Glaucoma in animals is a chronic eye disease that affects both dogs and cats, among other species. It is usually characterized by an increase in intraocular pressure (IOP), which damages the optic nerve and retina, leading to progressive loss of vision and even blindness. As intraocular fluid, known as aqueous humor, accumulates due to a failure of its natural drainage, the pressure inside the eye increases, causing irreversible damage to the internal ocular structures.
The importance of the optic nerve and aqueous humor
The optic nerve is essential in the visual process, since it is responsible for transmitting the images captured by the retina to the brain, where they are processed to generate vision. This nerve is very sensitive to changes in pressure inside the eye. The aqueous humor, on the other hand, is a liquid that flows continuously inside the eye, providing nutrients to the internal ocular structures and eliminating waste. Under normal conditions, this fluid is drained through a specialized system in the iridocorneal angle, but in cases of glaucoma, this outflow is blocked or reduced, causing an accumulation of fluid that raises eye pressure.
There are two main types of glaucoma: primary glaucoma and secondary glaucoma. Primary glaucoma is related to genetic and anatomical causes, being more frequent in predisposed breeds of dogs, such as Cocker Spaniel or Maltese Bichon. Secondary glaucoma, on the other hand, arises as a consequence of other ocular diseases or trauma, such as chronic uveitis, lens dislocation or cataracts. The latter type is more common in cats.
Symptoms of glaucoma in animals
Glaucoma is a difficult disease to detect in its early stages, as animals usually adapt to the gradual loss of vision without showing obvious symptoms. However, as the disease progresses, clinical signs become more evident. Symptoms of glaucoma include:
- Red eyes
- Severe eye pain, causing the animal to rub its eyes or avoid light.
- Dilated pupils that do not respond adequately to light
- Blurred vision
- Nausea, vomiting, irritability and behavioral changes due to pain
- Cloudy appearance or bluish halo in the affected eye
- Sensitivity to light (photophobia)
- Disorientation or difficulty moving around in familiar spaces
In more advanced stages, animals may exhibit aggressive behavior or irritability due to severe pain. It is important to remember that animals can adapt to vision loss without noticing it in early stages, so regular veterinary checkups are crucial to detect and treat this disease early.
Diagnosis of glaucoma
Diagnosis of glaucoma requires a thorough ophthalmologic evaluation. The most common tests include tonometry, which measures IOP and determines whether it is within normal limits, and ophthalmoscopy, to assess the condition of the optic nerve and retina. In some cases, gonioscopy may be performed to observe the iridocorneal angle, where the aqueous humor drains, and to determine if there is an obstruction in the flow of this fluid.
Early detection is essential to prevent irreversible damage to the optic nerve and loss of vision. Unfortunately, in many pets glaucoma presents acutely, with obvious symptoms, making intervention urgent.
Treatment of glaucoma in animals
Treatment of glaucoma in animals is aimed at reducing IOP and preventing further vision loss. There are two main approaches: medical treatment and surgical treatment.
- Medical treatment: In less severe cases, glaucoma can be managed with medications that reduce the production of aqueous humor or improve its drainage. These medications are usually eye drops, although systemic treatments are also available.
- Surgical treatment: When medical treatment is not sufficient, surgery is used. There are two main options:
- Laser: Used to reduce the production of aqueous humor in the affected eye.
- Drainage implants: Valves or tubes are placed to allow the aqueous humor to drain out of the eye, reducing internal pressure.
Both treatments are aimed at preventing the progression of glaucoma and preserving vision, although in advanced cases blindness may be inevitable.
Nutraceuticals in the management of glaucoma
Nutraceuticals play a complementary role in the management of glaucoma, helping to protect the optic nerve and improve ocular microcirculation. Glauco+ from Dr+Vet by AndersenPets is an example of a supplement specially formulated for animals with glaucoma. It contains ingredients such as:
- Ginkgo biloba, which improves ocular circulation and helps protect the optic nerve from ischemic damage.
- Vaccinium myrtillus (bilberry), rich in antioxidants that neutralize free radicals and improve ocular blood flow.
- Citicoline, a neuroprotectant that supports visual function and the central nervous system by protecting retinal ganglion cells from oxidative stress.
The use of these nutraceuticals can help slow the progression of glaucoma and improve the quality of life of affected pets, although they should always be combined with appropriate medical and surgical treatment.
Glaucoma prevention
Since glaucoma can be asymptomatic in its early stages, prevention is key. Genetically predisposed breeds, such as Cocker Spaniel, French Bulldog and Maltese Bichon, should undergo regular ophthalmologic checkups to detect any early signs of the disease. In some cases, veterinarians may prescribe preventive eye drops to lower IOP in pets with a family history of glaucoma.
In general, glaucoma is a disease that requires multidisciplinary management. The combination of medication, surgery and nutraceuticals may offer a better prognosis and preserve vision longer. It is essential that veterinarians watch for clinical signs and educate guardians on the importance of ophthalmologic examinations to detect glaucoma early.
