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 (2.0 mg/kg SQ) 20 min 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.     

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.     

Effects of unilateral topical administration of 0.5% tropicamide on anterior segment morphology and intraocular pressure in normal cats and cats with primary congenital glaucoma

Objective To determine the effects of topical 0.5% tropicamide on anterior segment morphology (ASM) and intraocular pressure (IOP) in normal and glaucomatous cats. Animals used Normal cats and cats with inherited primary congenital glaucoma (PCG). Procedures Control IOP curves were performed in untreated normal and PCG cats. In the first experiment, tropicamide was applied OD in eight normal and nine PCG cats. IOP and pupillary diameter (PD) were measured at 0, 30, and 60 min, then hourly until 8 h post‐treatment. In a second experiment, six normal and seven PCG cats received tropicamide OD. High‐resolution ultrasound images were obtained at 0, 1, 5, and 10 h post‐treatment to measure ASM changes. IOP and PD were measured OD at 0, 1, 2, 3, 5, 7, and 9 h. Results In untreated normal cats IOP OU decreased throughout the day. In PCG cats IOP OU had wide fluctuations over time. In normal cats IOP response varied in the treated eye but did not change significantly in untreated eyes. IOP significantly increased from baseline in both eyes of all treated PCG cats. Increases in IOP were associated with some ASM changes. Cats with PCG had a significantly smaller angle recess areas, diminished ciliary clefts and decreased iris‐lens contact. ASM changes were not strongly correlated with IOP in all cats. Conclusions The ASM of PCG cats is markedly different from normal cats, and clinically significant increases in IOP OU occur in cats with PCG after tropicamide treatment. The mechanism for this increase remains unclear.     

Anterior and posterior segment photography. An alternative approach using a dSLR camera adaptor

Purpose To describe a novel digital single lens reflex (dSLR) camera adaptor for anterior and posterior segment photography. Methods The adaptor was used to evaluate canine, feline, and equine patients presenting to Tufts Ophthalmology service. Anterior segment imaging was conducted with the adaptor mounted between a dSLR camera body (Canon 7D) and a macro lens (Canon EF‐S 60mm/f2.8). Posterior segment imaging was performed with the aid of an indirect ophthalmic lens mounted in front of the macro lens. Coaxial illumination during viewing was provided by a single white light‐emitting diode (LED) within the adaptor, while illumination during exposure was provided by the pop‐up flash or an accessory flash. Corneal and/or lens reflections were eliminated using a pair of linear polarizers, having their azimuths at right angles to one another. Results This dSLR camera adaptor provides quality high‐resolution, reflection‐free, images of both the anterior and posterior segments. It was easy to transport, assemble, and handle. The necessary adjustments, positioning, and focusing required for quality images were easily performed. Conclusion The described dSLR camera adaptor provides an alternative to existing imaging systems. High‐resolution image acquisition occurred at a fraction of the cost of established imaging system, particularly those devoted to the posterior segment.     

Anterior segment angiography of the normal canine eye: A comparison between indocyanine green and sodium fluorescein

The objective of this study was to assess and compare indocyanine green (IG) and sodium fluorescein (SF) angiographic findings in the normal canine anterior segment using a digital single lens reflex (dSLR) camera adaptor. Images were obtained from 10 brown-eyed Beagles, free of ocular and systemic disease. All animals received butorphanol (0.2 mg/kg IM), maropitant citrate (1.0 mg/kg SC) and diphenhydramine (2.0 mg/kg SC) 20 min prior to propofol (4 mg/kg IV bolus, 0.2 mg/kg/min continuous rate infusion). Standard color imaging was performed prior to the administration of 0.25% IG (1 mg/kg IV). Imaging was performed using a full spectrum dSLR camera, dSLR camera adaptor, camera lens (Canon 60 mm f/2.8 Macro) and an accessory flash. Images were obtained at a rate of 1/s immediately following IG bolus for 30 s, then at 1, 2, 3, 4 and 5 min. Ten minutes later, 10% SF (20 mg/kg IV) was administered. Imaging was repeated using the same adaptor system and imaging sequence protocol. Arterial, capillary and venous phases were identified during anterior segment IG angiography (ASIGA) and their time sequences were recorded.ASIGA offered improved visualization of the iris vasculature in heavily pigmented eyes compared to anterior segment SF angiography (ASSFA), since visualization of the vascular pattern during ASSFA was not possible due to pigment masking. Leakage of SF was noted in a total of six eyes. The use of IG and SF was not associated with any observed adverse events. The adaptor described here provides a cost-effective alternative to existing imaging systems.     

Ultrasound biomicroscopy of the feline anterior segment

Ultrasound biomicroscopy was performed on enucleated feline globes as a model for use in vivo. Quantitative measurements were obtained from the anterior segment using a 50-MHz transducer. Mean values from 26 feline globes were axial corneal thickness, 0.74 mm; anterior chamber depth, 4.20 mm; distance from the first ciliary process to the limbus, 3.17 mm; angle recess, 0.38 mm; angle opening distance, 1.05 mm; iris base width 0.38 mm; iris middle width 0.52 mm; iris tip width 0.13 mm, and iris-lens overlap, 0.69 mm. Distinctive features of the feline anterior segment include a relatively wide iridocorneal angle and deep anterior chamber.     

Anterior lens capsule disruption and suspected malignant glaucoma in a dog

A Boston Terrier puppy presented with a full-thickness peripheral corneal defect, iris prolapse and anterior lens capsule tear in the left eye (OS). Phacofragmentation and primary repair of the corneal laceration was performed. At surgery, subluxation of the lens was also apparent. One day postoperative, there was severe corneal edema, diffuse hyphema, an intraocular pressure (IOP) of 65 mmHg and a small amount of vitreous that protruded from the corneal incision OS. Malignant glaucoma or pupillary block glaucoma were suspected. Intravenous mannitol was administered preoperatively and had no effect. An anterior vitrectomy was performed on the vitreous within the anterior chamber and pupil. One day postoperative the IOP was 16 mmHg in the right eye (OD) and 20 mmHg OS. Postoperative iridocyclitis was managed medically, and additional elevations in IOP were not recorded. Resolution of the elevated IOP following anterior vitrectomy was supportive of pupillary block or malignant glaucoma. Vision returned 3 weeks after the initial surgery. Two years after the initial injury, the eye is visual and comfortable with infrequent topical anti-inflammatory therapy.     

Cullen frontal sinus valved glaucoma shunt: preliminary findings in dogs with primary glaucoma

PURPOSE: To evaluate the efficacy of a novel, professionally manufactured, frontal sinus valved glaucoma shunt in maintaining normal intraocular pressure (IOP) and vision in dogs with primary glaucoma. METHODS: Three eyes of three dogs diagnosed with primary glaucoma were included in this prospective clinical study. A Cullen frontal sinus valved glaucoma shunt was implanted into each glaucomatous globe. Dogs were treated postoperatively with topical neomycin/polymyxin B/0.1% dexamethasone and 0.03% flurbiprofen every 6 h tapered over 8-12 weeks, and meloxicam at 0.1 mg/kg orally every 24 h for 7-10 days. IOP, intracameral shunt position and apparent patency, and vision were assessed twice daily for up to 4 (n= 3 eyes) and 10 (n= 2 eyes) days postoperatively, and then at re-examination periods of up to 36 weeks (n= 1 eye). Postoperative complications were recorded and documented photographically. RESULTS: Normal IOP was maintained in all shunted globes (range 10-29 mmHg; mean = 16.7 mmHg at 24 h; IOP = 23 mmHg at 36 weeks) postoperatively for 2 days (3/3 eyes), 8 weeks (2/2 eyes), and 36 weeks (1/1 eye) without additional antiglaucoma therapies. Photopic vision and shunt position and patency were maintained in all shunted globes for all follow-up periods. Postoperative complications included mild aqueous flare and fibrin (n= 3 eyes for 3-10 days postoperatively); intracameral shunt occlusion with fibrin (n= 1 eye at days 2 and 4); partial anterior chamber tube extrusion (n= 1 eye at day 4), and focal corneal edema (n= 1 eye at 18 weeks). Tissue plasminogen activator injected intracamerally through the silicone tube near the frontal sinus effectively resolved the fibrinous shunt occlusion. CONCLUSIONS: The Cullen frontal sinus valved glaucoma shunt shows promise for the management of canine primary glaucoma.     

Post mortem magnetic resonance imaging of multiple congenital ocular anomalies in a Comtois mare

Multiple congenital ocular anomalies syndrome consists of several abnormalities mainly localised to the anterior segment of the eye. This condition, comprising iridal or ciliary cysts with or without iridal hypoplasia, an excessively protruding cornea (‘cornea globosa’), miotic pupils, retinal dysplasia, cataract, and other lesions, has been reported in several breeds and is strongly related to the silver coat colour, as a result of a dominant mutant allele at the PMEL17 locus. This report describes the macroscopic, ultrasonographic, histological and magnetic resonance imaging findings of the ocular abnormalities in a Comtois mare with multiple congenital ocular anomalies syndrome.     

Anterior chamber to frontal sinus shunt for the diversion of aqueous humor: a pilot study in four normal dogs

Silicone tubing was used to divert aqueous humor from the anterior chamber of the right eye to the rostral compartment of the right frontal sinus in four clinically normal mixed-breed dogs. Biomicroscopic examination, and pneumoapplanation tonometry and tonography, completed for up to 18 weeks postoperatively, confirmed gonioimplant function in all four cases. The dogs were euthanized at 6, 8, 16 and 18 weeks postoperatively. Gonioimplant patency was further confirmed by postmortem examination of the globes, implants and frontal sinuses. Gross and light microscopic examinations revealed iridal attachments to the implant ( n  = 4), mild anterior uveitis ( n  = 3), anterior subcapsular cataracts ( n  = 4), and focal corneal ( n  = 3) and scleral ( n  = 3) scarring in the operated globes. Light microscopic examination of frontal sinus specimens revealed mild lymphocytic proliferation and fibrosis immediately adjacent to the implant entrance site. There were no bacteria detected on aerobic or anaerobic cultures of the frontal sinuses or light microscopic examination of the globes or frontal sinuses. Results indicate that the frontal sinus shunting of aqueous humor is a safe and effective means of extraorbital aqueous diversion with potential applicability in the management of glaucoma.     

Infrared digital imaging of the equine anterior segment

Ocular photographs are an increasingly important method of documenting lesions for inclusion in medical records, teaching purposes, and research. Availability of affordable high-quality digital imaging equipment has allowed for enhanced capture of desired images because of immediate on-camera viewing and editing. Conversion of the standard digital camera sensor to one that is sensitive to infrared light (i.e. > 760 nm < 1 mm wavelength) can be done inexpensively. In the equine eye, advantages of infrared digital photography include increased contrast of anterior segment images, identification and monitoring of pigmentary changes, and increased visualization of the anterior segment through a cloudy or edematous cornea.     

长爪沙鼠脑底动脉Willis环变异缺失类型与脑缺血模型症状相关性分析

通过观察398只长爪沙鼠右侧颈总动脉结扎脑缺血模型,比较研究其脑底动脉Willis环缺失类型和半脑缺血模型症状的相关性。结果显示,长爪沙鼠脑底动脉Willis环的前、后交通支各有4种类型。在Willis环后交通支缺失的前提下,当行单侧颈总动脉结扎时,一侧脑缺血症状显著程度与前交通支变异类型有关,其中前交通支完整型与其余3种类型的症状有显著性差异(P=0.000)。结果表明,经颈总动脉结扎后半脑缺血模型高发生率和典型症状的基础是Willis环后交通支缺失并伴有前交缺失或细小为前提的。     

Experimental peritonitis induced by oral administration of indomethacin in Mongolian gerbils

The possibility of inducing peritoneal inflammation in three murine species (gerbils, rats and mice) via the oral administration of indomethacin was investigated with the overall aim of developing an experimental animal model for human peritonitis. Gerbils given high doses of indomethacin at a rate of 30 mg and 40 mg/kg body weight showed swelling of the abdomen, depression and dyspnea within 4 days after the treatment. The severity of the clinical symptoms increased with time. The animals were confirmed as having developed peritonitis based on the pathological features including inflammation of the peritoneum, and fibrinous adhesion of the abdominal organs in the abdominal cavity. The severity of peritonitis increased with increasing dose of indomethacin, and was not related to the gender of the animal. On the other hand, peritoneal inflammation did not develop in the rats and mice even at high doses. Therefore, the administration of 30 mg/kg body weight of indomethacin is an effective and simple method of inducing peritonitis in 5-week-old Mongolian gerbils. The animal peritonitis model used in this study can be used as an effective tool for examining potential therapeutic compounds for preventing peritoneal damage during peritonitis, and provide insight into the pathophysiology of peritonitis.     

不同地域长爪沙鼠群体间遗传状况分析

应用27个生化基因位点,分别对首都医科大学实验动物科学部和浙江省实验动物中心饲育的2个长爪沙鼠群体进行了遗传分析。结果显示,首都医科大学实验动物科学部长爪沙鼠群体遗传适应性、遗传多样性水平、遗传变异程度都明显高于浙江省实验动物中心沙鼠群体（P〈0.05）,并且这2个沙鼠群体间未出现较为明显的遗传分化（FST〉0.05）。