Cataract Surgery Took an Hour. Getting a 54-Year-Old Chimp Ready Took Months

Pierre is a 54-year-old chimpanzee who spent months learning to hold still for eyedrops before he could see the person giving them. Then a veterinary eye surgeon performed cataract surgery, and within hours he was responding to what he saw.¹²

Pierre lives at Chimp Haven, a nonprofit sanctuary in Keithville, Louisiana, about 22 miles southwest of Shreveport. It is home to more than 300 chimpanzees retired from research.⁵ Popular Science calls it the largest chimpanzee sanctuary in the world.¹ According to Chimp Haven’s statement, as reproduced by Good News Network, this was the first cataract surgery performed for one of its residents.²

That matters beyond one chimp. The story shows how patient, voluntary training can open the door to advanced medical care for aging animals that can’t simply be told to sit still.

Losing his way around the enclosure

Pierre came to the sanctuary about 25 years ago, after the New York research laboratory where he had been held closed.³ Staff noticed him pulling away from his group and feeling his way around his enclosure with his hands.³

Chimp Haven’s attending veterinarian, Dr. DaShaunté Coleman, found cataracts affecting his vision and depth perception.³ Accounts differ on how far his sight had gone. Popular Science and Chimp Haven’s statement describe him as completely blind, while Rise for Animals says he was losing his sight.¹²³

While his vision declined, caregivers used sound cues and specialized feeding approaches. They also added handholds, ladders and other supports to the areas he used most.²

Training for eyedrops without seeing them

Before the operation, the team spent months on positive-reinforcement training, which means rewarding the behavior you want, until Pierre would voluntarily present his eyes for drops and close checkups. He learned all of this while he couldn’t see.¹²

His longtime trainer used audio cues, a soft bamboo stick for gentle physical guidance and his favorite treats. Eventually Pierre would press his face against the safety mesh of his enclosure with his eyes open, ready for the drops.¹ That is a level of eyedrop cooperation plenty of humans never achieve.

“Pierre has always excelled at positive reinforcement training, so he was already familiar with his trainers and many physical cues,” Coleman told Popular Science.¹

An hour of surgery, then a favorite movie

Veterinary ophthalmologist Dr. Kenneth Pierce confirmed the diagnosis and judged Pierre a good candidate for surgery. Pierre was put under general anesthesia.³ The board-certified surgeon’s procedure took about an hour.¹²

Within hours Pierre was responding to what he saw. Rise for Animals reports he was tracking small objects within 12 hours.³ Popular Science reports he was watching a favorite movie.¹

“Watching Pierre look at me again was something I will never forget,” Reininger, his longtime caregiver, told Popular Science.¹

Back with Jill, and back up high

Within days, Pierre was reunited with Jill, one of his closest chimpanzee companions. He later rejoined his social group earlier than expected.¹² He also started climbing tall structures he had been avoiding.³

“This will open up a whole new world for him,” Coleman said, as quoted by Rise for Animals.³

The reports cover Pierre’s early recovery. In Chimp Haven’s statement, Coleman called it “a wonderful example of what individualized care can look like for an aging chimpanzee.”²