Symblepharon in kittens: a retrospective study of 40 kittens and 54 eyes (2002-2022).

OBJECTIVES: The aim of this study was to retrospectively evaluate the signalment, treatment, surgical technique and outcomes for feline symblepharon. METHODS: A retrospective medical record review and standardized grading of clinical descriptions and photographs was undertaken. RESULTS: Forty kittens (54 eyes) aged 3-46 weeks had symblepharon of five types in various combinations: eyelid deformation (24 kittens; 32 eyes); ankyloblepharon (four kittens; four eyes); conjunctiva-to-conjunctiva (11 kittens; 12 eyes); third eyelid-to-conjunctiva (24 kittens; 29 eyes); and corneoconjunctival adhesions (14 kittens; 16 eyes). At initial presentation, 23 (43%) eyes were affected by one type of symblepharon, 25 (46%) eyes by two types and six (11%) eyes by three types; 11 (20%) corneas were ulcerated. Twenty-four (44%) eyes of 18 (45%) kittens were managed medically. Surgery was performed under general anesthesia/sedation (30 occasions) or topical anesthesia (21 occasions) on 30 (56%) eyes of 22 kittens; 12 eyes (40%) underwent multiple surgeries. Four techniques were commonly employed: separation of conjunctival-to-conjunctival adhesions ± eyelid margins (14 eyes); resection of third eyelid adhesions ± temporary tacking of the third eyelid (modified Arlt's pterygium technique; 18 eyes); en bloc resection of the third eyelid (two eyes); and separation of corneoconjunctival adhesions (14 eyes). Median duration of follow-up was 55 days (range 1-1051). Median symblepharon grade in kittens treated surgically improved for all types except corneoconjunctival symblepharon. Median symblepharon grade in kittens receiving medical management remained the same or improved. Corneoconjunctival symblepharon opacity decreased for eyes treated surgically but increased for eyes treated medically. Three eyes were enucleated due to complications of corneoconjunctival symblepharon. At final presentation, symblepharon persisted in 46 (85%) eyes; however, menace response was evident in 13/16 eyes and dazzle reflex in 23/23 eyes. CONCLUSIONS AND RELEVANCE: Symblepharon is a heterogeneous group of conditions with diverse anatomic involvement, clinical appearance and impact, optimal treatment and prognosis for vision.

Pilot study supporting the existence of novel lymphatic channels within the canine anterior uveal tract using Lyve-1 and CD31.

OBJECTIVE: To demonstrate the existence of lymphatics in the canine anterior uvea using lymphatic-specific markers Lyve-1, Prox-1, and podoplanin, the endothelial cell marker CD31, and basement membrane matrix marker collagen IV. DESIGN: Prospective Study. ANIMALS: Eight normal globes from animals euthanized for unrelated health problems. PROCEDURES: Sagittally cut serial sections of six normal canine eyes were immunofluorescence double-stained with Lyve-1 and CD31 and single-stained with colorimetric Prox-1 and collagen IV. Three serial sections from 2 additional eyes were cut in the coronal plane at the level of the ciliary body and immunofluorescence double-stained with Lyve-1 and CD31 to map lymphatic channel distribution. Lymphatics from normal canine lymph nodes were used for validation of podoplanin. RESULTS: Four of 6 of the sagitally sectioned eyes had Lyve-1-positive lymphatic-like structures that were distinct from CD31-positive blood vessels in the iris base and ciliary body. Both of the coronally sectioned globes had Lyve-1-positive lymphatic-like structures in the ciliary body. The location of these structures was evaluated and found to be diffusely present circumferentially around the ciliary body. CONCLUSION AND CLINICAL RELEVANCE: These results support the existence of lymphatic channels in the anterior uveal tract of the canine eye. This could indicate the presence of a novel uveolymphatic outflow pathway, which may play a role in aqueous humor outflow. Future studies are needed to confirm the existence and elucidate the role of this proposed uveolymphatic outflow pathway and potentially develop novel treatment options for managing glaucoma.

Adaptations for amphibious vision in sea otters (Enhydra lutris): structural and functional observations.

Sea otters (Enhydra lutris) are amphibious mammals that maintain equal in-air and underwater visual acuity. However, their lens-based underwater accommodative mechanism presumably requires a small pupil that may limit sensitivity across light levels. In this study, we consider adaptations for amphibious living by assessing the tapetum lucidum, retina, and pupil dynamics in sea otters. The sea otter tapetum lucidum resembles that of terrestrial carnivores in thickness and fundic coverage. A heavily rod-dominated retina appears qualitatively similar to the ferret and domestic cat, and a thick outer nuclear layer relative to a thinner inner nuclear layer is consistent with nocturnal vertebrates and other amphibious carnivores. Pupil size range in two living sea otters is smaller relative to other amphibious marine carnivores (pinnipeds) when accounting for test conditions. The pupillary light response seems slower than other aquatic and terrestrial species tested in comparable brightness, although direct comparisons require further assessment. Our results suggest that sea otters have retained features for low-light vision but rapid adjustments and acute underwater vision may be constrained across varying light levels by a combination of pupil shape, absolute eye size, and the presumed coupling between anterior lens curvature and pupil size during accommodation.

Effects of chronic low-dose radiation on cataract prevalence and characterization in wild boar (Sus scrofa) from Fukushima, Japan.

This study evaluated cataracts in wild boar exposed to chronic low-dose radiation. We examined wild boar from within and outside the Fukushima Exclusion Zone for nuclear, cortical, and posterior subcapsular (PSC) cataracts in vivo and photographically. Plausible upper-bound, lifetime radiation dose for each boar was estimated from radioactivity levels in each animal's home range combined with tissue concentrations of 134+137Cesium. Fifteen exposed and twenty control boar were evaluated. There were no significant differences in overall prevalence or score for cortical or PSC cataracts between exposed and control animals. Nuclear (centrally located) cataracts were significantly more prevalent in exposed boar (p < 0.05) and had statistically higher median scores. Plausible upper-bound, lifetime radiation dose ranged from 1 to 1,600 mGy in exposed animals, with no correlation between dose and cortical or PSC score. While radiation dose and nuclear score were positively associated, the impact of age could not be completely separated from the relationship. Additionally, the clinical significance of even the highest scoring nuclear cataract was negligible. Based on the population sampled, wild boar in the Fukushima Exclusion Zone do not have a significantly higher prevalence or risk of cortical or PSC cataracts compared to control animals.

OPHTHALMIC EXAMINATION FINDINGS AND INTRAOCULAR PRESSURE MEASUREMENTS IN SIX SPECIES OF ANURA.

A complete ophthalmic exam, including intraocular pressure (IOP) measurement, is key to diagnosing ocular diseases such as uveitis and glaucoma in frogs. We performed complete ophthalmic anterior segment examinations and IOP rebound tonometry measurements using two different settings (other "p" and canine "d") for six anuran species. The objectives were to describe common ocular abnormalities found in these species, to compare IOP values between different tonometer settings, and to compare IOPs between species. Examinations revealed abnormalities including cataracts (11/98 total eyes), lenticular sclerosis (10/98) and lipid keratopathy (9/98). IOP was measured with the TonoVet® and the ranges (oculus uterque, OU mm Hg other "p" setting, canine "d" setting) were giant waxy monkey tree frogs (Phyllomedusa bicolor) (3.5-7.6; 6.5-11.7; n = 5), mission golden-eyed tree frogs (Trachycephalus resinifictrix) (7.0-9.7, 13.2-15.7; n = 6), boreal toads (Bufo boreas boreas) (0.8-5.5, 5.7-10.5; n = 13), Mexican giant tree frogs (Pachymedusa dacnicolor) (3.8-5.0, 8.3-11.8; n = 3), Lake Titicaca frogs (Telmatobius culeus) (8.8-10.5, 14.0-17.2; n = 8), and mossy tree frogs (Theloderma corticale) (9.7-11.0, 15.7-17.0; n = 5). The TonoVet canine "d" setting IOP measurements were statistically higher (P = 0.01) than the other "p" setting measurements for all species except the giant waxy monkey tree frogs. IOP was significantly lower for giant waxy monkey tree frog eyes with cataracts (P < 0.05) with the other "p" setting. IOP did not statistically differ in eyes with lenticular sclerosis. IOP can be measured by rebound tonometer in anurans, but more research is needed for species-specific references using consistent settings.

Iridocorneal angle assessment of companion rabbits using gonioscopy, spectral-domain optical coherence tomography (Optovue iVue® ), high-resolution ultrasound, and Pentacam® HR imaging.

OBJECTIVE: Iridocorneal angle (ICA) narrowing is a known risk factor for primary glaucoma in multiple species, but has not been described in companion rabbits. This study aimed to develop an ICA grading scheme for companion rabbits to enable early glaucoma predisposition diagnosis. ANIMALS STUDIED: Twenty healthy rabbits of varying breeds and ages. PROCEDURES: Rabbits received complete ophthalmic examinations, including gonioscopy, and imaging of the ICA using spectral-domain optical coherence tomography (SD-OCT), Scheimpflug imaging (Pentacam® HR), and high-resolution ultrasound (HRUS). Angle opening distance (AOD) and angle recess area (ARA) of the ICA were measured and assessed for agreement using a Bland-Altman analysis. A five-stage gonioscopy grading scheme was created, and Spearman-rank test assessed for correlation between gonioscopy grades and ICA measurements. Differences among age and sex were analyzed with a nonparametric ANOVA and Wilcoxon rank-sum test, respectively. RESULTS: Analysis revealed AOD medians of 0.28mm for SD-OCT [95% CI: 0.24-0.31], 0.20mm for Pentacam® HR [95% CI: 0.18-0.21], and 0.25mm for HRUS [95% CI: 0.22-0.28]. The median ARA was 0.14mm2 for SD-OCT [95% CI: 0.117-0.163], 0.09mm2 for Pentacam® HR [95% CI: 0.082-0.100], and 0.06mm2 for HRUS [95% CI: 0.046-0.054]. The association between gonioscopy grade and SD-OCT ARA was significant (P < 0.05), and there was a significant difference (P < 0.001) between imaging modalities for both ARA and AOD. CONCLUSIONS: Gonioscopy grade correlated well with SD-OCT ARA. Therefore, SD-OCT is recommended as a noncontact method for evaluating companion rabbit ICA. Each imaging device should not be used interchangeably for ICA evaluation.

Surgically induced astigmatism in canines following sutured dorsonasal vs dorsotemporal clear corneal incisions.

OBJECTIVES: To investigate use of the Pentacam® HR for evaluation of surgically induced corneal astigmatism (SIA) in canines undergoing bilateral phacoemulsification and determine differences between dorsonasal and dorsotemporal clear corneal incisions. ANIMALS: Client-owned canines undergoing bilateral phacoemulsification. PROCEDURES: Patients received anterior segment imaging pre-operatively, immediately post-operatively, and 2-4 months post-operatively (follow-up). Total corneal refractive power was used to determine SIA. Surgically induced astigmatism was compared between right and left eyes, representing dorsotemporal and dorsonasal incisions, respectively. Repeated measures analyses were used between time points and paired t test compared SIA between eyes. RESULTS: Complete imaging series were obtained for seven patients. Follow-up imaging occurred at a median of 112 days (range 60-132 days) post-operatively. For repeated measures analyses, significant differences were found between pre- and immediate post-operative values (P < 0.01), and between immediate post-operative and follow-up values (P < 0.01). There was no significant difference between pre-operative and follow-up values. Surgically induced astigmatism was significantly different between right and left eyes, with values of 2.01 ± 1.24 D and 3.05 ± 1.58 D at 3 mm radius (P < 0.05), and 2.04 ± 1.18 D and 3.06 ± 1.27 D at 4 mm radius (P < 0.05) for dorsotemporal and dorsonasal incisions, respectively. CONCLUSIONS: Preliminary investigation revealed improvement of corneal SIA 2-4 months post-operatively, but development of significantly more SIA in dorsonasal vs dorsotemporal incisions. This prompts consideration of patient or microscope rotation to create a more dorsotemporal incision when possible.

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.

Treatment of spontaneous chronic corneal epithelial defects (SCCEDs) with diamond burr debridement vs combination diamond burr debridement and superficial grid keratotomy.

OBJECTIVE: To evaluate the efficacy of diamond burr debridement (DBD) vs a combination of diamond burr debridement with superficial grid keratotomy (DBD+SGK) for the treatment of spontaneous chronic corneal epithelial defects (SCCEDs) in dogs. PROCEDURE: Medical records of dogs diagnosed with SCCEDs from three different institutions that received a DBD or DBD+SGK between 2003 and 2015 were reviewed. Age, breed, sex, history of a previous SCCED, procedures performed, time to healing, and complications were statistically analyzed. RESULTS: One hundred and ninety-four dogs met the inclusion criteria. Eighty-two of 106 eyes (77.4%) received a DBD and healed following the first treatment (13.3 ± 4.9 days to recheck, range 2-27). Sixty-eight of 88 eyes (77.3%) received a DBD+SGK and healed following the first treatment (15.4 ± 5.0 days to recheck, range 5-45). No significant difference in healing outcome was found between the two treatments (P = 1). For SCCEDs that healed after a single treatment (n = 150), complications occurred in 13.3% (n = 20) of eyes with no difference in complications between the DBD and DBD+SGK groups (P = .86). Thirty-five of 44 eyes (80.0%) healed after the second treatment (16 ± 8.2 days from second treatment to third visit, range 5-47); nine of 44 eyes (20.0%) were not healed (12 ± 6.2 days from second treatment to third visit, range 5-25). The second treatment method did not influence healing rates (P = .64). CONCLUSIONS: DBD and DBD+SGK are equally effective treatment methods for canine SCCEDs. No differences in complication rates after one treatment were observed between DBD and DBD+SGK.

Causes and outcomes of dogs presenting with hyphema to a referral hospital in Colorado: a retrospective analysis of 99 cases.

OBJECTIVE: To investigate the causes of hyphema in dogs and identify factors associated with poor visual outcomes. ANIMALS STUDIED: Ninety-nine dogs (120 eyes) that presented with hyphema. PROCEDURE: Medical records from the Colorado State University Veterinary Teaching Hospital between the years 2004-2015 were reviewed. RESULTS: Overall, 36.4% of dogs were diagnosed with hyphema from systemic causes, 32.9% due to local ocular disease, 26.1% due to trauma, and 4.5% due to idiopathic causes. Regardless of cause, 55.4% of eyes were blind at their last recheck, but the percentage of eyes that lost vision ranged from 11.1 to 100%, depending on the cause. Causes of hyphema with poor outcomes were ocular neoplasia, chronic uveitis, and trauma. Enucleation was performed or recommended in 36 eyes (39.5%), and 27 eyes (31.4%) were diagnosed with glaucoma. Initial exam findings associated with a significantly increased risk of blindness were absent consensual PLR (odds ratio (OR) = 28.6), absent dazzle (OR = 19.4), elevated intraocular pressure (IOP) (OR = 9.1), presence of a retinal detachment (OR = 7.6), unilateral hyphema (OR = 5.8), and complete hyphema (OR = 3.9). Factors associated with a significantly increased risk of glaucoma included hyphema present for 8-30 days (OR > 6), absent consensual PLR (OR = 6.4), absent dazzle (OR = 5.3), and the presence of a retinal detachment at the final evaluation (OR = 5.8). CONCLUSION: Prognosis for vision is highly dependent on the cause of hyphema and initial exam findings. Poor prognostic factors on presentation include absent dazzle, absent consensual PLR, elevated IOP, unilateral hyphema, and complete hyphema.

Comparison of anterior segment health in wild and captive common murres.

OBJECTIVE: To evaluate and compare the anterior segment health of wild and captive common murres. PROCEDURES: Thirty wild common murres (Uria aalge) were captured and housed in freshwater pools and had an adnexal and anterior segment exam performed prior to a subsequent wildlife health study. The examination included phenol red thread tear tests, fluorescein staining, slit-lamp biomicroscopy, rebound tonometry, and conjunctival culture sampling. Six captive common murres housed in natural seawater at the Monterey Bay Aquarium were examined in a similar manner. RESULTS: The most common ophthalmic lesion in the wild birds was corneal fibrosis with 55% prevalence, and over half of these were potentially vision threatening. Lenticular opacity (cataract or sclerosis or both) was the most common lesion in captive murres seen in 67% of the eyes. Mean phenol red tear test for all eyes without ulcers was 20 ± 3.6 mm. Mean intraocular pressure for all eyes without ulcers or flare was 23 ± 2.6 mmHg. The wild murres had a low percentage (17%) of positive conjunctival cultures. The captive murres had no growth on any culture. CONCLUSIONS: Wild murres are more likely to suffer corneal lesions, whereas captive murres are more likely to experience age-related lenticular diseases. Corneal scarring indicates that wild murres are frequently exposed to ocular trauma and the body condition scores indicate they appear to remain successful predators despite some vision compromise.

Canine central corneal thickness measurements via Pentacam-HR® , optical coherence tomography (Optovue iVue® ), and high-resolution ultrasound biomicroscopy.

OBJECTIVE: To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR® Scheimpflug imaging (Pentacam), Optovue® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. ANIMALS STUDIED: Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. PROCEDURES: Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland-Altman analysis was performed to evaluate agreement between instruments. RESULTS: Mean CCT ± SD measured by Pentacam was 629.73 ± 64.57 µm, by SD-OCT was 610.56 ± 57.48 µm, and by UBM was 689.77 ± 55.93 µm. On average, Pentacam CCT was 19.17 ± 32.90 µm (3%) thicker than SD-OCT and 65.12 ± 44.52 µm (10.3%) thinner than UBM. SD-OCT was on average 82.47 µm (13.5% ) thinner than UBM. The 95% limits of agreement were (-45.31, 83.65), (-152.38, 22.13), and (-126.674, -38.270) for Pentacam vs. SD-OCT, Pentacam vs. UBM, and SD-OCT vs. UBM respectively. All differences were statistically significant (P < 0.01). CONCLUSIONS: Considering there is an average of 7.5% normal diurnal variation in canine CCT, a 3.0% difference between Pentacam and SD-OCT values is likely not clinically relevant. However, Pentacam measurements were both statistically and clinically significantly different from UBM and SD-OCT measurements.

Presumptive keratoglobus in a great horned owl (Bubo virginianus).

A juvenile to young adult, male, great horned owl (Bubo virginianus,GHOW) was presented to the wildlife rehabilitation hospital at Lindsay Wildlife Museum (WRHLWM) due to trauma to the right patagium from barbed wire entanglement. On presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. A severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. The fundus was normal in both eyes (OU). Over the course of several days, both corneas developed edema combined with further dessication at the ocular surface associated with diffuse dorsal fluorescein stain uptake. Repeated ophthalmic examinations found normal intraocular pressures and an inability to move the third eyelid over the enlarged corneas. The bird was deemed nonreleasable due to severe wing damage and poor prognosis associated with eye abnormalities and was humanely euthanized. Postmortem CT, enucleation, and histopathology were performed to evaluate the ocular anatomical abnormality and confirm the suspected diagnosis of keratoglobus. This GHOW represents the first reported case of presumptive keratoglobus in a raptor.

Oral administration of famciclovir for treatment of spontaneous ocular, respiratory, or dermatologic disease attributed to feline herpesvirus type 1: 59 cases (2006-2013).

OBJECTIVE To evaluate outcomes for cats treated with orally administered famciclovir 3 times/d for clinical signs attributed to naturally occurring feline herpesvirus type 1 (FHV-1) infection and to assess variables related to owner satisfaction with the treatment. DESIGN Retrospective case series. ANIMALS 59 client-owned cats. PROCEDURES Medical records were reviewed to identify cats treated for presumed FHV-1 infection from 2006 through 2013 with ≥ 1 follow-up visit. Signalment, duration of clinical signs, prior treatment, examination findings, diagnostic test results, concurrent treatments, and outcome data were recorded. Owners were asked to complete a survey regarding patient- and treatment-related variables. Data were compared between cats that received low (approx 40 mg/kg [18 mg/lb]) and high (approx 90 mg/kg [41 mg/lb]) doses of famciclovir, PO, 3 times/d. RESULTS Patient age ranged from 0.03 to 16 years. Conjunctivitis (51/59 [86%]), keratitis (51 [86%]), blepharitis (19 [32%]), nasal discharge or sneezing (10 [17%]), and dermatitis (4 [7%]) were common findings. Clinical improvement was subjectively graded as marked in 30 (51%) cats, mild in 20 (34%), and nonapparent in 9 (15%). Median time to improvement was significantly shorter, and degree of improvement was significantly greater in the highdose group than in the low-dose group. Adverse effects potentially attributable to famciclovir administration were reported for 10 cats. On the basis of survey responses, most (29/32 [91%]) owners were satisfied with their cat's treatment. CONCLUSIONS AND CLINICAL RELEVANCE Famciclovir at the prescribed dosages was associated with improved clinical signs in cats with presumed FHV-1 infection, and few adverse effects were attributed to the treatment. Further studies are needed to assess whether a famciclovir dosage of 90 versus 40 mg/kg, PO, 3 times/d would result in increased efficacy and shorter treatment time.

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.

Population pharmacokinetics of doxycycline in the tears and plasma of northern elephant seals (Mirounga angustirostris) following oral drug administration.

OBJECTIVE: To assess tear and plasma concentrations of doxycycline following oral administration to northern elephant seals (Mirounga angustirostris). DESIGN: Pharmacokinetic study. ANIMALS: 18 juvenile northern elephant seals without signs of ocular disease. PROCEDURES: Study seals were receiving no medications other than a multivitamin and were free from signs of ocular disease as assessed by an ophthalmic examination. Doxycycline (10 or 20 mg/kg [4.5 or 9.1 mg/lb]) was administered orally every 24 hours for 4 days. Tear and plasma samples were collected at fixed time points, and doxycycline concentration was assessed by means of liquid chromatography-tandem mass spectrometry. Concentration-time data were calculated via noncompartmental analysis. RESULTS: Following administration of doxycycline (10 mg/kg/d, PO), maximum plasma doxycycline concentration was 2.2 µg/mL at 6.1 hours on day 1 and was 1.5 µg/mL at 4.0 hours on day 4. Administration of doxycycline (20 mg/kg/d, PO) produced a maximum plasma doxycycline concentration of 2.4 µg/mL at 2.3 hours on day 1 and 1.9 µg/mL at 5.8 hours on day 4. Doxycycline elimination half-life on day 4 in animals receiving doxycycline at a dosage of 10 or 20 mg/kg/d was 6.7 or 5.6 hours, respectively. Mean plasma-to-tear doxycycline concentration ratios over all days were not significantly different between the low-dose (9.85) and high-dose (9.83) groups. For both groups, doxycycline was detectable in tears for at least 6 days following cessation of dosing. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of doxycycline at the doses tested in the present study resulted in concentrations in the plasma and tears of northern elephant seals likely to be clinically effective for treatment of selected cases of systemic infectious disease, bacterial ulcerative keratitis, and ocular surface inflammation. This route of administration should be considered for treatment of corneal disease in northern elephant seals and possibly other related pinniped species.

Effects of chemical restraint on electroretinograms recorded sequentially in awake, sedated, and anesthetized dogs.

OBJECTIVE: To quantitatively and qualitatively compare electroretinography (ERG) recordings in awake, sedated, and anesthetized dogs. ANIMALS: Six 6-month-old Beagles. PROCEDURES: A brief ERG protocol for dogs was used. Following 1-minute and subsequent 5-minute dark adaptation, mixed rod-cone responses were recorded bilaterally with a handheld multispecies ERG device with dogs in each of 3 states of consciousness: awake, sedated (dexmedetomidine and butorphanol), and anesthetized (atropine and hydromorphone, followed by propofol and midazolam and anesthetic maintenance with isoflurane). Low- and high-frequency noise levels were quantified via Fourier analysis, and the effect of consciousness state on signal amplitude, implicit time, and noise was analyzed via repeated-measures ANOVA. In addition, 13 veterinary ophthalmologists who were unaware of the dogs' consciousness states subjectively graded the ERG recording quality, and scores for each tracing were compared. RESULTS: ERG amplitudes were highest in awake dogs and lowest in anesthetized dogs. Implicit times were shortest in awake dogs and longest in anesthetized dogs. Differences in b-wave amplitudes and a-wave implicit times were significant. Neither low- nor high-frequency noise levels differed significantly among consciousness states. Furthermore, no significant differences were identified among observers' scores assigned to ERG tracings. CONCLUSIONS AND CLINICAL RELEVANCE: Anesthesia and sedation resulted in significant attenuation and delay of ERG responses in dogs. Chemical restraint of dogs had no consistently significant effect on low- or high-frequency noise levels or on observer perception of signal quality.

Leishmaniasis in a dog native to Colorado.

CASE DESCRIPTION: A 1-year-old 32.5-kg (71.5-lb) sexually intact male foxhound-Treeing Walker Coonhound cross was evaluated because of a 2.5-month history of dermatologic lesions, weight loss, and diarrhea. CLINICAL FINDINGS: Physical examination revealed muscle wasting, lymphadenopathy, and multifocal pruritic dermatologic lesions of alopecia, thickening, erythema, and follicular casting. Hematologic and serum biochemical analyses revealed nonregenerative anemia, mono-cytosis, hypercalcemia, hyperproteinemia, and hyperglobulinemia. Proteinuria was identified on urinalysis. Hepatomegaly, splenomegaly, and diffuse abdominal lymphadenomegaly were detected on abdominal ultrasonography. A diagnosis of leishmaniasis was confirmed by ELISA detection of serum antibodies against Leishmania spp, a high serum indirect fluorescent antibody titer (1:1,024) against Leishmania infantum, amplification of Leishmania DNA on PCR assay of a whole blood sample and a lymph node aspirate, and histologic identification of suspected Leishmania amastigotes in skin specimens. In addition, the dog had a low CD4+:CD8+ lymphocyte ratio of 1:1. TREATMENT AND OUTCOME: The dog was euthanized because of the severity of leishmaniasis and poor prognosis. This dog was from a litter of 10 puppies that included 4 stillborn puppies, 2 puppies that died as neonates, and 1 littermate that was euthanized at 1 year of age because of a high serum antibody titer against Leishmania spp. Eventually the foxhound dam was euthanized because of a high serum antibody titer against Leishmania spp. The dog had been raised with an unaffected littermate, its sire, and an unrelated Treeing Walker Coonhound female that were seronegative for Leishmania infection. CLINICAL RELEVANCE: Although vertical disease transmission was suspected, it is possible that L infantum is now endemic in Colorado. Leishmaniasis should be considered in dogs with scaly dermatoses.

Characterization of eversion syndrome in captive Scyphomedusa jellyfish.

OBJECTIVE: To determine whether Scyphomedusa jellyfish with eversion syndrome had alterations in husbandry conditions, elemental content, or histologic appearance, compared with unaffected jellyfish. ANIMALS: 123 jellyfish (44 with eversion syndrome and 79 without) at 6 institutions. PROCEDURES: Elemental analyses were performed on 24 jellyfish with eversion syndrome and 49 without, and histologic examinations were performed on 20 jellyfish with eversion syndrome and 30 without. A questionnaire distributed to 39 institutions with Scyphomedusa jellyfish was used to gather information about husbandry, environmental conditions, and prevalence of eversion syndrome. RESULTS: For the 39 institutions that responded to the questionnaire, prevalence of eversion syndrome ranged from 0% to 30%. For Aurelia aurita, eversion was more common at institutions with only captive-raised and no wild-caught jellyfish. Eversion was most common among young (approx 1- to 2-month-old) growing jellyfish and older (> 6-month-old) jellyfish. Elemental analysis revealed only minor differences between affected and unaffected jellyfish, with great variation among jellyfish from the same institution and among jellyfish from different institutions. Striated muscle degeneration and necrosis and extracellular matrix (mesoglea) degeneration were evident on histologic examination of affected jellyfish. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that eversion syndrome is a complex phenomenon associated with degenerative changes of the bell matrix.

alpha-Luminol prevents decreases in glutamate, glutathione, and glutamine synthetase in the retinas of glaucomatous DBA/2J mice.

OBJECTIVE: To test the hypothesis that in DBA/2J mice, oxidative stress decreases glutamine synthetase (GS) levels resulting in a loss of neuronal glutamate and that the antioxidant alpha-luminol (GVT) decreases this stress and glutamate loss in some types of glaucoma. ANIMALS: DBA/2J mice were separated into two groups, of which one was not treated, and the other treated with GVT in the drinking water. At 7 months of age, retinas were examined from five untreated DBA/2J mice, seven GVT-treated mice, and five C57BL/6 mice (negative controls). METHODS: Serial 0.5 microm plastic sections were immunogold stained for glutamate, GS, and total glutathione, followed by image analysis for staining patterns and density. RESULTS: Focal decreases in glutamate immunostaining were common in the inner nuclear layer (INL) of DBA/2J retinas, but not in C57BL/6 or GVT-treated DBA/2J retinas. Decreases in glutathione and GS immunostaining were found in DBA/2J retinal regions where neuronal glutamate immunostaining was reduced. Retinas from GVT-treated DBA/2J had no significant decreases in INL levels of glutamate, glutathione, or GS. CONCLUSIONS: Retinas of dogs with primary glaucoma are reported to have focal depletion of neuronal glutamate. In DBA/2J mice, similar changes occur prior to the development of clinical disease. In these focal glutamate-depleted regions, levels of glutathione and GS are also reduced, consistent with the hypothesis that oxidative stress contributes to retinal changes in glaucoma. The ability of GVT, an antioxidant, to inhibit retinal abnormalities in DBA/2J mice provides further support for this hypothesis.