FOCAL LOSS OF EPITHELIUM ASSOCIATED WITH HYDROGEL CONTACT LENS WEAR

Carol Lakkis

Abstract

A spontaneous, focal loss of epithelium associated with hydrogel contact lens wear occurred in the right eye of a 20 year old, myopic (-9.00D), female, daily wear patient. Originally the patient was wearing high water content (67%) soft contact lenses quite successfully for more than two years on a daily wear basis. The patient was then switched over to low water content (38%) soft contact lenses by her practitioner to enable thermal disinfection. The patient had been wearing these lenses for just under a year on a daily wear basis (7 days/week, 14 hours/day) prior to presentation. Symptoms were limited to mild discomfort and moderate hyperemia. The lesion appeared as a large central area (2.5mm) of full thickness epithelial loss. The area stained brightly with NaFl, which penetrated extensively into the deep layers of the surrounding epithelium. Folds in the posterior stroma were readily visible with biomicroscopy. Subsequent history and examination elicited the information that the right eye had greatly reduced corneal sensitivity as a result of a congenital defect in the ophthalmic division of the right trigeminal nerve. A reasonable hypothesis for the development of the condition can be easily assembled. An area of reduced epithelial adhesion occurred, most likely as a result of contact lens induced hypoxia; however, the patient was not fully aware of ongoing compromise to the desensitized right cornea. Eventually the 'plug' of loosely adherent epithelium was removed with the contact lens, indicating a dual mechanical and hypoxic aetiology for this condition. This case has three important implications. First, oxygen transmissibility should be the governing factor when choosing a lens design. Second, when fitting contact lenses to patients with reduced corneal sensitivity, extreme care must be taken as the risk of corneal insult is enhanced. Third, a reduction in corneal neural activity can increase corneal susceptibility to hypoxia.

Details

Year: 1992

Program Number: Poster 18

Author Affiliation: n/a

Co-Authors: Richard Lindsay, Noel Brennan

Co-Author Affiliation: n/a

Room: Great Hall