Conjunctival epithelial flaps are associated with which lens characteristics?

Conjunctival epithelial flaps are associated with which lens characteristics?

• A. Soft hydrogel lenses with low modulus and loose fit
• B. Silicone hydrogel lenses with high modulus and tight fit (extended wear)
• C. Rigid gas permeable lenses worn daily
• D. Traditional hydrogel lenses with moderate modulus and loose fit

Answer: (B)

Conjunctival epithelial flaps arise from mechanical trauma to the bulbar conjunctiva at the lens edge. When a lens is stiff (high modulus) and fits tightly, its edge rubs and shears against the conjunctiva, lifting a sheet of superficial epithelial cells. Wearing such a lens for extended periods keeps that mechanical interaction ongoing, increasing the chance of flap formation. Silicone hydrogel lenses can have higher modulus and, with a tight fit used for extended wear, are most likely to produce this effect. Softer, looser-fitting lenses cause less edge trauma, and daily-wear rigid lenses or traditional hydrogels with moderate modulus and looser fit are less associated with these epithelial flaps.

Conjunctival epithelial flaps arise from mechanical trauma to the bulbar conjunctiva at the lens edge. When a lens is stiff (high modulus) and fits tightly, its edge rubs and shears against the conjunctiva, lifting a sheet of superficial epithelial cells. Wearing such a lens for extended periods keeps that mechanical interaction ongoing, increasing the chance of flap formation. Silicone hydrogel lenses can have higher modulus and, with a tight fit used for extended wear, are most likely to produce this effect. Softer, looser-fitting lenses cause less edge trauma, and daily-wear rigid lenses or traditional hydrogels with moderate modulus and looser fit are less associated with these epithelial flaps.