Veterinarians used Bioptigen’s Envisu R2300 ophthalmic imaging system in the successful surgical removal of a cataract from C’sar, a 38-year-old African elephant residing at the North Carolina Zoo.
The surgery in November represented only the fifth time elephant cataract surgery has been performed anywhere in the world. And it marked the first time that a spectral domain optical coherence tomography (SDOCT) imaging system was used on an elephant.
North Carolina Zoo officials say that C’sar’s behavior has improved dramatically since surgery – to the extent that they hope he can resume grazing in one of his three-and-a-half acre savannahs this spring. He has been sheltered within his barn and paddock since last March after cataracts in both eyes essentially blinded him, preventing him from safely and confidently roaming in larger spaces.
Dr. Eric Buckland, president and CEO of Bioptigen, said the company’s Envisu R2300 was a logical choice for C’sar’s surgery because it is the only ophthalmic SDOCT system available commercially with a hand-held scanner – a clear benefit for surgeons working with a supine six-ton elephant.
“Our hand-held technology allowed surgeons to bring the imager to the elephant, which obviously is better than having to bring an elephant to an imager,” Buckland said. “And the attributes of our Envisu system allowed users to modify it for the unique size of an elephant’s eye. No other product on the market can do that.”
The Envisu R2300 allowed veterinarians to visualize the cornea, the cataract and the capsular bag prior to surgery.
Dr. Richard J. McMullen Jr., assistant professor of ophthalmology at the College of Veterinary Medicine at N.C. State University, removed the cataract from C’sar’s eye. It was the first time he used Bioptigen’s Envisu system.
“The biggest difference between OCT and ultrasound is the amount of detail you can see in the cornea, especially within the stroma and epithelium,” he said. “As a surgeon, it was very interesting and useful to have that degree of magnification.”
The four-hour surgery was performed in the zoo’s elephant barn. McMullen and his team had hoped to implant a specially created artificial lens in C’sar’s eye, but damaged tissue could not support it, McMullen said. Had the lens been used, it would have been the first artificial lens implantation ever performed on an elephant.
The lack of a replacement lens means C’sar will see farsighted but should function just fine, McMullen said. He added that artificial lens implantation following cataract removal only recently has been adapted in the horse.
C'sar – the oldest male elephant at the North Carolina Zoo – has lived there longer than any other member of the permanent animal population. With his distinguished lopsided silhouette – one ear has laid flat against his head since childhood – C’sar is a favorite among visitors, said Rod Hackney, zoo spokesman.
Said the zoo’s mammal curator, Guy Lichty,“C’sar’s surgery was highly successful and has dramatically improved his quality of life, even without the replacement lens. We are anxious to give him access to one of the larger exhibits, weather permitting, to see if he can safely negotiate the space and find his way back to the barn before nightfall. If he succeeds, staff and visitors will surely celebrate that day. Otherwise, we’ll have to discuss perhaps operating on his other eye in hopes of further improvement.”
The North Carolina Zoo in Asheboro is recognized as one of the nation’s finest zoos. It was the first American zoo designed from inception around the natural-habitat philosophy of presenting animals and plants in exhibits that closely resemble their wild environments.
The N.C. State University College of Veterinary Medicine is ranked third among the nation’s 28 colleges of veterinary medicine by U.S. News and World Report. Its state-of-the-art Randall B. Terry Jr. Companion Animal Veterinary Medical Center is one of the country’s most advanced veterinary hospitals.
Bioptigen Inc. is an ISO 13485-certified medical device company that develops innovative ophthalmologic imaging technologies. The company has received regulatory approval to market its hand-held Envisu R2000-series systems for pre-clinical use and its C2000-series systems for clinical use within the European Union. Availability of the C2000 series for clinical use in the United States is dependent upon review and market clearance by the U.S. Food and Drug Administration.
Bioptigen’s Envisu R-class systems are ideally suited to non-invasive ophthalmic imaging of animals ranging from zebrafish to elephants. Using low-power, near-infrared light, Envisu generates real-time, depth-resolved, high-resolution images of ocular microstructures from the cornea to the retina.