Acute band keratopathy following intracameral Viscoat

Band keratopathy developed rapidly in two patients following uneventful phacoemulsification and intraocular lens implantation using BSS Plus (balanced salt solution enriched with glutathione, bicarbonate, and glucose) infusion and Viscoat (chondroitin sulfate-sodium hyaluronate), which was left in the anterior chamber at the conclusion of the procedure. Histopathologic evaluation of corneal tissue obtained from one patient at the time of edetic acid chelation revealed histochemical findings consistent with anterior stromal calcification. To investigate a possible relationship between Viscoat and the rapid onset of band keratopathy, Viscoat formulated with varying concentrations of phosphate buffer was injected intracamerally into 42 rabbit eyes. Within 48 hours, clinically obvious corneal opacification developed in nine (47%) of 19 eyes injected with the commercial preparation of Viscoat. Also, similar opacification developed in ten (77%) of 13 eyes that received Viscoat formulated with twice the phosphate concentration of the commercial preparation. Band keratopathy did not develop any of ten eyes that received Viscoat with one fourth the commercial phosphate concentration. In selected opacified corneas, the presence of phosphorus in the subepithelial and posterior corneal stroma was confirmed by histochemical stains and energy-dispersive x-ray analysis.