Poor old Fifi loses her eyesight

Seventeen year old tortoise shell Fifi came to us in June this year with a complaint of not being able to see. Her owner noticed on several occasions that Fifi had been bumping into objects in the house and seemed to veer off to the side when she walks. This incident happened suddenly with no known inciting cause. Fifi seemed well apart from the impaired vision. Obviously very concerned, her owner brought Fifi to our attention in hope of getting her vision back.

When Fifi was examined, both her pupils were very dilated and they were non-responsive to light when shined directly to her eyes. On further examination with a direct ophthalmoscope, we found that there was evidence of bleeding in the right eye. These findings raised high suspicion for retinal hemorrhage and detachment due to a high systemic blood pressure. Sure enough, when the blood pressure was measured, it was 230 mmHg (the normal upper limit for cats is around 160 mmHg). No other significant findings were found that could relate to the sudden blindness. So based on these results we know that the reason Fifi was not able to see is because her high blood pressure has caused the retina in both her eyes to detach from the underlying layer of blood vessels.

Bilateral retinal detachment and hemorrhage is a serious eye condition that almost always leads to blindness if not treated promptly, and even with prompt treatment chances of regaining vision in most cases are low. Possible causes of retinal detachment, to name a few, are congenital retinal dysplasia, trauma, vascular disorders, hypertension, infectious chorioretinitis, immune-mediated, and idiopathic. To further rule out other possibilities, a routine seniors blood panel was performed on Fifi. The blood results showed elevation in Fifi's kidneys enzymes which is highly suggestive of chronic renal disease, a known cause of hypertension especially in older cats. Hence a diagnosis of retinal detachment and hemorrhage due to systemic hypertension from chronic renal disease was reached.

Fifi has since been on several medications to try to quickly reduce her blood pressure in hope that once the blood pressure is under control, the retina might have a chance to sit back in its original position and some form of vision is able to return. Unfortunately for Fifi, a week since her initial presentation, there was still no change in her vision, although her blood pressure is gradually reducing over time. Because of the progressive nature of the kidney disease, all we are hoping to achieve here is that Fifi's blood pressure is well controlled so that the hypertension does not affect other organs in the body, namely the brain and heart. The kidneys also need protection so that they do not deteriorate quickly. Therefore Fifi needs to be on tablets for the rest of her life, something that her owner has been coping well so far. As far as the vision goes, Fifi is coping well at home. She does not go outside anymore and is finding her way around in the house with the help of her good old memories of where things sit normally. So if her owner does not switch the furnishing around, Fifi should get around just fine at home. We will keep you posted if there is any changes to Fifi's eyesight.

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