Online Photo Diagnosis

By Gregory W. DeNaeyer, OD

This photograph shows midperipheral epithelial microcysts. The patient had been wearing his −1.50D OD and −1.75D OS CIBA Vision Night & Day lenses on an extended wear basis. He reported removing and sleeping without his lenses once or twice a week. The patient replaced his lenses on a monthly basis. His visual acuity was 20/20 in both eyes, and he was asymptomatic.

Epithelial microcysts are discrete uniform vesicles that are often seen in the midperipheral cornea. They are thought to be cellular debris that originate at the basement membrane, migrate towards the surface, and rupture. Epithelial microcysts are the result of corneal hypoxia secondary to contact lens wear. They are more likely to occur in patients who wear low-Dk lenses or who wear lenses on an extended wear schedule. They should be differentiated from microcysts that occur in Meesmann's corneal dystrophy, which are unrelated to corneal hypoxia.

Figure 2 of this patient shows some staining where the cysts have surfaced. The breakdown of the epithelial surface increases this patient's risk for secondary opportunistic infection, especially if this should worsen. A conservative approach to treating microcystic edema is to have patients discontinue lens wear until resolution of the microcysts, which can take one-to-two months. Refitting patients into higher-Dk lenses and/or prescribing lenses on a daily wear basis should prevent recurrence.

Reference

• White, P. Contact Lens Complications Part II Contact Lens Spectrum Issue: February 2000.
• Caroline, P. Andre, M. Epithelial Microcysts in an Extended Wear Patient Contact Lens Spectrum Issue: April 1998.

Contact Lens Spectrum, Issue: April 2009