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Old July 8th, 2008, 09:43 PM
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Dr Lee Dr Lee is offline
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Join Date: Jun 2007
Location: East Coast
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Different on the west coast?

Originally Posted by petdr View Post
It is common to use artificial lenses in human cataract surgery, but not so in animals, particularly dogs.
It may be regional but here in Arizona our veterinary ophthalmologists (Eye Care for Animals - four locations in Arizona) actually do implant an artificial lens as a replacement when removing the cataract affected lens. They state that about 95% of their patients receive the artificial lens. I called their facility today and asked the material of the artificial lens in cataract surgeries used in dogs, they said it is acrylic. They have different sizes for various sized eyes.

Here is an excerpt with regard to the quality of vision with the lenses from
Cataract Surgery
British Small Animal Veterinary Congress 2006
M. Davidson, DVM, DACVO
College of Veterinary Medicine, North Carolina State University
Raleigh, NC, USA

Prosthetic Intraocular Lenses

Implantation of prosthetic intraocular lenses (IOLs) in dogs following cataract surgery was introduced at approximately the same time as phacoemulsification. Most veterinary ophthalmologists currently implant a 41 diopter IOL in dogs to correct the refractive error induced by removal of the lens, and placement of an IOL in dogs is becoming the standard of care. Without an IOL, dogs have a hyperopia (farsightedness) of approximately 15 diopters. This has been estimated to correlate to a visual acuity of 20/200-20/600 on the Snellen eye chart commonly used in people. Retrospective studies have documented similar success rates with and without use of an IOL, and placement of an IOL in the capsular sac has been shown, in humans, to reduce the severity of capsular fibrosis, a common postoperative complication. Until recently, the standard design of a canine IOL was 'one-piece,' constructed of polymethyl-methacrylate (PMMA), with an optic and haptic portion, and designed to be implanted through a 7-8 mm incision. A second wave of development of canine IOLs has resulted in the design of 'foldable' intraocular lens constructed of soft acrylic materials and designed to be implanted through a 3-4mm incision. In addition to offering the advantage of a smaller incision, many of these foldable lens have a 'square-edge' posterior optic configuration, which has been shown to reduce the likelihood and severity of posterior capsular opacification.
Christopher A. Lee, DVM, MPH, Diplomate ACVPM
Preventive Medicine Specialist With a Focus on Immunology and Infectious Disease
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