They are termed “scleral” lenses because they completely cover the cornea and extend onto the sclera (the white part of the eye).
Scleral lenses offer certain advantages over corneal lenses. First, large-diameter lenses may be more comfortable than corneal lenses. The cornea is one of the most highly sensitive tissues in the body. The conjunctiva (soft, clear tissue that lies over the sclera) is much less sensitive than the cornea. Lenses that rest primarily on the conjunctiva may induce less sensation than smaller lenses that rest upon the cornea. Second, because the lens is filled with saline, it is bathed all day to rejuvenate the ocular surface. Scleral lenses extend under the upper and lower lids and rarely move.
What patients could potentially benefit from scleral lenses?
- Post-corneal transplant
- Pellucid marginal degeneration
- Severe dry eyes
- Graft versus host disease
- Sjögren’s syndrome
- Stevens-Johnson syndrome
- Neurotrophic keratopathy
- Chronic inflammatory conditions
- Limbal stem cell deficiency
- Ocular cicatricial pemphigoid