Visionary Surgery Aids Elephant

Richard McMullen has just finished the biggest case of his life – literally. On May 31, McMullen successfully completed the second of two cataract surgeries on an elephant named C’sar.

C’sar is a 38-year-old African bull elephant who has been in residence at the North Carolina Zoo since 1978. In fact, he was one of the first animals acquired by the zoo. In 2010, he was diagnosed with cataracts in both eyes, and his eyesight grew progressively worse. His handlers and the zoo veterinarians made the decision to remove the cataracts, and they contacted McMullen to perform the surgery. They operated on C’sar’s left eye in November 2011.

When that surgery was successful, they scheduled the second cataract removal for May, in order to be sure that the first eye had completely healed.

“An elephant’s eye is actually very similar in size to a horse’s eye, so that’s the model I used to prepare for this surgery,” says McMullen. “Horses’ eyes, however, are very susceptible to infection, which was my major concern. But C’sar responded well to the surgery and his recovery went very smoothly.”

McMullen is an assistant professor of ophthalmology (practice limited to eyes) in NC State’s College of Veterinary Medicine.

Down, Boy

The most difficult part of the surgery was training C’sar to lie down on his side so that the surgeon could get to the eye.

“With a six-ton elephant, you definitely bring the surgical theatre to him, not the other way around,” says McMullen. “The nice thing was that when he was lying down his eye was already about three feet off the ground, which is the perfect height to work with when you’re in one of the surgical chairs we use for these operations.”

C’sar’s eyesight has improved significantly as a result of the surgery, although he is still farsighted.

“We had originally planned to implant corrective lenses when we removed the cataracts, but the internal structures of his eyes wouldn’t support them,” McMullen says.

NC State’s ophthalmology service and zoo veterinarians are looking into specially designed contact lenses that may be used to correct C’sar’s farsightedness, although much will depend upon the elephant’s recovery and the condition of his eyes.

“If he does end up with contacts, it will definitely be a first,” McMullen says. “And it could have ramifications for a lot of other animals as well.”

Photos courtesy of NC State Department of Educational Media and Design
Biomedical photography by John Conte.