Three elderly royal penguins were fitted with custom-made eye lenses during surgery to remove cataracts in what is believed to be the world’s first procedure of its kind to improve their eyesight, a Singapore zoo has revealed.
In a statement, veterinarians from the Mandai Wildlife Group said the birds were among six elderly penguins who underwent cataract surgery two months ago and have since made a full recovery.
They include three Royal Penguins aged 20 years and older, and three Humboldt Penguins, aged 7 to 13, who live in Jurong Bird Park, Singapore.
Cataracts, which cause cloudy areas in the eye that make it difficult to see, are a common age-related condition in both people and animals.
“We noticed the cloudiness in their (eyes) and they moved as if they had trouble seeing things in front of them,” says veterinarian Ellen Rasidi, explaining the decision to remove the cataracts.
A royal penguin undergoes cataract surgery at a clinic in Singapore. Photo: Mandai Wildlife Group
The royal penguins received custom-made intraocular lens implants, says Gladys Boo, a veterinary ophthalmologist who participated in the surgeries, which she said were “a milestone in veterinary medicine.”
The lenses were custom-made in Germany with precise measurements to fit each penguin’s eye – a process that took two months, says Boo.
“As a larger species, royal penguins have eyes large enough and stable enough to keep custom lenses in place, so we decided to proceed with this world-first procedure to further improve their vision beyond cataract removal.” says Boo.
Behind-the-scenes photos show the delicate procedure, which Boo says is especially tricky for penguins due to their unique characteristics, such as a third eyelid that protects their eyes underwater but tends to close under surgery.
After the surgery, the six penguins had to remain out of the water and zookeepers had to put eye drops on them twice a day.
Royal penguins are the second largest penguin species and are found in the Southern Ocean and sub-Antarctic.
Although they are not threatened, they are protected under wildlife legislation. They can weigh up to 18 kilos and reach up to 1 meter in height and can live up to 30 years in captivity.
Zookeepers and veterinarians said they had seen “an increase in responsiveness and activity levels” in the penguins after surgery.
“It’s good to see them more active, which indicates an improvement in vision,” says Rasidi, the veterinarian. “Royal penguins are also adapting well to the new lenses.”
A device measures the pressure in the eye of a Humboldt penguin. Photo: Mandai Wildlife Group
Singapore’s world-renowned Jurong Bird Park was once home to around 3,500 birds, including parrots, flamingos and eagles, before closing last August to prepare for a move to new premises, where it will join the city’s zoo, the night safari and a new luxury resort to form an ecotourism hub.
The park has been involved in several high-profile rescue and rehabilitation efforts over the years – including treating a hornbill with cancer by fitting it with a 3D-printed prosthetic beak.
