What are Scleral Lenses?
Scleral lenses are rigid gas permeable lenses (RGP) that vault over the cornea and rest on the sclera and conjunctival tissue for improved vision and increased patient comfort. Scleral lenses are used to treat cornea pathologies and ocular surface disease that soft lenses and glasses are unable to adequately correct. Scleral lenses are larger than corneal RGP lenses and range in size from 15 mm to greater than 18 mm.
- Scleral lenses are RGPs that vault the cornea and rest on the sclera.
- Scleral lenses are used to treat corneal pathologies and ocular surface disease.
- Scleral lenses provide improved comfort and vision when compared with a corneal RGP.
Understanding Scleral Lenses
Developed in the late nineteenth century, scleral lenses were the first type of contact lens to restore vision and protect the eye surface. Their use decreased after the development of rigid corneal lenses in the middle of the twentieth century and soft lenses in the 1970’s, but there has been a resurgence with new technology in lens manufacturing and imaging. Scleral lenses are often the only option for contact lens wear for a broad range of ocular conditions. They can initially present with fitting challenges, but are exceptional for patients with special visual needs.
Benefits of Scleral Lenses
There are significant benefits to scleral lenses over corneal lenses for patients with irregular corneas. Prior to lens application, the lens bowl is typically filled with preservative-free normal saline. Scleral lenses have a fluid reservoir which is the fluid-filled space between the back surface of the lens and the front of the cornea. This fluid reservoir provides hydration to the cornea and is beneficial for patients with dry eye disease. There should be little to no movement on the lens leading to increased comfort and lens stability. Scleral lenses sit on the conjunctiva, which has less nerves so they tend to provide significantly improved comfort over a lens that rests on a highly innervated cornea. A scleral lens also offers the vision of a corneal lens creating a regular surface for patients with corneal irregularities like keratoconus or corneal ectasia.
Conditions Treated with Scleral Lenses
Scleral lenses are used to treat patients with irregular corneas from various pathologies including corneal ectasia (keratoconus, post-laser assisted in-situ keratomileusis [LASIK] ectasia, pellucid marginal degeneration), post-radial keratotomy, post-keratoplasty, and corneal scarring. Scleral lenses may also be recommended to improve comfort for patients with debilitating ocular surface disease who have difficulty functioning visually due to extreme discomfort, photophobia, and pain.
Scleral Lenses Expectations
Patients who are fit with scleral lenses should expect improved vision and comfort over traditional RGP lenses. They can expect a thorough fitting process with multiple changes to both lens power and fit to ensure the lens is best for their specific corneal condition. Scleral lenses are only covered by some insurance companies for patients with a specific medical diagnosis. Most often, they are fit when vision cannot be improved with traditional methods like glasses or soft contact lenses.