Glaucoma
An ocular emergency characterized by increased intraocular pressure (IOP) that causes severe eye pain and rapid irreversible blindness.
💬 In Plain English
Glaucoma occurs when fluid inside the eyeball (aqueous humor) cannot drain properly through the microscopic drainage angle, causing pressure inside the eye to spike dangerously high. A normal pet eye pressure is between 10 and 25 mmHg; in acute glaucoma, pressures often surge past 50 or 60 mmHg. This causes intense, migraine-like pain, cloudy blue haziness over the cornea, dilated non-responsive pupils, and bulging of the eyeball (buphthalmos). Because high pressure crushes the sensitive retinal cells and optic nerve within hours, glaucoma is a true medical emergency where every minute counts to save vision.
🔬 Clinical & Technical Depth
For Vets & TechniciansFormal Clinical Definition
Heterogeneous group of ocular disorders characterized by elevation of intraocular pressure (IOP) beyond physiologic limits tolerated by the optic nerve and retina, resulting in neurodegenerative vision loss.
Why Veterinarians Use It
Veterinarians use a tonometer to measure IOP in any red, cloudy, or painful eye to diagnose glaucoma before optic nerve atrophy occurs.
Clinical Context Encountered
Seen in emergency clinics when a pet suddenly squints, develops a cloudy eye, or bumps into furniture.
Clinical Reference Guide (Medical Condition)
Typical Presentation
Severe blepharospasm, epiphora, corneal edema ("blue eye"), fixed dilated pupil, episcleral congestion.
Management Priorities
- Emergency topical prostaglandin analogues (latanoprost)
- Carbonic anhydrase inhibitors
- Prophylactic treatment of fellow eye
- •A suddenly cloudy, red, squinting, or enlarged eye is an immediate ophthalmic emergency: permanent blindness can occur within 24 to 48 hours without pressure-lowering therapy.
❓ Questions to Ask Your Veterinarian
Take these actionable questions with you to your next clinic visit or appointment:
- 1What is the measured intraocular pressure (IOP) in both eyes right now?
- 2Is this primary inherited glaucoma or secondary to uveitis or lens luxation?
- 3What preventative drops should be started immediately in the unaffected eye?
Academic & Clinical References
- ACVO Guidelines on Canine and Feline Glaucoma ManagementOrganization: American College of Veterinary Ophthalmologists (ACVO) • Accessed: 2026-01-10https://www.acvo.org