Cyclophotocoagulation in Dogs

Cyclophotocoagulation is a laser surgery used to treat glaucoma in dogs provided by a veterinary ophthalmologist. The treatment option for glaucoma involves the surgical destruction of the eye’s ciliary body. 

Cyclophotocoagulation is commonly performed using two types of laser technology: transscleral cyclophotocoagulation or endoscopic cyclophotocoagulation. Both treatment options work to alter the eye’s fluid forming cells, shaping them to produce less fluids through use of a laser. If successful, this treatment option will lower the pressure caused by fluid buildup inside the eye by decreasing the orbital fluid production.

An injection of local anesthetic is placed around and behind the affected eye. Due to the use of anesthetic, any current pain medications should be halted for approximately one week prior to the surgical date.

Cyclophotocoagulation is commonly performed using two types of laser technology: Transscleral Cyclophotocoagulation or Endoscopic Cyclophotocoagulation. 

Transscleral Cyclophotocoagulation

A probe laser is placed on the white portion of the eye, just outside the iris and atop the cornea (the clear covering of the eye). The transscleral laser requires a diode laser that will emit light energy of 810 nm. Once the tissues reach a temperature of 42-60 degrees Celsius, the blood vessels will contract, destroying cells inside the ciliary body and, therefore, altering the fluid emitted from this orbital structure. 

Transscleral Cyclophotocoagulation laser methods usually require 15 to 25 treatment spots. 

Endoscopic Cyclophotocoagulation

A small incision is made at the cornea’s edge and a small telescopic device is inserted into the opening. This telescope allows an internal visualization of the affected portions of the eye creating internal fluid production, known as the ciliary body. The laser’s energy can then be placed directly on the internal cause of the glaucoma. 

Cyclophotocoagulation has been reported to have a 60% success rate in restoring a canine’s vision with approximately 15% of failure to control intraocular pressure. In the remaining 25-30%, the procedure was successful, but due to optic nerve damage, the canine’s vision was not restored. Short-term resolution is the traditional outcome in canines due to the scarring of filtering fistulas, which will require antifibrotic drugs, such as mitomycin C, to delay scarring. A repeated cyclophotocoagulation treatment may be necessary later on in the canine’s life.

Immediately following surgery, systemic or topical glaucoma medication often aids in decreasing intraocular pressure spikes common after cyclophotocoagulation surgery. The use of these glaucoma medications is generally lowered in dosages over the next two months, as the canine recovers. 

Improvement following cyclophotocoagulation surgery is generally seen within the first month, but a full recovery can take up to 14 months for some canines. 

Postoperative medications commonly prescribed to canines include; topical difluprednate, topical prednisolone acetate 1%, topical broad-spectrum antibiotics and/or a topical non-steroidal anti-inflammatory drug. The duration these take-home drugs will be used depends on the dog’s current health, secondary illnesses and the procedure type. An Elizabethan collar will also be worn following surgery to prevent the canine from scratching or manipulating the affected eye. 

Cyclophotocoagulation laser repair surgery can cost anywhere from $2,500 to $3,000, which often exceeds the budget of the pet owner. Medicated glaucoma  ointments used prior to surgery can cost about $118 per 2.5ml bottle, which is often preferred cost-wise. 

The risks associated with cyclophotocoagulation include hemorrhage, retinal detachment, persistent uveitis, and anesthesia effects. Despite having undergone surgical corrections, there is a chance the glaucoma could reoccur. The benefits of cyclophotocoagulation include direct visualization of the pressurized ciliary body which insures the laser energy is directed toward the affected area, limiting unnecessary exposure. The use of laser energy is also less invasive than other surgical options and only a minimal amount of laser energy is used.

In the majority of canine glaucoma cases, the condition is hereditary, a genetic mutation present in the specific breed. Commonly found in dog breeds including the Siberian husky, Chow, Poodle, Cocker spaniel and a number of toy breed dogs. In other cases, glaucoma can be caused by lens dislocation, intraocular tumors, chronic retinal detachment or intraocular inflammation. 

In order to prevent non-congenital glaucoma from occurring, dog owners are advised to limit the chance of possible trauma to the eye. Foreign bodies trapped in the eye, prolapsed third eyelid, conjunctivitis and other abnormalities noted by the owner should be reported promptly to a veterinary professional. Regularly scheduled veterinary check-ups can help to catch an eye condition at its early stages and provide a positive outcome.