sex, and ethnicity and were randomized to either a MiSight 1-day contact lens (test) or Proclear 1-day (control; omafilcon A) and worn on a daily disposable basis. Primary outcome measures were the change in cycloplegic spherical equivalent refraction (SERE) and axial length. Of the subjects enrolled, 75.5% (109/144) completed the clinical trial (53 test, 56 control). Unadjusted change in spherical equivalent refraction was -0.73 D (59%) less in the test group than in the control group (p < .001). Mean change in axial length was 0.32 mm (52%) less in the test group than in the control group (p < .001). Changes in SERE and axial length were highly correlated (r = -0.90, p < .001). Over the course of the study, there were no cases of serious ocular adverse events reported. Four asymptomatic corneal infiltrative (one test, three control) events were observed at scheduled study visits. The authors concluded that the results demonstrate the effectiveness of the MiSight daily disposable soft contact lens in slowing change in spherical equivalent refraction and axial length. 

Chalmers et al (2021) conducted a retrospective cohort review (ReCSS study) to estimate a rate of microbial keratitis and other adverse events in conventional daily wear soft contact lenses (SCL) in children initially fit between the ages of 8-12 years of age, ascertaining the safety of SCL wear in children in real-world clinical practice settings. The study reviewed clinical charts from 963 children: 782 patients in 7 US eye care clinics and 181 subjects from 2 international randomized clinical trials. Subjects were first fitted while 8 to 12 years old with various SCL designs, prescriptions and replacement schedules, and observed through to age 16. Clinical records from visits with potential adverse events (AEs) were electronically scanned and reviewed to consensus by an Adjudication Panel. The study encompassed 2713 years‐of‐wear and 4611 contact lens visits. The cohort was 46% male, 60% were first fitted with daily disposable SCLs, the average age at first fitting was 10.5 years old, with a mean of 2.8 ± 1.5 years‐of‐wear of follow‐up observed. There were 122 potential ocular AEs observed from 118/963 (12.2%) subjects; the annualized rate of non‐infectious inflammatory AEs was 0.66%/year (95% CI 0.39–1.05) and 0.48%/year (0.25–0.82) for contact lens papillary conjunctivitis. After adjudication, two presumed or probable microbial keratitis (MK) cases were identified, a rate of 7.4/10 000 years‐of‐wear (95% CI 1.8–29.6). Both were in teenage boys and one resulted in a small scar without loss of visual acuity. The authors concluded that this estimated the MK rate and the rate of other inflammatory AEs in a cohort of SCL wearers from 8 through to 16 years of age. Both rates are comparable to established rates among adults wearing SCLs.

Each lens is supplied sterile in a blister containing buffered isotonic saline solution. For best results, it is recommended that the patient wears the lens for a minimum of 10 hours per day for at least 6 days per week. Daily wear lenses are not indicated for overnight wear, and patients should be instructed not to wear lenses while sleeping.

PVR-PROSE Scleral Lens

PVR PROSE Treatment uses prosthetic lenses that are large-diameter gas permeable contact lenses, specially designed to vault over the entire corneal surface and rest on the "white" of the eye.  In doing so, PVR PROSE lenses functionally replace the irregular cornea with a perfectly smooth optical surface to correct vision problems caused by keratoconus, Lasik failures, post-surgical complications, and other corneal irregularities.  PVR PROSE lenses are designed to vault the corneal surface and rest on the less sensitive surface of the sclera, these lenses often are more comfortable for a person with corneal irregularities, like keratoconus.  A special liquid fills the space between the back surface of the lens and the front surface of the cornea.  This liquid acts as a buffer and protects the compromised corneal tissue.

Echo Frames/Smart Audio Glasses

Echo Frames are smart audio glasses that provide hands-free access to Alexa.  Customers can listen to audio entertainment, control their smart home, stay productive and organized, and communicate hands-free.  Echo Frames launched in 2019, are available in the U.S. only, and have over 5,300 customer reviews with a 4.2 out of 5-star rating.  Echo Frames are lightweight, IPX4 splash-resistant for water and sweat and are available in prescription ready frames, polarized sunglass lenses with UV400 protection or blue light filtering lenses.  However, there is a lack of evidence that the use of Echo Frames / smart audio glasses would improve health outcomes.

Mulfari et al (2017) noted that in the field of deep learning, this study presented the design of a wearable computer vision system for visually impaired users.  The Assistive Technology solution exploits a powerful single-board computer and smart glasses with a camera in order to allow its user to examine objects within his/her surrounding environment, while it employs Google TensorFlow machine learning framework in order to real time classify the acquired stills.  The authors concluded that the proposed aid could enhance the awareness of the explored environment and it interacted with its user by means of audio messages.

Caria et al (2019) stated that the growing interest in augmented reality (AR) systems is becoming increasingly evident in all production sectors.  However, to the authors' knowledge, a literature gap has been found with regard to the application of smart glasses for AR in the agriculture and livestock sector.  In fact, this technology allows farmers to manage animal husbandry in line with precision agriculture principles.  These researchers examined the performances of an AR head-wearable device as a valuable and integrative tool in precision livestock farming.  In this study, the GlassUp F4 Smart Glasses (F4SG) for AR were examined.  Laboratory and farm tests were carried out to examine the implementation of this new technology in livestock farms.  The results highlighted several advantages of F4SG applications in farm activities.  The clear and fast readability of the information related to a single issue, combined with the large number of readings that SG performed, allowed F4SG adoption even in large farms.  Furthermore, the 7 hours of battery life and the good quality of audio-video features highlighted their valuable attitude in remote assistance, supporting farmers on the field.  Nevertheless, other studies are needed to provide more findings for future development of software applications specifically designed for agricultural purposes.

Yoon et al (2021) noted that observation of medical trainees' care performance by experts can be extremely helpful for ensuring safety and providing quality care.  The advanced technology of smart glasses enables health professionals to video stream their operations to remote supporters for collaboration and cooperation.  This study monitored the clinical situation by using smart glasses for remote co-operative training via video streaming and clinical decision-making via simulation based on a scenario of emergency nursing care for patients with arrhythmia.  The clinical operations of bedside trainees, who is Google Glass Enterprise Edition 2 (Glass EE2) wearers, were live streamed via their Google Glasses, which were viewed at a remote site by remote supporters via a desktop computer.  Data were obtained from 31 nursing students using 8 essay questions regarding their experience as desktop-side remote supporters.  Most of the participants reported feeling uneasy regarding identifying clinical situations (84 %), patients' condition (72 %), and trainees' performance (69 %).  The current system demonstrated sufficient performance with a satisfactory level of image quality and auditory communication, while network and connectivity were areas that require further improvement.  The reported barriers to identifying situations on the remote desktop were predominantly a narrow field of view and motion blur in videos captured by Glass EE2s; and using the customized mirror mode.  The authors concluded that the current commercial Glass EE2 could facilitate enriched communication between remotely located supporters and trainees by sharing live videos and audio during clinical operations.  Moreover, these researchers stated that further improvement of hardware and software user interfaces are needed to ensure better applicability of smart glasses and video streaming functions to clinical practice settings.

Blue Light Filtering Contact Lenses

In a prospective, longitudinal, pilot study, Sanchez-Gonzalez et al (2021) examined the effect of contact lenses with blue light filters on contrast sensitivity and any alteration in tear quantity and quality.  This trial entailed 3 visits by each subject.  Monocular visual acuity (VA), contrast sensitivity (CS), phenol red thread test, and tear breakup time (TBUT) were measured at each visit.  There were significant differences in logarithmic CS between the groups.  The TBUT was significantly lower after using video display terminals than before (p < 0.05).  No differences in TBUT were observed between groups video display terminals and contact lenses having the blue filter (p > 0.05); however, higher mean values were observed in the group after video display terminal use with contact lenses having the blue filter than that with standard contact lenses (p > 0.05 in both groups).  In addition, the mean value of phenol red thread test on the group after video display terminal use with contact lenses having the blue filter was lower than the group before its use (p > 0.05).  The authors concluded that the findings of this study established a possible relationship between tear stability, improved CS, and the use of a blue filter in contact lenses.  These preliminary findings from a pilot study need to be validated by well-designed studies.

Furthermore ,the American Academy of Ophthalmology (AAO, 2023) noted that eyeglasses that claim to filter out blue light from computers, smartphones, and tablets are becoming increasingly popular.  Advertisements for these glasses claim that over-exposure to blue light can lead to various problems, including digital eye strain, sleep cycle disruption, or even blinding eye diseases; however, there is a lack of evidence that the blue light from screen of electronic devices is damaging to the eyes.  The AAO does not recommend any special eye-wear for computer use. 

An UpToDate review on “What's new in sleep medicine” (Eichler et al, 2023) states that “Lack of evidence that blue light-filtering lenses improve sleep -- Blue light-filtering glasses are marketed widely to reduce adverse effects of light-emitting screens on sleep, but supporting evidence is lacking.  A recent systematic review identified six small, randomized trials examining sleep outcomes with use of blue light-filtering lenses.  Trial results were inconsistent, and meta-analysis could not be performed due to high heterogeneity and lack of quantitative outcome data.  We counsel patients to avoid use of electronics at least 30 minutes before usual bedtime and in the middle of the night if nocturnal awakenings occur.  Based on available evidence, we advise that blue light-filtering glasses are not a substitute for avoidance of screens”.

Contact Lenses for Aniridia

Weissbart and Ayres (2016) stated that aniridia can be congenital or traumatic in etiology and can result in glare and other visual disturbances; therapeutic options include colored contact lenses, corneal tattooing, and corneal stromal implants, although these carry significant risks of infection and corneal scarring.  Prosthetic iris devices can often simultaneously treat aphakia or cataract as well as aniridia, and various models are currently available world-wide from Morcher GMBH (Germany), Ophtec USA Inc. (U.S.) and HumanOptics (Germany).  Surgical planning and technique are important in optimizing the safety of these devices.  The CustomFlex iris prosthesis from HumanOptics can be implanted within the capsular bag or ciliary sulcus with scleral fixation and offers excellent cosmetic outcomes.  Currently, the HumanOptics prosthetic iris is being examined in a multi-center clinical trial.

Vincent (2017) noted that ocular pathology that manifests at an early age has the potential to alter the vision-dependent emmetropisation mechanism, which co-ordinates ocular growth throughout childhood.  The disruption of this feedback mechanism in children with congenital or early-onset visual impairment often results in the development of significant ametropia, including high levels of spherical refractive error, astigmatism and anisometropia.  The author examined the use of contact lenses as a refractive correction, low vision aid and therapeutic intervention in the rehabilitation of patients with bilateral, irreversible visual loss due to congenital ocular disease.  The advantages and disadvantages of the use of contact lenses for increased magnification (telescopes and microscopes) or field expansion (reverse telescopes) were discussed, along with the benefits and practical considerations for the correction of pathological high myopia.  The historical and present use of therapeutic tinted contact lenses to reduce photo-sensitivity and nystagmus in achromatopsia, albinism and aniridia were also presented, including clinical considerations for the contact lens practitioner.  In addition to the known optical benefits in comparison to spectacles for high levels of ametropia (an improved field of view for myopes and fewer inherent oblique aberrations), contact lenses may be of significant psycho-social benefit for patients with low vision, due to enhanced cosmesis and reduced conspicuity and potential related effects of improved self-esteem and peer acceptance.

In a prospective, case-series study, Wang et al (2017) examined patients with congenital aniridia and cataract who underwent phacoemulsification, capsular tension ring placement, and foldable IOP implantation.  A total of 10 patients (17 eyes) underwent cataract surgery via a 3.2-mm clear corneal incision.  A continuous circular capsulorhexis with less than 6 mm diameter was employed.  A capsular tension ring and HOYA yellow foldable posterior chamber IOL lens was implanted.  All patients wore color contact lenses post-operatively.  Paired t-test was used to compare VA, intra-ocular pressure (IOP), and corneal endothelial changes before and after surgery.  A single surgeon carried out all surgeries.  The best-corrected visual acuity (BCVA) improved from value 1.03 ± 0.27LogMAR pre-operatively to value 0.78 ± 0.26LogMAR post-operatively (p = 0.000).  The photophobic symptoms improved significantly following surgery.  The mean corneal endothelial cell density before and after surgery was 3,280 ± 473 cells/mm2 and 2,669 ± 850 cells/mm2, respectively (p = 0.006).  None of the patients developed corneal endothelial decompensation or secondary glaucoma following surgery.  The authors concluded that treatment of congenital aniridia and co-existent cataract by phacoemulsification, posterior chamber foldable lens implantation, capsular tension ring placement was safe and effective.  Use of colored contact lenses in the post-operative period could reduce photophobic symptoms in this group of patients.

Miyoshi et al (2021) reported a case of fitting with a photochromic silicone hydrogel contact lens under a rigid gas-permeable lens (piggyback system) for photophobia and low-vision correction following traumatic aniridia and aphakia.  This case entailed a 40-year-old woman who was referred to the authors’ practice for contact lens fitting in her right eye, which was left aphakic after an open globe injury.  She also presented with traumatic aniridia in the right eye, and her left eye had been previously eviscerated.  A successful fitting was obtained with a photochromic silicone hydrogel (senofilcon A) contact lens, with a Dk/t of 121 × 10-9, under an aspheric design, +13.00 D rigid gas-permeable lens.  The patient displayed VA and contrast sensitivity improvement and reported decreased photophobia.

Tibrewal et al (2022) stated that congenital aniridia is a pan-ocular disorder characterized by partial or total loss of iris tissue as the defining feature.  Classic aniridia, however, has a spectrum of ocular findings, including foveal hypoplasia, optic nerve hypoplasia, nystagmus, late-onset cataract, glaucoma, as well as keratopathy.  The latter 3 are reasons for further visual compromise in such patients.  This disorder is often due to mutations in the PAX6 (Paired box protein Pax-6) gene.  Recently, aniridia-like phenotypes have been reported due to non-PAX6 mutations as in PITX2, FOXC1, FOXD3, TRIM44, and CYP1B1 as well wherein there is an overlap of aniridia, such as iris defects with congenital glaucoma or anterior segment dysgenesis.  These investigators described the various clinical features of classic aniridia, the co-morbidities and their management, the mutation spectrum of the genes involved, genotype-phenotype correlation of PAX6 and non-PAX6 mutations, and the genetic testing plan.  The various systemic associations and their implications in screening and genetic testing have been discussed. Lastly, the authors discussed future course of aniridia treatment in the form of drugs (such as ataluren) and targeted gene therapy.  These researchers stated that the use of colored contact lenses to prevent glare has been described in traumatic aniridia; however, their use is limited in congenital aniridia due to the presence of aniridia-associated keratopathy (AAK).  A smart contact lens with artificial iris based on guest-host liquid crystal cells has been studied recently in terms of optical quality in aniridia patients and has been shown to improve vision and reduce retinal illumination.  This scleral contact lens entirely spares the limbus and may be a good option for patients who are predisposed to limbal stem cell deficiency.

Romano et al (2023) noted that congenital aniridia is a rare, pan-ocular disorder with a main phenotypic characteristic of a partial or complete absence of the iris existing alongside other ocular morbidities such as cataract, keratopathy, optic nerve and foveal hypoplasia, and nystagmus.  The iris abnormality, however, often results in symptoms such as photophobia, glare, and decreased VA, as well as cosmetic dissatisfaction.  Current therapeutic options for the iris deficit include colored iris contact lenses, corneal tattooing, and tinted contact lenses.  Symptoms arising from small iris defects can be resolved with surgical management using micro-tying suture techniques such as McCannel or Siepser.  Currently, larger iris defects can be treated with artificial iris implants.  New prosthetic options range from colored IOLs to flexible custom-made silicone iris implants.  With a range of therapeutic options available and given the challenges of multiple co-morbidities in aniridia, the authors examined the literature relating to the use of artificial iris implants in congenital aniridia, with a focus on the different surgical implantation techniques, the clinical outcomes achieved, complications occurred, and risk of bias of the studies included.

Gour et al (2023) stated that congenital aniridia is a rare genetic eye disorder characterized by the complete or partial absence of the iris from birth.  Various theories and animal models have been proposed to understand and explain the pathogenesis of aniridia.  In the majority of cases, aniridia is caused by a mutation in the PAX6 gene, which affects multiple structures within the eye.  Treatment of these ocular complications is challenging and carries a high risk of side effects.  However, emerging approaches for the treatment of aniridia-associated keratopathy, iris abnormalities, cataract abnormalities, and foveal hypoplasia show promise for improved outcomes.  Genetic counseling plays a very important role to make informed choices. The authors provided an overview of the newer diagnostic and therapeutic approaches such as next generation sequencing (NGS), gene therapy, in-vivo silencing, and miRNA modulation.  Moreover, these investigators stated that routinely available colored contact lenses are best avoided in aniridia due to the risk of aniridia-associated keratopathy; however, scleral contact lenses may be a better option.  A smart scleral contact lens with liquid crystal-based artificial iris has been developed which provides a promising option in patients with aniridia.

StatPearls’ webpage on “Aniridia” (Tripathy and Salini 2023) stated that “In early childhood, the management includes optimal refractive correction, amblyopia therapy, and correction of squint.  Painted contact lenses may reduce photophobia, improve cosmesis, and improve vision.  Tinted contact lenses may also be an option.  Such contact lenses also reduce nystagmus.  Photochromatic or tinted glasses may be helpful”.

Han and Rhee (2024) stated that contact lenses are Food and Drug Administration (FDA)-regulated medical devices that are a safe and effective method for the correction of refractive error.  They are worn by an estimated 45 million Americans.  Decorative contact lenses (DCLs) can be used for patients with medical conditions such as failed corneas or aniridia; however, DCLs have also gained popularity in the young, contact lens-naive population.  DCL users often buy lenses via unregulated sources without a clinical examination and education on proper use by an eye-care professional.  These lenses have a significantly higher risk of infection when compared with contact lenses for the correction of refractive error.  To reduce the incidence of microbial keratitis, regulators and eye-care professionals must make coordinated efforts to generate and disseminate prevention messages to all contact lens users.  Furthermore, physician and patient reporting of contact lens-related complications to regulatory agencies enhances the pathway to risk reduction.  The authors reviewed DCL use and supply, with a specific focus on the increased risk of contact lens-related complications in unsupervised DCL use.

Furthermore, an UpToDate review on “Overview of contact lenses” (Lipson, 2024) states that “Soft lenses can be tinted or hand-painted to improve cosmesis in patients with scarred corneas or to create an artificial pupil in patients with aniridia, albinism, or damaged/distorted pupils”.

Hydrogel-Embedded Contact Lens for Ocular Drug Delivery

Bengani et al (2020) noted that ocular inflammation is one of the leading causes of blindness globally, and steroids in topical ophthalmic solutions (e.g., dexamethasone [DEX] eye-drops) are the mainstay of treatment for ocular inflammation.  For many non-infectious ocular inflammatory diseases, such as uveitis, eye-drops are administered as often as once-hourly.  The high frequency of administration coupled with the side effects of eye-drops results in poor adherence for patients.  Drug-eluting contact lenses have long been sought as a potentially superior alternative for sustained ocular drug delivery; however, loading sufficient drug into contact lenses and control the release of the drug is still a challenge.  A DEX-releasing contact lens (DEX-Lens) was developed by encapsulating a DEX-polymer film within the periphery of a hydrogel-based contact lens.  These researchers demonstrated safety and effectiveness of the DEX-Lens in rabbit models in the treatment of anterior ocular inflammation.  The DEX-Lens delivered drug for 7 days in-vivo (rabbit model).  In an ocular irritation study (Draize test) with DEX-Lens extracts, no AEs were observed in normal rabbit eyes.  DEX-Lenses effectively inhibited suture-induced corneal neo-vascularization and inflammation for 7 days and lipopolysaccharide-induced anterior uveitis for 5 days.  The effectiveness of DEX-Lenses was similar to that of hourly-administered DEX eye-drops.  In the corneal neo-vascularization study, substantial corneal edema was observed in rabbit eyes that received no treatment and those that wore a vehicle lens as compared to rabbit eyes that wore the DEX-Lens.  Throughout these studies, DEX-Lenses were well-tolerated and did not exhibit signs of toxicity.  The authors concluded that DEX-eluting contact lenses may be an option for the treatment of ocular inflammation and a platform for ocular drug delivery.

The authors stated that one of the drawbacks of this trial was that the models of inflammation used were not severe enough to allow these investigators to determine if the DEX-Lens was more effective than DEX eye-drops, which were effective in preventing inflammation when given hourly.  These researchers chose a suture induced model of corneal neovascularization (CNV) because it was aligned with the clinical scenario of corneal suture placement during full thickness corneal transplants.  In the uveitis model, the inflammatory response was not as robust as some other methods of inducing uveitis including injection of a tuberculosis antigen; and it was not possible to differentiate between the effectiveness of hourly DEX eye-drops and DEX-Lens treatments.  In general, the model of uveitis that these researchers employed generated elevated protein levels within the aqueous humor without causing significant pain or distress to the animals thereafter.  Consistent with previous studies that employed the same study design in rabbits, the clinical inflammatory response evident on slit lamp examination during this study was mild and transient for all the treatment groups.  For example, there were no significant slit lamp examination findings indicative of a robust inflammatory response (e.g., conjunctival redness or aqueous humor cell) in any of the treatment groups.  There were no safety concerns, such as an increase in intra-ocular pressure (IOP) or ocular surface toxicity, noted for any of the animals studied.  These investigators hypothesized that because the DEX-Lens provided significantly more drug to the aqueous humor than DEX eye-drops, the DEX-Lens may be able to reduce inflammation more than DEX eye-drops in uveitis models that were associated with more intra-ocular inflammation.

Torres-Luna et al (2020) stated that conventional ophthalmic dosage forms such as eye-drops pose a significant challenge because physiological barriers and clearance mechanisms limit ocular bio-availability.  Hydrogels are promising therapeutic materials for ocular drug delivery because of their high bio-compatibility and their ability to hold and release therapeutic agents.  Even though they are generally associated with the delivery of hydrophilic drugs, several approaches have been developed to integrate hydrophobic ophthalmic drugs into hydrogels.  Because of the limitations associated with the traditional topical eye-drop delivery of hydrophobic drugs, hydrogel-based systems represent a viable alternative for controlled ocular drug delivery.  These investigators presented an overview on the ophthalmic applications of hydrogels for the delivery of hydrophobic drugs, with special focus on diseases occurring in the anterior segment of the eye.  They summarized the key hydrogels for incorporation and delivery of hydrophobic drugs, including SCLs, stimuli-responsive hydrogels, cyclodextrin-based polymeric hydrogels, and nanoparticle-loaded hydrogels.  The authors concluded that the strategies of integrating hydrophobic drugs into hydrogels as discussed in this review provided significant potential in ocular therapeutics.

Fang et al (2021) noted that an increasing number of people are affected by eye diseases globally, eventually resulting in visual impairment or complete blindness.  Conventional treatment entails the use of eye-drops; however, these formulations often confer low ocular bio-availability and frequent dosing is needed.  Thus, there is a need to develop more effective drug delivery systems to address these constraints.  Hydrogels are multi-functional ophthalmic drug delivery systems capable of extending drug residence time as well as sustaining release of drugs.  These investigators discussed common ocular diseases and corresponding therapeutic drugs.  In addition, they summarized various types of hydrogels reported for ophthalmic drug delivery, including in-situ gelling hydrogels, contact lenses, low-molecular-weight supra-molecular hydrogels, cyclodextrin/poly (ethylene glycol)-based supra-molecular hydrogels and hydrogel-forming micro-needles.  Furthermore, they high-lighted marketed hydrogel-based ophthalmic formulations as well as clinical trials.  Lastly, they discussed critical considerations regarding clinical translation of biologics-loaded hydrogels.

Pan et al (2023) stated that the rapid clearance of instilled drugs from the ocular surface due to tear flushing and excretion results in low drug bio-availability, necessitating the development of new drug delivery routes.  These researchers developed an antibiotic hydrogel eye-drop that could extend the pre-corneal retention of a drug following topical instillation to address the risk of side effects (e.g., irritation and inhibition of enzymes), resulting from frequent and high-dosage administrations of antibiotics used to obtain the desired therapeutic drug concentration.  The covalent conjugation of small peptides to antibiotics (e.g., chloramphenicol) first endows the self-assembly ability of peptide-drug conjugate to generate supra-molecular hydrogels.  Furthermore, the further addition of calcium ions, which are also widely present in endogenous tears, tunes the elasticity of supra-molecular hydrogels, making them ideal for ocular drug delivery.  The in-vitro assay demonstrated that the supra-molecular hydrogels exhibited potent inhibitory activities against both gram-negative (e.g., Escherichia coli) and gram-positive (e.g., Staphylococcus aureus) bacteria, whereas they were innocuous toward human corneal epithelial cells.  In addition, the in-vivo experiment revealed that the supra-molecular hydrogels remarkably increased pre-corneal retention without ocular irritation; thus, demonstrating appreciable therapeutic effectiveness for the treatment of bacterial keratitis.  The authors concluded that this work, as a biomimetic design of antibiotic eye-drops in the ocular micro-environment, addressed the current issues of ocular drug delivery in the clinic and further provided approaches to improve the bio-availability of drugs, which may result in an approach of peptide-drug-based supra-molecular hydrogel for ocular drug delivery in clinics to combat ocular bacterial infections.

Manjeri and George (2024) noted that topical administration is the commonly preferred method of administering ophthalmic medications, with the majority of available the form of eye-drops or ointments.  However, the topical application of ophthalmological medications has less bio-availability and a short residence time because of the physiological and anatomical constraints of the eye, making efficient ophthalmic drug delivery a challenging task.  Micro-fluidic contact lenses have the advantage of delivering drugs into the eye in a controlled and on-demand manner.  These researchers highlighted the use of hydrogel-embedded micro-cavities on polydimethylsiloxane (PDMS)-based contact lenses for ocular drug delivery applications.  The fabrication technique discussed here is the spontaneous formation of the spherical cavity by hydrogel monomer droplet, followed by the simultaneous thermal curing of hydrogel and PDMS, creating a spherical cavity as small as 150 μm.  The spherical cavity is embedded with pH-responsive hydrogel for on-demand drug delivery.  The drug loaded in the hydrogel matrix is released into the ocular environment by diffusion.  The spherical cavity with a narrow opening restricts the diffusion to a minimum under normal ocular pH conditions (pH greater than 6).  When the ocular pH is lowered (pH less than 6), the pH-responsive hydrogel inside the spherical cavity de-swell and accelerates the drug release.

Chen et al (2024) stated that the modulation of inflammation is effective in the treatment of many ocular surface diseases; therefore, the low bio-availability of common anti-inflammatory eye-drops urges the development of ocular drug delivery systems to extend the ocular retention and enhance the cellular uptake for improving the anti-inflammatory effect of eye-drops.  These researchers covalently conjugated 2 molecules of clinically anti-inflammatory drug (i.e., DEX) with a small peptide (i.e., Tyr-Glu-Asn-Pro-Thr-Tyr) to generate an anti-inflammatory hydrogel eye-drop.  With a self-assembled ability, the designed supra-molecular hydrogel achieved gel-sol-gel transition by varying shearing forces that enhanced the pre-corneal retention of drug.  The fluorescent imaging showed the efficient cellular uptake of designed conjugate via clathrin-mediated endocytosis.  A rodent model of endotoxin-induced uveitis verified that the supra-molecular hydrogel eye-drop suppressed inflammation responses without ocular irritation.  The authors concluded that as a rational approach to design anti-inflammatory drugs as eye-drops, this work overcame the frequent instillation of clinical eye-drops and further improved the bio-availability of anti-inflammatory drugs, which may provide an effective way to treat ocular surface inflammation.

Wei et al (2024) noted that dry eye disease (DED) is a multi-factorial ocular surface disease with a rising incidence; thus, it is important to construct a reliable and efficient drug delivery system for the treatment of DED.  These researchers loaded C-dots nanozyme into a thermos-sensitive in-situ gel to create C-dots@Gel, presenting a promising composite ocular drug delivery system for the management of DED.  This composite ocular drug delivery system (C-dots@Gel) showed the ability to enhance adherence to the corneal surface and extend the ocular surface retention time; thus, enhancing bio-availability. In addition, no discernible ocular surface irritation or systemic toxicity was observed.  In the DED mouse model induced by benzalkonium chloride (BAC), it was verified that C-dots@Gel effectively mitigated DED by stabilizing the tear film, prolonging tear secretion, repairing corneal surface damage, as well as augmenting the population of conjunctival goblet cells.  The authors concluded that compared to conventional dosage forms (C-dots), the C-dots@Gel could prolong exhibited enhanced retention time on the ocular surface and increased bio-availability, resulting in a satisfactory therapeutic outcome for DED.

---

References