When eye drops or other treatments have failed, glaucoma surgery might be your last option for your pet.
Defining Glaucoma in Dogs
Glaucoma is an over abundance of the fluid called aqueous humor. This fluid's job is travel around the eye and transport nutrients to the various regions. It helps to maintain the eye's shape and pressure-control within the eyeball. Once the fluid has done its job, it drains away.
Glaucoma is a result of more aqueous humor being produced than is being drained away, possibly due to a blockage. This results in a buildup of pressure within the eye, to the point of being painful. Bulging eyes are a sign and result of this pressure buildup.
Why Your Dog Needs Surgery
Glaucoma is, unfortunately, not considered a very treatable condition. However with a combination of other treatments, it can potentially be managed. Surgery is necessary in a lot of these cases depending on the cause of your dog's glaucoma. Before determining what kind of surgery your dog needs, a vet will check to see whether the pupil is still mobile, how much inflammation has occurred inside of the eye, and whether or not the optic nerve and retina appear otherwise healthy. They will also be on the lookout for signs of tumors.
Types of Surgery
A Laser or Cryocycloablation (use of a freezing probe) surgery can be used to kill some of the eye cells that are producing the fluid. Depending on whether your dog still has vision in the eye will depend on how many of the cells are killed off. A dog with vision left will only destroy enough of the cells to decrease pressure within the eye. The drawback to this technique is the inflammation that occurs post-op. While this can work as a short-term fix, there is no telling if the pressure will spike again if no tube or shunt is available for the excess fluid to drain.
Goniovalve is the insertion of a small tube used to drain the extra fluid. This is used when the dog still has visibility in that eye.
Intraocular prosthesis is the removal of the inside of the eye, generally when a tumor is present. The outside "shell" of the eye is left and a silicone ball is placed inside of it. This is only done when the eye has lost all visibility and cannot be saved. This is an option for owners who are not comfortable with the idea of a full eye removal.
Enucleation is a last-resort, but must be turned to in the event the eye cannot be saved in any other way. Enucleation is the removal of the entire eye, wherein the eyelids would be sewn shut. Because many owners have a hard time with the idea of the loss of their dog's eye (or eyes, if both are affected), a vet generally tries not to resort to this.
Intravitreal injections are where a vet will inject the eye with a medication which will kill the fluid-producing cells. Sometimes the eye will be so atrophied that owners are displeased with the aesthetic result. It is one of the cheaper choices of surgery, and good for dogs who cannot withstand longer surgeries (the time a dog must be under for this procedure is very brief), but the results are often unpredictable.