Scleral lens is an oversized rigid gas permeable contact lens which covers the entire cornea and part of the sclera (white part of the eye). Scleral lens is ideal for patients with irregular astigmatism due to Keratoconus, Pellicuid marginal degeneration, post-radial keratotomy, post-LASIK and post-corneal graft patients.
Traditionally, patients with irregular astigmatism from various pathologies are fitted with rigid gas permeable (RGP) lenses to improve their vision. However, due to the irregular curvature of the diseased cornea, regular rigid gas permeable lenses do not settle well on the cornea. Patients frequently experience discomfort from excessive lens movement due to dislodgement. Vision can also be compromised from an imperfect fit.
Scleral lenses provide a better fit on an irregular cornea since it is vaulted over the entire irregular cornea. Therefore, it offers better comfort and stability of vision.
In addition, scleral lenses have also been used in patients with dry eyes because the scleral lens is filled with fluid prior to insertion. The fluid comes in contact with the cornea which keeps the cornea hydrated during its wear.