Doctors Perform Cataract Surgery on Gorilla

Animal care specialists at San Diego Zoo Park noticed cloudiness in the left eye of one of their female lowland gorillas.

Leslie, a beautiful 3-year-old, had a damaged lens, causing her to favor her right eye. A team of eye experts were brought in to examine her, and they determined it was a cataract.

Specialists from San Diego Zoo Global and UC San Diego Health performed their first cataract surgery on a gorilla.

While cataracts can happen to gorillas as they age, Leslie's youth led the medical staff to believe this one likely stemmed from an injury from jumping on rocks or playing with other gorillas.

On Dec. 10, Leslie was brought into San Diego Zoo Global's Paul Harter Veterinary Medical Center for the operation. Dr. Chris W. Heichel was the lead surgeon for the eye repair.

Safari Park veterinarians organized a team of internal and external experts for the surgery.
Closer study of Leslie's condition confirmed her lens had changed and the left eye was shifting haphazardly, prompting Leslie to favor use of her right eye. Ken Bohn/San Diego Zoo Global

"Fortunately, the similarities between the anatomy of human and gorilla eyes are great enough to allow us to safely navigate the procedure without complication," Heichel told UC San Diego Health. "The remainder of the eye appeared to be in excellent health, indicating exceptional vision potential for the rest of Leslie's life."

Leslie rested comfortably in the operating room and was given a pharmaceutical muscle blocker to prevent movement for the delicate procedure.

Used a specialized microscope and instruments designed for cataract surgery to successfully extract a cataract in the left of 3-year-old gorilla.
Chris W. Heichel, cataract surgery specialist at Shiley Eye Institute at UC San Diego Health, prepares to work on Leslie's eye. Ken Bohn/San Diego Zoo Global

Heichel and his team used specialized microscopes and instruments to successfully remove the cataract and insert the new artificial lens.

As she recovers, Leslie will require optical and oral antibiotics and steroids to prevent infection and to control postoperative inflammation.

She will be closely monitored, but she's already back with her troop at the Gorilla Forest habitat at the Safari Park.

"In a human patient, we can laser the envelope to remove the cloudiness," said Heichel. "That might not be quite so easy for Leslie, therefore I made a little opening in the back of the envelope to maintain her clear vision in the future. I am grateful for the chance I had to work with the exceptional San Diego Zoo Global team to help have a positive impact on Leslie's life."

The Safari park's animal care team also went the extra mile to make sure Leslie's 31-year-old mother, Kokamo, was not stressed or upset while Leslie was gone.

They gave anesthetics to them both at the same time. While Leslie was in surgery, Kokamo received her routine health check.

As for Leslie, she's in great health and can look forward to clear eyesight for the rest of her life.