Punctate fluorescein staining scores in dogs with or without aqueous tear deficiency.

OBJECTIVE: To compare the superficial punctate fluorescein staining in dogs with and without aqueous tear deficiency. PROCEDURES: An eye from each client-owned dogs presented to Triangle Animal Eye Clinic between January and December 2018 underwent tear and ocular surface tests, which included the Schirmer tear test (STT), phenol red thread test (PRT), and strip meniscometry tube tear test (SMT). Punctate fluorescein staining of the cornea (PFS-C) and the upper palpebral conjunctiva (PFS-UPC) were also performed. Fifty-seven dogs with STT results of <15 mm/min had aqueous tear deficiency (AD); 31 dogs had <10 mm/min and 26 dogs had ≥10 mm/min. The 162 dogs with STT results of ≥15 mm/min did not have AD. The test results of the groups were compared using Kruskal-Wallis and Steel-Dwass multiple comparison tests. RESULTS: Two hundred and nineteen eyes from 219 dogs were enrolled in this study. The PRT and SMT results, presented as mean ± SD, were significantly lower in the AD group than in the non-AD group (PRT: 29.5 ± 8.1 vs 36.9 ± 5.6 mm/15 s; SMT: 6.2 ± 3.8 vs 10.8 ± 2.8 mm/5 s). The PFS scores were significantly higher in the AD group than in the non-AD group (PFS-C: 4.4 ± 0.7 and 3.7 ± 0.8; PFS-UPC: 2.3 ± 0.5 and 1.7 ± 0.5). CONCLUSIONS: These results suggest that aqueous tear deficiency is not only reflected by PRT and SMT but also PFS-C and PFS-UPC.

Effects of pupil size on canine visual evoked potential with pattern stimulation.

The purpose of this study was to investigate the effects of pupil diameter on canine visual evoked potentials with pattern stimulation (P-VEP). Atropine eye drop (1.0%) was applied to both eyes as a cycloplegic drug, and tafluprost eye drop (0.015%) was applied to one eye that was selected randomly for miosis (miosis group). The other eye did not receive tafluprost (mydriasis group). P-VEP was recorded at three pattern sizes. The P100 implicit time at a small pattern size in the mydriasis group was significantly prolonged compared to the miosis group. We hypothesized that the prolonged P100 implicit time under mydriatic conditions was due to increased spherical aberrations and concluded that mydriatic conditions affected P100 implicit time in canine P-VEP recordings.

Surgical removal of cataract in an Asiatic black bear (Ursus thibetanus) by phacoemulsification and aspiration.

A twenty-year-old male Asiatic black bear (Ursus thibetanus) presented at the Rakuno Gakuen University Animal Medical Center with a 10-year history of bilateral blindness and cataracts. Surgical treatment of bilateral cataracts by extracapsular lensextraction using phacoemulsification and aspiration (PEA) was performed under general anesthesia. An anterior capsulectomy was performed using micro iris scissors and micro anterior lens capsule forceps. The cataract was removed with PEA using the two-handed technique. After surgery, systemic corticosteroids, anti-inflammatory drugs and antibiotics were administered. After cataract removal, the bear had recovered vision, and good quality vision has been maintained to date (15 months). PEA can be a safe and effective treatment for cataracts that impair vision in bears.

Histopathologic changes associated with Meibomian Gland dropout in a dog.

PURPOSE: To perform histopathologic analysis of tissue manifesting meibomian gland dropout on noncontact infrared meibography in a dog. METHODS: A 14-year-old intact male Cairn terrier was evaluated at Triangle Animal Eye Clinic for dense corneal opacity of the right eye. A complete ocular examination was performed, including slit-lamp biomicroscopy, tonometry, and noncontact meibography. Pigmentary glaucoma with elevation of intraocular pressure was diagnosed, and meibography revealed morphological changes suggestive of gland dropout in the middle of the upper right eyelid. RESULTS: The globe was enucleated by the transpalpebral method, and palpebral tissue was subjected to histopathologic analysis. The analysis revealed an almost complete loss of meibomian gland structure accompanied by slight enlargement and proliferation of fibroblasts as well as by infiltration of plasma cells and lymphocytes. CONCLUSIONS: Meibomian gland dropout as detected by meibography can be associated with chronic inflammation.

Assessment of meibomian gland morphology by noncontact infrared meibography in Shih Tzu dogs with or without keratoconjunctivitis sicca.

OBJECTIVE: To investigate meibomian gland (MG) morphology by noncontact infrared meibography in Shih Tzu dogs with or without keratoconjunctivitis sicca (KCS). PROCEDURES: Fourteen eyes of 12 Shih Tzu dogs (mean age of 10.7 years, range of 7-13 years) presented to Yakumo Animal Hospital or Triangle Animal Eye Clinic from 2011 to 2017 with clinical signs and a Schirmer tear test (STT) result consistent with KCS (<10 mm/min) were examined. Twenty-eight eyes of 16 Shih Tzu dogs (mean age of 12.4 years, range of 8 to 15 years) with a STT > 15 mm/min served as healthy controls. Both groups of dogs underwent routine slitlamp biomicroscopy followed by noncontact infrared meibography of the upper eyelid with both desktop-type and mobile-type systems. Results Meibography revealed morphological abnormalities of MGs in 13 eyes of 11 dogs with KCS. The abnormalities included gland shortening in 64% and gland dropout in 64% of the 14 eyes in the KCS group. Morphological changes were also observed in MGs of 16 eyes of 10 dogs in the control group. These changes included shortening in 46% and dropout in 17.8% of the 28 eyes in the control group. Dropout was significantly more common in eyes with KCS than in control eyes (P < 0.01). Conclusions The frequency of MG abnormalities is increased in Shih Tzus with KCS compared with control animals. A reduced quality of the tear film associated with increased evaporation and reduced retention of tear fluid likely exacerbates the effects of a reduced tear volume in animals with aqueous deficiency.