Contact Lens Case Reports
A Potential Effect of Conjunctival Prolapse
BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO
In last month’s Contact Lens Case Reports column, we described a proposed theory regarding the etiology of the scleral lens complication called “conjunctival prolapse.” We proposed that in susceptible patients, the conjunctiva is “sucked” into areas beneath the lens at which significant clearance may exist. This excessive clearance most often occurs inferiorly due to two factors:
1. The slight inferior positioning of scleral lenses that occurs secondary to superior limbal impingement and/or to gravitational forces pulling the corneal/limbal-clearance lens to a slightly inferior position.
2. The lower corneal height (inferior depression) commonly seen in some pathologic eyes such as those that have keratoconus or pellucid marginal degeneration (PMD).
Historically, the condition has been considered relatively minor; however, it may not be as benign as originally suspected.
Our last column described a 43-year-old male who had advanced PMD, successfully wearing scleral lenses for the past two years. His wearing time has always been between 12 hours to 16 hours a day, and his only complication was that of conjunctival prolapse (Figure 1). We were curious as to whether the prolapsed conjunctiva could be pulled back into its appropriate position or whether the conjunctiva had anchored itself to the underlying corneal surface.
Figure 1. Conjunctival prolapse in a patient who has advanced PMD.
We anesthetized the patient’s right eye and used a cotton-tipped applicator to try to “peel back” the prolapsed conjunctiva (Figure 2). After a number of attempts, it was clear that the conjunctiva could not be moved and was firmly anchored to the surface of the underlying cornea.
Figure 2. Our attempt to “peel back” the prolapsed conjunctiva.
It appears from this and other cases that with time, the prolapsed conjunctiva forms synechia that cannot be easily broken by manual manipulation. As we know, synechia are most commonly associated with internal adhesions of the iris to the cornea or to the crystalline lens; however, external adhesions can occur in conditions such as pseudo pterygia and now in some cases of conjunctival prolapse.
A Possible Management Strategy
Despite this finding, we continue to consider conjunctival prolapse a relatively benign complication. We believe that as we learn more about the complication, we will be better able to manage the condition—most likely in the form of asymmetrical scleral lens designs in which corneal/limbal clearance can be independently controlled 360 degrees around the eye. CLS
Patrick Caroline is an associate professor of optometry at Pacific University. Mark André is an associate professor of optometry at Pacific University. He is also a consultant for Cooper-Vision.