97th DOG Annual Meeting 1999



M. J. Jakobczyk-Zmija, C. W. Spraul, O. Gareis, P. Wagner, G. K. Lang

Purpose: Intravitreal silicone oil injection have been performed for complicated cases of retinal detachment, which is frequently followed by cataract formation. The purpose of this study is to report histologic findings of posterior subcapsular cataract formation in human eyes filled with silicone oil

Methods: Patients who had on clinical examination a subcapsular cataract formation secondary to silicone oil injection were available for this study. All patients had been treated with pars plana vitrectomy and silicone oil injection for complicated cases of retinal detachment. The posterior capsule was removed during the posterior capsulorhexis for silicone oil removal following a routine phacoemulsification and cortex cleanup. The posterior capsule was divided by half and one half was submitted for routine light microscopy and stained with PAS and HE and immunochemistry for collagen types I - VI were performed. The other half was promptly fixed in 2.5% glutaraldehyde and after two hours was postfixed with 0.1 M cocodylate buffer and 1% osmium tetroxide. Semithin sections were stained with uranyl acetate and lead citrate.

Results: We analyzed the posterior capsules of 6 patients with posterior subcapsular cataract formation secondary to silicone oil injection. The mean age of the patients was 37.5 years; range 25 to 47 years. Silicone oil tamponade was in place for a mean of 15.3 months; range 11 - 24 months. Histologic examination demonstrated hyperplastic spindle-like cells encircled by basement membrane material associated with a fibrillary substance and collagen fibers. Ultrastructural examination showed that these cells contained intracytoplasmic subplasmalemmal aggregates of 40 to 60 Å diameter and associated fusiform densities - a feature of myofibroblastic differentiation.

Conclusions: The histologic findings in our specimens are similar to what has been found in anterior subcapsular cataract formation and which has been termed anterior fibrous pseudometaplasia. In analogy to these changes we termed this phenomenon posterior fibrous pseudometaplasia which may be the final common pathway of alteration of lens epithelium and which was interpreted as a partial change, or change of certain characteristics of posteriorly migrated lens epithelial cells due to metabolic alterations.

This study was supported in part by Gertrud Kusen Stiftung in Bendestorf.

University Eye Hospital and Clinic, Prittwitzstrasse: 43, D-89075 Ulm, FRG;