Effect of diameter and depth on the response to solid polysulfone intracorneal lenses in cats
H. Climenhaga, J. M. Macdonald, B. E. McCarey and G. O. Waring 3rd
Department of Ophthalmology, Emory University, School of Medicine, Atlanta, GA.
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.
