To the Editor.
—I read with interest the two articles pertaining to Viscoat (chondroitin sulfate-sodium hyaluronate) (Cooper-Vision CILCO, Bellevue, Wash) in the July and September 1987 issues of the Archives. I would like to commend the authors, Anita S. Nevyas, MD, et al,1 and Perry S. Binder, MD, et al,2 for their excellent articles regarding the formation of corneal calcium precipitates when the original investigational formula of Viscoat was used in conjunction with BSS Plus (balanced salt solution enriched with glutathione, bicarbonate, and glucose) (Alcon Laboratories Inc, Fort Worth, Tex). This formulation of Viscoat was discontinued from distribution in late December 1985.I would like to emphasize, however, that both articles detail the clinical effects of Viscoat on patients whose surgery was performed before this formulation was discontinued. Since Viscoat's phosphate buffer was reduced to approximately one fourth the original level there have been no reported cases of
Laks L. Phosphate Concentration of Viscoat. Arch Ophthalmol. 1987;105(11):1480. doi:10.1001/archopht.1987.01060110026014