Etiologies of nontraumatic feline uveitis in the UK: A retrospective observational study of 72 cats.

Background: Uveitis is a common ophthalmic diagnosis in cats, that can lead to discomfort and loss of vision. Identification of nonidiopathic cases facilitates treatment and could reduce morbidity associated with this condition. Aim: To evaluate etiologies of nontraumatic uveitis in the UK, to compare diagnostic features between idiopathic cases and those with an established underlying etiology, and to investigate the association of clinical signs and abnormal diagnostic findings with a confirmed etiology. Methods: Records of cats diagnosed with uveitis at a UK referral center between August 2009 and April 2018 were retrospectively reviewed, excluding traumatic (and reflex) cases. Cases were categorized based on whether an underlying etiology had been established in cases with confirmed etiology, idiopathic, and inconclusive cases. All cases had a minimum of 12-month follow-up unless an underlying etiology had been established. Population characteristics, clinical signs, diagnostic investigation features, and results were reported. Results: 72 cases of uveitis were included, of which male cats and domestic breeds were overrepresented. An underlying etiology was determined in 23.6% of cases: 9.7% had infectious diseases, 5.6% had systemic neoplasia, 4.2% had primary ocular neoplasia, and 4.2% had metabolic disease. Idiopathic uveitis comprised 37.5% of cases, and the remaining 38.9% were inconclusive, of which 35.7% died or were euthanased within the follow-up period. Among the study population, no significant age difference was found between cats with idiopathic disease or confirmed etiology. The unilateral disease was reported in 56.9% of cases and was not different across the idiopathic cases and confirmed etiology groups. The most common ophthalmic clinical sign was an aqueous flare, followed by keratic precipitates and hypotony. Iris color change (p = 0.015) and the presence of an intraocular mass (p = 0.025) were associated with an underlying etiology. Conclusion: Idiopathic uveitis was found to be the most common diagnosis in this study population. However, a similar proportion of cases had possible underlying etiologies as a high proportion manifested systemic disease within the follow-up time. An underlying etiology could be established only in a quarter of cases. Further studies are required to standardize the investigations required when assessing cats with uveitis to minimize patient morbidity.

Corneo-limbo-conjunctival transposition to treat deep and perforating corneal ulcers in dogs: A review of 418 eyes and corneal clarity scoring in 111 eyes.

PURPOSE: To report surgical and corneal clarity scores (CCSs) of corneo-limbo-conjunctival transpositions (CLCTs) in a large number of canine cases. METHODS: Retrospective review of records that underwent CLCT to repair deep ulcers or perforations between 2002 and 2018. Signalment, concurrent eye disease, additional procedures, pathogenesis, medication, graft orientation, follow-up, and CCSs were recorded. RESULTS: 418 eyes of 399 dogs were included. Brachycephalics were most commonly affected, comprising 325/418 (77.75%) of the eyes. The most commonly affected breeds were Pugs, Shih Tzus, Cavalier King Charles Spaniels, and French Bulldogs, with 116/418 (27.75%), 64/418 (15.31%), 34/418 (8.13%), and 34/418 (8.13%) ulcerated eyes, respectively. Mean age at surgery was 5.5 years (range 59 days-17.7 years), and median follow-up time was 100 days (range 3 days-7.64 years). The most common etiopathogenesis was spontaneous ulceration in 205/418 eyes (49.04%) of which 191 (93.17%) occurred in brachycephalics. Primary keratoconjunctivitis sicca affected 122/418 eyes (29.19%) and injury 39/418 eyes (9.33%). Mean ulcer width was 3.5 mm (0.5-10 mm). Success rate was 97.13% (406/418 eyes). Failure end points recorded included no menace response, secondary glaucoma, and endophthalmitis. Pre-existing perforation was found in 101/418 (24.16%) of the eyes and significantly increased failure rate (P < .001). The median CCS was G3 (G0-G4), which was lower for Pugs (G2). Graft orientation affected CCS, but did not reach statistical significance. CONCLUSION: The high success rate and CCS for CLCT in dogs make it a good technique to treat deep ulcers but a less desirable outcome is anticipated when treating perforations and Pugs.

Progressive retrocorneal pigmentation in dogs: A clinical report of 34 cases.

OBJECTIVES: To describe the signalment, ophthalmic examination findings, and follow-up of dogs affected with a previously unreported retrocorneal pigmentary lesion. MATERIALS AND METHODS: Retrospective record evaluation spanning 2009-2019. RESULTS: Retrocorneal pigmentary lesions were described in 34 patients (46 eyes). German Shepherds (n = 7), Jack Russel terriers (n = 5), and terrier crosses (n = 4) made up 16/34 (47.1%) of the cases. The mean age was 13.5 years (range 1.4-14.2 years), and 16/30 (53.3%) dogs were female. Most dogs were affected unilaterally (22/34 (64.7%)), the others bilaterally, and 5/34 (14.7%) were referred for it while the others were incidentally diagnosed. The lesions affected the ventral, peripheral, inner cornea and had a round/undulated leading edge. The number of corneal clock hours affected was known for 41/46 (89.1%) eyes and involved 1-3 clock hours in 32/41 (78.1%) eyes, 4-6 in 6/41 (14.6%), 7-9 in 2/41 (4.9%), and 10 in 1/41 (2.4%). The central cornea was affected in 9/46 (19.6%) eyes, and in 5/9 (55.6%), the median corneal clarity score was G2 (scale: G0-G4). The commonest additional findings included free-floating uveal cysts (11/34 dogs, 32.4%), cataracts (6/34 dogs, 17.6%), and primary glaucoma (5/34 dogs, 14.7%). Gonioscopy was available in 16/34 (47.1%) dogs and was normal except in primary glaucoma cases. Follow-up was documented in 13/34 (38.2%) dogs with a mean follow-up of 17 months (range: 5-26 months). Lesion progression was documented in 6/13 (46.2%) dogs. CONCLUSIONS: Retrocorneal pigmentation occurs as a slowly progressive lesion of older dogs that could impact vision. Histological studies of affected eyes are warranted.

A modified technique of keratoleptynsis ("letter-box") for treatment of canine corneal edema associated with endothelial dysfunction.

PURPOSE: To describe a modified keratoleptynsis procedure, as a method of preserving central corneal function, and evaluate the outcome in vision, reduction of corneal thickness and treatment of epithelial corneal ulcers in cases with endothelial cell dysfunction. METHODS: Forty-four dogs (72 eyes) were affected by progressive corneal edema, with or without ulcerative keratitis. All patients were treated with a dorsal and ventral superficial keratectomy followed by conjunctival flaps, maintaining a clear central cornea. Corneal thickness measurements were obtained via ultrasound biomicroscopy. RESULTS: All eyes showed resolution of ocular discomfort postoperatively, with a median time to resolution of 35 days. Two years post-surgery, vision had been lost in 2 of 29 eyes (7%). From the initial population, 23 dogs (39 eyes) had follow-up evaluations of corneal thickness. The mean central corneal thickness was 1359 ± 251 µm prior to surgery. Thickening of the central cornea was observed one week after surgery to 1559 ± 263 µm. Decreased corneal thickness was reported, at 1 month, 4 months, 10 months and 2 years postoperatively (1285 ± 267 µm, 1102 ± 150 µm, 1121 ± 288 µm, 1193 ± 283 µm, respectively). All eyes showed a similar trend of increasing and then decreasing corneal thickness. CONCLUSIONS: This surgical technique provided statistically significant reduction in central corneal thickness and sustained relief of ocular pain. Reduction in corneal thickness appeared to be maintained 2 years post-surgery, and all patients remained comfortable. Superficial corneal pigmentation and fibrosis resulted in vision loss in two eyes.

Oculodermal Melanocytosis: Nevus of Ota in a Dog.

This report describes the clinical presentation, diagnosis, and histopathologic features of oculodermal melanocytosis in a young dog. A 3-year-old male neutered Labrador Retriever presented with conjunctival and scleral hyperpigmentation of the right eye, with concurrent ipsilateral cutaneous hyperpigmentation involving the right side of the face. Initial skin and conjunctival biopsies revealed an accumulation of histologically benign melanocytes within the dermis and conjunctival stroma, respectively. Enucleation was elected 19 months later by the referring veterinarian due to the progression of ocular pigmentation with concurrent marked corneal lipidosis and the suspicion of a scleral mass. On gross and histopathologic examination of the globe, there was marked panuveal melanocytosis with extension into the sclera, bulbar conjunctiva, and connective tissue surrounding the optic nerve, as well as sharply demarcated ipsilateral hyperpigmentation of the facial skin. The findings are characteristic of oculodermal melanocytosis (nevus of Ota), a dermal melanocytic hamartoma presenting as cutaneous facial hyperpigmentation that corresponds to the distribution of the ophthalmic and maxillary branches of the trigeminal nerve, often with ipsilateral ocular involvement.

Immediate effects of diamond burr debridement in patients with spontaneous chronic corneal epithelial defects, light and electron microscopic evaluation.

PURPOSE: To evaluate immediate effects of diamond burr debridement (DBD) on the cornea of canine patients diagnosed with spontaneous chronic corneal epithelial defects (SCCEDs). ANIMALS STUDIED: Eight client owned dogs with SCCEDs. METHODS: Nine eyes from eight dogs with SCCEDs underwent superficial keratectomy (SK). The ulcerated area was divided into quadrants with a 300-micron restricted depth knife. Two of four quadrants underwent DBD for 40-60 s. A SK followed immediately. One burred section and one nonburred section were fixed with formaldehyde 10% and underwent light microscopy (LM). The remaining quadrants from five eyes were fixed with glutaraldehyde 2.5% and underwent transmission electron microscopy (TEM). Masked pathologists evaluated the samples. A student's paired t-test was used to analyze the data. RESULTS: With LM all nonburred samples had a superficial stromal hyaline acellular zone (HAZ), seven of the burred samples had an intermittent HAZ and in two burred samples this zone was absent. The HAZ thickness of burred samples (1.062 ± 0.664 µm) was significantly thinner than that of the nonburred samples (4.309 ± 1.348 µm) (P < 0.0001). Transmission electron microscopy showed an absence of basement membrane and the presence of an amorphous, fine fibrillar material in the superficial stroma in nonburred samples. This material was intermittent or absent in burred samples. CONCLUSION: DBD significantly reduces the superficial stromal HAZ in SCCEDs. A reduction of its thickness may be responsible for the healing rates reported with DBD.

Calculation of posterior chamber intraocular lens (IOL) size and dioptric power for use in pet rabbits undergoing phacoemulsification.

OBJECTIVES: To calculate the size and dioptric power of a posterior chamber intraocular lens (IOL) to achieve emmetropia in adult rabbits and to compare the dioptric power calculation results using a proprietary predictive formula to a retinoscopy-based method. ANIMALS STUDIED: Three wild rabbit cadavers, seven pet rabbits with cataracts and ten healthy pet rabbits. MATERIALS AND METHODS: Implant size was calculated using a capsular tension ring (CTR) (Acrivet® , Berlin, Germany). Published and cadaveric biometric data were used in the predictive formula. An IOL power-escalation study compared the predicted values to the refraction results of one pet rabbit (P1) fitted with a + 41D canine IOL (Acrivet® ) and six pet rabbits (P2-P7) fitted with prototype IOLs (Acrivet® ). Retinoscopy of 10 healthy pet rabbits served as controls. RESULTS: A 13.5 mm CTR fitted in all rabbits and permitted the use of a 13 mm IOL. The predicted IOL power ranged between +24D and +25D. The +41D IOL resulted in a refraction error of +8D. Progressive recalculation through a calibration formula led to the insertion of three +49D IOLs in two pet rabbits and a refraction of +6D to +8D, followed by seven +58D IOLs in four pet rabbits and a refraction median of 0D (range: -1.5D to +1D). CONCLUSIONS: A 13 mm prototype IOL of +58D achieves emmetropia and is of adequate size for rabbits. The combined use of a CTR and retinoscopy is a useful method to calculate the size and refractive power of a new, species-specific, veterinary IOL.

Differential diagnoses, investigation, and management of a periocular swelling close to the nasolacrimal duct in a horse - A case report of Dacryops.

To describe the differential diagnoses, investigation, and management of a periocular swelling close to the nasolacrimal duct in a horse that was consistent with a nasolacrimal duct dacryops (lacrimal cyst). A 16-year-old gelding, Connemara cross presented with a history of a periocular swelling rostroventral medial to the right eye that had been sampled by the referring veterinary surgeon. A cystic lesion was diagnosed following standing computed tomography. Surgical removal of the cystic lesion was performed, and the tissue was submitted for histopathologic and immunohistochemical examination. Surgical removal of the cyst was curative, and there was no recurrence of clinical signs 7 months later. There was a small amount of mineralized material in the center of the cyst. Histopathologic and immunohistochemical examination confirmed a nasolacrimal duct cyst. Dacryops can form in horses as well as other species and appears to have a favorable outcome if surgically removed.

Preliminary results of a prospective study of inter- and intra-user variability of the Royal Veterinary College corneal clarity score (RVC-CCS) for use in veterinary practice.

OBJECTIVE: To introduce a new corneal clarity score for use in small animals and describe its inter- and intra-user variability. ANIMALS STUDIED: Twelve dogs and two cats with corneal abnormalities and five dogs with healthy corneas. MATERIALS AND METHODS: Four examiners scored every patient twice and never consecutively, focusing on the central cornea. The peripheral cornea was scored separately. The following scoring system was used to describe corneal clarity: G0: no fundus reflection is visible on retroillumination (RI) using a head-mounted indirect ophthalmoscope. G1: a fundus reflection is visible with RI. G2: a 0.1-mm diameter light beam is visible on the anterior surface of the iris and/or lens. G3: gross fundic features are visible when viewed with indirect ophthalmoscopy (IO) using a head-mounted indirect ophthalmoscope and a hand-held 30D lens, although fine details are not clear. G4: fine details of the fundic features are clearly visible with IO. The minimum grades given were analyzed for inter- and intra-user variability with kappa analysis. RESULTS: Intra- and interuser variability of the central corneal clarity ranged from 0.78 to 0.96, showing substantial to almost perfect reproducibility, and from 0.66 to 0.91, showing substantial to almost perfect reliability, respectively. Intra- and interuser variability of the peripheral cornea ranged from 0.83 to 0.95, showing almost perfect agreement, and from 0.53 to 0.91, showing moderate to almost perfect agreement. CONCLUSIONS: The RVC-CCS is well suited to assess and monitor central corneal clarity in small animals and to compare outcomes between studies and different surgeons.

Aqueous humor fibrinolytic activity in dogs with cataracts.

OBJECTIVE: To investigate fibrinolytic activity in aqueous humor (AH) of healthy and sick dogs, with and without cataracts. PROCEDURE: Prospective observational clinical study. A total of 45 dogs were included in the study. Physical and ophthalmic examinations, complete blood cell count (CBC) and serum biochemistry panel were performed in all animals. According to the ocular and systemic diagnoses, animals were classified into three groups: sick dogs without cataracts (20 dogs; 40 eyes), diabetic dogs with cataracts (11 dogs; 22 eyes), and healthy dogs with cataracts (14 dogs; 25 eyes). Bilateral AH and blood samples were collected during intraocular surgery (25 dogs; 47 eyes), or immediately after euthanasia (20 dogs; 40 eyes). Citrated samples were centrifuged and stored at -81 °C until analysis. Plasma and AH D-dimer concentration were determined using a quantitative immunoturbidimetric latex agglutination assay. RESULTS: A total of 108 canine samples (45 plasma and 87 AH samples) were obtained. D-dimer concentration in log-scale, in AH of eyes with diabetic cataract was significantly higher than AH of eyes with nondiabetic cataract, with a difference of 0.9 ng/mL 95% confidence interval (CI) (0.2; 1.6) P = 0.0116 and higher than that of sick animals with healthy eyes, with a estimated difference of -0.89 ng/mL 95% CI (-1.52; -0.25) P = 0.0061. Plasma D-dimer concentration was significantly higher in the group of animals with systemic disease [median 606 ng/mL, Interquartil Range (IQR) 145-1956 ng/mL] than in healthy dogs (median 47.5 ng/mL, IQR 4-250 ng/mL) (P = 0.002) and diabetic dogs (median 60.5 ng/mL, IQR 0-147.5 ng/mL) (P < 0.001). CONCLUSION: AH fibrinolysis is present in dogs, being significantly higher in animals with diabetic cataracts than in those without cataracts, and those with nondiabetic cataracts.

Uveodermatologic lymphoma in two young related Portuguese water dogs.

PURPOSE: Canine lymphoma (CL) is one of the most common forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental factors associated with CL may provide benefits for the study of non-Hodgkin's and Hodgkin's lymphoma in humans. Uveodermatologic lymphoma is reported in a single household of Portuguese water dog, and the etiology is discussed. METHODS: A 1-year-old female intact Portuguese water dog was referred to the Ophthalmology Service of the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of acute blepharospasm of the right eye in association with a multinodular dermatosis. Physical and ophthalmological examination and a complete diagnostic work-up, including skin and ocular histopathology and immunohistochemistry, were performed. Three months prior, in Galicia (Spain), 1200 km away from Barcelona, a male dog of the same litter showed very similar oculodermatological clinical signs and skin histopathology, and immunohistochemistry were obtained. RESULTS: The clinical diagnoses were anterior exudative uveitis, iridal masses, and secondary glaucoma. Histopathology and immunohistochemistry revealed a nonepitheliotropic lymphoma rich in B cell in dog 1 and rich in T cell in dog 2. CONCLUSION: It is proposed that an underlying genetic predisposition could have played a role in the development of lymphoma in these two young related dogs.