Canine glaucoma is not like human glaucoma in some very significant ways, even though the same medications are used to treat it. The worst difference: According to Dr. Annora Sheehan Gaerig, DVM, a veterinary ophthalmic resident at Eye Care for Animals in Wheeling, IL, glaucoma in dogs progresses much faster than in humans. At best, medications may slow progress to blindness in an affected eye for weeks to months.
Medication is started immediately to preserve the unaffected eye as well, which can delay onset in the unaffected eye from an average of 8 months untreated to about 2-3 years later. But as Dr. Amy Hom, DVM, of Eye Care for Animals in St. Charles, IL, reminded me, those are averages. You could get lucky and have your dog’s glaucoma well controlled for years—or unlucky and have your dog go blind within a month of the first squinty discomfort.
If the glaucoma is caught very early, a laser technique offers about 75% success in slowing pressure buildup and saving vision for a time—but that also means a 25% chance of failure, leaving your dog with post-op pain and no advantage. A hard decision, that.