Glaucoma
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Emergency presentation is possibleA suddenly red, cloudy or enlarged eye, fixed dilated pupil or apparent vision loss requires emergency assessment.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Glaucoma is damage to the optic nerve and retina associated with pressure within the eye that is too high for that eye to tolerate. In cats, glaucoma is commonly secondary to another ocular disease rather than a primary inherited problem. Uveitis, intraocular tumours, lens abnormalities and previous trauma are important causes.
The rise in pressure occurs when aqueous fluid cannot drain normally from the eye. As pressure increases, the optic nerve is damaged and vision can be lost irreversibly. Cats may show a red eye, dilated pupil, corneal cloudiness, enlargement of the globe or reduced vision. Chronic disease can be surprisingly subtle because cats may not show obvious pain in the way people expect.
An acutely painful cat may hide, eat less, avoid bright light or resist having the head touched. Affected eyes can feel firmer, but owners should never attempt to estimate eye pressure by pressing on the globe.
The underlying cause matters because treatment of secondary glaucoma must address both pressure and the disease blocking normal drainage.
Vision lost from glaucoma generally cannot be restored. The priority is therefore rapid pressure control when vision may still be present and reliable pain control when the eye is already blind. Early recognition can make the difference between preserving sight and managing a permanently blind painful eye.
Cats often present later than dogs because primary glaucoma is less common and chronic secondary pressure elevation may produce few early outward signs. Once the optic nerve is damaged, lowering pressure improves comfort but cannot reconstruct lost vision.
It is quick and can be performed in an awake cat with topical anaesthetic. Pressure is interpreted alongside the appearance of both eyes because severe uveitis can initially lower pressure before secondary glaucoma develops.
Screening & Early Detection
Any cat with a suddenly red, cloudy or enlarged eye, a fixed dilated pupil or apparent loss of vision should be examined promptly. Glaucoma can progress without dramatic discharge, so persistent ocular change should not be managed as simple conjunctivitis without measuring eye pressure.
Tonometry is the key screening and diagnostic test.
The veterinarian examines the lens, iris and drainage angle where possible and looks for inflammation or an intraocular mass. Ocular ultrasound is useful when the cornea or lens is too opaque to see deeper structures. Blood pressure and systemic testing may be added if retinal or inflammatory disease suggests a broader cause.
Primary inherited glaucoma is uncommon in cats, so there is no general breed-wide screening programme comparable with some dogs. Early detection instead depends on prompt measurement in any suspicious eye and monitoring cats with chronic uveitis or other conditions known to impair aqueous drainage.
Glaucoma is diagnosed with tonometry, which directly measures intraocular pressure, combined with a full eye examination. Ultrasound can be useful when the interior of the eye cannot be seen because of cloudiness. Gonioscopy and specialist examination may be used in selected cases. This makes measurement especially important in cats with uveitis or intraocular disease.
Treatment & Management
Treatment aims to lower intraocular pressure quickly and address the cause. Topical pressure-lowering medication is commonly used, and additional systemic treatment may be required during an acute crisis. Drug choice depends on the underlying ocular disease because not every glaucoma medication is appropriate in every cat.
If uveitis is driving secondary glaucoma, inflammation is controlled as well as pressure, provided the cornea and other structures allow safe anti-inflammatory therapy. Intraocular tumours or lens disease may require surgery. A veterinary ophthalmologist can advise on advanced pressure-control procedures when useful vision remains.
When an eye is permanently blind and cannot be kept comfortable with medication, surgical removal of the eye is often the most humane option. Cats generally adapt remarkably well to one eye, and removal eliminates chronic glaucoma pain. Cosmetic orbital implants may be available in selected cases.
Long-term monitoring is needed because secondary disease can change and the opposite eye may also require assessment depending on the cause. Medication should not be stopped solely because the eye looks less red. Pressure must be remeasured to confirm control. Sudden recurrence of pain or cloudiness warrants urgent review.
Breeds or species affected
Abyssinian
Open cat breed description, care requirements and conditions
American Bobtail
Open cat breed description, care requirements and conditions
American Curl
Open cat breed description, care requirements and conditions
American Shorthair
Open cat breed description, care requirements and conditions
American Wirehair
Open cat breed description, care requirements and conditions
Arabian Mau
Open cat breed description, care requirements and conditions
Aegean
Open cat breed description, care requirements and conditions
Australian Mist
Open cat breed description, care requirements and conditions
Balinese
Open cat breed description, care requirements and conditions
Bengal
Open cat breed description, care requirements and conditions
Birman
Open cat breed description, care requirements and conditions
Bombay
Open cat breed description, care requirements and conditions
British Longhair
Open cat breed description, care requirements and conditions
British Shorthair
Open cat breed description, care requirements and conditions
Burmese
Open cat breed description, care requirements and conditions
Burmilla
Open cat breed description, care requirements and conditions
Chartreux
Open cat breed description, care requirements and conditions
Chausie
Open cat breed description, care requirements and conditions
Colorpoint Shorthair
Open cat breed description, care requirements and conditions
Cornish Rex
Open cat breed description, care requirements and conditions
Cymric
Open cat breed description, care requirements and conditions
Devon Rex
Open cat breed description, care requirements and conditions
Domestic Longhair
Open cat breed description, care requirements and conditions
Domestic Medium Hair
Open cat breed description, care requirements and conditions
Domestic Shorthair
Open cat breed description, care requirements and conditions
Donskoy
Open cat breed description, care requirements and conditions
Egyptian Mau
Open cat breed description, care requirements and conditions
European Shorthair
Open cat breed description, care requirements and conditions
Exotic Shorthair
Open cat breed description, care requirements and conditions
Havana Brown
Open cat breed description, care requirements and conditions
Highlander
Open cat breed description, care requirements and conditions
Himalayan
Open cat breed description, care requirements and conditions
Japanese Bobtail
Open cat breed description, care requirements and conditions
Khao Manee
Open cat breed description, care requirements and conditions
Korat
Open cat breed description, care requirements and conditions
Kurilian Bobtail
Open cat breed description, care requirements and conditions
LaPerm
Open cat breed description, care requirements and conditions
Lykoi
Open cat breed description, care requirements and conditions
Maine Coon
Open cat breed description, care requirements and conditions
Manx
Open cat breed description, care requirements and conditions
Minuet
Open cat breed description, care requirements and conditions
Minskin
Open cat breed description, care requirements and conditions
Munchkin
Open cat breed description, care requirements and conditions
Nebelung
Open cat breed description, care requirements and conditions
Norwegian Forest Cat
Open cat breed description, care requirements and conditions
Ocicat
Open cat breed description, care requirements and conditions
Oriental Longhair
Open cat breed description, care requirements and conditions
Oriental Shorthair
Open cat breed description, care requirements and conditions
Persian
Open cat breed description, care requirements and conditions
Peterbald
Open cat breed description, care requirements and conditions
Pixiebob
Open cat breed description, care requirements and conditions
RagaMuffin
Open cat breed description, care requirements and conditions
Ragdoll
Open cat breed description, care requirements and conditions
Russian Blue
Open cat breed description, care requirements and conditions
Savannah
Open cat breed description, care requirements and conditions
Scottish Fold
Open cat breed description, care requirements and conditions
Scottish Straight
Open cat breed description, care requirements and conditions
Selkirk Rex
Open cat breed description, care requirements and conditions
Siamese
Open cat breed description, care requirements and conditions
Siberian
Open cat breed description, care requirements and conditions
Singapura
Open cat breed description, care requirements and conditions
Snowshoe
Open cat breed description, care requirements and conditions
Somali
Open cat breed description, care requirements and conditions
Sphynx
Open cat breed description, care requirements and conditions
Thai
Open cat breed description, care requirements and conditions
Tonkinese
Open cat breed description, care requirements and conditions
Toybob
Open cat breed description, care requirements and conditions
Toyger
Open cat breed description, care requirements and conditions
Turkish Angora
Open cat breed description, care requirements and conditions
Turkish Van
Open cat breed description, care requirements and conditions
Bambino
Open cat breed description, care requirements and conditions
Cheetoh
Open cat breed description, care requirements and conditions
Dwelf
Open cat breed description, care requirements and conditions
Elf Cat
Open cat breed description, care requirements and conditions
Genetta
Open cat breed description, care requirements and conditions
Kinkalow
Open cat breed description, care requirements and conditions
Lambkin
Open cat breed description, care requirements and conditions
Serengeti
Open cat breed description, care requirements and conditions
Skookum
Open cat breed description, care requirements and conditions
Ukrainian Levkoy
Open cat breed description, care requirements and conditions