Cyclophotocoagulation in Cats

In a cat's eye, fluid is produced by ciliary bodies to keep the interior of the eye lubricated. The eye then eliminates the fluid with a drain. When something prevents this fluid from draining, the eye builds in pressure, causing severe damage to the retina and the optic nerve. This occurrence is called glaucoma, and it leads to permanent blindness in the cat. The issue is quite painful to the animal.

One method of treatment for glaucoma is cyclophotocoagulation. This non-contact procedure is performed using endolaser cyclophotocoagulation (ECP), which is performed with an endoscopic tool with a laser attached to it. This laser uses minimal energy to effectively target the ciliary body while sparing the surrounding eye tissue. Cyclophotocoagulation is not offered at many veterinary locations and must be performed by a veterinary ophthalmologist. It is generally done after normal glaucoma treatment has proved ineffective. It may also be done if the patient is at risk of glaucoma and is undergoing cataract surgery.

To determine whether cyclophotocoagulation is the right procedure for the cat, its intraocular pressure (IOP) will need to be measured. If it is extremely elevated, treatment is necessary. Other tests will need to be run to help identify the cause of the glaucoma. This may include gonioscopy, indirect ophthalmoscopy, or slit lamp biomicroscopy. 

To begin the treatment of glaucoma with cyclophotocoagulation, in most cases the lens of the eye will need to be removed. After that has been done, a probe is inserted into the eye. This probe contains a laser that is aimed directly at the ciliary body so that its cells may be destroyed. Once this has been completed, an artificial lens will be placed in the eye. An artificial drain may also be added to the eye in some instances.

Using cyclophotocoagulation can delay blindness in the affected cat by a median of 31 months. This is four times longer than if the eye is left untreated. While cyclophotocoagulation is not a permanent solution for the cat, it is the most effective option available. 

By the time that this procedure is performed, one of the eyes has usually already gone blind. This is due to the fact that eye enlargement is often the first clue that glaucoma exists, and only occurs after the eye has gone completely blind. Treatment is attempted to save the other eye and leave the animal with some sight. The procedure is often paired with a lens removal to prevent the formation of cataracts. Other options are available for addressing glaucoma, however most do not save the affected eye. 

The cat will need to be closely monitored while coming off of the anesthesia. Any vomiting can be a sign of severe complications. All wounds made to the eye must be kept hydrated. Nonsteroidal antiinflammatory drugs such as prednisolone acetate drops will be prescribed for up to two months following the cyclophotocoagulation. If an underlying cause exists, after it is diagnosed it will need to be treated. This treatment may be long-term and costly.

The cost to have cyclophotocoagulation performed on your cat will likely be around $1,000. There are medications in both drop and pill form that can help delay the progression of glaucoma, but these methods are expensive and are not used as long-term solutions. Some may choose to have the cat's eye removed or injected with a substance that kills all fluid-producing cells. Both of these options are of similar cost but will permanently address the issue. Often cats cope very well even if they are left completely blind.

The most severe complications with cyclophotocoagulation are related to reactions to the anesthesia, and are rare. Some cats may experience continued uveitis, hemorrhaging, or retinal detachment following the procedure. Despite having cyclophotocoagulation performed, the cat may continue to develop glaucoma. It also may be difficult to find an animal hospital that offers this treatment. Life-long treatment is very expensive and can ultimately fail, leading some to opt for removal of the eye. Leaving the affected eye in the cat is quite painful for the animal.

If the cat has primary glaucoma, nothing can be done to prevent the genetic predisposition from taking place. All cats who are diagnosed with this issue should be prevented from breeding. The best way to help a cat suffering from glaucoma is to diagnose it early. Performing regular vision tests on your cat can help identify sight problems. If your cat is suffering from increased intraocular pressure, do not put it in a harness as this can further heighten the IOP. Supplementing your cat with specific antioxidants can help prevent ocular nerve cells from dying. Ensuring your cat is in a low-stress environment also can slow the progression of glaucoma.