Glaucoma is one of the most feared eye diseases among pet owners. It is a progressive condition that affects both humans and animals and, if not treated in time, can lead to irreversible blindness.
What is Glaucoma and How Does it Manifest in Dogs and Cats?
Glaucoma is an eye disease that progressively damages the optic nerve, leading to a decline in the animal’s vision.
But why does it happen? The eye continuously produces a fluid called aqueous humor. This fluid drains out of the eye through a delicate ocular drainage system. A balance between the production and outflow of this fluid keeps intraocular pressure within a healthy range. If the drainage pathways become blocked, the fluid accumulates inside the eye, increasing intraocular pressure and potentially causing irreversible damage to the optic nerve.
Types and Causes of Glaucoma
Glaucoma can be classified into two types based on its origin:
- Primary Glaucoma is the most common type in dogs. It is due to genetic or anatomical causes. Certain breeds are more predisposed to this disease, such as Cocker Spaniels, Maltese, Beagles, and French Bulldogs.
- Secondary Glaucoma, more common in cats, is associated with another ocular condition, such as uveitis (inflammation inside the eye), or may result from trauma.
Symptoms of Glaucoma
In its early stages, when intraocular pressure just begins to rise, symptoms can be subtle and hard to detect. The visual field gradually narrows, and the animal may appear slightly clumsy.
As glaucoma progresses and intraocular pressure rises significantly, the symptoms become more evident. You may observe red eyes, obvious signs of disorientation, reduced activity, loss of appetite, and even aggressive behavior.
To catch glaucoma in its early stages, it is important to regularly monitor intraocular pressure in at-risk breeds and to seek veterinary attention promptly at the first sign of a red eye or visual disturbances in any breed.
Diagnosis of Glaucoma
Two key tests are used to diagnose glaucoma: tonometry and gonioscopy. These allow us to measure intraocular pressure (the main risk factor in glaucoma) and partially assess the aqueous humor drainage system.
We also use high-frequency ultrasound (UBM) and optical coherence tomography (OCT) to examine the iridocorneal angle, the ciliary cleft, and the optic nerve head. This information helps us monitor the progression of glaucoma and tailor treatment for each patient.
Treatment of Glaucoma
The first line of treatment for glaucoma is medical. We use eye drops to either reduce the production of aqueous humor or increase its drainage, along with medications to protect the optic nerve.
If the eye doesn’t respond well to medication, surgical options may be used to preserve vision or relieve pain in an already blind eye. At IVeM, we place gonioimplants (tiny valves inside the eye) and use diode laser therapy to improve fluid drainage or decrease its production, thereby preserving vision. In eyes that have suffered irreversible vision loss, our goal is to eliminate the pain associated with glaucoma. For these cases, we use intrascleral prostheses or perform enucleations (eye removal surgery).
Early detection of glaucoma can slow its progression and help preserve your pet’s vision. At IVeM, we specialize in maintaining your pet’s eye health. Don’t hesitate to contact us with any questions regarding veterinary ophthalmology.
