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Objective: To describe the clinical appearance, histopathology, and treatment of equine intraocular melanocytic neoplasia in adult horses., Animals and Procedure: A retrospective review of medical records was conducted. Data recorded included signalment, ocular examination findings, physical examination findings, therapeutic interventions, and case outcomes. Histopathologic characteristics of enucleated globes were evaluated. A Student's t -test was used to evaluate differences in the interval from diagnosis to last known outcome between horses receiving therapeutic interventions and horses undergoing monitoring alone., Results: Of the 55 horses included, Arabian was the most common breed (15/55, 27%). Gray was the most common coat color (85%). Physical examination was completed for 75% of horses at time of diagnosis, and of those, 67% had cutaneous melanoma. The interval from diagnosis to last known outcome was not different ( P = 0.312) between horses that underwent monitoring alone (median: 2.0 y) and those that received treatment (mean: 2.25 y)., Conclusion: Equine intraocular melanocytic neoplasms are highly associated with cutaneous melanoma and gray coat color, and they are more prevalent than previously published reports suggest., Clinical Relevance: A complete ophthalmic examination is indicated for all horses with cutaneous melanoma. Additional research into the timing and rationale for treatment of intraocular melanocytic neoplasia is necessary., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Purpose: To examine the relationship between Minimum Inhibitory Concentration (MICs) and response to therapy of 6 Fusarium spp. and 5 Aspergillus fumigatus isolated from equine ulcerative keratitis cases., Procedure: Fungi were identified by morphology and Internal Transcribed Spacer (ITS) polymerase chain reaction (PCR) with sequencing and evaluated at the University of Texas Fungal Testing Laboratory for susceptibility to three azole antifungals (miconazole, voriconazole, posaconazole), natamycin, and two echinocandins (anidulafungin, caspofungin). A Mann-Whitney rank sum test was used for the comparison of time to heal between infections of different fungal genera and in vitro susceptibility to the drug administered., Results: Fusarium spp. were resistant to azole antifungals in 6/6 cases (100%). Fusarium spp. were susceptible to echinocandins and natamycin in all cases. A. fumigatus was resistant to anidulafungin in 1/5 cases (20%) and posaconazole in 1/5 cases (20%) The remainder of A. fumigatus isolates were susceptible to all antifungal agents tested. Fusarium isolates were treated with antifungals to which they were not susceptible; however, all cases of A. fumigatus were treated with antifungals to which they were susceptible. All Fusarium cases and A. fumigatus cases experienced clinical resolution, regardless of surgical intervention. There was no statistical correlation between fungal genus and time to heal (p < .082)., Conclusions: The in vitro susceptibility indicated that all cases of Fusarium spp. were resistant to azole antifungal drugs which were used as treatment. Clinical outcomes, however, showed that all cases healed despite resistance to antifungals., (© 2022 American College of Veterinary Ophthalmologists.)

Objective: To describe common bacterial organisms cultured from retrobulbar cellulitis and abscess lesions, in vitro susceptibility patterns, common diagnostic techniques utilized, etiologies encountered, and prevalence of blindness., Animals Studied: Thirty-eight dogs diagnosed with retrobulbar cellulitis or abscessation from 2007 to 2017., Procedure: For cases of orbital cellulitis or abscess, signalment, orbital imaging, cytology, histopathology, bacterial culture and susceptibility testing, presence of vision at the initial examination and resolution, and presumed cellulitis/abscess etiology were recorded., Results: Most cases were medically (78.9%) versus surgically managed (18.4%). Most common form of orbital imaging was computed tomography (48.5%) followed by ocular ultrasound (18.2%). Fifteen of eighteen cultures (83.3%) showed growth of aerobic bacterial organisms, anaerobic bacterial organisms, or both. Most common aerobic bacteria were gram-negative bacilli (40.0%) followed by Corynebacterium sp. (26.7%) and α-hemolytic Streptococci sp. (26.7%) but Micrococcus and Bacillus spp. were also identified. Most common anaerobic bacteria were gram-negative bacilli (40.0%). Antibiotics with highest susceptibility patterns included gentamicin, followed equally by amoxicillin/clavulanic acid, cephalothin, chloramphenicol, and imipenem. No bacteria were susceptible to cefovecin. Six cases presented with vision loss due to retrobulbar disease (15.8%). Idiopathic (50%) disease and tooth root abscessation (23.7%) were most commonly diagnosed cause of orbital disease., Conclusion: Retrobulbar cellulitis/abscess is a serious and vision-threatening process, which can be effectively managed by broad-spectrum antibiotics such as gentamicin or amoxicillin/clavulanic acid, but not cefovecin. This study identified three organisms that have not been previously reported to be associated with orbital cellulitis (Corynebacterium sp., Bacillus sp. and Micrococcus sp.)., (© 2021 American College of Veterinary Ophthalmologists.)

Purpose: To determine the immediate and chronic effects of topical 0.1% diclofenac and 0.03% flurbiprofen on corneal sensitivity in normal canine eyes., Animals Studied: Eighteen normal, nonbrachycephalic dogs., Methods: A prospective, randomized, masked, crossover study was performed. To determine the immediate effects associated with treatment, the study drug was instilled into the eye every 5 min for five doses, and corneal sensitivity of treated and untreated eyes was obtained prior to treatment and every 15 min post-treatment for 60 min. To determine the chronic effects, the study drug was instilled every 12 h for 30 days, and corneal sensitivity of treated and untreated eyes was obtained prior to treatment on days 0 and 30. A washout period of at least 30 days occurred between drug crossover. Ambient temperature and humidity were measured throughout the study., Results: After multiple instillations, there was no difference in corneal sensitivity between eyes over time for diclofenac (P = 0.67) or flurbiprofen (P = 0.54), with a median sensitivity of 25 mm (1.8 g/mm 2 ). After chronic dosing, there was no difference in corneal sensitivity between eyes over time for diclofenac (P = 0.82) or flurbiprofen (P = 0.56), with a median sensitivity of 35 mm (1.0 g/mm 2 ). Decreasing ambient humidity was associated with an increase in sensitivity measurements (P = 0.0001)., Conclusions: Neither diclofenac nor flurbiprofen had an effect on corneal sensitivity after multiple-drops or twice-daily dosing for 30 days. Ambient humidity may have an effect on corneal sensitivity measurements, with a longer filament length eliciting a blink response at lower humidity., (© 2016 American College of Veterinary Ophthalmologists.)

Objective: To describe the technique and utility of three-dimensional (3D) printing for orbital and peri-orbital masses and discuss other potential applications for 3D printing., Animals Studied: Three dogs with a chronic history of nonpainful exophthalmos., Procedures: Computed tomography (CT) and subsequent 3D printing of the head was performed on each case. CT confirmed a confined mass, and an ultrasound-guided biopsy was obtained in each circumstance. An orbitotomy was tentatively planned for each case, and a 3D print of each head with the associated globe and mass was created to assist in surgical planning., Results: In case 1, the mass was located in the cranioventral aspect of the right orbit, and the histopathologic diagnosis was adenoma. In case 2, the mass was located within the lateral masseter muscle, ventral to the right orbit between the zygomatic arch and the ramus of the mandible. The histopathologic diagnosis in case 2 was consistent with a lipoma. In case 3, the mass was located in the ventral orbit, and the histopathologic diagnosis was histiocytic cellular infiltrate., Conclusions: Three-dimensional printing in cases with orbital and peri-orbital masses has exceptional potential for improved surgical planning and provides another modality for visualization to help veterinarians, students, and owners understand distribution of disease. Additionally, as the techniques of 3D printing continue to evolve, the potential exists to revolutionize ocular surgery and drug delivery., (© 2016 American College of Veterinary Ophthalmologists.)

OBJECTIVE To determine tear film concentrations of doxycycline in ophthalmologically normal dogs following oral doxycycline administration. DESIGN Crossover study. ANIMALS 10 privately owned dolichocephalic or mesaticephalic dogs free of ophthalmic disease. PROCEDURES Dogs were randomly assigned to receive doxycycline hyclate first at 5 mg/kg (2.3 mg/lb) or 10 mg/kg (4.5 mg/lb), PO, every 12 hours for 5 days, beginning on day 1. Doxycycline was administered 1 hour prior to feeding. Tear samples were collected from days 1 through 10 approximately 3 hours after the morning dose was administered. Following a 3-week washout period, dogs received the alternative dose in the same conditions. Doxycycline concentration in tear samples from 1 eye (same eye used for both sessions) was measured via liquid chromatography-mass spectrometry and compared between the 2 doxycycline doses. RESULTS Doxycycline was detected in tear samples of all dogs from days 1 through 10 for both doxycycline doses. Median peak doxycycline concentrations for the 5 mg/kg and 10 mg/kg doses were 2.19 ng/mL on day 3 and 4.32 ng/mL on day 4, respectively. Concentrations differed significantly with time, but this difference was not influenced by dose, dose order, or eye. A significant positive correlation was identified between doxycycline concentration and body weight (r = 0.22). CONCLUSIONS AND CLINICAL RELEVANCE Detectable doxycycline concentrations were achieved in the tear film of ophthalmologically normal dogs following oral administration of doxycycline at 5 or 10 mg/kg, every 12 hours. Dose had no significant effect on tear film concentration of the drug.

Objective: To describe the use of hydropulsion with sterile isotonic buffered ophthalmic solution (ie, eyewash) for the treatment of superficial corneal foreign bodies in veterinary patients and evaluate signalment, clinical findings, and outcomes following the procedure., Design: Retrospective case series., Animals: 11 dogs, 2 cats, and 2 horses., Procedures: Medical records were retrospectively reviewed to identify patients that underwent hydropulsion treatment for a superficial, nonpenetrating corneal foreign body confirmed by ophthalmic examination. Data regarding signalment, reason for evaluation, ocular diagnoses, and treatment were recorded. Hydropulsion was performed with a 6-mL syringe filled with eyewash solution and a 25-gauge needle with the needle tip removed. Owners and referring veterinarians of patients that did not have a recheck examination recorded were contacted by telephone for follow-up information., Results: The corneal foreign body was an incidental finding in 3 of 15 patients. The most common clinical signs included blepharospasm, conjunctival hyperemia, and corneal vascularization. Hydropulsion was successful for foreign body removal in all 15 cases. No complications were observed during or following the procedure. In the 9 patients that had a follow-up examination, the cornea tested negative for retention of topically applied fluorescein (with a mean of 6.3 days from treatment to follow-up). At the time of last follow-up examination or telephone follow-up, no patients were reported to have clinical signs of ocular discomfort or corneal opacity associated with the affected site., Conclusions and Clinical Relevance: In these patients, hydropulsion was easily performed with readily available materials and was successful for the removal of superficial corneal foreign bodies with no adverse effects.

Purpose: We determined whether naturally-occurring lenticular myopia in English Springer spaniels (ESS) has a genetic component., Methods: Streak retinoscopy was performed on 226 related ESS 30 minutes after the onset of pharmacologic mydriasis and cycloplegia. A pedigree was constructed to determine relationships between affected offspring and parents. Estimation of heritability was done in a Bayesian analysis (facilitated by the MCMCglmm package of R) of refractive error in a model, including terms for sex and coat color. Myopia was defined as ≤-0.5 diopters (D) spherical equivalent., Results: The median refractive error for ESS was 0.25 D (range, -3.5 to +4.5 D). Median age was 0.2 years (range, 0.1-15 years). The prevalence of myopia in related ESS was 19% (42/226). The ESS had a strong correlation (r = 0.95) for refractive error between the two eyes. Moderate heritability was present for refractive error with a mean value of 0.29 (95% highest probability density, 0.07-0.50)., Conclusions: The distribution of refractive error, and subsequently lenticular myopia, has a moderate genetic component in ESS. Further investigation of genes responsible for regulation of the development of refractive ocular components in canines is warranted.

Objective: To determine the characteristics of, prevalence of, and risk factors for corneal pigmentation (CP) in Pugs., Design: Prospective cross-sectional study., Animals: 295 Pugs > 16 weeks old., Procedures: Ophthalmic examination of the anterior segment of each eye was performed, including determination of tear film characteristics (Schirmer tear test and tear film breakup time) and corneal sensitivity. Digital photographs of the head and each eye were obtained. Corneal pigmentation of eyes was graded as absent, very mild, mild, moderate, or severe. Signalment and medical history information and American Kennel Club registration status were recorded. Results-CP was detected in at least 1 eye of 243 of the 295 (82.4%) Pugs; CP was typically very mild or mild. Detection of CP was not significantly associated with coat color, age, eyelid conformation, or tear film characteristics but was significantly associated with sex of dogs. The severity of CP was not significantly associated with American Kennel Club registration status or age, but was significantly associated with sex, tear film characteristics, and coat color. Iris hypoplasia was detected in 72.1% of the Pugs. Iris-to-iris persistent pupillary membranes were detected in 85.3% of the Pugs., Conclusions and Clinical Relevance: Prevalence of CP in Pugs in this study was high. Unexpectedly high prevalences of iris hypoplasia and persistent pupillary membranes were also identified. The condition identified in these Pugs was a pigmentary keratopathy, rather than pigmentary keratitis or corneal melanosis. This condition may have a genetic basis, and further studies are warranted to determine etiology.

Objective: To compare the diagnostic quality of computed tomography (CT) images of normal ocular and orbital structures acquired with and without the use of general anesthesia in the cat., Animal Studied: Eleven privately owned cats with nasal disease presenting to a single referral hospital., Procedures: All cats received a complete ophthalmic examination. A 16 multislice helical CT system was utilized to acquire images of the skull and neck with and without the use of general anesthesia. Images were acquired before and after the administration of intravenous iodinated contrast. Images of normal ocular and orbital structures were evaluated via consensus by two board-certified radiologists. Visibility of ocular and orbital structures, degree of motion, and streak artifact were assessed and scored for each image set in the transverse, dorsal, and sagittal planes., Results: The use of general anesthesia did not significantly affect the diagnostic quality of images. No motion artifact was observed in any CT image. Streak artifact was significantly increased in scans performed in the transverse orientation but not in the dorsal orientation or sagittal orientation and did not affect the diagnostic quality of the images. Contrast enhancement did not significantly enhance the visibility of any ocular or orbital structures., Conclusion: Diagnostic CT images of normal ocular and orbital structures can be acquired without the use of general anesthesia in the cat., (© 2012 American College of Veterinary Ophthalmologists.)

Objective:   To describe a protocol for the examination of free-living raptors and report the ophthalmic examination findings of seven raptor species native to central Illinois, namely the barred owl, Cooper's hawk, eastern screech owl, great horned owl, American kestrel, red-tailed hawk, and turkey vulture and to determine if the findings relative to visual prognosis affected eligibility for future release., Animals Studied:   Seventy-nine free-living raptors., Procedures:   Under manual restraint, complete ophthalmic examination including slit-lamp biomicroscopy and indirect funduscopy, applanation tonometry, rebound tonometry, ocular morphometrics, B-mode ultrasound, and electroretinography (ERG) were performed on each bird. Histopathology of enucleated globes was performed after euthanasia or death in selected cases., Results:   The examination protocol was easily performed using manual restraint alone on all birds. Ocular lesions were detected in 48.1% of birds, with 47.3% affected unilaterally and 52.6% affected bilaterally. Ocular lesions were considered to be vision threatening in 29.0% of the unilaterally affected birds and 29.0% of the bilaterally affected birds. The most common case outcomes were discharge from hospital to rehabilitation facility (45.6%) followed by euthanasia (43.0%). The presence of an ocular lesion or a vision-threatening ocular lesion was not significantly associated with outcome. Reference ranges are reported for B-mode ultrasound, ocular morphometrics, and horizontal corneal diameter in all species., Conclusion:   Complete ophthalmic examination can be supplemented by the use of ocular morphometrics, ultrasound, and ERG in the manually restrained raptor. These advanced diagnostic techniques may be useful in developing more objective criteria for evaluating eligibility for release following rehabilitation of free-living birds of prey., (© 2011 American College of Veterinary Ophthalmologists.)

Objective: To determine types and frequency of ophthalmic lesions detected in neonatal foals evaluated for nonophthalmic disease at 3 veterinary referral hospitals and to investigate associations between systemic and ophthalmic diseases in these foals., Design: Prospective cross-sectional study., Animals: 70 foals < 30 days old., Procedures: Complete ophthalmic examinations were performed. Signalment, clinical signs, mentation during ophthalmic examination, results of clinicopathologic tests, and diagnosis of systemic disease were recorded. Descriptive data analysis including a χ(2) test for associations was performed., Results: Most foals (39/70 [55.7%]) with systemic disease had ≥ 1 ophthalmic lesion detected. Of the 39 foals with ophthalmic disease, 24 (61.5%) had potentially vision-threatening lesions. Clinically important abnormalities included conjunctival hyperemia or episcleral injection (30/70 [42.9%]), uveitis (18/70 [25.7%]), ulcerative keratitis (13/70 [18.6%]), nonulcerative keratitis (10/70 [14.3%]), entropion (8/70 [11.4%]), retinal hemorrhage (8/70 [11.4%]), and cataract (6/70 [8.6%]). Foals with sepsis were significantly more likely to have uveitis than were those without sepsis. Foals with sepsis and uveitis were also significantly less likely to survive to discharge than were foals that had sepsis without uveitis. Acquired ophthalmic disease (detected in 37/70 [52.9%] foals) was significantly more common than congenital ophthalmic disease (detected in 9/70 [12.9%])., Conclusions and Clinical Relevance: Ophthalmic lesions were detected in 55.7% of neonatal foals with systemic disease. Acquired ophthalmic disease was more commonly detected than congenital ophthalmic disease. Foals with sepsis were more likely to have uveitis than were foals without sepsis. A complete ophthalmic examination is indicated in neonatal foals evaluated for systemic disease.

Reasons for Performing Study: There is little scientific information available about the ability of ocular disease to cause a systemic inflammatory response. Horses are frequently affected with ocular disease and ensuring their systemic health prior to performing vision saving surgery under anaesthesia is essential for the successful treatment of ophthalmic disease., Hypothesis: Ocular disease will cause elevations in the concentration of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood., Methods: Whole blood and serum samples were obtained from 38 mature horses with ulcerative keratitis or uveitis and no evidence of systemic disease, 9 mature horses with no evidence of ocular or systemic disease (negative controls) and 10 mature horses with systemic inflammatory disease and no evidence of ocular disease (positive controls). Blood samples were assayed for concentrations of the acute phase proteins fibrinogen and serum amyloid A., Results: Fibrinogen and serum amyloid A were significantly different in the positive control group compared to the negative control, corneal disease and uveitis groups (P<0.126). There was no significant difference between the negative control, corneal disease and uveitis groups (P<0.001)., Conclusions: Ulcerative keratitis and anterior uveitis are not associated with elevated concentrations of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood., Potential Relevance: When the clinician is presented with a patient with ocular disease and elevated plasma fibrinogen or serum amyloid A concentrations, a nonocular inflammatory focus should be suspected., (© 2011 EVJ Ltd.)

Objective: To perform electroretinography on normal anesthetized western gray kangaroos (Macropus fuliginosus). Animals studied  Six captive western gray kangaroos., Procedures: The kangaroos were anesthetized using a combination of ketamine and medetomidine via a remote drug delivery system, then were maintained on isoflurane after endotracheal intubation and reversal of the medetomidine with atipamazole. After a minimum of 20 min of dark adaptation, electroretinograms were obtained using a handheld electroretinography (ERG) machine using a single flash protocol at three light intensities: 10 mcd.s/m(2), 3000 mcd.s/m(2), 10 000 mcd.s/m(2)., Results: At 10 mcd.s/m(2) the mean b-wave amplitude and implicit time was 102.0 μV (SD ± 41.3 and 95% CI 68.9-135.1) and 78.4 ms (SD ± 8.3 and 95% CI 71.8-85.0). At 3000 mcd.s/m(2) the mean a-wave amplitude and implicit time was 69.9 μV (SD ± 20.5 and 95% CI 53.5-86.3) and 17.6 ms (SD ± 1.5 and 95% CI 16.4-18.8) and the mean b-wave amplitude and implicit time was 175.4 μV (SD ± 35.9 and 95% CI 146.7-204.1) and 74.1 ms (SD ± 3.5 and 95% CI 71.2-76.9). At 10 000 mcd.s/m(2) the mean a-wave amplitude and implicit time was 89.1 μV (SD ± 27.1 and 95% CI 67.5-110.8) and 16.8 ms (SD ± 1.0 and 95% CI 16.0-17.0) and the mean b-wave amplitude and implicit time was 203.7 μV (SD ± 41.4 and 95% CI 170.6-236.8) and 75.4 ms (SD ± 3.3 and 95% CI 72.8-78.1)., Conclusion: Electroretinography outside of the typical clinical setting is feasible using a portable ERG system and allows for quick analysis of retinal function in exotic species.

Complete ophthalmic examination of a mob of western gray kangaroos (Macropus fuliginosus) was performed under chemical restraint. Examination included intraocular pressure (IOP) measurement by rebound and applanation tonometry, fluorescein staining, corneal diameter measurement, slit-lamp biomicroscopy and indirect funduscopy. The corneal diameters had a mean of 19.52 mm, SD 2.16 mm, 95% confidence interval (CI) 18.71-20.32 mm. Ocular abnormalities were noted in 4/8 (50%) of examined kangaroos. Intraocular pressure as estimated by rebound tonometry was 9.00 mm Hg with a 25-75% quartile range of 6.5-10.75 mm Hg and a minimum-maximum range of 5.00-23.00 mm Hg. Intraocular pressure as estimated by applanation tonometry was 11.50 mm Hg with a 25-75% quartile range of 10.00-17.00 mm Hg and a minimum-maximum range of 9.00-20.00 mm Hg. This is the first report of ocular examination findings in a mob of captive western gray kangaroos and provides ranges and values for tonometry and corneal diameter.

Objective: Pathologic intraocular neovascularization is a key component of many canine ophthalmic diseases such as uveitis, retinal detachment, intraocular neoplasms, and corneal perforation. The purpose of this study was to evaluate the structure of pre-iridal fibrovascular membranes (PIFMs) associated with several different disease processes and to identify specific factors associated with their development in the canine eye., Procedure: This study examined 36 enucleated canine eyes with the diagnosis of PIFM and one of the following: lens-induced uveitis, retinal detachment, iridociliary adenoma, corneal perforation, severe hyphema, or vitreal gliovascular membranes (canine ocular gliovascular syndrome, COGS). Three histologic stains and six immunohistochemical stains were performed in all 36 PIFM eyes and four histologically normal eyes, including: hematoxylin and eosin, alcian blue periodic acid schiff (PAS), Masson's trichrome, platelet endothelial cell adhesion molecule-1 (CD31), smooth muscle actin, vimentin, laminin, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2)., Results: Pre-iridal fibrovascular membrane extracellular matrix staining was consistent with collagen and mucins in all cases and positive for laminin in most cases. All PIFMs contained CD31-positive vessels and predominantly lymphoplasmacytic inflammation. Both PIFM vessels and spindle cells were positive for laminin, vimentin, smooth muscle actin, VEGF, and COX-2. Secondary intraocular pathology and immunohistochemical staining of other intraocular structures are also reported., Conclusions: Pre-iridal fibrovascular membrane morphology and immunohistochemical characteristics were similar across six canine disease processes, suggesting analogous pathophysiologic mechanisms. COX-2 and VEGF were identified using immunohistochemistry and may play a role in PIFM development.

An 8-year-old male castrated Domestic Short-haired cat was examined for a 1-week history of blepharospasm and mucoid ocular discharge OS. Examination revealed ulcerative keratitis with stromal loss, stromal infiltrate, corneal edema, perilimbal vascularization and miosis. Cytology of the cornea revealed multiple dichotomously branching, septate fungal hyphae and severe, predominantly neutrophilic inflammation. PCR of the cytology samples confirmed the presence of Aspergillus flavus while fungal and bacterial cultures were negative. Treatment with topical 1% voriconazole solution was successful in resolving the keratomycosis.

Objective: To evaluate effects of intracameral injection of preservative-free 1% and 2% lidocaine hydrochloride solution on the anterior segment of the eyes in dogs., Animals: 16 adult healthy dogs (8 male and 8 female) judged to be free of ocular disease., Procedure: Dogs were randomly assigned to 2 groups of 8 dogs each. Group 1 dogs received an intracameral injection of 0.10 mL of preservative-free 1% lidocaine solution in the designated eye, and group 2 dogs received 0.10 mL of preservative-free 2% lidocaine solution in the designated eye. After injection, intraocular pressure was measured every 12 hours for 48 hours and then every 24 hours until 168 hours after injection. Slit-lamp biomicroscopy was performed preceding intracameral injection, 8 hours after injection, and then every 24 hours until 168 hours after injection. Ultrasonic pachymetry and specular microscopy were performed preceding intracameral injection and 72 and 168 hours after injection. Corneal thickness and endothelial cell density and morphology were compared with baseline measurements., Results: No significant differences were found in intraocular pressure, corneal thickness, endothelial cell density, and morphologic features in either group, compared with baseline. A significant difference in aqueous flare was found for treated and control eyes 8, 24, and 48 hours after injection, compared with baseline. No significant difference in aqueous flare was found between treated and control eyes within either group., Conclusions and Clinical Relevance: No adverse ocular effects were detected after intracameral injection of preservative-free 1% or 2% lidocaine solution; thus, its use would be safe for intraocular pain management in dogs.

Objective: Determine the effect of a 3-dimensional alginate matrix on the growth and differentiation of cells isolated from porcine retinal pigment epithelium (RPE)., Procedures: Porcine RPE cells were harvested from enucleated eyecups, isolated by differential gravity sedimentation and cultured in either alginate alone (Group 1) or on plastic tissue culture plates followed by alginate (Group 2). Group 1 cells were cultured in alginate to evaluate the efficacy of the matrix as a culture medium. Group 2 cells were initially cultured on plastic to induce dedifferentiation. The cells were then harvested, suspended in alginate beads, and incubated for a second culture period to determine if the induced dedifferentiation was reversible., Results: The number of Group 1 cells was significantly greater (P < or = 0.01) at the end of the culture period. The amount of pigment and cell morphology of Group 1 cells at the end of the culture period was similar to that seen at initial cell isolation. The initial culture of Group 2 cells on plastic showed characteristic features of dedifferentiation marked by the loss of pigment and alterations in microscopic appearance. Secondary culture of dedifferentiated Group 2 cells in alginate beads resulted in a return to pigmentation and characteristic morphology for a majority of the cultured cells., Conclusions: Porcine RPE cells can be propagated in alginate culture with a significant increase in cell numbers while maintaining normal morphology. Under the conditions described in the present study, the dedifferentiation of porcine RPE induced by standard in vitro culture methods is reversible.

The most commonly performed feline ocular surgeries are described with emphasis on any anatomic or pathophysiologic differences that are unique to the feline eye, adnexa, and orbit.

One of the keys to the accurate diagnosis of ocular disease is the appropriate selection and interpretation of ocular tissue samples. Without a good understanding of which test(s) to select and how to interpret test results, the clinician may arrive at an incorrect diagnosis and prescribe improper and/or ineffective therapy. This article outlines some of the more common ocular diagnostic procedures and gives guidance in the interpretation of test results.

Objective: To evaluate, for clinically normal dogs, results of Schirmer tear tests in eyes without topical anesthetic (STT) and to detect differences associated with breed, sex, age, day, and time of day in eyes in which STT was performed after use of topical anesthetic (STTa)., Animals: 41 Beagles, 43 Labrador Retrievers, 25 Golden Retrievers, 26 English Springer Spaniels, and 22 Shetland Sheepdogs., Procedure: Beagles had STT and STTa values measured twice daily for 5 days. Client-owned dogs of 4 other breeds had STT and STTa values measured once., Results: Mean +/- SD values of Beagles for STT and STTa were 20.2 +/- 2.5 and 3.8 +/- 2.7 mm/min. Mean values for STT and STTa were as follows: Labrador Retriever, 22.9 +/- 4.1 and 9.6 +/- 3.8 mm/min; English Springer Spaniel; 20.7 +/- 3.2 and 5.4 +/- 3.4 mm/min; Golden Retriever, 21.8 + 3.7 and 8.8 +/- 3.1 mm/min; and Shetland Sheepdog, 15.8 +/- 1.8 and 3.6 +/- 2.8 mm/min. Overall mean values for STT and STTa were 20.2 +/- 3.0 and 6.2 +/- 3.1 mm/min. Differences for STT and STTa were detected among breeds, but significant differences were not associated with sex or age within each breed or in overall values for all dogs., Conclusions and Clinical Relevance: Results for the STT reported here compare favorably with reported values, except for results of Shetland Sheepdogs; however, results for the STTa differ dramatically from reported values. Clinicians should consider effects attributable to breed when evaluating results of STT and STTa in dogs.

An 11-year-old Shetland Sheepdog was presented for exophthalmos caused by a locally extensive, poorly defined mass located behind the right eye. The primary orbital mass was identified by light microscopy and immunohistochemistry as a T-cell rich B-cell lymphoma (TCRBCL) composed predominantly of BLA.36-positive large neoplastic lymphoid cells admixed with fewer CD3- and CD79a-positive small lymphocytes. The dog was treated for lymphoma, but 6 months after presentation it was euthanatized for suspected hepatic and gastrointestinal metastasis. Gross findings revealed an enlarged liver with multiple well-demarcated, randomly distributed 0.1-1.5-cm white nodules, five firm white submucosal jejunal nodules, and ileocecal, mediastinal, and hilar lymphadenopathy. Metastatic liver lesions consisted of sheets of monomorphic large neoplastic lymphoid cells that effaced and expanded portal and centrilobular zones. These cells were morphologically similar to the large neoplastic cells of the original orbital tumor and were CD3-negative and variably BLA.36-positive, consistent with B-cell lineage. Similar cells comprised the jejunal nodules and effaced the lymph nodes. The progression of TCRBCL to a diffuse B-cell lymphoma in this case is consistent with reported human cases and has not been previously reported in the dog.

Objective: To determine the electrodiagnostic and histologic response of short-term increases of intraocular pressure (IOP) on transient pattern electroretinograms (PERG) and flash electroretinograms (FERG) in the eyes of dogs., Animals: 8 healthy mixed-breed dogs., Procedure: Transient PERG and FERG waveforms were recorded from dogs (while anesthetized) as IOP was increased from baseline (7 to 19 mm Hg) to 90 mm Hg. One hundred mean PERG responses and a single FERG response were recorded at each step during 3 recording sessions. Globes of each dog were enucleated after euthanasia on posttreatment day 7 and evaluated by a pathologist., Results: Increases in spatial frequency resulted in decreased amplitudes of N2 (second negative PERG peak). Increases in IOP resulted in decreases in all 3 PERG waveforms and the FERG waveform. All values began to return to baseline after short-term increases in IOP on day 0, and waveforms were not significantly different on posttreatment days 3 and 7, Conclusions: Data suggest that short-term increases in IOP affect PERG and FERG waveforms, and PERG waveforms are more sensitive to increases in IOP Differences were not detected between treated and control eyes on histologic examination. Further studies are necessary to determine at what IOP permanent damage to ganglion and photoreceptor cells will develop and whether PERG is a reliable clinical diagnostic technique for use in dogs to reveal retinal damage that is secondary to increased IOP prior to changes in waveforms generated by FERG in dogs.

Corneal ulcers are one of the most common ocular disease presentations in the horse. With the use of correct diagnostic techniques and selection of an appropriate treatment regimen, most cases result in a satisfactory outcome. The eye does not respond well to inflammation, and in complicated ulcers, this should be managed aggressively using systemic NSAIDs with a high priority assigned to removing the infectious agent. Care needs to be taken to avoid topical or systemic corticosteroid use for the treatment of equine ocular disease, however, unless the clinician is completely sure that the corneal disease is not caused by an infectious process. The use of combination corticosteroid-antibiotic ophthalmic preparations without an appropriate treatment rationale can result in doing more harm than good. It is important to have a treatment plan and to monitor the elected treatment regimen. The clinician should decide on some objective criteria at initiation of treatment so that any changes are made rationally. This approach should also include consideration of early referral of the eye's care to a veterinary ophthalmologist.

A case of primary intraocular melanoma in an alpaca is reported. This patient also presented with a mild normocytic, normochromic anemia and hypoproteinemia. These can be markers of an immunodeficiency syndrome associated with llamas. Although this patient did not appear to have clinical signs of this syndrome, its presence needed to be ruled out as animals affected with this syndrome are subject to recurrent severe debilitating diseases and death. To our knowledge, intraocular melanoma has not been previously reported in an alpaca.

Objective: To develop and test a noninvasive technique for determining age in dogs and cats on the basis of changes in lens reflections and transparency., Animals: 85 dogs representing 5 breeds and 73 domestic shorthair cats., Procedure: While examining dilated eyes in a darkened room, using a penlight, 2 experienced examiners who were blinded to actual age of animals individually measured the diameter of reflections from the anterior (La) and posterior (Lb) surfaces of the lens and scored lens transparency (Ltr) from 1 (clear) to 5 (severe opacity). Models were developed to predict age on the basis of these measurements., Results: Aging models developed for dogs and cats were as follows: Age(dogs) = 2.197 - 0.070 x (La) + 1.361 x (Lb) + 1.193 x (Ltr) and Age(cats) = 1.988 + 1.024 x (La) + 2.220 x (Lb) + 1.019 x (Ltr), where age was expressed in years, and La and Lb were in millimeters. All variables, except La in dogs, contributed significantly to accuracy of the models. Correlation between predicted and actual ages, as measured by Pearson's product-moment correlation coefficient, was significant in both species (P < 0.0001). Significant differences were not found between examiners or between the first and second evaluations by the same examiner., Conclusions and Clinical Relevance: A noninvasive technique based on evaluation of lens reflections and transparency can provide clinically useful predictions of age in mature dogs and cats. This technique could be an important tool for veterinarians or humane shelters in determining differential diagnoses and assessing longevity and adoptability of mature animals of unknown age.

Objective: To evaluate clinical signs of ocular blastomycosis in dogs, to determine response of blastomycosis-infected eyes to treatment with systemically administered amphotericin B and ketoconazole, and to identify prognostic indicators of successful antifungal treatment., Design: Retrospective study., Animals: 73 dogs., Procedure: Medical records were reviewed for all dogs with confirmed blastomycosis and ocular disease seen at our hospital between 1985 and 1993., Results: 6 eyes had anterior segment disease, 24 had posterior segment disease, and 78 had endophthalmitis. 40 eyes were treated with a combination of amphotericin B and ketoconazole, and 16 of the 40 responded favorably. However, 16 of the 24 eyes that were not severely affected responded favorably, but none of the 16 eyes that were severely affected did., Clinical Implications: Dogs with blastomycosis had posterior segment disease, without complete retinal separation, had a good prognosis for retaining vision. Results of histologic examination suggested that secondary glaucoma was a manifestation of endophthalmitis and was indicative of a grave prognosis for response to antifungal and antiglaucoma treatment.

Fibrin clots were induced in eyes of dogs by injection of autogenous citrated plasma into the anterior chamber. Twenty-four hours after clot formation, one 50-microliters drop of tissue plasminogen activator at a concentration of 5 mg/ml (group 1, n = 7) was administered topically 9 times at 5-minute intervals, or a collagen shield that was hydrated with tissue plasminogen activator at a concentration of 5 mg/ml (group 2, n = 7) was applied. The contralateral eye served as a nontreated control. Serial photographs were taken of the fibrin clots after topical application of tissue plasminogen activator. Computerized morphometric analysis was then used to evaluate changes in cross-sectional surface area of the fibrin clot. There was no significant mean percentage decrease in clot surface area of treated eyes of group-1 dogs or in treated eyes of group-2 dogs. In addition, there was no significant difference in mean percentage decrease in clot surface area between treated eyes of group-1 and group-2 dogs.

Eye enucleations performed on 109 dogs, 29 horses, and 23 cats involved placement of 136 silicone orbital implants and 7 mesh implants. Mean follow-up times were 2.4 years (range, 3 weeks to 9 years) in dogs, 3.4 years (range, 10 days to 10.5 years) in horses, and 1.5 years (range, 3 weeks to 7.5 years) in cats. Implants failed in 1 of 96 dogs (1.04%), 3 of 29 horses (10.3%), and 3 of 18 cats (16.7%). Implant failure was attributable to various causes in all species; however, cats appeared to be more prone to late extrusion that were dogs and horses. Implantation of an orbital prosthesis was a safe and inexpensive method for improving cosmetic appearance after enucleation in dogs, horses, and cats.

Specific details on surgical procedures, although not covered here, are available in other references. Factors enhancing the overall cosmetic appearance obtained with procedures are emphasized, providing information that should allow veterinarians to offer clients a good cosmetic appearance and effective treatment for disfiguring ocular problems in their horses. Questions regarding procedures should be addressed to your referral ophthalmologist or, in the case of a corneoscleral prosthesis, the ocularist assisting.