Clinical Pearls for the equine eye exam - DVM
  • SEARCH:
News Center
DVM Featuring Information from:

ADVERTISEMENT

Clinical Pearls for the equine eye exam
Vision and cozmfort best assessed in patient's familiar environment


DVM360 MAGAZINE


Temporary tarsorrhaphy is a very useful adjunct therapy to protect against rubbing, and to provide a support to the cornea after surgery (Figure 3). It is also useful where facial paralysis prevents normal eyelid motion, such as after lateral facial trauma or head entrapment in a confined space. Tarsorrhaphies may be placed in the standing sedated horse with local nerve blockade, a line block and sufficient caution to avoid iatrogenic injury to the globe. It is critical to ensure that the suture emerges from the center of the eyelid margin and not any nearer to the conjunctiva, otherwise corneal ulceration will result. Sutures may be tied as simple interrupted or horizontal mattress, using 5.0 silk or smaller material. A stent may be crafted out of IV tubing, a rubber band or foam if desired. I prefer 1 or 2 simple interrupted sutures without stents, tied in the lateral one-third of the palpebral fissure.

Medication format Most ocular pathologies are treated easily with topical ointment, providing extended contact time and ease of administration. More-serious injuries might require frequent administration, and the build up of the petroleum base reduces the drug's contact with the cornea and hence its effectiveness. Epithelialization of indolent-type corneal ulcers may also be reduced by ointment coating. Ointment induces a severe endophthalmitis if it enters the anterior chamber, for example if a deep corneal ulcer perforates. Ointments should not be administered to cases of iris prolapse.

When ophthalmic solutions are preferable, the most certain application is via a SPL. Infrequent administration can be achieved by loading 0.15-0.2 mL of solution into a 1-mL or 3-mL syringe with a 25- or 27-gauge hub (no needle), and gently spraying the corneal surface while protecting the hub end. Few individuals will permit direct administration from the dropper vial, but rotating the head facilitates this technique in tolerant individuals. Multiple drops should be administered.

Subconjunctival administration of solutions provides a local depot, which can supplement topical medication. Drugs can cross the sclera to the anterior chamber, or leak from the injection site back onto the cornea. A very small-gauge needle should be used to minimize leakage. Particular caution is necessary with corticosteroids. In the event of an infected ulcer, the depot might require surgical excision. Additional formats, such as encapsulated slow-release devices might become more popular in the future. A cyclosporine device can be implanted beneath the sclera to provide excellent control of uveitis in many ERU patients.

Dr. Cutler is a staff ophthalmologist with the Animal Eye Specialty Clinics in West Palm Beach and Wellington, Fla. He is a consultant to the equine specialists at Palm Beach Equine Clinic in Wellington and Reid and Associates in Loxahatchee, Fla. He is board certified by the American College of Veterinary Internal Medicine and by the American College of Veterinary Ophthalmologists. He received his veterinary degree from the Veterinary College of Ireland, University College Dublin, and his MS degree and residencies at the University of Florida. His interests include equine corneal disease and surgery, particularly transplantation. Visit his clinics' web sites at http://www.animaleyedocs.com/ and http://www.equineclinic.com/


ADVERTISEMENT

Source: DVM360 MAGAZINE,
Click here