Ty looks at the upcoming interaction as mealtime, but it’s also an optical training session to accustom the 440-pound animal to the hand-held instruments that will be used in his future eye exams.
As for Shelley, these 15 minutes are simply the best part of her day, when she gets to work with one of her favorite Shedd animals.
First, Ty gets a little warm-up “tactile”—a friendly rub on the throat from Shelley. Then, with a hand signal from Susan, the massive mammal holds perfectly still in an extended “target.”
When Susan gives the okay, Shelley shines the bright light of an ophthalmoscope into his left eye for two seconds. The instrument lets veterinarians see the interior structure of the eye—a standard part of any vision exam. With a short toot on her trainer’s whistle and several fish, Susan lets Ty know he’s done a good job. Then the procedure is repeated for his right eye.
Shelley puts away the ophthalmoscope and brings out a TonoVet, or veterinary tonometer, which measures the fluid pressure inside the eye, “just like when we get a glaucoma test during an eye exam,” she says
The TonoVet has a tiny soft-plastic probe that makes split-second contact with the cornea. It takes six featherweight pulses of the probe to get a reading. Shelley has been doing one or two pulses each session to get Ty accustomed to it.
“Let’s do one pulse,” Susan says as she has Ty target on her hand for six seconds. “Okay, let’s do multiple pulses.”
Ty’s attention is riveted on the trainer as Shelley counts six pulses on the sea lion’s left eye.
“Nice! Excellent!” Susan says, giving Ty more fish.
Shelley moves to Ty’s right side and does one pulse. Susan gives her the go-ahead to do six. Ty’s gaze never wavers from the trainer. Then, after more fish from Susan and an affectionate scratch on the side of the neck from Shelley, Ty barrels back to his pool in the area behind Grainger Sea Lion Cove.
While you might not have thought, “Do sea lions do this, too?” as your eye doctor asked you to read the smallest line on the eye chart, Shelley says that every Shedd animal with eyes gets an optical exam. (The corals get a pass.)
“Each animal gets a different kind of exam,” she continues. “For the turtles, we use the ophthalmoscope. With the sea otters, we also use the TonoVet for a more complete exam. With sharks and other fishes, we shine the light in their eyes, and we might also do a fluorescein stain, which picks up any defects on the surface of the cornea, like a scratch or an ulcer. But they’re all going to get eye exams.”
It’s hard to explain the benefits of preventive vision care to a sea lion, or sea otter, or sea turtle—larger animals that might not want to sit still through an unfamiliar procedure—so the trainers and animal health staffers ease them into the experience using approximations—baby steps—to get them accustomed to the equipment and the motion so close to their faces.
“For us,” Shelley says, “the training sessions are such a great opportunity for animal health staffers to develop relationships with the trainers and the sea lions or other animals, and that is so vitally important to overall care.”
Susan, who has been working with sea lions for most of her three-and-a-half years at Shedd, started acclimating Ty to the light of the ophthalmoscope using a flashlight with layers of paper over the lens. “As he got used to it, I took away pieces of paper to make the light brighter and shine more directly in his eye.”
Then she introduced Shelley into the procedure. Shelley only stood near Ty, holding, but not using, the TonoVet. At each session, Shelley brought the instrument closer to Ty’s eyes, making sure he remained relaxed.
“The big jump was to know when he was ready for us to use it,” Susan says. “One day we decided to do one pulse. We don’t know if he felt it, but he started to blink his eye, and at the next session, he anticipated the pulse. So we switched to his right eye, which has limited sight because of a cataract that developed long before he came to Shedd.” When Ty couldn’t anticipate the pulse, training progressed quickly and made it easier to move back to his good eye.
Sometime in the next few months, one of Shedd’s veterinarians will perform the actual exam on Ty. Will he be ready? “Most definitely,” says Susan.
—Karen Furnweger, web editor