Iatrogenic limbal stem cell deficiency

Purpose. To describe a group of patients with limbal stem cell (SC) deficiency without prior diagnosis of a specific disease entity known to be causative of SC deficiency. Methods. We performed a retrospective review of the records of all patients with ocular surface disease seen at the University of Minnesota between 1987 and 1996. Patients were categorized according to origin of limbal deficiency. Patients who did not have a specific diagnosis previously described as being causative of limbal deficiency were analyzed. Risk factors, clinical findings, and sequelae were evaluated. Results. Fourteen eyes of 12 patients with SC deficiency not caused by a known diagnosis were described. All eyes had prior ocular surgery involving the corneoscleral limbus. Eleven eyes had been receiving long-term topical medications, and all eyes had concurrent external disease such as pterygium, keratoconjunctivitis sicca, rosacea, herpes simplex virus keratitis, or aphakic or pseudophakic corneal edema. All eyes had superior quadrants affected, corresponding to areas of prior limbal surgery. Sequelae of disease included corneal scarring and neovascularization, with seven eyes having visual acuity of 20/150 or worse. Conclusion. Because the epitheliopathy started peripherally and extended centrally in all patients, we believe it represents an SC deficiency. The fact that all patients were affected superiorly, at sites of a prior limbal surgical incision, points to surgical trauma to the SC as the likely major etiologic factor for the deficiency. The surgical trauma to the limbal SC probably made these cells more susceptible to damage from other external disease influences and toxicity from long-term topical medications. Because the SC deficiency is the result of prior ocular surgery and long-term topical medications, we propose the term "iatrogenic limbal stem cell deficiency.".