What happens when a creature that depends on its sight for survival as much as an owl does starts to go blind? Carolyn Screech recalls the pioneering surgery that saved the sight of a Siberian Eagle Owl and helped him to continue leading a long and healthy life.
Boris is a Siberian Eagle Owl and one of only a few pure-bred Siberian eagle owls in captivity in this country. He is almost 25 years old but, for an eagle owl, he is still a relatively young man as he could live for many more years and breed for as many as 15 years more.
Unfortunately Boris was going blind due to cataracts in both of his eyes. As you can imagine, this was a very disturbing experience for an owl. However, at the end of January 1999, he was the recipient of pioneering surgery.
We had no idea when we agreed to take Boris into our care as a permanent resident, and to help restore his sight, what a worrying task this would be. We spent many anxious days hoping that Boris could cope with all the stress, and seeking consolation for ourselves that it would all be worthwhile in the end.
Under the knife
On Tuesday January 26 1999, at the Eye veterinary clinic in Hereford, Boris was whisked away to a specially-prepared theatre for his two-and-a-half-hour operation. The anaesthetist inserted a tube into his respiratory tract via a small incision to administer the anaesthetic which temporarily stopped Boris from breathing. His responses were monitored by heartbeat alone on a machine throughout the operation.
The removal of the cataracts was performed by making a tiny incision into the 14mm by 7mm oval lenses of the eyes. A device spinning at 40,000 rpm turned the solid cataracts into a liquid, a process known as phaco-emulsification, and this liquid substance was then removed by suction.
The operation has successfully restored 60 per cent vision to his left eye, and 90 per cent in the right eye, but his brain and eye co-ordination took a few weeks to adjust properly, which made him slightly disorientated.
BBC Science approached us with an interest in Boris’ plight, and the fact that this was pioneering surgery. They filmed the operation for Rolf Harris’ Amazing World of Animals programme which was shown on BBC television on Sunday September 19 1999.
Ophthalmologist vet Neil Wilson performed the post-operative eye check after a fortnight, when the eyes were healing so well that we were then able to discontinue the eye drops and daily injection treatments.
We were delighted when his progress had improved enough that he could see to fly to his perches. He has now moved into his new super-large aviary with his new partner Pushkin.