Cataract as a complication of severe microbial keratitis.

Complicated cataract results from local ocular disease; we report five cases that followed severe anterior segment infection. Three patients had Pseudomonas keratitis and two Acanthamoeba keratitis. All patients had severe keratitis and iridocyclitis. Mature cataracts developed after a mean of 5.5 months from the onset. Cataract formation with severe keratitis may be attributable to bacterial toxins, iridocyclitis and treatment toxicity. All these factors may cause cataract by interference with lens metabolism. One of our cases had no steroid treatment; the remaining four had between 7.7 and 28.14 mg of topical steroid (256-938 drops of Dexamethasone 0.1%). Cataract formation may result from severe microbial keratitis alone but is probably enhanced by concurrent treatment with high doses of topical steroid. The potential for cataract formation must be considered when managing microbial keratitis with the use of steroids and when planning surgical rehabilitation of the anterior segment.