Successfully meet the challenges presented by these patients

With the prevalence of glaucoma in the United States predicted to approach 4 million people over the next decade, many of our contact lens patients will be undergoing therapeutic management, ranging from topical pharmaceuticals to surgical intervention.¹ The type of glaucoma treatment has potential implications for both current and new contact lens wearers. Here, I discuss management strategies to successfully meet the challenges of managing contact lens wearers who have glaucoma.

MEDICATION COMPLIANCE AND LOGISTICS

The most common issue facing contact lens wearers who have glaucoma is safe compliance with their medication regimen. Fortunately, most patients use on once-per-day or twice-daily dosing.

• For the former group, simply have them instill their medication after lens removal.
• For the latter group, instruct them to wait 15 minutes prior to inserting their lenses.
• It’s a bit more complicated for those requiring mid-day dosing. Daily disposable wearers can insert a fresh pair. For those who clean and disinfect lenses, alternating between two pairs daily may be advisable.

OCULAR SURFACE MANAGEMENT

It is critical to be aware of the negative impact of glaucoma medications on the ocular surface. Hollo et al. defined glaucoma therapy-related ocular surface disease as an “imbalance of the ocular surface homeostasis caused by the toxic effect of chronic topical medication, which leads to tear film instability, epithelial damage, and inflammation.”² Patients may present with a range of ocular surface pathology including, but not limited to, superficial punctate keratitis, tear-film instability, allergy and dry eye disease. The consequences of these issues for our contact lens wearers may be mild to severe and include reduced visual quality. A comprehensive anterior segment evaluation, including TBUT, staining, MMP-9 testing and meibography, will help to guide management.

Key to protecting the ocular surface is reducing exposure to benzalkonium chloride (BAK), among other preservatives. When possible, I recommend switching the patient to preservative-free glaucoma and lubricating drops and prescribing daily disposable contact lenses or hydrogen peroxide disinfection.

POST-SURGICAL WEAR

The indications for contact lens wear after glaucoma surgery include correction of ametropia, the management of corneal irregularity and the treatment of a leaking bleb. The type of surgery and the refractive status are the main considerations in choosing a lens design. While there is no contraindication to fitting patients post minimally invasive glaucoma surgery, patients having undergone filtration surgery (trabeculectomy) present unique challenges, due to the risk of blebitis or endophthalmitis. The goal in contact lens fitting is to design a lens that will not erode the bleb, which is often already thin and at greater risk for infection, due to treatment with mitomycin C and 5-Fluorouracil.

The options include:

• Standard diameter, low modulus, frequent replacement soft lenses that drape easily over the lower 1/3 of the bleb. These can be used for the correction of simple refractive error.
• Low modulus, high-Dk soft contact lenses to slow or stop aqueous leakage through a bleb. If the bleb is close to the limbus, a standard bandage lens can be applied.
• When necessary, a custom design lens that has a large diameter. Treat concomitantly with topical aqueous suppression (e.g. beta-blockers or carbonic anhydrase inhibitors and prophylactic antibiotic drops).

For those patients who have moderate corneal irregularity, or patients currently wearing GP lenses, aim for an interpalpebral fit post glaucoma surgery. Avoid a lid-attached fit; design a lens that centers well, with minimal excursion to avoid interaction with the superior limbus.

Scleral lenses may be necessary for higher degrees of corneal irregularity or GP intolerance. When fitting scleral lenses in glaucoma patients, consider both the potential effect of the lens on the IOP as well as the effect of the lens on the drainage device and blebs. In patients who don’t have filtering devices, it has been suggested that large diameter lenses that have a wide haptic may have less potential to interfere with aqueous outflow.³

Small diameter scleral lenses that have notches or focal microvaults can be considered for patients who have patch grafts or blebs. The goal is to reduce compression of the drainage device as well as to avoid mechanical erosion of the overlying bulbar conjunctiva.

SAFE, REWARDING EXPERIENCE

In summary, with our careful consideration of risks, benefits and attention to lens material and design, we can ensure a safe, comfortable and visually rewarding contact lens-wearing experience. OM

REFERENCES

1. Eye Health Data and Statistics. National Eye Institute website. https://www.nei.nih.gov/learn-about-eye-health/resources-for-health-educators/eye-health-data-and-statistics/glaucoma-data-and-statistics . Updated July 17, 2019. Accessed Jan. 19, 2021.
2. Hollo G, Katsanos A, Boboridis KG, Murat I, Konstas AGP. Preservative-free prostaglandin analogs and prostaglandin/timolol fixed combinations in the treatment of glaucoma: efficacy, safety and potential advantages. Drugs. 2018;78(1):39-64. doi: 10.1007/s40265-017-0843-9.
3. Fadel, D, Kramer E. Potential contraindications to scleral lens wear. Cont Lens and Anterior Eye. 2019;42(1):92-103. doi.org/10.1016/j.clae.2018.10.024.

DR. RESNICK is president and managing partner at Drs. Farkas, Kassalow, Resnick and Associates, a contact lens and anterior segment specialty practice in New York. She is a diplomate in the Cornea, Contact Lens and Refractive Technology section of the AAO, a diplomate of the ABO and a fellow of the Scleral Lens Education Society.