Evaluation of equine corneal disease using ultrasound biomicroscopy.

OBJECTIVE: To describe the clinical use of ultrasound biomicroscopy (UBM) to evaluate equine corneal disease. METHODS: Images were obtained using a 50-MHz probe ultrasound biomicroscopy system (Quantel Aviso) and Clear Scan® probe cover. Six horses with corneal disease were evaluated via UBM for lesion size, lesion depth, and continuity of Descemet's membrane. Horses were sedated and received auriculopalpebral nerve blocks and application of topical anesthetic prior to UBM. RESULTS: Ultrasound biomicroscopy was easily performed in all cases. UBM evaluation of three cases of corneo-limbal squamous cell carcinoma yielded information regarding lesion depth for planning of keratectomies using fixed-depth keratomes and subsequent ß-radiation therapy. Corneal depth and continuity of Descemet's membrane were determined in two horses with stromal abscesses and allowed for planning of therapeutic options. In one horse with a corneal foreign body, UBM contributed to accurate assessment of the foreign body's stromal depth, which could not be assessed during ophthalmic examination due to extensive corneal cellular infiltrate. The information regarding corneal depth allowed for more accurate pre-surgical planning in patients with opaque corneal lesions. CONCLUSIONS: Ultrasound biomicroscopy was easily performed and provided useful information regarding lesion depth and continuity of Descemet's membrane for patients with corneo-limbal squamous cell carcinoma, stromal abscesses, and a corneal foreign body, allowing for increased precision in pre-surgical planning and development of therapeutic protocols.

Clinical and pathologic evaluation of chorioretinal lesions in wild owl species.

OBJECTIVE: Investigate histopathology and spectral-domain optical coherence tomography (OCT) imaging of wild owls with chorioretinitis and identify any potential correlation with an infectious etiology. MATERIALS AND METHODS: Ophthalmic examination and retinal OCT imaging were performed on fifteen great horned (Strix varia) and barred (Bubo virginianus) owls (30 eyes) with chorioretinitis and five owls with normal eyes (10 eyes). Testing to investigate the presence of potential infectious diseases included a complete blood count, biochemistry, protein electrophoresis, West Nile virus (WNV) plaque reduction neutralization test, Toxoplasma gondii modified direct agglutination test, WNV RT-PCR, and Avian Influenza RT-PCR. A necropsy was performed on all owls, including ocular histopathology. RESULTS: Fundus lesions included retinal detachment (7/15 owls), depigmented lesions (12/15), pigment clumping (8/15), and retinal tear (4/15). All birds were negative for WNV and Avian Influenza on RT-PCR. Of the owls with chorioretinitis, 3/15 were seropositive for WNV and 7/15 for T. gondii. Optical coherence tomography of 25/30 affected eyes revealed outer retinal lesions (19/25 eyes), retinal detachment (16/25), and retinal tears (3/25). Histopathological examination revealed outer nuclear layer atrophy (19/30 eyes), retinal detachment (18/30), retinal tears (7/30), suprachoroidal hemorrhage (12/30), scleral rupture (3/30), and ossicle fracture (3/30). CONCLUSIONS: Although 20% of birds were seropositive for WNV and 46.6% for T. gondii, histopathologic findings supported that the posterior segment lesions in the study group were likely due to blunt ocular trauma rather than an infectious etiology. The results of OCT imaging and histopathology documented retinal changes most consistent with blunt ocular trauma.

Corneoconjunctival transposition with and without ACell® for deep corneal ulcer repair in 18 dogs.

OBJECTIVE: To document a case series using corneoconjunctival transposition (CCT) surgery with and without bioscaffolding matrix (ACell® ) to repair deep corneal ulcers and perforations in dogs. ANIMALS STUDIED: Eighteen dogs of various breeds that presented with deep or perforating corneal ulcers. PROCEDURES: Corneoconjunctival transposition grafts with or without ACell® were sutured using a simple interrupted 8-0 or 9-0 polyglactin 910 pattern. RESULTS: A total of eighteen dogs (19 eyes) were diagnosed with deep corneal ulcers (n = 7) and perforating corneal ulcers (n = 12). A CCT was performed in all eyes, with ten of them additionally receiving an ACell® graft. The majority of lesions were located axially in 14/19 (81%) eyes. Grafts were harvested from dorsal (n = 8), temporal (n = 5), ventral (n = 4), or nasal (n = 2) quadrants. Brachycephalic breeds (13/18) were over-represented. Keratoconjunctivitis sicca was present in 10/19 eyes (52.6%). Bacterial isolates were cultured from 8/19 eyes. Post-operative therapy included topical antibiotics, plasma, cycloplegics, oral antibiotics, and oral nonsteroidal anti-inflammatory drugs. CCT integration with and without ACell® occurred at a median of 20 days (range 7-38 days) post-operatively with no significant difference between groups. Median follow-up time was 188 days. Short-term post-operative complications included granulation tissue formation (19/19), corneal edema (4/19), graft retraction (4/19), and anterior synechia (1/19). Long-term complications in 14 eyes with follow-up >30 days included superficial corneal pigmentation (6/14) and epithelial inclusion cysts (5/14). Two eyes were nonvisual at last follow-up due to cataract formation. CONCLUSIONS: Corneoconjunctival transposition with ACell® can be utilized for corneal ulcer repair in dogs.

Effect of topical non-steroidal anti-inflammatory drugs on healing times and complications in dogs with spontaneous chronic corneal epithelial defects.

BACKGROUND: Little is published regarding topical NSAID effect on corneal healing in dogs. This retrospective cohort study aimed to compare healing times and complications in dogs with spontaneous chronic corneal epithelial defects (SCCED) treated with and without topical non-steroidal anti-inflammatory drugs (NSAID). METHODS: Medical records of 66 dogs (71 eyes) diagnosed with SCCED between 2008 and 2019 were included. Eyes were divided into: (1) those receiving topical NSAIDs (n = 33) versus (2) those not receiving topical NSAID (n = 38). Follow-up until healed, such as comfortable eye, negative fluorescein stain was required. Use of topical or systemic anti-inflammatories outside of NSAID or presence of ocular disorders or systemic endocrinopathies that may contribute to delayed healing resulted in study exclusion. RESULTS: Healing times were significantly longer in eyes that received topical NSAID (p = 0.008), however, the use of more topical medications for treatment was also associated with longer healing times (p = 0.001). The majority of eyes in the NSAID group received multiple medications, compared to the non-NSAID group, so it was not possible to separate the effects of NSAID from a number of medications. Complications occurred in three eyes of three dogs within the NSAID group. CONCLUSIONS: In these canine SCCED eyes, the use of more topical medications, including NSAID, was associated with significantly delayed healing time.