Get the Dirt on Scleral Lenses
BY VISHAKHA THAKRAR, OD, FAAO
Gas permeable scleral contact lenses have gained much attention over the past few years. They were first described about 25 years ago, but have only recently been prescribed by a higher volume of practitioners.
Scleral lenses serve as invaluable tools to manage patients who have corneal ectasia and severe ocular surface disease including keratoconus, pellucid marginal degeneration, Sjögren's syndrome, Stevens-Johnson syndrome, cicatricial pemphigoid, atopic keratoconjunctivitis and graft versus host disease. These lenses help prevent tear film evaporation, provide a moist chamber for the cornea and limbus, and protect the anterior surface of the eye from environmental and mechanical trauma while correcting optical irregularities.
Many patients who benefit from scleral lenses have severe tear film abnormalities. These patients often produce high levels of mucus and have accompanying conditions such as blepharitis and meibomianitis that can further disrupt the tear film. Therefore, keeping scleral lenses clean often presents a challenge.
Tears do not flush in and out of scleral lenses as with corneal GPs. The lens creates an environment that is sealed or semi-sealed in which only small amounts of tears can enter and exit the postlens tear reservoir. For this reason, debris may collect on the anterior surface (Figure 1) and cause fogging, irritation and dryness. If trapped behind the lens, the debris can stagnate and cause corneal epithelial defects and possible lens adhesion to the perilimbal or scleral regions.
Patients who have inflammatory or autoimmune diseases require immunosuppressive therapy and often take medications such as methotrexate, cyclosporine or prednisone. These medications may not be adequate to suppress the ocular immune response. Many such patients benefit from adjunctive therapy from anti-inflammatories such as Restasis (Allergan) or topical steroids, non-preserved artificial tears and anti-allergy medications such as Patanol (Alcon). Mucolytics such as acetylcysteine may be beneficial, but tend to reduce mucous production only in certain patients.
PHOTO COURTESY OF DR. ROBERT BREECE, MEDLENS INNOVATIONS, INC.
Figure 1. Surface deposits on a scleral lens.
Scleral Lens Care
Many patients are able to successfully use GP cleaners such as Boston Simplus, Boston Original or Boston Advanced (all Bausch & Lomb). However, patients who deposit heavily or suffer from hypersensitivities may benefit from benzyl alcohol-based cleaners such as Optimum (Lobob Laboratories) or MeniCare GP (Menicon). These solutions work well to remove lipid and protein deposits and remove debris from lens surfaces to improve wettability. Optimum is also available in an extra strength cleaner for patients who deposit more heavily. These solutions are beneficial in dry eye and atopic patients.
Heavy depositors may also need to clean the lens with a cotton swab applicator at least once a week. This is particularly effective for patients who have larger fingers and find it difficult to clean the back surface of the lens. Some patients may need to remove their lenses in the middle of the day to clean them.
Fitting scleral lenses is an outstanding way to manage ectasia and severe ocular surface disease. However, you may need to modify traditional care and cleaning methods to maintain consistent and successful wear. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #150.
Dr. Thakrar has a specialty contact lens practice and is a clinical optometrist at the TLC Laser Eye Center in Mississauga, Ontario. She is a graduate of The Ohio State University and completed a residency in cornea and contact Lenses at the New England College of Optometry.