A 25-year-old female presented for a scleral lens follow-up. She had been fitted in scleral lenses 6 weeks prior for correction of refractive error. She reported no significant issues with vision at follow-up, just mild dryness as the day went on. After lens removal, upon slit lamp examination, the below was observed. What is your diagnosis? How would you resolve this finding?

The patient was found to have peripheral corneal epithelial bullae nearly 360º around in both eyes. Evaluation with the scleral lenses on eye demonstrated that the lens was landing on the peripheral cornea just inside the limbus. The rings of bullae therefore are mechanical in nature and not from hypoxia. This is apparent when you observe the contact lens fit with fluorescein (Figure 2).

Mechanical bullae related to scleral lens wear are due to the use of a lens diameter that does not provide a large enough vaulting chamber to allow the lens to land beyond the limbus onto the conjunctival-scleral complex. When a patient’s corneal diameter is at or exceeds the chord diameter of the aspect of the lens designed to vault, the lens will automatically land on the peripheral cornea. Adjustments to the limbal clearance zone of a lens are inadequate, as the intended zone for limbal clearance is inside the point of contact between the lens and the cornea, so limbal clearance adjustments only provide more space inside the point of contact, not over the point of contact.

The only correct strategy for resolving epithelial bullae caused by scleral lens compression is to choose a lens with a larger vaulting chamber diameter. This typically means just choosing a larger diameter in general, though that is not always the case as different designs have different widths of each zone.

Patients who experience epithelial bullae from scleral lens compression may have little or no symptoms at first, but symptoms will typically increase over time, and long-term changes to the corneal tissue can occur if left long enough (scarring). It is wise, regardless of whether the patient is symptomatic or not at the time of discovery, to refit the patient immediately rather than wait to see if symptoms or complications occur.

In this case, the patient was refitted into a larger-diameter scleral lens OD and OS. After proper fitting and ongoing follow up, the patient was successful with her scleral lenses and remained free of any of the previous complications noted with the smaller diameter.