Iridociliary adenoma in a sheep (Iranian Shaal breed): A case report.

Ocular tumors are rarely seen in farm animals. Iridociliary epithelial tumors are the second most common tumor of the eye in dogs and cats, but there is just one report of this tumor in sheep. This case report described the history, clinical signs, histopathological and immunohistochemical findings, and surgical management of an iridociliary adenoma tumor in a 3-year-old Iranian Shaal sheep with signs of anorexia, depression, loss of vision, and a mass covering the left eye. The mass had protruded from the left eye globe but had not penetrated the periocular tissues. Enucleation was performed to excise the tumor. Periodic acid-Schiff (PAS) and Alcian blue staining methods were done for the mass, but the result for both of them was negative. Slides were also immunostained for antibodies against cytokeratin AE1/AE3, vimentin, and S-100 protein. The results were positive for vimentin but negative for cytokeratin and S-100. According to the results of histopathology and immunohistochemistry, the type of tumor was diagnosed as iridociliary adenoma. To our knowledge, it was the second report of the iridociliary tumor in the sheep and the first report of this tumor in the Iranian Shaal breed.

Comparison of two eyelid speculums and their effect on intraocular pressure in clinically normal cats.

OBJECTIVES: The present study was undertaken to determine the possible effects of the placement two different types of eyelid speculum on intraocular pressure (IOP) measurement in clinically normal cats. METHODS: Thirty healthy cats were divided randomly into two groups of 15, group B (Barraquer wire speculum) and group W (Williams eye speculum). All cats were sedated with intramuscular medetomidine (Dorbene vet; 100 µg/kg) then placed in right lateral recumbency, and IOP was recorded in the left eye using a Tono-Pen Vet tonometer without and with an eyelid speculum in place in both groups. RESULTS: The without-speculum IOPs for cats in group B and group W were 13.8 ± 3.0 mmHg and 13.2 ± 3.6 mmHg, respectively, and did not differ significantly. A significant increase in IOP (19.8 ± 3.7 mmHg) was observed in group W in with-speculum measurements in comparison to the without-speculum values (P <0.001).There was no significant difference between with- and without-speculum IOP values (13.8 ± 2.7 mmHg) in group B (P = 1.0). CONCLUSIONS AND RELEVANCE: The Barraquer wire speculum has no effect on IOP compared with the Williams eye speculum in normal cats, and may be an appropriate choice in cats for intraocular surgeries that cannot tolerate acute increases in IOP.

Multicentric lymphoma in a Rottweiler dog with bilateral ocular involvement: A case report.

A 10-year-old, male Rottweilerdog was presented to Small Animal Hospital of Tehran University with a history of lethargy, anorexia, weight loss, vomiting, polyuria, polydipsia and blindness. The dog showed symptoms of depression, high body temperature (39.2 ˚C), tachypnea (40 breaths min-1) and cachexia. In ophthalmic examination, bilateral hyphema (hemmorrahge in anterior chamber of the eye) and blindness were detected. The pulse of the animal was normal (90 beats min-1) and obvious general lymphadenopathy was determined. Lymph nodes were firm, freely movable, and painless on palpation. Initial differential diagnosis of lymphoma included lymphoma, metastatic neoplasia, lymphoid hyperplasia, and lymphadenitis. In hematology and cytology tests, this case was suspected to lymphoma. Immunohistochemical staining of neoplastic lymph node revealed that nearly 20.00 - 25.00% of neoplastic cells were strongly positive for anti CD3, whereas they were negative for both CD20 and CD79a. According to the microscopic and immunohistochemical findings, a diagnosis of T cell lymphoma was made. The present report is the first case of multicentric lymphoma with ocular metastasis in a dog in Iran.

Effect of body position on intraocular pressure in clinically normal cats.

Objectives The objective of this study was to investigate the effect of body position on intraocular pressure in clinically normal cats. Methods Sixteen clinically normal cats without any ocular abnormalities were used in this study. Cats were sequentially placed in three different recumbency positions (sternal recumbency, right lateral recumbency and dorsal position). For each of the three body positions, intraocular pressure (IOP) was recorded in the left eye using a Tono-Pen Vet tonometer (Reichert). Results Mean IOP readings in cats in the sternal recumbency, right lateral recumbency and dorsal positions were 15.6 ± 4.1, 16.6 ± 6.4 and 18.6 ± 6.8 mmHg, respectively. A significant increase was observed in IOP in cats in the dorsal position compared with the IOP observed in cats in sternal recumbency ( P = 0.01) and right lateral recumbency ( P = 0.04). There was no significant difference between the IOP recorded in the lateral recumbency and sternal recumbency ( P = 0.17) positions. Conclusions and relevance Body position has a significant effect on the IOP of cats. IOP increases when cats are placed in dorsal recumbency.

Determination of reference values for intraocular pressure and Schirmer tear test results in clinically normal domestic donkeys (Equus asinus).

This study was conducted to establish normal reference range for the Schirmer tear test (STT) and intraocular pressure (IOP) in clinically normal donkeys for use in clinical practice. Sixteen adult Ethiopian domestic donkeys were used in this study. Complete ophthalmic examinations were performed without chemical restraint. STT values were evaluated in both eyes of all donkeys using a commercial STT strip. IOP was measured in both eyes with a Tono-Pen Vet (Reichert. USA) without using regional nerve blocks. STT values for all eyes (n=32) were 22.1±6.9 mm/minute with a range of 13-35 mm/minute. Comparison of mean STT values between right (n=16) and left eyes (n=16) showed no differences (P=0.6). Mean ±sd IOP values by applanation tonometry were 17.8±3.7 mmHg (range 13.5-24.5 mmHg). Comparison of mean IOP values between right (n=16) and left eyes (n=16) showed no differences (P=0.7). This initial survey provides means and ranges for IOP and STT values in donkeys. These data will assist veterinary ophthalmologists in more accurate diagnosis and management of ophthalmic diseases in donkeys, including keratoconjunctivitis sicca and glaucoma.

Twenty-four-Hour Measurement of Intraocular Pressure in Guinea Pigs (Cavia porcellus).

The objective of this study was to measure intraocular pressure (IOP) in intact, healthy guinea pigs (15 male, 15 female) every 2 h for a 24-h period. First, IOP was measured by using rebound tonometry (RBT). After a 1-min rest period, 0.5% proparacaine ophthalmic solution, a topical anesthetic, was applied to both eyes; 4 min after anesthetic instillation, IOP was measured by using applanation tonometry (APT). The IOP was lower during the light period (0700 to 1900) than during the dark phase (2000 to 0600). The lowest IOP by both RBT and APT (3.68 and 13.37 mm Hg, respectively) occurred at 0700, whereas maximal IOP occurred at 2300 for RBT (8.12 mm Hg) but at 2100 for APT (20.62 mm Hg). No significant differences in IOP between the left and right eyes or between RBT and APT were noted. In addition, daily variations in the IOP of guinea pigs seem to be independent of sex and body weight. The results of this study may be beneficial in the diagnosis and observation of glaucoma in guinea pigs.

Effects of two concentrations of topical tropicamide on the Schirmer tear test in clinically normal cats.

OBJECTIVES: The aim of this study was to evaluate the effect of topical tropicamide at two concentrations (0.5% and 1.0%) on the Schirmer tear test (STT) results in clinically normal cats. METHODS: Twenty-four adult domestic shorthair cats were randomly assigned to three groups. In all three groups, ophthalmic solutions were instilled in a randomly selected eye and the opposite eye served as the control. In groups 1, 2 and 3 one drop of 0.5% tropicamide, 1.0% tropicamide and distilled water was used, respectively. Tear production in both eyes was tested 30 and 60 mins after instillation in all three groups. RESULTS: Baseline mean ± SEM STT values for the treated eyes in groups 1, 2 and 3 were 13.37 ± 2.91 mm/min, 10.87 ± 1.39 mm/min and 11.37 ± 1.65 mm/min, respectively. Thirty minutes after the drug instillation in the treated eye, mean ± SEM STT values in groups 1, 2 and 3 were 4.87 ± 3.05 mm/min, 2.00 ± 0.84 mm/min and 11.25 ± 1.81 mm/min, respectively. The mean ± SEM STT levels of the treated eye after 60 mins were 3.75 ± 1.87 mm/min, 0.5 ± 0.37 mm/min and 11.42 ± 1.78 mm/min in groups 1, 2 and 3, respectively. CONCLUSIONS AND RELEVANCE: Use of 0.5% topical tropicamide, instead of 1.0% tropicamide, as a mydriatic agent, can be recommended in cats. Tear production measurement should be performed prior to the administration of tropicamide, regardless of the concentration of this drug.

Lack of effects of intramuscular medetomidine on intraocular pressure in clinically normal cats.

OBJECTIVES: This study aimed to determine the effects of intramuscular medetomidine on the results of tonometry in healthy cats. METHODS: Sixteen healthy cats were randomly divided into two groups of eight cats. The first group was sedated with intramuscular medetomidine alone (100 µg/kg) and the second group received only saline (0.5 ml/5 kg). Intraocular pressure (IOP) values were measured immediately before (T0) and after the injections at 15 mins (T15) and 25 mins (T25) in both groups. RESULTS: Sedation with medetomidine did not cause a statistically significant change in the mean IOP values. The pretreatment mean ± SD IOPs in the treatment and control groups were 16.2 ± 3.1 and 15.9 ± 4.0 mmHg, respectively. In the medetomidine group the mean ± SD IOPs at T15 and T25 were 16.1 ± 4.1 (P = 0.9) and 14.6 ± 2.2 (P = 0.1). CONCLUSIONS AND RELEVANCE: Based on this study in healthy cats, medetomidine may be a good choice as a sedative agent in uncooperative cats when IOP measurements are needed. Further investigations in cats with abnormal IOPs are warranted.

Measurement of Tear Production Using the Phenol Red Thread Test in the Common Mynah ( Acridotheres tristis ).

To evaluate tear production in the common mynah ( Acridotheres tristis ) using the phenol red thread test (PRTT) and to make a comparison of measurements with the PRTT placed in the fornices of lower and upper eyelids, tear production of both eyes in 22 healthy adult captive mynah birds was evaluated. After positioning of threads in the fornices of upper and lower eyelids, the PRTT values of the birds were 17.5 ± 3.1 mm/15 s and 19.2 ± 2.5 mm/15 s, respectively. A significant difference was found between PRTT values for upper eyelids and lower eyelids (P = 0.01). This study provides novel data for normal reference ranges of PRTT values in healthy common mynah birds and shows that a difference is found depending on where the PRTT thread is placed.

Effects of short-term oral administration of trimethoprim-sulfamethoxazole on tear production in clinically normal Syrian hamsters.

OBJECTIVE: To determine effects of 14 days of oral administration of trimethoprim-sulfamethoxazole on aqueous tear production in clinically normal Syrian hamsters. ANIMAL STUDIED: Fifteen healthy adult Syrian hamsters. PROCEDURE: Baseline phenol red thread test (PRTT) values were recorded 1 day prior to treatment. Eight hamsters in treated group received 15 mg/kg trimethoprim-sulfamethoxazole orally twice a day for 14 days. The remaining seven hamsters were used as untreated controls and received a placebo. All ophthalmic tests were performed without chemical restraint. PRTT values were evaluated in both eyes of all Syrian hamsters using a commercial PRTT strip of a single lot number. RESULTS: The mean ± SD baseline PRTT values for treatment group and control group were 7.25 ± 1.3 mm/15 s and 5.42 ± 1.13 mm/15 s, respectively. After 14 days of drug administration, the mean ± SD PRTT values for treatment group and control group were 5.62 ± 1.5 and 5.64 ± 0.74, respectively. Significant decreases in the PRTT values, compared with baseline values, were observed in the treatment group on day 15 (P = 0.042). CONCLUSIONS: Trimethoprim-sulfamethoxazole decreased tear production in the hamster in this study.

Effect of topical 1% tropicamide on Schirmer tear test results in clinically normal horses.

OBJECTIVE: To observe the effect of topical 1% tropicamide on equine tear production as measured by Schirmer I tear test. MATERIALS AND METHODS: Fourteen adult horses received one drop of 1% tropicamide ophthalmic solution in one eye and the opposite eye served as the control. The tear production in both eyes was tested at 1, 2, 4, 6, and 24 h after 1% tropicamide administration. RESULTS: Measurements made 1 h after treatment revealed a significant reduction in Schirmer tear test values in tropicamide treated eyes (P = 0.002). The observed decrease in tear production was maintained up to 4 h after treatment (P = 0.002). Although tropicamide-induced decrease in STT values was observed in the treated eyes, the contralateral eyes did not show significant changes in Schirmer tear test results. CONCLUSION: Single dose of topical 1% tropicamide resulted in statistically significant reduction in Schirmer tear test values in clinically normal horses.

Oculocardiac reflex induced by zygomatic arch fracture in a crossbreed dog.

A 3-year-old crossbreed male dog was presented with a history of blunt facial trauma. Skull radiographs showed right zygomatic arch fracture. An electrocardiogram revealed bradycardia, first-degree atrioventricular block and QT prolongation. Standard biochemical profile including electrolytes was normal. Atropine response test (0.04 mg/kg intravenously) restored normal sinus rhythm at a rate of 140 bpm with normal QT and PR intervals. This observation is consistent with oculocardiac reflex secondary to zygomatic arch fracture.