How to Tell If Your Cat or Dog Has Glaucoma

1 What Eye Pressure Is and the Causes

What is eye pressure? At the pupil, fluid passes through a mesh-like drainage angle and leaves the eye. In a healthy eye, fluid is made and drained at equal rates, so a cat’s eye pressure stays around 2 to 3.6 kPa. When drainage is blocked, pressure rises. High pressure kills optic nerve cells and can cause blindness.

Causes: glaucoma has two types, primary and secondary. 1. Primary glaucoma has no prior eye disease and tends to strike certain purebred dogs. 2. Secondary glaucoma follows another eye disease that blocks fluid drainage, most often eye inflammation, lens dislocation, or eye trauma.

2 Symptoms, Diagnosis, and Treatment

Common symptoms: 1. cloudy-looking cornea and an enlarged eyeball, 2. a dilated pupil or no response to light, 3. cloudy or swollen cornea, 4. loss of vision, 5. bulging, red, swollen eye, 6. poor appetite and depressed spirit, 7. headache and head pressing.

How it is diagnosed: a history check on past treatment; visual exam for red conjunctiva or pale cornea and abnormal bulging; touch for a firm eyeball; a vision test for weak light response; blood work; an eye-pressure test, where normal is 2 to 3.6 kPa, 2.7 to 4 kPa is moderate, 4.0 to 5.3 kPa is high, and 5.3 to 6.7 kPa is markedly high; and a fundus exam for optic nerve changes, plus gonioscopy.

Treatment: drug therapy. Acute glaucoma can be treated with IV fluids and osmotic drugs such as mannitol to lower pressure, but glaucoma cannot be fully cured and needs regular pressure checks, usually every three months. Surgery: removal of the eyeball may be done to relieve the pain glaucoma causes.