THE TOP TEN OPHTHALMIC MISTAKES OPHTHALMOLOGY Kerry L. Ketring, DVM, DACVO

There are several “mistakes” veterinarians make in diagnosis and evaluating clinical signs and response to therapy. The “Top Ten” is presented in the form of the typical statements I get from the owners such as “My veterinarian said…” An example of the case is illustrated and the “mistakes” in thinking are discussed. These “Top Ten” are the most critical and/or common mistakes seen.

This lecture could more accurately be named “The Top Eleven Ophthalmic Mistakes.” The mistake I haven’t included is one with far reaching and potentially catastrophic consequences if you ignore it. This mistake is to be unaware of the breed incidence of many ocular diseases. If you are aware of the diseases reported in a specific breed, you may make an early diagnosis and search the literature for the most up-to-date treatment. You can consult readily available lists to find out which breeds are predisposed to painful and blinding ocular diseases such as glaucoma and keratoconjunctivitis sicca (KCS) and then evaluate these individuals on a yearly physical to make an early vision saving diagnosis. The American College of Veterinary Ophthalmologists, through the Orthopedic Foundation for Animals (OFA) Eye Certification Registry has an available list of breeds and their reported diseases. You can receive this information electronically by emailing [email protected].

Number Ten “My veterinarian has tried five antibiotic ointments and solutions, but the ulcer in Butch’s (9-year-old boxer) eye isn’t any better.”

Mistake: This is termed an indolent ulcer and is the number one cause of superficial ulcers in older . Indolent ulcers are caused by a degenerative change and are not bacterial! If it gets better with antibiotics, it is just luck. Surgical treatment, i.e., debridement, keratotomy with additional topical medications are indicated. The owners should be told their will never go blind with this disease, but that it can recur in either eye. Any older dog can develop this type of ulcer, but boxer and boxer crosses have a high incidence.

Number Nine “My veterinarian told me Boo (6-year-old mix) had inflammation, but now he has glaucoma. He’s been on antibiotics and a pill for glaucoma, but he is not getting any better.”

Mistake: Atropine was never used initially treat the anterior uveitis. Antibiotics have little effect in most cases of anterior uveitis or glaucoma. Secondary glaucoma will not respond to routine primary glaucoma therapy. Never treat medically an irreversibly blind glaucomatous eye.

Number Eight “My veterinarian said Gizmo (4-year-old shih tzu) has allergies causing conjunctivitis. Now she has a deep ulcer that may rupture.”

Mistake: In my opinion, dogs do not have allergies that cause only conjunctivitis. However, many breeds have a predisposition to KCS resulting in recurring conjunctivitis that may vary based on circumstances, i.e., outside more in summer and spring. Mild affected cases (Schirmer tear test [STT] 10-15 mm/min) will improve with almost any topical solution or ointment that supplies moisture to the cornea. Central corneal ulcers are caused by KCS and/or lagophthalmos. In addition, all these one-eyed pugs didn’t get poked in the eye. The pug is a great example of KCS with an associated lagophthalmos. Breeds predisposed to KCS are listed in Table 1.

Number Seven “My veterinarian says Blackie (10-year-old domestic short hair) has an ulcer, but the antibiotic ointments aren’t helping. Now his eye is getting worse. He has been very healthy since we got him from the shelter.”

Mistake: Any cat from a shelter has an excellent chance of having been exposed to feline herpes virus. This virus can and often does remain dormant for years. Recrudescence or relapse is common and can be caused by stress from a number of possibilities. Feline herpes virus is the number one cause of corneal ulceration in cats. Antibiotics are of no value and can make the condition worse. There are specific antiviral drugs for both topical and oral administration.

Number Six “My veterinarian tells me Buster (2-year-old Boston ) has glaucoma. He is really difficult to treat and his red eyes have only gotten worse with these drops.” The owner then holds up a green lidded container of 2% Pilocarpine.

Mistake: Typically, the veterinarian used the Tono-Pen to measure intraocular pressure (IOP). With this instrument, a falsely elevated IOP is a common problem, especially in an animal that is uncooperative. External pressure on the neck or lids during restraint can easily elevate the pressure to 40mmHg. Pilocarpine frequently causes a local irritation for the first 72 hours. This is manifested by increased blepharospasms, conjunctival hyperemia, and even an anterior uveitis. Concentrations greater than 1% are more irritating and have no significant improvement in hypotensive effect. I know of no ophthalmologist that still uses pilocarpine for glaucoma.

Number Five “My veterinarian told me Shadow’s (1-year-old Siberian husky) cloudy eye is caused by glaucoma. These really expensive drops are the same ones my mother used, but I don’t have insurance to pay for them like she does”

Mistake: Tonometry and a complete ocular examination in both eyes were not performed. This breed and others are predisposed to Vogt-Koyanagi-Horada-like syndrome (VKH) or canine uveodermatologic syndrome. Additional breeds also have a primary anterior uveitis which can lead to secondary glaucoma. All of these breeds are listed in Table 2. Latanoprost (Xalatan®) should only be used in the treatment of primary glaucoma.

Number Four “My veterinarian said Rex (12-year-old German shepherd dog) needs surgery. You can see his gray cataract and his eyes glow at night.”

Mistake: The glow is the tapetal reflex. A dog cannot be totally blind due to only and still have a tapetal reflex. Additionally, a dog blind with cataracts should still have a positive pupillary light response (PLR) and a positive dazzle reflex (blinks when a bright light is directed into the pupil). The gray appearance of the pupil is normal aging change of the lens termed nuclear sclerosis. It is more difficult to examine the fundus due to the nuclear sclerosis. But subtle attenuation and sacculation of retinal vessels, acute blindness, sluggish PLR, negative dazzle, and the age of the dog all point towards sudden acquired retinal degeneration (SARD).

Number Three “My veterinarian thinks Gretchen (7-year-old, diabetic miniature schnauzer) should be started on cataract drops. If she is not better when her diabetes is controlled, he will refer to an ophthalmologist. But now she is blind, her eyes are all red, and all she does is sleep”

Mistake: Every diabetic dog deserves a thorough ocular examination immediately or at least at the first sign of cataracts. All diabetic cataracts result in some degree of phacolytic uveitis. Untreated, this develops into a severe anterior uveitis and secondary glaucoma. The glaucoma is usually refractory to medication and requires enucleation, just to make the patient comfortable. There is no product on the market that prevents or slows cataract formation. All advertised products are nutraceuticals and have only antidotal proof of efficacy. They have no scientific bases and are not under U.S. Food and Drug Administration (FDA) guidelines.

Number Two “My veterinarian believes Shannon (5-year-old golden retriever) has a tumor in the eye and that the eye should be removed.”

Mistake: Golden retrievers, Labrador retrievers, and Boston have a high incidence of iris and ciliary body cysts. The condition is most often bilateral. These appear as free floating translucent pigmented spheres in the anterior chamber or may be attached at the pupil margin. They may be filled with blood. These cysts may rupture and pigment may be deposited in the iris, lens, or cornea. Ruptured cysts with blood may also result in intraocular hemorrhage. The diagnosis is based on knowing the breed incidence and being able to transilluminate the pigmented cyst.

Number One “My veterinarian treated Belle’s (11-year-old bassett hound) right eye six weeks ago with antibiotics and now he is treating the left eye, but she is totally blind.

Mistake: The first “mistake” was not recognizing a breed with primary glaucoma. The second was not enucleating the blind, painful first eye before it became phthisical. Not treating the remaining eye prophylactically was the third mistake. Although prophylactic medication may not be effective forever, it has been shown to be beneficial. Blind dogs that are comfortable do great! If vision can’t be returned in the second eye (poor prognosis at this time), it too should be enucleated or an intraocular prosthesis put in place. Veterinarians and clients do not relate the inactivity in uncontrolled glaucoma in dogs to the chronic pain they suffer. After over 30 years in practice, I am still impressed with how well blind and comfortable dogs function in their environment. All dogs that are predisposed to primary glaucoma should have their intraocular pressure checked yearly along with education for the client concerning early signs glaucoma (Table 3).

Table 1. Canine Breeds Disposition to Keratoconjunctivitis Sicca (KCS) Beagle English bulldog Pug Bloodhound English springer spaniel Samoyed English setter German shepherd dog Schnauzer (all varieties) Cavalier King Charles spaniel Golden retriever Shih tzu Chihuahua Gordon setter Chow chow Kerry Blue terrier West Highland white terrier Clumber spaniel Lhasa apso Cocker spaniel Pekingese Dachshund Poodle (all varieties)

Table 2. Breeds Predisposed to Vogt-Koyanagi-Horada-like syndrome (VKH) and Idiopathic Anterior Uveitis Akita Bernese mountain dog Poodle Chow chow Samoyed Cocker spaniel Schnauzer Collie Shetland sheepdog Dachshund Siberian husky Golden retriever Saint Bernard

Table 3. Breeds Predisposed to Primary Glaucoma

Af ghan Dachshund Akita Dalmatian Pekingese Alaskan malamute Pembroke Welsh corgi American Eskimo English cocker spaniel Petit Basset Griffon Vendéen Australian cattle dog English springer spaniel Poodle Basset hound Flat-coated retriever Pug Beagle (field trial) Giant schnauzer Saluki Golden retriever Samoyed Bichon frise Great Dane Blue heeler Greyhound Sealyham terrier Border collie Irish setter Shih tzu Boston terrier Italian greyhound Bouvier des Flanders Keeshond Siberian husky Brittany Labrador retriever Smooth Bullmastiff Cardigan Welsh corgi Maltese Welsh springer spaniel Welsh terrier Chihu ahua Miniature Doberman pinscher West Highland white terrier Chinese shar pei Whippet Chow chow Norwegian elkhound Cocker spaniel