For Dr. William Wiley, medical director of the Cleveland Eye Clinic and Clear Choice Laser Eye Center in Ohio, cataract surgery is a procedure he routinely performs on humans. Earlier this month, he got the opportunity to change up this routine a bit when he was asked by the Akron Zoo to perform cataract surgery on Ana — a one pound golden lion tamarin.
Although the zoo's veterinary ophthalmologist had experience performing cataract surgeries on animals, Wiley was asked to be involved since the animal having surgery was a primate and there would be some similarities to human anatomy. “The anatomy (of Ana's eye) was almost exactly like a human as far as the appearance,” Wiley explained.
However, the main challenge came in terms of size, as Ana's eye was much smaller than a human eye. Because of this, Wiley and his team of surgical volunteers had to use micro-instruments and even fashion new instruments, such as a lid speculum, that would be small enough for Ana's eye. “We tried looking at our preemie lid speculum for babies and they were three times too big, so we had to use something about a third the size of what’s used in infants to get exposure,” he explained.
Ana, the golden lion tamarin.
Ana's size also made anesthesia a challenge. "Because she was undergoing the risk of anesthesia, we thought to do both eyes at once to avoid the risk of multiple sedations," Wiley added.
According to Wiley, the actual surgery took about 20 minutes per eye. The surgery took place at the Akron Zoo on June 3rd, and included a team of volunteers from Wiley's office, as well as Sightpath Medical, who Wiley said volunteered their time and expertise to bring the mobile equipment needed for the surgery.
In regards to post-operative care, as Ana is a wild animal administering eye drops was not really an option. To help ensure her eyes healed properly, Wiley administered compounded medications during surgery to eliminate the need for post-operative drops.
Now a few weeks since her surgery, Wiley said Ana is recovering well and has already shown improvement.
"(Ana) has a twin brother in the exhibit — in the primate culture, they groom each other as part of their social interaction," Wiley explained. "Ana couldn’t see her brother to groom him and so he was getting upset — (he) stopped grooming her and it was causing social friction between the two of them. But he was the seeing eye monkey — she would literally grab his tail and he would lead her around the exhibit for her to ambulate."
Since her surgery, Wiley said Ana is now able to see her food, see her brother and move around the exhibit.
Wiley said although they were able to remove the cataracts from both eyes, Ana is now functionally aphakic as they were unable to put in an intraocular lens due to the size of her eyes. While Ana is functioning well now, if it becomes a problem in the future Wiley said they are considering working with a lens company to see if they would be interested in making a lens small enough to use for Ana.
Overall, Wiley said the entire experience was exciting, and he was happy to see how much interest the case generated when telling friends and family about it. "It's not something you see every day," he said. "It tugs on a different heartstring when an animal has a problem and we have the ability to help it with our modern medicine. I think people find that intriguing and touching — it's become the local story that everyone is interested in."