EXPERIMENTAL IMPLANTATION OF POSTERIOR CHAMBER PROTOTYPE INTRAOCULAR LENSES FOR THE FELINE EYE

Objective-To measure postoperative anterior chamber depth (ACD), corne al curvature, and refractive state of feline eyes after lens removal a nd implantation of a prosthetic intraocular lens (IOL) and determine a ppropriate IOL use in cats. Animals-8 clinically normal adult cats. Pr ocedure-A-scan ultrasonic biometry, keratometry, and streak retinoscop y were performed on both eyes of each cat before and after lens remova l and implantation of a prosthetic IOL. Three diopter (D) IOL strength s were used: 48, 51, and 60 D. Measurements were recorded for 12 weeks after surgery. Results-IOL were well tolerated by cats, with no serio us complications attributable to implantation or presence of the IOL. The ACD was significantly greater after (8.30 mm) than before (4.97 mm ) surgery; however, it became slightly more shallow during the 4 weeks after surgery, suggesting that the IOL shifted anteriorly in the eye. Significant difference in corneal curvature was not detected before o r after surgery among eyes with various IOL. Twelve weeks after surger y, eyes with 48-, 51-, and 60-D IOL had mean +/- SD refractive state o f +2.1 +/- 0.49, +0.42 +/- 0.20, and -2.6 +/- 0.78 D, respectively. Li near regression analysis of refractive state on IOL power for all eyes at 12 weeks after surgery predicted that +52.8-D IOL was necessary to best approximate emmetropia in these cats. Conclusion and Clinical Re levance-IOL of substantially higher diopter strength than that needed in dogs was required to achieve emmetropia after lens extraction in ca ts. A 52- to 53-D IOL is required to correct feline eyes to near emmet ropia after lens removal.