Dennis Brooks, DVM, PhD, Dipl. ACVO, of the University of Florida veterinary school, led the panel at the in-depth session on ophthalmology at the 2007 AAEP convention in Orlando, Fla., held Dec. 1-5. He was excited to share many new ideas that have developed in the last six months to allow veterinarians to save eyes and sight. He stressed that in most cases an eye exam does not require special equipment, but it does require a "lack of fear" in addition to a bright light, a direct ophthalmoscope or otoscope (an instrument for examining ears), and skills to perform a thorough exam.

Brooks pointed out that human physicians have a number of vision tests, including asking a patient to count fingers, but a veterinarian is limited by the nature of the beast. Assessment of a menace reflex from hand motion is a crude measure, making it hard to determine if the horse is reacting to the feel of air or to hand motion. The best equine test for vision is the "dazzle reflex," a sensitive test for retinal function. An observer watches to see if the horse squints in response to shining a bright light into the injured eye. Although there might be a variable pupillary response to the light, squinting denotes the perception of light. If the horse’s cornea is opaque, yet he squints, then the retina is still working.

Another useful test is the "flashlight test" or indirect papillary reflex that stimulates the bad eye with light while observing for pupillary reaction in the other eye. Often inflammation is confined to the front of an eye, and a positive indirect pupillary reflex indicates that there is a chance to save sight and the damaged eye.

<