A bidirectional corneoconjunctival transposition for the treatment of feline corneal sequestrum.

A case is presented of a 1-year-old Persian cat with a corneal sequestrum treated with a bidirectional corneoconjunctival transposition. The size of this lesion precluded use of a traditional corneoconjunctival transposition. At the time of writing, the patient maintained a clear visual axis with minimal scarring and no recurrence 6 months post-operatively. This report describes a novel surgical technique used to successfully treat a large feline corneal sequestrum.

Management of spontaneous chronic corneal epithelial defects (SCCEDs) in dogs with diamond burr debridement and placement of a bandage contact lens.

Objective To describe the outcome of canine spontaneous chronic corneal epithelial defects (SCCED) treated with diamond burr debridement (DBD) and bandage contact lens placement (BCL). Animal studied Forty eyes of 36 dogs presenting to a single private practice. Procedures A retrospective review of medical records was performed. Cases were eligible for inclusion if they were newly diagnosed with SCCED by a veterinary ophthalmologist and treated with DBD/BCL. All patients received a complete ocular examination followed by DBD using a battery-powered, handheld motorized burr (Algerbrush(®) , Alger Equipment Company, Lago Vista, TX, USA). A BCL was placed post-debridement in all patients. Data were analyzed for sex, age, breed, duration of clinical signs prior to DBD; number of debridements required before healing was achieved; contact lens retention, complications attributed to DBD, and additional surgical interventions were required to achieve healing. Results The median time to first recheck examination was 7 days (IQR 7-9 days) with 28/40 (70%) of cases healed at this examination. The mean time to second recheck examination was 15.5 ± 5.5 days with 37/40 (92.5%) healed by this examination. The median time to final recheck examination was 19 days (IQR 18-35.5 days) with a range of 18-52 days. All cases resolved by the third and final recheck examination. A second DBD/BCL was performed in 5/40 (12.5%) of cases. The BCL retention rate was 95% over all examination time points. No case required a keratectomy or other surgical intervention to achieve healing. The only complication observed was one case of suspected bacterial keratitis post-DBD/BCL. Conclusions Results suggest that DBD/BCL is safe and effective for treatment of canine SCCED.

Clinical utility of a complete diagnostic protocol for the ocular evaluation of free-living raptors.

OBJECTIVE: To describe a protocol for the examination of free-living raptors and report the ophthalmic examination findings of seven raptor species native to central Illinois, namely the barred owl, Cooper's hawk, eastern screech owl, great horned owl, American kestrel, red-tailed hawk, and turkey vulture and to determine if the findings relative to visual prognosis affected eligibility for future release. ANIMALS STUDIED: Seventy-nine free-living raptors. PROCEDURES: Under manual restraint, complete ophthalmic examination including slit-lamp biomicroscopy and indirect funduscopy, applanation tonometry, rebound tonometry, ocular morphometrics, B-mode ultrasound, and electroretinography (ERG) were performed on each bird. Histopathology of enucleated globes was performed after euthanasia or death in selected cases. RESULTS: The examination protocol was easily performed using manual restraint alone on all birds. Ocular lesions were detected in 48.1% of birds, with 47.3% affected unilaterally and 52.6% affected bilaterally. Ocular lesions were considered to be vision threatening in 29.0% of the unilaterally affected birds and 29.0% of the bilaterally affected birds. The most common case outcomes were discharge from hospital to rehabilitation facility (45.6%) followed by euthanasia (43.0%). The presence of an ocular lesion or a vision-threatening ocular lesion was not significantly associated with outcome. Reference ranges are reported for B-mode ultrasound, ocular morphometrics, and horizontal corneal diameter in all species. CONCLUSION: Complete ophthalmic examination can be supplemented by the use of ocular morphometrics, ultrasound, and ERG in the manually restrained raptor. These advanced diagnostic techniques may be useful in developing more objective criteria for evaluating eligibility for release following rehabilitation of free-living birds of prey.

Ophthalmic lesions in neonatal foals evaluated for nonophthalmic disease at referral hospitals.

OBJECTIVE: To determine types and frequency of ophthalmic lesions detected in neonatal foals evaluated for nonophthalmic disease at 3 veterinary referral hospitals and to investigate associations between systemic and ophthalmic diseases in these foals. DESIGN: Prospective cross-sectional study. ANIMALS: 70 foals < 30 days old. PROCEDURES: Complete ophthalmic examinations were performed. Signalment, clinical signs, mentation during ophthalmic examination, results of clinicopathologic tests, and diagnosis of systemic disease were recorded. Descriptive data analysis including a χ(2) test for associations was performed. RESULTS: Most foals (39/70 [55.7%]) with systemic disease had ≥ 1 ophthalmic lesion detected. Of the 39 foals with ophthalmic disease, 24 (61.5%) had potentially vision-threatening lesions. Clinically important abnormalities included conjunctival hyperemia or episcleral injection (30/70 [42.9%]), uveitis (18/70 [25.7%]), ulcerative keratitis (13/70 [18.6%]), nonulcerative keratitis (10/70 [14.3%]), entropion (8/70 [11.4%]), retinal hemorrhage (8/70 [11.4%]), and cataract (6/70 [8.6%]). Foals with sepsis were significantly more likely to have uveitis than were those without sepsis. Foals with sepsis and uveitis were also significantly less likely to survive to discharge than were foals that had sepsis without uveitis. Acquired ophthalmic disease (detected in 37/70 [52.9%] foals) was significantly more common than congenital ophthalmic disease (detected in 9/70 [12.9%]). CONCLUSIONS AND CLINICAL RELEVANCE: Ophthalmic lesions were detected in 55.7% of neonatal foals with systemic disease. Acquired ophthalmic disease was more commonly detected than congenital ophthalmic disease. Foals with sepsis were more likely to have uveitis than were foals without sepsis. A complete ophthalmic examination is indicated in neonatal foals evaluated for systemic disease.

Congenital nasolacrimal atresia in 4 alpacas.

Four alpacas, 2 wk to 1 y of age, were diagnosed with congenital atresia of the nasal puncta of the nasolacrimal duct. Dacryocystorhinography confirmed and localized the atresia. All animals were treated successfully by surgical creation of nasal puncta and patency was ensured by placement of a surgical stent for several weeks.

Ophthalmic examination findings in a captive colony of western gray kangaroos (Macropus fuliginosus).

Complete ophthalmic examination of a mob of western gray kangaroos (Macropus fuliginosus) was performed under chemical restraint. Examination included intraocular pressure (IOP) measurement by rebound and applanation tonometry, fluorescein staining, corneal diameter measurement, slit-lamp biomicroscopy and indirect funduscopy. The corneal diameters had a mean of 19.52 mm, SD 2.16 mm, 95% confidence interval (CI) 18.71-20.32 mm. Ocular abnormalities were noted in 4/8 (50%) of examined kangaroos. Intraocular pressure as estimated by rebound tonometry was 9.00 mm Hg with a 25-75% quartile range of 6.5-10.75 mm Hg and a minimum-maximum range of 5.00-23.00 mm Hg. Intraocular pressure as estimated by applanation tonometry was 11.50 mm Hg with a 25-75% quartile range of 10.00-17.00 mm Hg and a minimum-maximum range of 9.00-20.00 mm Hg. This is the first report of ocular examination findings in a mob of captive western gray kangaroos and provides ranges and values for tonometry and corneal diameter.

Electroretinography in the western gray kangaroo (Macropus fuliginosus).

OBJECTIVE: To perform electroretinography on normal anesthetized western gray kangaroos (Macropus fuliginosus). Animals studied Six captive western gray kangaroos. PROCEDURES: The kangaroos were anesthetized using a combination of ketamine and medetomidine via a remote drug delivery system, then were maintained on isoflurane after endotracheal intubation and reversal of the medetomidine with atipamazole. After a minimum of 20 min of dark adaptation, electroretinograms were obtained using a handheld electroretinography (ERG) machine using a single flash protocol at three light intensities: 10 mcd.s/m(2), 3000 mcd.s/m(2), 10 000 mcd.s/m(2). RESULTS: At 10 mcd.s/m(2) the mean b-wave amplitude and implicit time was 102.0 µV (SD ± 41.3 and 95% CI 68.9-135.1) and 78.4 ms (SD ± 8.3 and 95% CI 71.8-85.0). At 3000 mcd.s/m(2) the mean a-wave amplitude and implicit time was 69.9 µV (SD ± 20.5 and 95% CI 53.5-86.3) and 17.6 ms (SD ± 1.5 and 95% CI 16.4-18.8) and the mean b-wave amplitude and implicit time was 175.4 µV (SD ± 35.9 and 95% CI 146.7-204.1) and 74.1 ms (SD ± 3.5 and 95% CI 71.2-76.9). At 10 000 mcd.s/m(2) the mean a-wave amplitude and implicit time was 89.1 µV (SD ± 27.1 and 95% CI 67.5-110.8) and 16.8 ms (SD ± 1.0 and 95% CI 16.0-17.0) and the mean b-wave amplitude and implicit time was 203.7 µV (SD ± 41.4 and 95% CI 170.6-236.8) and 75.4 ms (SD ± 3.3 and 95% CI 72.8-78.1). CONCLUSION: Electroretinography outside of the typical clinical setting is feasible using a portable ERG system and allows for quick analysis of retinal function in exotic species.

Canine pre-iridal fibrovascular membranes: morphologic and immunohistochemical investigations.

OBJECTIVE: Pathologic intraocular neovascularization is a key component of many canine ophthalmic diseases such as uveitis, retinal detachment, intraocular neoplasms, and corneal perforation. The purpose of this study was to evaluate the structure of pre-iridal fibrovascular membranes (PIFMs) associated with several different disease processes and to identify specific factors associated with their development in the canine eye. PROCEDURE: This study examined 36 enucleated canine eyes with the diagnosis of PIFM and one of the following: lens-induced uveitis, retinal detachment, iridociliary adenoma, corneal perforation, severe hyphema, or vitreal gliovascular membranes (canine ocular gliovascular syndrome, COGS). Three histologic stains and six immunohistochemical stains were performed in all 36 PIFM eyes and four histologically normal eyes, including: hematoxylin and eosin, alcian blue periodic acid schiff (PAS), Masson's trichrome, platelet endothelial cell adhesion molecule-1 (CD31), smooth muscle actin, vimentin, laminin, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2). RESULTS: Pre-iridal fibrovascular membrane extracellular matrix staining was consistent with collagen and mucins in all cases and positive for laminin in most cases. All PIFMs contained CD31-positive vessels and predominantly lymphoplasmacytic inflammation. Both PIFM vessels and spindle cells were positive for laminin, vimentin, smooth muscle actin, VEGF, and COX-2. Secondary intraocular pathology and immunohistochemical staining of other intraocular structures are also reported. CONCLUSIONS: Pre-iridal fibrovascular membrane morphology and immunohistochemical characteristics were similar across six canine disease processes, suggesting analogous pathophysiologic mechanisms. COX-2 and VEGF were identified using immunohistochemistry and may play a role in PIFM development.

Aspergillus flavus keratomycosis in a cat treated with topical 1% voriconazole solution.

An 8-year-old male castrated Domestic Short-haired cat was examined for a 1-week history of blepharospasm and mucoid ocular discharge OS. Examination revealed ulcerative keratitis with stromal loss, stromal infiltrate, corneal edema, perilimbal vascularization and miosis. Cytology of the cornea revealed multiple dichotomously branching, septate fungal hyphae and severe, predominantly neutrophilic inflammation. PCR of the cytology samples confirmed the presence of Aspergillus flavus while fungal and bacterial cultures were negative. Treatment with topical 1% voriconazole solution was successful in resolving the keratomycosis.

Clinical and electroretinographic characteristics of congenital stationary night blindness in the Appaloosa and the association with the leopard complex.

OBJECTIVE: To determine the prevalence of congenital stationary night blindness (CSNB) in Appaloosa horses in western Canada, investigate the association with the leopard complex of white spotting patterns, and further characterize the clinical and electroretinographic aspects of CSNB in the Appaloosa. ANIMALS STUDIED: Three groups of 10 Appaloosas were studied based on coat patterns suggestive of LpLp, Lplp, and lplp genotype. PROCEDURES: Neurophthalmic examination, slit-lamp biomicroscopy, indirect ophthalmoscopy, measurement of corneal diameter, streak retinoscopy, scotopic and photopic full-field and flicker ERGs and oscillatory potentials (OPs) were completed bilaterally. RESULTS: All horses in the LpLp group were affected by CSNB, while none in the Lplp or lplp groups was affected. The LpLp and Lplp groups had significantly smaller vertical and horizontal corneal diameters than the lplp group had. Median refractive error was zero for all groups. Scotopic ERGs in the LpLp (CSNB-affected) group were consistent with previous descriptions. The CSNB-affected horses had significantly longer photopic a-wave implicit times, greater a-wave amplitudes, and lower b-wave amplitudes than the Lplp and lplp (normal) groups did. No differences were present in photopic flicker amplitude or implicit times. Scotopic flickers in the CSNB-affected horses were markedly reduced in amplitude and abnormal in appearance. No differences were noted in OP implicit times; however, amplitudes of some OPs were reduced in CSNB-affected horses. There were no differences in scotopic and photopic or flicker ERGs or OPs between the normal groups. CONCLUSIONS: CSNB was present in one-third of horses studied and there was a significant association between CSNB and the inheritance of two Lp alleles. ERG abnormalities support the hypothesis that CSNB is caused by a defect in neural transmission through the rod pathway involving the inner nuclear layer.

Chronic retinal detachment and giant retinal tears in 34 dogs: outcome comparison of no treatment, topical medical therapy, and retinal reattachment after vitrectomy.

The outcomes of dog's eyes with chronic (> 1 month) retinal detachment and giant retinal tears without therapy were compared with those treated with topical steroids and antiglaucoma medications, and with those that received a vitrectomy, retinal reattachment, endolaser therapy, and silicone oil tamponade. Fourteen of 16 eyes that did not receive therapy developed uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (6); and 2 dogs were euthanized due to blindness and uveitis. Two eyes in 2 dogs remain without treatment, 1 and 3 years later. Fifteen of 19 eyes that received topical therapy developed nonresponsive uveitis and secondary glaucoma, and were enucleated (4) or eviscerated (9), 1 dog that was affected bilaterally was euthanized; and 3 eyes remain on topical anti-inflammatory therapy and the medication has been discontinued on 1 eye. Four of 6 eyes surgically reattached remain without clinical manifestations of uveitis and secondary glaucoma and 3 of these eyes have functional vision. Light microscopic observations completed on failed globes in the 3 groups were similar.

Immunohistochemical investigation of canine episcleritis.

OBJECTIVES: To identify macrophages, B cells and T cells in archived canine episcleral biopsies and to correlate these findings with the clinical presentation and therapeutic outcome. PROCEDURES: Archived formalin-fixed biopsies were immunohistochemically labeled for CD18, CD79a, and CD3 to identify macrophages, B cells and T cells, respectively. Slides were digitally photographed and positive cells were manually counted. Signalment, duration of illness, affected eye(s), treatment, and therapeutic outcome were reviewed for each dog. Dogs were divided into groups based on clinical presentation (unilateral episcleritis, bilateral episcleritis or nodular granulomatous episclerokeratitis (NGE). RESULTS: Twenty-four cases were evaluated. There were 19 episcleritis (13 unilateral, six bilateral) and five NGE cases. The mean age for clinical manifestations of unilateral episcleritis was 6.8 years, bilateral episcleritis was 8.7 years, and NGE was 3.8 years. The Cocker Spaniel was over-represented in the episcleritis groups. All NGE cases were Collies. Approximately 50% of the unilateral episcleritis cases resolved and did not require long-term therapy. Almost all cases of bilateral episcleritis and NGE required continuous medical therapy to maintain remission. There was a significantly higher percentage of B lymphocytes in biopsies from lesions that required ongoing medical therapy to maintain lesion remission than in the lesions that resolved, and for which medications were discontinued (P = 0.0471). CONCLUSIONS: The prognosis for resolution of NGE and bilateral episcleritis without long-term medical therapy is poor. There is a significant difference in the inflammatory cell population in episcleritis that resolved with medical therapy vs. episcleritis that required ongoing medical therapy.