Experimental implantation of posterior chamber prototype intraocular lenses for the feline eye.
OBJECTIVE
To measure postoperative anterior chamber depth (ACD), corneal curvature, and refractive state of feline eyes after lens removal and implantation of a prosthetic intraocular lens (IOL) and determine appropriate IOL use in cats.


METHODS
8 clinically normal adult cats.


METHODS
A-scan ultrasonic biometry, keratometry, and streak retinoscopy were performed on both eyes of each cat before and after lens removal and implantation of a prosthetic IOL. Three diopter (D) IOL strengths were used: 48, 51, and 60 D. Measurements were recorded for 12 weeks after surgery.


RESULTS
IOL were well tolerated by cats, with no serious 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 or after surgery among eyes with various IOL. Twelve weeks after surgery, eyes with 48-, 51-, and 60-D IOL had mean +/- SD refractive state of +2.1 +/- 0.49, +0.42 +/- 0.20, and -2.6 +/- 0.78 D, respectively. Linear 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.


CONCLUSIONS
IOL of substantially higher diopter strength than that needed in dogs was required to achieve emmetropia after lens extraction in cats. A 52- to 53-D IOL is required to correct feline eyes to near emmetropia after lens removal.
Department of Companion Animal and Special Species Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
B C
BC
Gilger
M G
MG
Davidson
C M
CM
Colitz
D000818:Animals; D000867:Anterior Chamber / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D001699:Biometry / Q000379:methods; D002415:Cats / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery*; D003315:Cornea / Q000033:anatomy & histology*; D004285:Dogs; D019654:Lens Implantation, Intraocular / Q000662:veterinary*; D016014:Linear Models; D012029:Refraction, Ocular / Q000502:physiology*; D014463:Ultrasonography; D014792:Visual Acuity