Equine pectinate ligament descemetization is associated with age.

PURPOSE: To evaluate the correlation between equine pectinate ligament descemetization and ocular disease. METHODS: The pathology database of the North Carolina State University Veterinary Medical Center was searched from 2010-2021 for all equine globes. Disease status was then assigned as affected by glaucoma, uveitis, or "other" based upon clinical records. The iridocorneal angles (ICA) of each globe were evaluated for the presence of pectinate ligament descemetization, the length of descemetization, as well as for the degree of angle collapse and the extent of cellular infiltrate or proteinaceous debris. One slide from each eye was evaluated by two separate, blinded investigators (HW & TS). RESULTS: A total of 66 eyes from 61 horses were identified, with a total of 124 sections of ICA of sufficient quality to review. 16 horses were affected by uveitis, 8 by glaucoma, 7 by both glaucoma and uveitis, and 30 horses by other ocular disease, most commonly ocular surface disease or neoplasia, which served as controls. Pectinate ligament descemetization was most prevalent in the control group compared to the glaucoma and uveitis groups. Pectinate ligament descemetization length was positively correlated with age, with an increase of 13.5 µm per year of age (p = .016). Infiltrate scores and angle closure scores were higher in both the glaucoma and uveitis group compared to the control group (p < .001). CONCLUSIONS: Equine pectinate ligament descemetization appears to be correlated with increased age and should not be used as a histologic marker for the presence of glaucoma.

Polidocanol monotherapy for a superficial orbital venous malformation in a horse.

OBJECTIVE: To describe the use of 1% polidocanol as the sole treatment for a superficial orbital venous malformation in a horse. ANIMAL: A 23-year-old Welsh Cobb cross gelding with a distensible swelling affecting the left lower eyelid, and secondary palpebral margin abnormalities and superficial keratitis. PROCEDURE: Color flow Doppler ultrasonography revealed non-pulsatile blood flow within the tortuous vascular network most consistent with a superficial orbital venous malformation appearing to involve the lateral palpebral and transverse facial veins. An intravenous catheter was placed within the lateral aspect of the venous malformation, and agitated saline was slowly injected into the vessel while simultaneously ultrasound imaging the medial aspect in which the bubbles were observed coursing across, consistent with lateral to medial flow. Contrast venography confirmed a corkscrew vessel along the ventral aspect of the orbital rim. Under standing sedation, 1% polidocanol solution was administered slowly through the intravenous catheter while manual pressure was applied on the medial and lateral aspects of the venous malformation. RESULTS: Ultrasonography performed immediately after administration of polidocanol confirmed venous stasis, and formation of a thrombus. No adverse side effects were noted. The venous malformation and associated palpebral margin abnormalities and superficial keratitis resolved at the time of re-examination at 4 months. CONCLUSION AND CLINICAL RELEVANCE: Polidocanol as the sole treatment for a superficial orbital venous malformation in a horse was well tolerated and led to clinical resolution. Sclerosant monotherapy may be a safe treatment option for superficial orbital venous malformations.

Lack of consensus on consensual response.

The pupillary light reflex (PLR) is a routinely utilized clinical test to quickly assess integrity of subcortical light perception pathways in patients. While interpretation is simple for ophthalmologists, interestingly discrepancy occurs in annotation of the test results, especially for the consensual response. An email survey sent to diplomates of either the American or European Colleges of Veterinary Ophthalmologists (ACVO and ECVO, respectively), requesting use of a 'direct/consensual' annotation convention, showed 58% of respondents preferred one convention while 39% preferred a different convention. The majority preferred convention was different between ACVO and ECVO respondents. Standardization of PLR annotation convention across specialists is recommended for clarity in medical record keeping and communication among colleagues.