Abstract
Abstract: :
Purpose: To describe a cohort of patients with progressive, irreversible, unilateral bullous keraropathy (BK) of undetermined etiology. Method: Data was collected retrospectively from patient records. A research clinic was held in November 2001. Thorough medical history, ocular examination, specular microscopy and pachymetry were performed. Corneal buttons from patients who underwent penetrating keratoplasty (PK) had histological analysis including herpes viral immunostaining and polymerase chain reaction (PCR). Result: Seven patients presented to the corneal service from 1999 to 2001. They comprised of 6 Caucasians and 1 Asian, 6 males and 1 female, with a mean age 68.7 years. Mean duration of onset was 6.8 months. The group were non contact lens wearers and did not have any past medical, social or drug history that may affect the cornea. The patients presented with unilateral BK without any discernable pattern. The visual acuities of the affected eyes were 6/9 or worse with mean corneal thickness of 722µm. Specular microscopy was not possible. In contrast, the fellow corneas were clinically normal, had a mean of 1980 endothelial cells/mm2 and pachymetry of 536µm. Both eyes were phakic. There were no evidence of pseudoexfoliation (PxF), herpetic eye disease, Fuch’s endothelial dystrophy (FED) or iridocorneal endothelial (ICE) syndrome. The affected eyes were initially treated with guttae steroids for a mean period of 5.6 months. In addition, 4 patients were also on acyclovir (topical, oral, or combination of both) for up to 3 months. None showed any significant improvement. After a mean follow up of 16.7 months, 4 eyes underwent PK. There were no recurrences in the grafts (mean post-PK follow up was 10.5 months). Histology revealed non-specific endothelial failure with no features of FED, PxF or ICE. Herpes viral studies were negative. In the non PK group (n = 3), mean pachymetry had increased to 793µm. The unaffected eyes remained normal in both groups throughout this period. Conclusion: Despite extensive investigations, the etiology of BK for this group of patients remained elusive. Causes of unilateral BK is documented in the literature include herpes viruses, PxF and ICE syndrome. However, none of our patients had any of these factors. The pathology seems to be limited to 1 eye (as the fellow eye remained normal), irreversible and progressive throughout the period of study. Although medical treatment was not beneficial, PK appears to offer a good prognosis. Further investigations and long term follow up may offer clues.
Keywords: 371 cornea: endothelium • 507 pathology: human • 369 cornea: clinical science