Orbital and Subcutaneous Emphysema Following Enucleation and Respiratory Distress in a Japanese Chin.

A 7 yr old, neutered male Japanese chin presented to the Cummings School of Veterinary Medicine at Tufts University (CSVMTU) for evaluation of chronic unilateral orbital swelling that worsened following an episode of respiratory distress. The left eye had been enucleated 5 yr previously. Intermittent mild-to-moderate left orbital swelling had been noted by the owner since the initial surgery. Examination demonstrated a moderate-to-severe, soft, fluctuant swelling involving the left orbit with erythema of the overlying skin. Crepitus was noted over the occipital tuberosity. Computed tomography revealed a large volume of gas involving the left orbit. The gas extended caudally within the subcutaneous tissues to both hemimandibles, dorsal to the cranium, and partially surrounded the cranial neck. The presence of a mucosa-lined, air-filled space with a patent nasolacrimal duct was noted on orbital exploration. The lining was removed and the duct closed. Histopathology confirmed the presence of an epithelial lining. No recurrence of the swelling was observed on examination 8 wk after surgery. This is the first report documenting acute worsening of orbital swelling following an episode of respiratory distress. This case highlights the importance of addressing the nasolacrimal duct while performing an enculeation in a brachycephalic dog.

Medical Treatment of Primary Canine Glaucoma.

Glaucoma is a painful and often blinding group of ocular diseases for which there is no cure. Although the definition of glaucoma is rapidly evolving, elevated intraocular pressure (IOP) remains the most consistent risk factor of glaucoma in the canine patient. Therapy should be aimed at neuroprotection. The mainstay of therapy focuses on reducing IOP and maintaining a visual and comfortable eye. This article discusses the most current ocular hypotensive agents, focusing on their basic pharmacology, efficacy at lowering IOP, and recommended use in the treatment of idiopathic canine glaucoma.

Fluorescein gonioangiography of the normal canine eye using a dSLR camera adaptor.

The purpose of this study was to describe fluorescein gonioangiography (FGA) of the normal canine eye using a digital single lens reflex (dSLR) camera adaptor. Dogs were anesthetized using intravenous propofol. Imaging was performed using a Lovac Barkan goniolens, dSLR camera, dSLR camera adaptor, camera lens, and accessory flash. Twelve dogs with a mean age of 2.0 +/- 0.8 years were imaged. No characteristic angiographic phases were observed. Leakage from the peri-limbal capillary network was a common finding and occurred 7.7 +/- 2.2 s post injection in 9 (75%) dogs. In 3 (25%) dogs, filling of the circumferential ciliary artery was observed 10.3 +/- 2.8 s post injection. Dye leakage within the iris base and into the aqueous humor was demonstrated in 4 (33%) and 6 dogs (50%) respectively. No adverse events were noted. This study demonstrates FGA findings in normal canine eyes using a cost effective dSLR camera adaptor.

Reliability of manual measurements of corneal thickness obtained from healthy canine eyes using spectral-domain optical coherence tomography (SD-OCT).

The purpose of this study was to manually measure corneal thickness in canine eyes using a spectral-domain optical coherence tomography (SD-OCT) device and to assess intra- and inter-observer reliability of this technique. Twenty healthy dogs with a mean age of 4.7 y were examined. A 6-mm corneal pachymetry protocol was carried out by 1 operator using 1 SD-OCT device in both eyes of each animal. Measurements were obtained manually and in duplicate by 2 independent investigators (> 24 h apart), using the built-in caliper function. Measurements included epithelial thickness (ET), non-epithelial thickness (NET), and central corneal thickness (CCT). The overall mean ET, NET, and CCT for all eyes examined were 72.3 ± 4.6 µm, 538.9 ± 42.5 µm, and 611.2 ± 40.3 µm, respectively. There was no significant difference in ET, NET, or CCT based on the eye examined [oculus dexter (OD) versus oculus sinister (OS)], age, or gender of the animal. There was no significant difference in replicate measurements of ET, NET, or CCT done by the same operator, although a small but significant difference was noted between operators for ET measurements only. The mean difference in ET between operators was 0.6 µm (P = 0.03). The coefficient of variation ranged from 0.5% to 9.27% and intraclass correlation coefficient ranged from 0.35 to 0.97. Based on these results, manual measurements of corneal thickness in canine eyes using a portable SD-OCT device provided ET, NET, and CCT measurements with clinically acceptable intra- and inter-observer reliability.

L'objectif de la présente étude était de mesurer manuellement l'épaisseur de la cornée des yeux canins en utilisant un appareil à tomographie par cohérence optique du domaine spectral (SD-OCT) et d'évaluer la fiabilité intra- et inter-observateur de cette technique. Vingt chiens en santé d'un âge moyen de 4,7 ans furent examinés. Un protocole de pachymétrie a été mené par un opérateur utilisant un appareil SD-OCT dans les deux yeux de chaque animal. Les mesures ont été obtenues manuellement et en duplicata par deux chercheurs indépendants (> 24 h de délai), en utilisant la fonction de pied à coulisse incluse. Les mesures incluaient l'épaisseur épithéliale (ET), l'épaisseur non-épithéliale (NET), et l'épaisseur au centre de la cornée (CCT). Les moyennes globales d'ET, de NET et de CCT pour tous les yeux examinés étaient respectivement de 72,3 ± 4,6 µm, 538,9 ± 42,5 µm, et 611,2 ± 40,3 µm. Il n'y avait aucune différence significative des valeurs de ET, NET, ou CCT selon l'oeil examiné (oeil droit versus oeil gauche), âge, ou sexe de l'animal. Il n'y avait aucune différence significative dans les mesures répétées de ET, NET, ou CCT faites par le même opérateur, et une petite mais significative différence fut notée entre les opérateurs pour les mesures de ET seulement. La différence moyenne dans les mesures de ET entre les opérateurs était de 0,6 µm (P = 0,03). Le coefficient de variation variait de 0,5 % à 9,27 % et le coefficient de corrélation intra-classe variait de 0,35 à 0,97. En fonction de ces résultats, la mesure manuelle de l'épaisseur de la cornée des yeux de chien à l'aide d'un appareil SD-OCT portatif fournit des données de ET, NET, et CCT avec une fiabilité intra- et inter observateur qui est cliniquement acceptable.(Traduit par Docteur Serge Messier).

Central corneal thickness measurements in normal dogs: a comparison between ultrasound pachymetry and optical coherence tomography.

OBJECTIVE: To compare central corneal thickness (CCT) measurements obtained from normal canines using a spectral-domain optical coherence tomography device (SD-OCT) and an ultrasonic pachymeter. ANIMALS: Fifteen clinically normal dogs. PROCEDURES: Dogs were briefly anesthetized with propofol. Central corneal thickness measurements were obtained from both eyes of each animal four times by one operator using a SD-OCT system. The CCT was automatically calculated using the pachymetry software generated from eight radial scans, 6 mm in length. Ultrasonic pachymetry was then performed in both eyes of each animal by one operator five times in succession. The CCT was recorded for each modality and compared statistically for agreement and bias. RESULTS: Fifteen dogs (seven castrated male, eight spayed female) with a mean age of 2.3 ± 1.3 years were examined. The mean CCT for all eyes examined via SD-OCT and ultrasonic pachymetry (velocity set at 1636 m/s) was 587.72 ± 32.44 µm and 598.54 ± 32.28 µm, respectively. Ultrasonic pachymetry consistently overestimated CCT as compared to OCT by a mean value of 10.82 µm (P < 0.0001). No significant difference in CCT was found based on the age or sex of the animal. There was no significant difference in CCT measurements between replicates performed by the same operator for each modality. The coefficient of variation within and between imaging modalities was low (range 0.63-2.5%). The intraclass correlation coefficient comparing methods was 0.92. CONCLUSIONS: Correlation between modalities was excellent; however, ultrasonic pachymetry set at a standard velocity of 1636 m/s overestimates CCT as compared to OCT.

Intra and inter-user reliability of central corneal thickness measurements obtained in healthy feline eyes using a portable spectral-domain optical coherence tomography device.

OBJECTIVE: To determine the intra and inter-user reliability of central corneal thickness (CCT) measurements obtained using a portable spectral-domain optical coherence tomography (SD-OCT) device in healthy feline eyes. ANIMALS: Twenty clinically normal cats. PROCEDURES: Gentle manual restraint was utilized for proper animal positioning. Central corneal thickness measurements were obtained from both eyes of each animal three times by two operators in succession. A 6 mm, corneal pachymetry protocol was performed using the Optovue® iVue SD-OCT system. The CCT was automatically calculated using the pachymetry software generated from eight radial scans, 6 mm in length. The CCT was recorded for each operator and compared statistically for both intra and inter-user reliability. RESULTS: Twenty cats (11 CM, 9 SF) with a mean age of 4.7 years were examined. The mean CCT for all eyes examined was 629.08 ± 47.05 µm. No significant difference in CCT was found based on the eye examined (OD vs. OS) or age of the animal. However, the CCT of spayed females was significantly higher (42.64 ± 18.0 µm) as compared to castrated males (P = 0.03). There was no significant difference in CCT measurements between replicates performed by the same operator or between operators. The mean difference in CCT between operators was 0.38 µm. The coefficient of variation for each user and between users was very low (range 0.68-1.5%). The intra-class correlation coefficient comparing operators was 0.975. CONCLUSIONS: The Optovue® iVue SD-OCT device is capable of obtaining CCT measurements with excellent intra and interoperator reliability in healthy feline eyes.

Anterior segment fluorescein angiography of the normal canine eye using a dSLR camera adaptor.

PURPOSE: To describe anterior segment fluorescein angiography (ASFA) of the normal canine eye using two different sedation/anesthetic protocols and a digital single lens-reflex (dSLR) camera adaptor. METHODS: Dogs free of ocular and systemic disease were used for this study. Dogs received maropitant citrate (1.0 mg/kg SQ) and diphenhydramine (2.0mg/kg SQ) 20min prior to butorphanol [n = 6] (0.2 mg/kg IV) or propofol [n=6] (4 mg/kg IV bolus, 0.2 mg/kg/min CRI). Standard color and red-free images were obtained prior to administration of 10% sodium fluorescein (20 mg/kg IV). Image acquisition was performed using a dSLR camera (Canon 7D), dSLR camera adaptor, camera lens (Canon EF-S 60 mm f/2.8 macro), and an accessory flash (Canon 580EXII). Imaging occurred at a rate of 1/s immediately following bolus for a total of 30 s, then at 1, 2, 3, 4, 5, and 10 min. RESULTS: Twelve dogs with a combined mean age of 5.1 years and various iris colors were imaged. Arterial, capillary, and venous phases were identified and time sequences recorded. Visibility of the vascular pattern was inversely related to iris pigmentation. Complete masking of blood flow was noted with heavily pigmented irises. Vessel leakage was noted in some eyes. Proper patient positioning and restricted ocular movements were critical in acquiring quality images. No adverse events were noted. CONCLUSION: This study demonstrated that quality high resolution ASFA images were obtainable using a novel dSLR camera adaptor. ASFA of the normal canine eye is limited to irises, which are moderately to poorly pigmented. Use of general anesthesia produced higher quality images and is recommended for ASFA in the dog.

Histopathologic evaluation of the anterior segment of eyes enucleated due to glaucoma secondary to primary lens displacement in 13 canine globes.

PURPOSE To describe histologic anterior segment changes in eyes affected with primary lens displacement (PLD) and secondary glaucoma. METHODS Histologic sections stained with H&E from canine eyes enucleated because of PLD and secondary glaucoma were examined. RESULTS Thirteen eyes from 12 patients were evaluated. Four dogs were castrated males and eight spayed females. Median age was 8 years of age (range 3-13). Breeds included seven terriers and five other breeds. All eyes examined demonstrated varying degrees of inflammation involving the iris and cleft. Mononuclear and melanophagic infiltration of the cleft was found in all specimens. Four globes also showed polymorphonuclear infiltrate. Pre-iridal fibrovascular membranes were clearly identified in 10 of 13 eyes. Total inflammatory score was significantly greater in all globes examined compared with an age-matched group of normal dogs. The posterior pigmented iris epithelium demonstrated a consistent pattern of hyperplasia and/or hypertrophy and cystic degeneration, more prominent in the more central regions. In some cases, hyperplasia was of greatest severity in the mid-iris and associated with thinning or flattening of the pupillary region. CONCLUSIONS These results suggest that lens instability may be associated with chronic inflammation and secondary glaucoma. Mechanical irritation from an unstable lens may result in hypertrophy and/or hyperplasia of the posterior pigmented iris epithelium and subsequent cellular exfoliation and release of melanin. An inflammatory reaction directly or indirectly related to melanin release may obstruct the outflow pathways ultimately leading to glaucoma and loss of vision. Use of topical steroids may be warranted in dogs with PLD.

Anterior segment fluorescein angiography of the normal feline eye using a dSLR camera adaptor.

PURPOSE: To describe anterior segment fluorescein angiography (ASFA) of the normal feline eye using a digital single-lens reflex (dSLR) camera adaptor. ANIMALS: Ten cats free of ocular and systemic disease were evaluated. METHODS: All cats received maropitant citrate (1.0 mg/kg SQ) and diphenhydramine (2.0 mg/kg SQ) 20 min prior to anesthesia using propofol (4 mg/kg IV bolus, 0.2 mg/kg/min CRI). Standard color and red-free images were obtained prior to the administration of 10% sodium fluorescein (20 mg/kg IV). Imaging was performed using a dSLR camera (Canon 7D), dSLR camera adaptor, camera lens (Canon EF-S 60 mm f/2.8 macro), and an accessory flash (Canon 580EXII). Imaging occurred at a rate of 1/second immediately following IV bolus of sodium fluorescein for a total of 30 s, then at 1, 2, 3, 4, 5, and 10 min. RESULTS: Ten cats with an average age of 3.7 ± 0.9 years and various iris colors were imaged. Arterial, capillary, and venous phases occurred 4.6, 7.8, and 8.9 s postinjection, respectively. Visibility of the vasculature was not impaired by the degree of iris pigmentation. Patency of a persistent pupillary membrane was noted in one cat. Vessel leakage was common, as well as, leakage into the aqueous humor. Proper patient positioning and restricted ocular movements were critical. No adverse events were noted. CONCLUSIONS: This study demonstrates ASFA findings in normal feline eyes using a cost-effective dSLR camera adaptor. Fluorescein leakage from vessels and into the aqueous humor was a common finding. Visibility of iris vasculature was not impaired by the degree of iris pigmentation.