The Ophthalmology Service in Iowa State’s Hixson-Lied Small Animal Hospital regularly treats dogs, cats and horses for a variety of eye issues.
Some farm animals will also find their way to the Ophthalmology Service.
But Milo was a first for Iowa State’s veterinary ophthalmologists.
“Milo was the most novel patient we have seen in the past few years as we don’t generally have direct wildlife exposure at the hospital,” said Dr. Melissa Kubai, assistant professor of veterinary clinical sciences. “It was the first time we have placed an epibulbar cyclosporine implants in a harbor seal.”
Milo resides at Omaha’s Henry Doorly Zoo & Aquarium where he developed pinniped keratopathy (PK). The disorder can result in perilimbal to diffuse corneal edema leading to ocular discomfort from non-healing corneal ulcers, along with developing neovascularization fibrosis and subsequent pigment accumulation on the cornea.
PK is a specific condition in pinnipeds living in human care. For Milo’s case, it’s hypothesized that he sustained an injury from another animal in the habitat, with environmental factors as a potential factor. PK can be caused by a variety of health factors including eye trauma, previous ocular disease and other disease factors, as well as environmental factors such as UV light, water quality, salinity, habitat color, habitat density and types of animals living in the habitat.
Kubai says the process could have contributed to Milo vision impairment and even potential vision loss if it wasn’t treated.
The treatment elected was epibulbar cyclosporine implants placement which Kubai and the ophthalmology team performed on Milo a few months ago. It is a procedure that she has performed on dogs and horses to alleviate the need for topical medications. Epibulbar cyclosporine implants have been reported in the literature to last around two years in pinnipeds.
But surgery on a harbor seal is not the same as a dog or horse.
“Harbor seals have a very tight globe to eyelid confirmation along with having very strong eyelid and extraocular muscles,” Kubai said. “To place the implants, we had to perform this procedure under general anesthesia and stay suture placement was required to place the implants.”
With the implants, Milo’s PK is under control, and it has reduced his risk of recurrent corneal ulcer or other ocular discomfort.
“His comfort has been improved, his vision has been maintained and the implants have eliminated the need for topical eye drops to control the PK,” Kubai said. “All of these have contributed to a significant improvement of his quality of life.”
“We are grateful to the team at Iowa State for their assistance with Milo’s case,” said Dr. Taylor Yaw, DVM and vice president of science and animal health. “We are particularly glad to have the opportunity to welcome both veterinary students on externship at our Zoo and students on the University’s rotation to participate in the procedure.
“This is a great example of what happens at our Zoo every day; extraordinary animal care and hands-on experience, education and inspiration for the next generation of animal professionals and conservation stewards.”
February 2025