Systemic hypertension (high blood pressure) is a common problem in companion animals, particularly cats. Frequently there are no obvious outward signs indicating your pet has high blood pressure. The first sign observed can be sudden onset of blindness. Long standing elevations in blood pressure lead to damage of the blood vessels throughout the body and this occurs in the retina of the eye as well. These damaged blood vessels leak fluid which accumulates under the retina and causes it to detach, resulting in blindness. Some owners will notice that their pet?s pupil is very large, that one pupil is a different size than in the other eye, or that the green ?eye shine? is more obvious. Other signs may be bleeding within the eye or neurologic changes.
DIAGNOSIS OF HYPERTENSIVE RETINOPATHY:
Normal blood pressure in cats and dogs is similar to humans and should be around 120 mmHg. Due to the effects of stress on our patients in the hospital, however, even normal animals can have blood pressure readings significantly higher than the normal range. Your doctor will take into consideration many factors in determining a treatment plan for your pet. It is important that your pet have the blood pressure monitored in a quiet setting and in a consistent manner with as little distress as possible for accurate measurements. If your pet is placed on medications it is imperative that these medications be consistently administered as directed by your veterinarian and never be stopped abruptly. If medications are stopped, signs will likely return.
TREATMENT OF HYPERTENSIVE RETINOPATHY:
Most cats and dogs affected with high blood pressure have developed this condition as a result of another underlying health problem such as kidney disease, heart disease or an endocrine disease (Hyperthyroidism, Cushing?s disease, Diabetes Mellitus, or others). In managing high blood pressure it is important to identify and treat any underlying diseases. Thus, a full health history, current blood work, and urine analysis are extremely helpful when dealing with this syndrome. Early diagnosis and treatment will improve overall health and decrease the risk of ongoing retinal damage and systemic side effects. Systemic hypertension is not only blinding, but can be a life threatening disease as well if severe damage to other organs occurs.
PROGNOSIS FOR HYPERTENSIVE RETINOPATHY:
Depending on the degree of retinal detachment, the amount of bleeding and the duration of retinal disease, your pet may regain vision with treatment. Regular eye examinations and blood pressure monitoring will be required long term. Your veterinary ophthalmologist and your primary veterinarian will work together to determine the best treatment and monitoring plan for your pet.
If you have any question about this information please contact your veterinarian.