A remote fluorescein staining and photography protocol for monitoring of ulcerative keratitis in small animal patients: A pilot study.

OBJECTIVE: To describe a protocol for corneal ulcer monitoring utilizing daily fluorescein staining and evaluation of owner-acquired anterior segment images. ANIMAL STUDIED: Nine client-owned small animal patients (eight dogs, one cat) diagnosed with superficial corneal ulcers at the University of Georgia Veterinary Capitalize Hospital. PROCEDURE(S): In addition to routine ulcer therapy, patients were discharged with supplies to perform daily fluorescein staining including a Quikvue® cobalt blue light camera adapter. Fluorescein staining was performed daily, photographs and/or videos were acquired at home by the patient's owner(s), and images were analyzed daily by trained personnel. In-house examinations were performed weekly and within 24 h after the ulcer had appeared healed on photographs. RESULTS: All (9/9) owners were able to take interpretable photographs. The majority (6/9) of patients had images successfully detailing their ulcer healing progress. One (1/9) patient appeared healed on images, but on subsequent examination had persistent ulceration covered by third eyelid elevation. Two (2/9) patients had persistent ulceration, consistent on both images and examination, but exited the study prematurely prior to ulcer healing. CONCLUSIONS: Remote fluorescein staining and image evaluation can be considered as an adjunct for monitoring ulcer healing but should not be used alone or as a substitute for ophthalmic examinations. Ulcers under the third eyelid have potential to be missed on image evaluation alone.

Using Visual and Digital Imagery to Quantify Horn Fly (Diptera: Muscidae) Densities.

The horn fly, Haematobia irritans L. (Diptera: Muscidae), is a persistent pest of cattle globally. A threshold of 200 flies per animal is considered the standard management goal; however, determining when that threshold has been exceeded is difficult using visual estimates that tend to overestimate the actual fly densities and are, at best, subjective. As a result, a more reliable and durable method of determining horn fly densities is needed. Here, we describe the methods commonly used to quantify horn fly densities including visual estimates and digital photography, and provide examples of quantification software and the prospect for computer automation methods.

Automated body condition scoring of dairy cows using 3-dimensional feature extraction from multiple body regions.

Machine vision technology has been used in automated body condition score (BCS) classification of dairy cows. The current vision-based classifications use information acquired from a limited number of body regions of the cow. Our study aimed to improve automated BCS classification by including multiple body condition-related features extracted from 3 viewpoints in 8 body regions. The data set of this study included 44 lactating cows with their BCS evenly distributed over the scale of BCS from 1.5 to 4.5 units. The body images of these cows were recorded over 2 consecutive days using 3-dimensional cameras positioned to view the cow from the top, right side, and rear. Each image was automatically processed to identify anatomical landmarks on the body surface. Around these anatomical landmarks, the bony prominences and body surface depressions were quantified to describe 8 body condition-related features. A manual BCS of each cow was independently assigned by 2 trained assessors using the same predefined protocol. With the extracted features as inputs and manual BCS as the reference, we built a nearest-neighbor classification model to classify BCS and obtained an overall classification sensitivity of 0.72 using a 10-fold cross-validation. We conclude that the sensitivity of automated BCS classification has been improved by expanding the selection of body condition-related features extracted from multiple body regions.

Interobserver agreement of digital dermatitis M-scores for photographs of the hind feet of standing dairy cattle.

Digital dermatitis (DD) is the leading infectious cause of lameness in dairy cattle, and it affects their welfare and productivity worldwide. At the herd level, DD is often assessed while cows are standing in a milking parlor, and lesions are most commonly evaluated using the M-score. The objective of this study was to examine the interobserver agreement for M-scores of the feet of standing cattle, based on digital color photographs of dairy cattle hind feet. A total of 88 photographs and written descriptors of the M-score were sent to 11 scorers working at 10 different institutions in 5 countries. The scorers received no formal training immediately before scoring the photographs; however, all regularly used the M-score to score DD. The answers for 36 photographs were excluded from the analysis because the photograph either had more than 1 M-stage as mode or not all scorers assigned an M-score to it. The M-scores of the 11 scorers from 52 photographs were available for analysis. Interobserver agreement was tested using Gwet's agreement coefficient (AC1) and the mode was assumed correct. Overall, moderate agreement emerged for the M-score (AC1 = 0.48). For the individual M-stages, almost perfect agreement existed for M0 (AC1 = 0.99), M1 (AC1 = 0.92), and M3 (AC1 = 0.82), and substantial agreement for M2 (AC1 = 0.61), M4 (AC1 = 0.65), and M4.1 (AC1 = 0.71). This outcome indicates the degree of individual variation in M-scoring in this context by unstandardized, experienced European observers, particularly for the M2, M4, and M4.1 stages. Standardized training is likely to improve the consistency of M-scoring and thus the generalizability of future DD research results on this important endemic disease.

Anterior segment parameters in normal dogs using the Pentacam® HR Scheimpflug system.

OBJECTIVE: To describe and compare normative anterior segment parameters between canine age groups using the Pentacam® HR Scheimpflug camera (Pentacam). ANIMALS STUDIED: Thirty-six sedated dogs (60 eyes) of varying ages and breeds were imaged with the Pentacam; only nondiseased anterior segments were included. PROCEDURES: Dogs were divided into three age groups: Group 1 (1-5 years), Group 2 (6-10 years), and Group 3 (11-15 years). Values assessed included central corneal thickness (CCT), anterior and posterior corneal elevation (ACE/PCE), anterior and posterior corneal curvature metrics, corneal volume (CV), anterior and posterior corneal astigmatism (AA/PA), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). Tukey-adjusted pairwise comparisons were performed. RESULTS: Overall CCT (mean ± SD) was 631.07 ± 59.91 µm. Central corneal thickness was 608.60 ± 48.63 µm for Group 1, 648.57 ± 51.06 µm for Group 2, and 635.37 ± 73.71 µm for Group 3. Anterior corneal elevation (ACE) measured 9.08 ± 0.58 mm, PCE measured 8.04 ± 0.50 mm, and CV was 58.13 ± 5.39 mm3 . Astigmatism values were 1.34 ± 0.94 D for AA and 0.46 ± 0.44 D for PA. Anterior chamber values were 3.76 ± 0.56 mm for ACD, 383.68 ± 66.24 mm3 for ACV, and 23.62 ± 29.33˚ for ACA. Significant differences were found between Groups 1 and 2 for CV (55.08 ± 4.08 mm3 and 60.32 ± 4.19 mm3 , respectively), (P = 0.02). CONCLUSIONS: Corneal volume significantly increased between Group 1 and Group 2. Central corneal thickness increased from Group 1 to Group 3, but was not significant with the current sample size. There were no other differences between age groups.

Anterior segment parameters measured in young healthy cats using a rotating Scheimpflug camera.

OBJECTIVE: The purpose of this study is to measure parameters of the anterior segment of normal feline eyes using a rotating Scheimpflug camera in young and adult cats. PROCEDURE: Sixteen domestic short-haired (DSH) healthy cats (seven castrated males and nine spayed females) with a mean age of 17 months (SD = 3.5) were anesthetized. Cats were considered immature and adults if they were < or ≥12 months of age, respectively. The keratometric values, the anterior chamber depth (ACD), and central corneal thickness (CCT) of the right eye of each animal were measured using a Pentacam Oculus topographer. The repeatability of the measures was assessed by calculating the coefficient of variation of the successive measures in cats (five repetitions per cat). We performed an ANOVA to test the effect of age on the parameters measures. RESULTS: The mean CCT and ACD were 601.97 ± 38 µm and 5.27 ± 0.04 mm, respectively. No significant differences were observed between adult and young cat's measures. The average keratometric value was 39.6 ± 0.3 D. The mean average cylindrical error was 2.48 ± 0.35 D (43.75% "against-the-rule" astigmatism and 43.75% "oblique" astigmatism). CONCLUSION: The Oculus Pentacam under clinical conditions give CCT and ACD values very similar to those reported in previous studies. Corneal astigmatism measures were markedly elevated (>2 D). Further studies with a larger population of cats of various breeds and ages are needed to confirm or refute these results, using a rotating Scheimpflug camera.

Inter-observer agreement between two observers for bovine digital dermatitis identification in New Zealand using digital photographs.

AIMS: To assess the inter-observer agreement for detecting bovine digital dermatitis (BDD) lesions in digital colour photographs of the hind feet of cows, which had been taken while the animals were standing to be milked, between two trained observers. METHODS: Thirty-six photographs were selected from a total of 184 photographs held by the first author (R1), who had classified them as negative (n=11) or positive (n=25) for BDD. They were delivered to a technician (R2) who had previously visually inspected cattle for BDD lesions, and who then recorded the photographs as being either BDD-positive or BDD-negative. The percentage agreement between R1 and R2, and two other inter-observer agreement statistics, Cohen's κ and Gwet's first-order chance correction agreement coefficient (AC1), were calculated. The cumulative membership probabilities of Cohen's κ and Gwet's AC1 were then calculated for different benchmark ranges of κ. RESULTS: The percentage agreement between R1 and R2 was 33/36 (92%), Cohen's κ was 0.80 (95% CI=0.57-1.0) and Gwet's AC1 was 0.86 (95% CI=0.69-1.0). Based on the cumulative membership probabilities for Gwet's AC1, there was 75% probability that the two observers had almost perfect agreement (κ≥0.81). For both Cohen's κ and Gwet's AC1, there was >95% probability that the two observers had at least substantial agreement (κ≥0.61). CONCLUSIONS: The two trained observers had at least substantial agreement in identifying from a digital photograph as to whether BDD lesions were present or absent. Therefore results from the two could be used interchangeably. CLINICAL RELEVANCE: Visual assessment for BDD lesions in the milking parlour can be subjective. However a high agreement between these two trained BDD inspectors means BDD prevalence reported from different regions in New Zealand by these two can be directly compared.

Foot-propelled swimming kinematics and turning strategies in common loons.

Loons (Gaviiformes) are arguably one of the most successful groups of swimming birds. As specialist foot-propelled swimmers, loons are capable of diving up to 70 m, remaining underwater for several minutes, and capturing fish. Despite the swimming prowess of loons, their undomesticated nature has prevented prior quantitative analysis. Our study used high-speed underwater cameras to film healthy common loons (Gavia immer) at the Tufts Wildlife Clinic in order to analyze their swimming and turning strategies. Loons swim by synchronously paddling their feet laterally at an average of 1.8 Hz. Combining flexion-extension of the ankle with rotation at the knee, loon swimming resembles grebe swimming and likely generates lift forces for propulsion. Loons modulate swimming speed by altering power stroke duration and use head bobbing to enhance underwater vision. We observed that loons execute tight but slow turns compared with other aquatic swimmers, potentially associated with hunting by flushing fish from refuges at short range. To execute turns, loons use several strategies. Loons increase the force produced on the outside of the turn by increasing the speed of the outboard foot, which also begins its power stroke before the inboard foot. During turns, loons bank their body away from the turn and alter the motion of the feet to maintain the turn. Our findings demonstrate that foot-propelled swimming has evolved convergently in loons and grebes, but divergently from cormorants. The swimming and turning strategies used by loons that allow them to capture fish could inspire robotic designs or novel paddling techniques.

Photography-based method for assessing fluorescein clearance test in dogs.

BACKGROUND: The fluorescein clearance test (FCT) provides insight into the tear film dynamics. The purpose of this study was to describe an inexpensive and practical method for assessing FCT in dogs, using photography and software analysis, and to assess the retention time of 1 vs. 2 eye drops on the canine ocular surface. METHODS: (i) In vivo - Eight healthy German Shepherd dogs were recruited. Following topical anesthesia with 0.5% proxymetacaine, each eye sequentially received (1 week apart) either 1 drop (35 µL) or 2 drops (70 µL) of 0.5% fluorescein. A Schirmer strip was inserted in the ventral conjunctival fornix for 10 s at the following times: each 10 min for 100 min, 24 h, 48 h and 72 h. (ii) In vitro - Schirmer strips were placed for 10 s in contact with microplate wells containing 1 or 2 drops of 0.5% fluorescein. In both experiments, the fluorescein-impregnated Schirmer strips were immediately imaged, and the area and intensity of fluorescein uptake were analyzed with ImageJ software. For the in vitro experiment, images were evaluated by the same examiner (repeatability) or two examiners (reproducibility). RESULTS: Photography-based FCT was easy to perform and showed high repeatability and reproducibility (coefficients of variation ≤2.75%). In vivo, the area and intensity of fluorescein uptake on Schirmer strips were significantly greater at 30 min and 40 min post- fluorescein instillation in the 2 drops vs. 1 drop groups (p ≤ 0.044). Compared to baseline, the residual fluorescein uptake on Schirmer strips was < 5% at 60 min and 90 min in the 1 drop and 2 drops groups, respectively. CONCLUSIONS: Photography-based FCT is a practical and reliable diagnostic tool with various clinical and research applications in veterinary medicine. Instillation of two drops provided greater amount and longer retention on the anesthetized canine ocular surface than a single drop. Fluorescein clearance time of a single drop in dolichocephalic dogs is 60 min.

Evaluating the submission of digital images as a method of surveillance for Ixodes scapularis ticks.

Widespread access to the internet is offering new possibilities for data collection in surveillance. We explore, in this study, the possibility of using an electronic tool to monitor occurrence of the tick vector of Lyme disease, Ixodes scapularis. The study aimed to compare the capacity for ticks to be identified in web-based submissions of digital images/photographs, to the traditional specimen-based identification method used by the provincial public health laboratory in Quebec, Canada. Forty-one veterinary clinics participated in the study by submitting digital images of ticks collected from pets via a website for image-based identification by an entomologist. The tick specimens were then sent to the provincial public health laboratory to be identified by the 'gold standard' method using a microscope. Of the images submitted online, 74·3% (284/382) were considered of high-enough quality to allow identification. The laboratory identified 382 tick specimens from seven different species, with I. scapularis representing 76% of the total submissions. Of the 284 ticks suitable for image-based species identification, 276 (97·2%) were correctly identified (Kappa statistic of 0·92, Z = 15·46, P < 0·001). This study demonstrates that image-based tick identification may be an accurate and useful method of detecting ticks for surveillance when images are of suitable quality.

Fundus photography with a smartphone in indirect ophthalmoscopy in dogs and cats.

OBJECTIVE: To introduce a simple method for fundus photography of dogs and cats using a smartphone and indirect ophthalmoscopy lenses. METHODS: Fundus photographs of dogs and cats with transparent ocular media were obtained with 15D, 20D, 28D, and 40D indirect lenses and an iPhone-6, in a dark room and after pharmacologic pupil dilation. The photographs were recorded as still images using a video application and a video-to-still image application. Two types of neutral density (ND) filters were used as required for reduction of the torch illumination power of the iPhone. RESULTS: The images obtained in this study were upside-down as a result of the optics used. A 180-degree rotation was used to show their natural anatomical orientation. The image field of view varied with the diopter strength of the indirect lens used. The 40-diopter lens offered the widest field. CONCLUSION: Still images obtained with a smartphone, and indirect lenses may be useful for client communication and teaching in small animal ophthalmology.

Assessment of a smartphone-based camera for fundus imaging in animals.

OBJECTIVE: To assess the use of an optical device (D-EYE; Si14 S.p.A.) attached to a modern smartphone (iPhone 5; Apple Inc.) for imaging the fundus in small animals. ANIMALS STUDIED: Five dogs, five cats, and five rabbits with clear media were imaged using a prototype of the D-EYE. PROCEDURE: The optical device was composed of lenses, polarizing filters, a beam splitter, a diaphragm, and mirrors, attached to a smartphone via a metal shell. Images were obtained 20 min after pupil dilation with topical 0.5% tropicamide in a darkened room, to ensure maximum pupillary dilation. Focus was set to the infinite when the autofocus was overwhelmed. Light intensity was adapted to each animal via the application (minimum light intensity for imaging the tapetal region, maximum light intensity for imaging the nontapetal region). Both still images and video sequences were recorded for each animal. RESULTS: Posterior segment structures were visible in all animals: optic nerve head, tapetum lucidum (when present), nontapetal region, retinal vessels, and choroidal vessels (when the retinal pigment epithelium and the choroidal pigmentation were discreet). Focal light artifacts were common when photographing the tapetum lucidum. Recording videos allowed the visualization of dynamic phenomena. CONCLUSIONS: The D-EYE assessed appears to be an easy means of obtaining images of the posterior segment structures.

Validation of photo-identification as a mark-recapture method in the spotted eagle ray Aetobatus narinari.

The spotted eagle ray Aetobatus narinari is characterized by pigmentation patterns that are retained for up to 3·5 years. These pigmentations can be used to identify individuals through photo-identification. Only one study has validated this technique, but no study has estimated the percentage of correct identification of the rays using this technique. In order to carry out demographic research, a reliable photographic identification technique is needed. To achieve this validation for A. narinari, a double-mark system was established over 11 months and photographs of the dorsal surface of 191 rays were taken. Three body parts with distinctive natural patterns were analysed (dorsal surface of the cephalic region, dorsal surface of the pectoral fins and dorsal surface of the pelvic fins) in order to determine the body part that could be used to give the highest percentage of correct identification. The dorsal surface of the pectoral fins of A. narinari provides the most accurate photo-identification to distinguish individuals (88·2%).

Can you estimate body composition in dogs from photographs?

BACKGROUND: A validated method for assessing the visual characteristics of body condition from photographs (vBCS), would be a useful initial screening tool for client-owned dogs. METHODS: In this retrospective study, photographs taken before and after weight loss from 155 overweight and obese dogs attending a weight management referral clinic were used in designing and testing the feasibility of vBCS. Observers with a range of experience examined the photographs, and estimated body condition indirectly (vBCS) using three different methods. In the first method (vBCSmeasured), the ratio of abdominal width to thoracic width (A:T) was measured, and cut-points used to determine body condition; the second method (iBCSsubjective) involved semi-quantitative examination using visual descriptors of BCS; the third (vBCSadjusted) was a combined approach whereby A:T ratio was first determined, and the final score modified if necessary after assessing photographs. RESULTS: When an experienced observer performed vBCS, there were moderate-to-good associations between body fat (measured by dual-energy X-ray absorptiometry) and the three vBCS methods (median Rs: 0.51-0.75; P < 0.001), and also moderate-to-substantial agreement with actual BCS (median kappa 0.51-0.63; P < 0.001). For operators with a range of experience, moderate-to-substantial agreement was generally seen between actual BCS and the scores determined by all three methods (median Kappa 0.55-0.70, P < 0.001), but the strength of agreement varied amongst observers. Age, sex, breed, coat length, and coat colour had no significant effect on vBCS (P > 0.05 for all). Compared with ideal weight and obese dogs, errors in assessing body condition were more common for overweight dogs (e.g. BCS 6-7/9, P < 0.001) by vBCSadjusted (P = 0.008), and vBCSsubjective (P = 0.021), but not by vBCSmeasured (P = 0.150). For vBCSadjusted, body condition was most often overestimated whilst, for vBCSsubjective, body condition was most often under-estimated. CONCLUSIONS: An estimate of body condition can be obtained from an indirect assessment of photographs, but performance varies amongst observers.

Comparison between Pentacam-HR and optical coherence tomographycentral corneal thickness measurements in healthy feline eyes.

OBJECTIVES: To measure the central corneal thickness (CCT) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam(®) -HR) and to compare these values with those obtained with spectral-domain optical coherence tomography (OCT, Optovue(®) iVue). ANIMALS STUDIED: Thirty one sedated Domestic Short-haired cats. PROCEDURES: Two repeated CCT measurements were obtained from both eyes using Pentacam measured at the pupil center and corneal apex (CCTpupil and CCTapex ) and using SD-OCT (CCTOCT ). Agreement between the imaging modalities for CCT and intradevice repeatability was evaluated with Bland-Altman analysis. Mixed modeling was used to test for a difference between methods. RESULTS: The calculated mean ± SD CCT was CCTOCT  = 584.93 ± 39.05 µm, CCTpupil  = 608.25 ± 47.26 µm, and CCTapex  = 606.41 ± 44.18 µm. There was a statistically significant difference between CCTOCT vs. CCTpupil (P < 0.0007) and CCTOCT vs. CCTapex (P < 0.0003) (n = 59 eyes). The 95% limits of agreement (LoA) for CCTOCT vs. CCTpupil was (-89.57 µm, 40.04 µm) and for CCTOCT vs. CCTapex was (-79.62 µm, 33.79 µm) (n = 59 eyes). 95% LoA between repeated CCT measurements by SD-OCT was (-10.23 µm, 9.32 µm) and by Pentacam was (-22.66 µm, 18.30 µm) at pupil and (-15.81 µm, 16.17 µm) at corneal apex (n = 11 eyes). CONCLUSIONS: SD-OCT and Pentacam provide excellent CCT measurement repeatability. Pentacamapex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD-OCT and Pentacam for CCT is good.

The Surgeon's View: Comparison of Two Digital Video Recording Systems in Veterinary Surgery.

Video recording and photography during surgical procedures are useful in veterinary medicine for several reasons, including legal, educational, and archival purposes. Many systems are available, such as hand cameras, light-mounted cameras, and head cameras. We chose a reasonably priced head camera that is among the smallest video cameras available. To best describe its possible uses and advantages, we recorded video and images of eight different surgical cases and procedures, both in hospital and field settings. All procedures were recorded both with a head-mounted camera and a commercial hand-held photo camera. Then sixteen volunteers (eight senior clinicians and eight final-year students) completed an evaluation questionnaire. Both cameras produced high-quality photographs and videos, but observers rated the head camera significantly better regarding point of view and their understanding of the surgical operation. The head camera was considered significantly more useful in teaching surgical procedures. Interestingly, senior clinicians tended to assign generally lower scores compared to students. The head camera we tested is an effective, easy-to-use tool for recording surgeries and various veterinary procedures in all situations, with no need for assistance from a dedicated operator. It can be a valuable aid for veterinarians working in all fields of the profession and a useful tool for veterinary surgical education.

Using a smartphone-based digital fundus camera for screening of retinal and optic nerve diseases in veterinary medicine: A preliminary investigation.

BACKGROUND: Ophthalmoscopy is a valuable tool in clinical practice. We report the use of a novel smartphone-based handheld device for visualisation and photo-documentation of the ocular fundus in veterinary medicine. METHODS: Selected veterinary patients of a referral ophthalmology service were included if one or both eyes had clear ocular media, allowing for examination of the fundus. Following pharmacological mydriasis, fundic images were obtained with a handheld fundus camera (Volk VistaView). For comparison, the fundus of a subset of animals was also imaged with a veterinary-specific fundus camera (Optomed Smartscope VET2). RESULTS: The large field of view achieved by the Volk VistaView allowed for rapid and thorough observation of the ocular fundus in animals, providing a tool to visualise and record common pathologies of the posterior segment. Captured fundic images were sometimes overexposed, with the tapetal fundus artificially appearing hyperreflective when using the Volk VistaView camera, a finding that was less frequent when activating a 'veterinary mode' that reduced the sensitivity of the camera's sensor. The Volk VistaView compared well with the Optomed Smartscope VET2. LIMITATION: The main study limitation was the small sample size. CONCLUSIONS: The Volk VistaView camera was easy to use and provided good-quality fundic images in veterinary patients with healthy or diseased eyes, offering a wide field of view that was ideal for screening purposes.

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.

A portable, contact animal fundus imaging system based on Rol's GRIN lenses.

OBJECTIVE: To demonstrate a cost-effective, portable, and simple-to-use fundus imaging system for laboratory animals. ANIMALS STUDIED: Albino rats, pigmented mice, albino guinea pigs, and New Zealand white rabbits. PROCEDURE: A contact fundus imaging system was designed and constructed using standard optical and mechanical components: a digital camera, an otoscope, a fiber optic light source, and standard optical lenses and mounts. Digital fundus video and photography of two albino rats, two pigmented mice, two New Zealand white rabbits, and two albino guinea pigs were obtained. For all animals examined, pupils were dilated and local anesthetic was administered. RESULTS: Digital images of the fundus were obtained in all animals. Contrast of retinal vasculature and overall image quality varied from one species to another, as the axial length, ocular optics, and retinal reflectance varied significantly across species. Light intensity and focus were optimized via the light source and lens focusing mount to produce high-quality images for each animal. CONCLUSIONS: The portable, cost-effective contact fundus imaging system was easy to use for fundus examination of laboratory animals.

Fluorescein angiography of the canine posterior segment using a dSLR camera adaptor.

PURPOSE: To describe the use of a digital single lens reflex (dSLR) camera adaptor for conducting posterior segment fluorescein angiography in canines. METHODS: Ten beagle dogs free of ocular and systemic disease were used. All dogs received maropitant citrate (1.0 mg/kg SQ), diphenhydramine (2.0 mg/kg SQ), and topical 1% tropicamide 20 min prior to sedation using butorphanol (0.2 mg/kg IV). Standard color and red-free fundus images were obtained prior to the 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 60 mm macro), and a 60D indirect ophthalmic lens, in addition to an accessory flash (Canon 580EXII). Two combinations of excitation and barrier filters were assessed (absorptive vs. interference). Imaging occurred at a rate of 1/s immediately following the fluorescein bolus for a total of 30 s and then at 1, 2, 3, 4, and 5 min. RESULTS: Quality high resolution fluorescein angiographic images of the canine posterior segment were obtainable. All angiographic phases were identified and time sequences were recorded. Use of interference filters improved image contrast and transmission properties as compared to absorptive filters. No adverse events were noted. CONCLUSIONS: The described dSLR camera adaptor provides an alternative to existing posterior segment imaging systems capable of performing fluorescein angiography. High resolution image acquisition occurred at a fraction of the cost of established imaging systems.