40 research outputs found

    Electroretinogram evaluation of equine eyes with extensive ‘bullet-hole’ fundic lesions

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    Objective To evaluate the impact of extensive bullet-hole nontapetal fundic lesions in horses on retinal function as measured by full field electroretinography (ERG). Materials and Methods Full field ERG was performed on two horses with numerous bullet-hole lesions in the nontapetal fundus of both eyes. The ERG was first recorded from the eye with the more extensive lesions in response to a low intensity light stimulus (0.03 cd·s/m2) that was given at times (T) T = 5, 10, 15, 20 minutes of dark adaptation. Consecutively, combined rod-cone response was evaluated bilaterally in response to high intensity light stimulus (3 cd·s/m2), followed by cone function evaluation by flicker stimulus (3 cd·s/m2 at 30Hz). Off-line analysis of the ERG recordings was then performed. Results Despite extensive bullet-hole lesions in the nontapetal fundus bilaterally in both horses retinal function as measured by ERG did not show any observable deficits. The b-wave amplitude of the full-field ERG increased continuously from 5 to 20 minutes of dark adaptation peaking at 446”v and 377”v for horse number 1 and 2 respectively. The b-wave amplitudes of the combined rod-cone response were OS- 459”v and OD- 392”v for horse number 1 and OS- 491”v and OD- 608”v for horse number 2. The amplitude of the flicker ERG for horse number 1 was OS- 86 ”v and OD- 110 ”v and for horse number 2 OS- 80 ”v and OD- 74 ”v. Conclusions Extensive bullet-hole chorioretinal lesions do not appear to compromise outer retinal function in these horses

    Uveal Hematocysts in a Golden Retriever Dog

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    Case Description. A 7-year-old neutered male golden retriever presented for examination 1 month following the observation of multifocal round brown structures in the anterior chamber of the left eye and similar, but blood-filled, structures in the right eye. Clinical Findings. Ophthalmic examination revealed bilateral iris hyperpigmentation, pigment deposition on the anterior lens capsule, and uveal cysts. The uveal cysts in the right eye were partially blood filled. Clinical findings were consistent with pigmentary uveitis of golden retrievers. Treatment and Outcome. The patient has been maintained on topical anti-inflammatories and no progression of the disease has occurred in eight months. Clinical Relevance. This paper emphasizes the importance of recognizing the unique clinical signs of pigmentary uveitis and highlights uveal hematocysts, a rare manifestation of the disease

    Bioavailability and biochemical effects of diclofenac sodium 0.1% ophthalmic solution in the domestic chicken (Gallus gallus domesticus)

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    Objective To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration. Animals Thirty healthy domestic chickens Procedures Over seven days, 6 birds were treated unilaterally with 1 drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided for 7 days, every 12 hours in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds were also analyzed by HPLC-MS for detection of diclofenac sodium. Results Changes in pre- and post-treatment plasma albumin were significant (P \u3c 0.05) in groups 2 and 3, but not for group 1. Pre- and post-treatment changes in total protein and uric acid pre- and post-treatment were not significant for any group. Diclofenac sodium was not detectable (limit of detection = 0.10 ng/mL) in plasma samples from birds in group 1. Concentration of drug in group 3 was statistically greater than group 2 (P = 0.0008). Conclusions and Clinical Relevance Topical ophthalmic diclofenac sodium 0.1% administered every 12 hours in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken at 15 minutes post-administration, but did not cause overt changes in parameters used to monitor renal physiology

    MicroPulseℱ transscleral cyclophotocoagulation in the treatment of canine glaucoma: Preliminary results (12 dogs)

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    Objective: To describe the clinical application and effect of MicroPulseℱ transscleral cyclophotocoagulation (MP‐TSCPC) in dogs with glaucoma. Animals studied: Twelve dogs with primary (n = 8) or secondary (n = 4) glaucoma, aged 2‐13 years (mean ± SD, 7.2 ± 3.8 years). Procedures: MP‐TSCPC was performed under sedation or general anesthesia. Laser duty cycle was 31.3%, laser power varied from 2000‐2800 mW, and each hemisphere was treated for 90‐180 seconds. The probe was applied to each quadrant in a “sweeping motion,” sparing the 3 and 9 o\u27clock positions. Results: The number of MP‐TSCPC procedures per eye varied from 1 to 3 (1.4 ± 0.7). Intraocular pressure (IOP) was controlled (\u3c25 mm Hg) in 11/12 dogs (92%) within 1‐15 days post‐operatively. The IOP control at 1 month and the duration between repeated procedures were significantly greater in eyes treated with high energy laser (2800 mW) compared to 2000‐2500 mW. Long‐term follow‐up (315.3 ± 100.7 days) showed controlled IOP in 5/12 (42%) and vision retention in 4/8 (50%) dogs. In unsuccessful cases, loss of IOP control or vision loss occurred within 3‐245 days (109.1 ± 93.7 days) and 28‐261 days (114 ± 101.6 days), respectively, resulting in a salvage procedure in 6 dogs. Complications were as follows: corneal hypoesthesia (92%), anterior uveitis (67%), post‐operative ocular hypertension (50%), neurotrophic corneal ulcer (25%), keratoconjunctivitis sicca (8%), and rubeosis iridis (8%). Conclusions: MP‐TSCPC is a viable tool for managing canine glaucoma, although further studies are required to improve the long‐term effect and reduce the complication rate

    Fluorophotometric Assessment of Tear Volume and Turnover Rate in Healthy Dogs and Cats

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    Purpose: The study establishes normative data of tear volume (TV) and tear turnover rate (TTR) in healthy dogs and cats, 2 species commonly used for translational research in ophthalmology. Methods: Thirty-six dogs and 24 cats were enrolled, encompassing a variety of breeds with diverse skull conformations (brachycephalic, mesocephalic, and dolichocephalic). Two microliters of 10% fluorescein were instilled onto the upper bulbar conjunctiva of both eyes, followed by tear collection with 2-ÎŒL capillary tubes at 0, 2, 4, 6, 10, 15, and 20 min. Fluorescein concentrations were measured with a computerized scanning ocular fluorophotometer. The TV and TTR were estimated based upon nonlinear mixed-effects analysis of fluorescein decay curves. Results: In dogs, median (interquartile range) TV, basal TTR (bTTR), and reflex TTR (rTTR) were 65.3 ΌL (42.3–87.9), 12.2%/min (3.7–22.1), and 50.0%/min (25.9–172.3), respectively. In cats, median (interquartile range) TV, bTTR, and rTTR were 32.1 ΌL (29.5–39.9), 10.9%/min (3.0–23.7), and 50.0%/min (28.4–89.4), respectively. Body weight (r = 0.44) and age (r = 0.30) were positively correlated (P ≀ 0.019) with TV in dogs. Age was negatively correlated (P ≀ 0.018) with TTR in dogs (r = −0.33) and cats (r = −0.24). However, TV and TTR were not associated with skull conformation in either species. Conclusions: Dogs have greater TV than cats but similar basal and rTTR. Tear parameters were impacted by body weight and age, but not by skull conformation. In both clinical and research settings, successive lacrimal tests should be spaced by ≄10 min to provide sufficient time for the tear film to replenish, as bTTR is ∌11%/min–12%/min in both species

    Lack of effect of a topical regenerative agent on re-epithelialization rate of canine spontaneous chronic corneal epithelial defects: A randomized, double-masked, placebo-controlled study

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    Spontaneous chronic corneal epithelial defects (SCCEDs) are characteristic ulcers in dogs that are refractory to healing. The aim of the study was to evaluate the use of a topical regenerative agent to promote healing of SCCEDs. Nineteen dogs (20 eyes) were randomized to receive either regenerative agent (10 eyes) or placebo (10 eyes) every 48 h following corneal debridement, which was repeated 1 week later if the SCCED had not yet healed. The mean ± standard deviation time to re-epithelialization was 17.3 ± 12.8 days for the group treated with a topical regenerative agent and 19.3 ± 11.7 days for the group treated with a placebo; the cumulative healing rates were not statistically different (P \u3e 0.650). A positive association was found between the initial size of the ulcer and the time to re-epithelialization (r = 0.555, P = 0.011). Although well tolerated by dogs, there was no therapeutic advantage in using a topical regenerative agent for re-epithelialization of SCCEDs

    Case Report Uveal Hematocysts in a Golden Retriever Dog

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    Case Description. A 7-year-old neutered male golden retriever presented for examination 1 month following the observation of multifocal round brown structures in the anterior chamber of the left eye and similar, but blood-filled, structures in the right eye. Clinical Findings. Ophthalmic examination revealed bilateral iris hyperpigmentation, pigment deposition on the anterior lens capsule, and uveal cysts. The uveal cysts in the right eye were partially blood filled. Clinical findings were consistent with pigmentary uveitis of golden retrievers. Treatment and Outcome. The patient has been maintained on topical anti-inflammatories and no progression of the disease has occurred in eight months. Clinical Relevance. This paper emphasizes the importance of recognizing the unique clinical signs of pigmentary uveitis and highlights uveal hematocysts, a rare manifestation of the disease. Case Description A 7-year-old neutered male golden retriever dog presented to the Iowa State University Lloyd Veterinary Medical Center for ophthalmic examination 1 month following identification of multifocal brown structures in the anterior chamber of the left eye and similar, but blood-filled, structures in the right eye. The primary care veterinarian discovered these structures during annual wellness examination. Ophthalmic examination revealed normal palpebral, dazzle, and pupillary light reflexes in both eyes. Vision was considered normal based on positive menace responses and appropriate navigation in the hospital environment. On careful inspection, both eyes had mild conjunctival hyperemia, diffuse iris hyperpigmentation, pigment deposition on the anterior lens capsule, and numerous uveal cysts in the anterior chamber. The uveal cysts in the right eye were blood filled Dilation of the left pupil occurred within 20 minutes of tropicamide 1% application; however, dilation of the right pupil was limited by the posterior synechia. Indirect ophthalmoscopy revealed no abnormalities of the fundus in either eye. Complete physical examination was unremarkable, with the exception of a body condition score of 6/9. Notably, cardiovascular parameters were normal and no petechiation, ecchymosis, or bruising was identified. Complete blood count, serum biochemistry panel, and thyroid panel were within normal limits. The patient's clinical signs were considered consistent with pigmentary uveitis of golden retrievers, and prednisolone acetate 1% and tropicamide 1% were each prescribed for use in both eyes once daily. Reevaluation of the eyes 2 weeks later revealed resolution of the conjunctival hyperemia in both eyes and rupture of one blood-filled cyst in the right eye, resulting in a 2 mm corneal endothelial opacity. Intraocular pressures were 6 and 9 mmHg in the left and right eye, respectively. Ophthalmic examination was otherwise unchanged and no adjustments to the medication regimen were made. At the time of publication, treatment has successfully controlled clinical progression of the disease for the preceding eight months. Reevaluations are recommended every 3-6 months to monitor for progression of pigmentary uveitis and development of sequelae

    A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability

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    AIM To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study. METHODS The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP = 362, MSA = 398), 627 had per protocol images (PSP = 297, MSA = 330). Intra-rater (n = 60) and inter-rater (n = 555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n = 441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis. RESULTS Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (≄ 0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75-0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1-F2; MSA: F2-F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity. CONCLUSIONS The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224

    Electroretinogram evaluation of equine eyes with extensive ‘bullet-hole’ fundic lesions

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    Objective To evaluate the impact of extensive bullet-hole nontapetal fundic lesions in horses on retinal function as measured by full field electroretinography (ERG). Materials and Methods Full field ERG was performed on two horses with numerous bullet-hole lesions in the nontapetal fundus of both eyes. The ERG was first recorded from the eye with the more extensive lesions in response to a low intensity light stimulus (0.03 cd·s/m2) that was given at times (T) T = 5, 10, 15, 20 minutes of dark adaptation. Consecutively, combined rod-cone response was evaluated bilaterally in response to high intensity light stimulus (3 cd·s/m2), followed by cone function evaluation by flicker stimulus (3 cd·s/m2 at 30Hz). Off-line analysis of the ERG recordings was then performed. Results Despite extensive bullet-hole lesions in the nontapetal fundus bilaterally in both horses retinal function as measured by ERG did not show any observable deficits. The b-wave amplitude of the full-field ERG increased continuously from 5 to 20 minutes of dark adaptation peaking at 446”v and 377”v for horse number 1 and 2 respectively. The b-wave amplitudes of the combined rod-cone response were OS- 459”v and OD- 392”v for horse number 1 and OS- 491”v and OD- 608”v for horse number 2. The amplitude of the flicker ERG for horse number 1 was OS- 86 ”v and OD- 110 ”v and for horse number 2 OS- 80 ”v and OD- 74 ”v. Conclusions Extensive bullet-hole chorioretinal lesions do not appear to compromise outer retinal function in these horses.This is the accepted version of the following article: Allbaugh RA, Ben-Shlomo, G, Whitley RD. Eletroretinogram evaluation of equine eyes with extensive ‘bullet-hole’ fundic lesions. Veterinary Ophthalmology 2014; 17, 129–133, which has been published in final form at http://dx.doi.org/10.1111/vop.12169</p
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