Three elderly king penguins have been fitted with custom-made eye lenses during surgery to remove cataracts in what is believed to be a world first procedure to improve their sight, according to a Singapore zoo.

In a statement Tuesday, vets with the Mandai Wildlife Group said the birds were among six elderly penguins to undergo cataract surgery two months ago and have since made a full recovery.

They include three king penguins age 20 and older, and three Humboldt penguins, ages 7 to 13, which live in Singapore’s Jurong Bird Park.

Cataracts, which causes cloudy areas in the eye that hinder sight, is a common age-related condition in both people and animals.

“We noticed the cloudiness in their (eyes) and moving about like they were having difficulty seeing things in front of them,” said veterinarian Ellen Rasidi, explaining the decision to remove the cataracts.

The king penguins received custom-made intraocular lens implants, said Gladys Boo, a veterinary ophthalmologist who took part in the surgeries, which she said marked “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, Boo said.

“As a larger species, the king penguins have eyes large and stable enough to hold the custom lenses in place so we decided to pursue this world-first procedure to further improve their vision above removing the cataract,” she said.

Photos recorded the delicate procedure, which Boo said was especially tricky for penguins due to their unique characteristics, such as a third eyelid that protects their eyes underwater but which tends to close under surgery.

Post-surgery, all six penguins had to remain out of the water and zookeepers administered eye drops twice daily.

King penguins are the second-largest species of penguin and are found in the Southern Ocean and sub-Antarctic.

While not endangered, they are protected under wildlife laws. They can weigh up to 18 kilograms and reach up to 1 meter tall and can live up to 30 years in captivity.

Zookeepers and vets said they observed “an increase in responsiveness and activity levels” in the penguins following the surgery.

“It is nice to see them more active, indicating their improved vision,” said Rasidi, the vet. “The king penguins are adapting well to the new lenses as well.”

Words to Learn 相关词汇

【 白内障】báinèizhàng cataract an eye condition that causes clouding of the lens

【眼科医生】yǎnkē yīshēng ophthalmologist a medical doctor who specializes in eye and vision care

新加坡一家动物园称，三只老年帝企鹅接受了改善视力的白内障手术，植入了定制的人工晶体，这是世界上第一台这样的手术。

万礼生态园集团的兽医在周二的一份声明中表示，两个月前六只老年企鹅接受了白内障手术，这三只帝企鹅已完全康复。

六只企鹅中的三只是20岁及以上的帝企鹅，还有三只是7至13岁的洪堡企鹅，它们生活在新加坡裕廊飞禽公园。

因为晶状体浑浊导致视力下降，白内障是人和其它动物常见的老年病。

“我们注意到他们（眼睛）混浊、行动不便，似乎很难看清面前的东西，”兽医艾伦•拉西迪解释为什么决定给它们做手术。

参与手术的眼科兽医格拉迪斯•布说，帝企鹅接受了定制的人工晶体植入，标志着

“兽医学的一个里程碑”。

布说，人工晶体在德国定制，经过精确的测量以适应每只企鹅的眼睛 —— 整个过程费时两个月。

她说，“作为体型较大的企鹅，帝企鹅的眼睛大而稳定，容易将定制的镜片固定到位，所以我们决定采用这个世界首创的手术以改善它们的视力，而不是摘除白内障。”

照片记录了这个过程，布说，由于企鹅的独特体征，手术对企鹅来说尤其棘手，企鹅的第三眼睑在水下能保护眼睛，但手术中常会闭合。

术后所有六只企鹅都必须远离水面，动物园管理员每天给它们滴两次眼液。

帝企鹅是第二大企鹅物种，分布在南大洋和亚南极洲。

虽然帝企鹅没有濒临灭绝，但受到野生动物法的保护。它们可以重达 18 公斤，高达1米，圈养可以存活30年。

动物园管理员和兽医说，他们观察到术后企鹅“反应能力和活动水平增加”。

“很高兴看到他们更活跃了，这表明他们的视力有改善，”兽医拉西迪说。“帝企鹅很好地适应了人工晶体。”