Effects of long-term rigid contact lens wear on the endothelium of corneal transplants for keratoconus 10 years after penetrating keratoplasty.

Contact lenses do not appear to cause changes in endothelial cell density in normal individuals. In eyes with abnormal corneal endothelium, however, the effects of contact lens wear may be more severe. We studied eyes with abnormally enlarged endothelial cells resulting from penetrating keratoplasty (PK). We identified 34 patients with phakic corneal transplants for keratoconus that had the following characteristics: first graft, no rejection episodes, no reoperations, and follow-up examinations for at least 5 postoperative years. Fifteen of these patients had been fit with daily wear rigid contact lenses (12 rigid gas permeable, 3 polymethylmethacrylate) postoperatively. Contact lens fitting occurred anywhere from 3 months to 2 years post-PK; 19 control subjects had not been fit with contact lenses. Twenty-one of the patients (nine contact lens wearers and 12 control subjects) were examined 10 years after keratoplasty. The contact lens group developed polymegethism, but there was no significant difference from the controls in endothelial cell density at 5 or 10 years post-PK. The cell density at 10 years was 824 +/- 156 cells/mm2 (mean +/- SD) in the contact lens group and 833 +/- 167 cells/mm2 in the control group (P = 0.90). The endothelial cell loss 10 years after keratoplasty was 73% for both groups. Thus, we found no effect on endothelial cell density from at least 7 years of daily rigid contact lens wear in eyes with corneal transplants for keratoconus.