In reply
Dr Epstein makes an excellent and valid point concerning the possible role of phosphate delivered with prednisolone in the rapid appearance of deep stromal calcium in our patients with ocular herpes. It is a factor that we considered, and one that we certainly cannot rule out.There are, however, some major differences between the patients he cites from the literature and our own. The 1977 article in the Archives describes three patients with markedly dry eyes, epithelial ulcers with deposition of gritty calcium at the ulcer base, and use of artificial tears with thimerosol, an organic mercury salt thought to be associated with development of band keratopathy.' It was postulated that the cumulative effect of these factors led to development of the superficial calcium deposits over a 2-to 3-week period. Our patients, in contrast, did not have dry eyes, the calcium did not deposit in the area of