by Noelle La Croix, DVM, Dip. ACVO
Twenty-five Ophthalmic Insights
Recently, a colleague asked me to list some of the basic insights into the practice of veterinary ophthalmology that I have learned over the years. The following is a non-comprehensive list (in no particular order) of some of that knowledge that I hope will aid in your treatment of ophthalmic cases.
- The Schirmer tear test, fluorescein staining, and tonometry should always be performed upon initial presentation of an ocular disorder. Both abnormal and normal results are useful in diagnosis.
- An ulceration should be reevaluated within 48 hours of initial presentation. Infections will typically reveal themselves within this time period.
- Various dog breeds (Cocker Spaniel, Bassett Hound, etc.) are predisposed to glaucoma. In these breeds, intraocular pressure (IOP) should be checked upon initial presentation of a “red eye” and then within the following 48 hours. A normal IOP does not preclude a subsequent pressure spike.
- The prognosis for vision in a patient with glaucoma is always poor despite available treatments. Owners need to understand and expect this diagnosis in simple terminology. The possibility of blindness and pain must be clearly explained.
- If you are wondering if a corneal ulcer is melting or not, then it most likely is (and I credit this fact to the great wisdom of Dr. Dennis Brooks).
- Blepharospasm in an animal with a corneal ulceration implies that the ulcer has yet to fully heal.
- Cats medicated with topical or oral steroids are predisposed to herpes outbreaks.
- The three most common causes of feline corneal disease are herpes, herpes, and herpes.
- Atropine can lower tear production.
- Topical steroids can increase IOP and thereby decrease the effectiveness of anti-glaucoma medications including latanoprost.
- Dogs will typically experience a post-anesthetic drop in tear production which can lead to corneal ulceration.
- An animal with a painful corneal ulceration and Schirmer tear test values below 10 mm/min is likely to suffer from decreased tear production that can be treated medically.
- An animal medicated with tear stimulants shows normal Schirmer tear test values because of the medication. Discontinuing the tear stimulants in these patients is not appropriate.
- Owner compliance with ocular medication schedules beyond twice daily is very limited, especially in long-term care. Medications should be prescribed accordingly.
- It is valuable to determine if an owner values vision or just ocular comfort in their pet. These considerations can influence treatment options and reduce an owner’s stress over possible outcomes.
- Ocular steroids (such as neomycin-polymyxin-dexamethasone or 1% prednisolone acetate) must be shaken prior to their instillation to maximize their effect.
- The penetration of prednisolone acetate into the cornea is influenced by its size. The most effective brands of prednisolone acetate contain the smallest particles and are manufactured by Falcon Pharmaceuticals or Alcon Laboratories.
- Owners should be instructed to wash their hands after instilling atropine into their pet’s eyes. This will prevent the owners from causing their own pupillary dilation.
- A dog with a glaucomatous eye is predisposed to developing glaucoma in its “normal” contralateral eye. The contralateral eye should therefore be medicated prophylactically with anti-glaucoma medications.
- A young dog with a very painful ulcer in the dorsal axial cornea has an ectopic cilium until proven otherwise.
- Animals with uveitis should be slowly tapered from their medications over three months and never quickly.
- A cellular infiltrate, flare, and/or hypopyon indicates that a corneal ulceration is infected.
- Owners should never make decisions under duress.
- Blind dogs do perfectly well. They do so well, that I am often surprised that I have a profession.
- There are numerous instances of ocular manifestations of systemic disease. It is important to evaluate all ocular conditions in the context of the patient’s overall presentation. Eye problems are often just part of the picture.
If you have any further questions, please feel free to speak with your veterinary ophthalmologist.
Noelle La Croix, DVM, Dip. ACVO
Veterinary Medical Center of Long Island
75 Sunrise Highway
West Islip, New York 11795
(631) 587-0800; fax (631) 587-2006