Managing Scleral Lens-Induced Conjunctival Prolapse
BY WILLIAM L. MILLER, OD, PHD, FAAO
Scleral lenses are unlike any other type of contact lens; as such, they have benefited many patients who are unable to wear other forms of contact lens correction. However, scleral lenses are also associated with complications that are not seen in other contact lens modalities.
Scleral contact lens-induced conjunctival prolapse (Figure 1) is one such condition that occurs in a small percentage of scleral lens wearers (Caroline and André, 2012; Walker et al, 2014). Conjunctival prolapse is also referred to as chalasis or hooding, and it represents an entrapment of the loosely elastic conjunctiva near the limbal region under a scleral contact lens. As you might expect, it is more common in elderly patients or in patients who have undergone multiple ocular surgeries. The ocular surface presentation is similar to that of other conditions that occur in non-scleral lens-wearing patients, such as conjunctivochalasis and lid parallel conjunctival folds. Conjunctival prolapse, as a clinical entity, looks more similar to conjunctivochalasis.
Figure 1. Conjunctival prolapse.
COURTESY OF MARIA WALKER, OD, MS, FAAO
Conjunctivochalasis Versus Conjunctival Prolapse
Conjunctivochalasis also occurs more frequently as patients age and in female patients (Mimura, Yamagami et al, 2009). Just like conjunctival prolapse, it often occurs inferiorly. It is related to dry eye disease and is thought to interfere with the lower tear prism, thus delaying tear clearance. Additionally, it is more problematic in downgaze and when digital pressure is applied; the latter may represent a similar mechanism for conjunctival prolapse.
Conjunctivochalasis is also more frequently seen in contact lens patients, especially GP lens wearers—again, the mechanism may be similar to that of conjunctival prolapse (Mimura, Usui et al, 2009). These mechanisms may include inflammation produced by mechanical stress that leads to friction and/or dryness.
Although considered benign in the short-term, conjunctival prolapse should be addressed because the long-term effects are unknown. Its presence, depending on the extent, may interfere with fluid exchange beneath the scleral lens (Severinsky et al, 2014).
The suggested pathogenesis is related to induced pressure forces that can pull the conjunctiva under the lens. These forces are greater with greater vault over the limbal area and may be related to the inferior scleral lens positioning in most patients. Minimizing the vault over the limbal region without creating an area of touch appears to be the best treatment and prevention strategy in susceptible patients. This can be achieved using nonrotationally symmetrical designs, especially in lenses that are larger than 15.0mm. In rare cases, a soft contact lens piggybacked under the scleral lens may serve to “fill” the vaulted area at the limbus; use a high-Dk lens, preferably a daily disposable, in such cases.
Another cause may be aggressive scleral lens application, which can also create suction forces under the lens. Instruct patients to apply their scleral lenses gently to the ocular surface. CLS
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Dr. Miller is an associate dean for academic affairs and professor at the Rosenberg School of Optometry, University of the Incarnate Word. He is a consultant or advisor to Alcon and Oasis Medical and has received research funding from CooperVision, Contamac, and SynergEyes and lecture or authorship honoraria from Alcon. You can reach him at email@example.com.