Glaucoma in Dogs & Cats
Overview
Glaucoma is typically increased pressure within the eye, and affects animals in the
same way that it affects humans. Cells
inside the eye produce a clear fluid called "aqueous humor" that maintains the shape of the eye
and nourishes the tissues inside the eye. The eye is constantly producing more aqueous humor,
and draining the excess to maintain the proper balance and eye pressure. Most cases
of glaucoma occur when the drain becomes clogged, resulting in the increase in
eye pressure. This can result in stretching and enlarging the eye, as well as
eventual blindness if not treated.
A sudden rise in pressure can damage the retina (which acts like the film in a camera)
and the optic nerve (which sends information from the eye to the brain). And unfortunately,
the damage is permanent and irreversible, resulting in partial or total vision loss.
See symptoms, diagnosis, and
self help points.
Primary & Secondary Glaucoma in Pets
Glaucoma is classified as either primary or secondary in animals.
Primary Glaucoma in Dogs & Cats
Primary glaucoma is an inherited condition, and is the most common cause of glaucoma in dogs,
particularly American Cocker Spaniels, Basset Hounds, Chow Chows, Shar Peis, Labrador Retrievers,
and Arctic Circle breed dogs (Huskies, Elkhounds, etc). Primary glaucoma is rare in cats.
Secondary Glaucoma in Dogs & Cats
Secondary Glaucoma occurs when other eye diseases cause decreased fluid drainage.
Common causes of secondary glaucoma are inflammation inside the eye (uveitis),
advanced cataracts, cancer in the eye, lens subluxation or luxation, and chronic
retinal detachment. Glaucoma in cats is usually secondary to chronic uveitis.
Determining if your pet has primary or secondary glaucoma is important because the treatment needed and
the prognosis for vision is different for each type. Veterinary ophthalmologists use slit lamp biomicroscopy,
indirect ophthalmoscopy, and gonioscopy to determine the type and cause of glaucoma in your pet.
Gonioscopy helps determine how predisposed the remaining visual eye is to develop glaucoma when
primary glaucoma is suspected. This test involves placing a special contact lens on the eye,
which allows examination of the drainage angle. Gonioscopy is usually performed under sedation or anesthesia.
Open & Closed Angle Glaucoma
Glaucoma is also divided into open angle and closed or narrow angle glaucoma. Narrow angle
glaucoma is the most common in dogs although beagles have a high incidence of the open form.
It occurs as a result of other diseases within the eye, such as inflammation, eye tumor,
trauma or a displaced lens that blocks drainage.
Symptoms of Glaucoma in Dogs and Cats
- Enlarged pupil that doesn't constrict normally in bright light.
- Red, teary and cloudy eyes (the problem is mistaken for conjunctivitis or an eye allergy)
- Dilated pupil
- Cloudiness in the cornea
- Pain, which may be exhibited by:
- Squinting
- Holding the eye closed or keeping the third eyelid up over the eye
- Crying out, if eye is bumped
- Your pet may rub at his eye with a paw, or rub his face against furniture and carpets.
He may also flutter his eyelids, or squint.
- Personality changes, such as depression, lethargy and sleepiness
Diagnosis of Pet Glaucoma
Although many veterinarians have the equipment needed to check for glaucoma, an animal ophthalmologist will be able to give you a more accurate diagnosis using a small device called a tonometer that tests the eye pressure. If the test indicates that glaucoma is present, a second test, called gonioscopy which determines if the glaucoma is the wide angle or narrow angle type. The doctor will also examine the shape and color of the optic nerve and examining the drainage channels. If the ophthalmologist finds that the pressure is elevated, or if the optic nerve looks unusual, s(he) will examine the drainage channels to determine what type of glaucoma your pet has.
Conventional Treatments
The treatment your doctor recommends will depend on the type of glaucoma your pet has. It may include:
eye drops or pills to reduce the fluid pressure
surgery treatments-ranging from laser treatment to removal of a blinded eye-or a combination of treatments
Interestingly, the same medication is given to humans as those given to pets for glaucoma.
The important thing to remember is that immediate medical attention is needed in order to preserve your pet's eyesight, if you suspect that it has glaucoma. At the same time, though, you can support your pet's vision by giving it nutritional support.
Natural Treatments for Glaucoma in Cats and Dogs
There are several vitamins, botanicals and other nutrients that helped to nourish the eyes:
Vitamins A, C and E have antioxidant properties which fight free radicals that can damage the lens of the eye.
Bilberry extract (nicknamed the "vision herb") is derived from a fruit similar to the blueberry, contains active ingredients for eye health and proper vision. The berries are rich in the antioxidant anthocyanosides, the red pigments that are beneficial in ophthalmology and vascular diseases.
Zinc is a mineral linked to good vision and may protect eye tissue from damaging light and inflammation. Zinc is found in healthy retinal tissue.
Taurine is an amino acid found to be "neuroprotective", meaning it helps protect nerves of the body from damage such as the optic nerve.
Lutein, a carotenoid found in dark, leafy greens, is also found in the retina of healthy eyes where it acts as a shield against harmful light and may help protect the eyes against damage from ultraviolet radiation.
Quercetin is a natural antioxidant bioflavonoid that protects cells from damage by free radicals.
Alpha Lipoic Acid is the "universal antioxidant" because it works in both water and fatty tissues, providing antioxidant protection to all your pet's cells. It restores numerous biological functions that become diminished with aging and helps to prevent cataracts.
Mixed Carotenoids contain antioxidants found in carotenoid-rich food, that is, produce that are rich in color. Two specific carotenoids, lutein and zeaxanthin, provide antioxidant protection in the macular region of the eye and have been found to reduce the incidence of caratacts.
Grape Seed Extract has a high content of compounds called oligomeric proanthocyanidins (OPCs), which are potent antixodiants. They provide a wide range of antioxidant benefits: supporting healthy skin, providing cardiovascular support, improving blood circulation and reducing the risk cataracts.
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