Effect of diameter and depth on the response to solid polysulfone intracorneal lenses in cats

Impermeable, solid polysulfone intracorneal lenses (ICLs) can change corneal refractive power but will not allow diffusion of nutrients from the aqueous to the anterior stroma. Lenses of 4, 5, 6, and 7 mm in diameter were implanted in 50 cat eyes at depths ranging from 45% to 95% of corneal thickness to determine the effect of depth and diameter. Two types of stromal opacities occurred during follow-up: peripheral amorphous opacity (100%) and crystalline-granular lipid central opacity (79%). No eyes implanted with a 4-mm ICL ulcerated, but ulceration occurred in 28% of the eyes overall. Because opacification occurred with all lens diameters and implantation depths, metabolic demands of the cornea are not met. No safe limit exists at which these ICLs can be predictably used in cat eyes.