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Objective: To determine and compare the fixation strength of conjunctival pedicle flaps to cornea achieved via conventional ophthalmic suture and three different adhesive compounds., Animals Studied: Ex vivo porcine globes., Procedures: Following a 6 mm wide 500-micron-restricted depth lamellar keratectomy, conjunctival pedicle flaps were secured to the keratectomy site with either 8-0 VICRYL® suture or one of three adhesive products, including Tisseel® bioadhesive, ReSure® synthetic adhesive, or ethyl cyanoacrylate adhesive (n = 10 per surgical group). Adhesive application protocol varied by product based upon adhesive biocompatibility. Corneoconjunctival tissues were then harvested, clamped in a tensile testing device, and loaded at a rate of 1 mm/s under video surveillance until the point of failure. Peak load was determined for each test and used to compare fixation strength between samples., Results: Forty conjunctival flaps were performed, with 6 omitted from evaluation due to dehiscence prior to tensile testing. Of the 34 flaps analyzed, 10 were secured with suture, 10 with cyanoacrylate, 8 with ReSure®, and 6 with Tisseel®. Flaps secured with suture withstood significantly higher applied tensile force compared with cyanoacrylate (p = .02474), ReSure® (p = .00000), and Tisseel® (p = .00002). Flaps secured with cyanoacrylate withstood significantly greater force than those secured with ReSure® and Tisseel® (p = .01194 and 0.01798, respectively). There was no significant difference in fixation strength between ReSure® and Tisseel® glue (p = .95675)., Conclusions: Conjunctival pedicle flap fixation using 8-0 VICRYL® suture fixation was able to withstand significantly greater maximum tensile force compared to ReSure®, Tisseel®, or cyanoacrylate adhesives. Fixation strength achieved with cyanoacrylate adhesive was significantly greater than that achieved with ReSure® or Tisseel®., (© 2024 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Objective:   To immunohistochemically evaluate expression of vascular endothelial growth factor receptor-1 (VEGFR1) and -2 (VEGFR2) in ocular tissue of healthy dogs and dogs affected with primary glaucoma, uveitic glaucoma, and intraocular neoplasia., Sample Population:   Enucleated globes from five dogs with primary glaucoma, five dogs with uveitic glaucoma, six dogs with intraocular neoplasms and three ophthalmically normal control dogs., Procedure:   Ocular tissues were obtained from enucleated globes of clinical cases or immediately following euthanasia for control dogs. Tissue sections were stained immunohistochemically for VEGFR1 and VEGFR2 via standard techniques and vascular tissue was qualitatively evaluated. Vascular endothelial VEGFR1 and VEGFR2 expression patterns are reported for normal and diseased ocular tissues. In addition, VEGFR1 and VEGFR2 expression patterns are reported for all normal ocular tissues., Results:   A constitutive expression pattern was detected for VEGFR1 by ocular vascular endothelial cells as well as nonvascular cells in the cornea, uvea, lens, and retina. VEGFR2 demonstrated limited expression in normal ocular tissue, but was widely expressed in vascular endothelium of diseased eyes, particularly in pre-iridal fibrovascular membranes., Conclusions:   The results of this study suggest a role for VEGF receptors in both physiologic and pathologic angiogenesis in canine ocular tissue. Manipulation of this pathway may be a rational consideration for therapeutic intervention in canine ocular disease exhibiting pathologic neovascularization., (© 2011 American College of Veterinary Ophthalmologists.)

Objective: To examine the concentrations of vascular endothelial growth factor (VEGF) in aqueous humor of dogs with intraocular disease and to evaluate the association of aqueous humor VEGF with pre-iridal fibrovascular membrane (PIFM) formation., Procedures: Two hundred and twenty six aqueous humor samples and 101 plasma samples were collected from 178 dogs with a variety of intraocular diseases (including cataract, primary glaucoma, uveitic glaucoma, aphakic/pseudophakic glaucoma, retinal detachment, lens luxation, and intraocular neoplasia), and aqueous humor was collected from 13 ophthalmically normal control dogs. Systemic disease status and administration of select medications were recorded. Aqueous and plasma VEGF was assayed via enzyme-linked immunosorbant assay validated for canine VEGF. Available histopathology samples were examined for the presence of PIFM. Where present, PIFMs were categorized as none, cellular, vascular or fibrous, and fibrovascular. Data were evaluated by mixed model anova, with application of Tukey-Kramer adjustment for multiple comparisons., Results: There was no association between aqueous humor and plasma VEGF levels. Compared with normal controls, aqueous humor VEGF was significantly elevated for all intraocular diseases (P < 0.05) except for primary and diabetic cataracts. Systemic disease and administered medications had no significant effect on aqueous humor VEGF concentration. Compared to dogs without PIFM, aqueous humor VEGF was significantly higher in dogs with fibrovascular PIFM (P = 0.001), but not cellular (P = 0.1704) or fibrous/vascular PIFM (P = 0.0667)., Conclusions: These findings confirm that VEGF is commonly elevated in aqueous humor of dogs with intraocular disease and likely plays a role in the causation or progression of a variety of intraocular disorders, including the development of PIFM., (© 2012 American College of Veterinary Ophthalmologists.)

A 14-year-old, female spayed Domestic Short-haired cat was presented for evaluation of progressive superficial corneal ulceration with mucoid ocular discharge, blepharospasm, and conjunctival hyperemia OD. Upon examination, ulcerative keratitis with stromal loss, chemosis, corneal edema, miosis, aqueous flare, and hyphema were noted. Corneal cytology revealed branching, septate fungal hyphae with bulbous terminations and associated ovoid structures, with suppurative inflammation. Fungal culture of corneal swabs confirmed the presence of Acremonium, although PCR of the cytology sample was negative. Ten days of treatment with topical 1% miconazole resulted in clinical deterioration before switching to topical 1% voriconazole solution, which was successful in resolving the infection. The apparent clinical efficacy of the topical antifungals used contrasted with the in vitro susceptibility profile., (© 2011 American College of Veterinary Ophthalmologists.)

Objective: To report ophthalmic findings in the Screech owl (Megascops asio). Sample population Twenty-three, apparently healthy adult captive Screech owls in Maryland., Procedures: OU of all owls underwent complete ophthalmic examination. One randomly assigned eye of each bird was measured by phenol red thread tear test (PRT), and the other eye by Schirmer tear test (STT). TonoVet rebound tonometry and TonoPen-XL applanation tonometry were performed in each eye to measure IOP. Conjunctival swabs were cultured from one eye of 10 birds, corneal diameter was measured in OU of eight birds, and streak retinoscopy was performed on OU of seven birds. Ten birds were anesthetized, and A-scan ultrasonography using a 15-MHz probe was performed to obtain axial intraocular measurements., Results: Ophthalmic abnormalities were noted in 24/46 (52%) of eyes. Median STT result was < or = 2 mm/min, ranging < or = 2-6 mm/min, and mean +/- SD PRT was 15 +/- 4.3 mm/15 s. Mean +/- SD IOP were 9 +/- 1.8 mmHg TonoVet-P, 14 +/- 2.4 mmHg TonoVet-D, and 11 +/- 1.9 mmHg TonoPen-XL. Coagulase negative staphylococcal organisms were cultured from all conjunctival swabs. Mean +/- SD corneal dimensions were 14.5 +/- 0.5 mm vertically and 15.25 +/- 0.5 mm horizontally. All refracted birds were within one diopter of emmetropia. Mean +/- SD axial distance from the cornea to the anterior lens capsule was 4.03 +/- 0.3 mm, from cornea to the posterior lens capsule was 10.8 +/- 0.5 mm, and from cornea to sclera was 20.33 +/- 0.6 mm., Conclusions: This study reports ophthalmic examination findings in Screech owls, and provide means and ranges for various ocular measurements. This is the first report of rebound tonometry and PRT in owls.

Objective: To document normal ophthalmic findings and ocular abnormalities in captive adult pygmy goats., Animals Studied: Ten healthy adult pygmy goats (five male, five female; 5-11 years of age; 26-45 kg body mass) underwent complete ophthalmic examinations., Procedure: Direct illumination, diffuse and slit-beam biomicroscopy, indirect ophthalmoscopy, IOP measurements and Schirmer tear tests were performed. TonoVet rebound tonometry, followed by topical application of 0.5% ophthalmic proparacaine, and Tono-Pen XL applanation tonometry were performed in each eye to obtain estimates of IOP., Results: Ophthalmic abnormalities included corneal scars and pigmentation, incipient cataracts, lenticular sclerosis, and vitreal veiling. Mean STT values were 15.8 mm/min, with a range of 10-30 mm/min. Mean IOP values were 11.8 mmHg for TonoVet-D, with a range of 9-14 mmHg; 7.9 mmHg for TonoVet-P, with a range of 6-12 mmHg; and 10.8 mmHg for Tono-Pen XL, with a range of 8-14 mmHg., Conclusions: Ophthalmic examination findings in adult pygmy goats, including normal means and ranges for STT and IOP measurements, using applanation and rebound tonometry, are provided.

Objective: To describe the clinical and diagnostic features of the canine sensorimotor syndrome caused by striatocapsular brain infarctions (SCI)., Animals Studied: Six dogs with diagnostic imaging or postmortem evidence of SCI., Procedures: Medical records of dogs with SCI were retrospectively reviewed and the signalment, history, clinical signs, antemortem clinicopathologic test results, diagnostic imaging findings, case outcomes, and pathologic findings recorded., Results: All dogs had an acute onset of nonprogressive homonymous visual field deficits and contralateral general proprioceptive (GP) deficits. Contralateral hemiparesis and facial hypalgesia were noted in 5/6 dogs. CT scans were normal in 2/4 dogs, and revealed poorly defined hypoattenuating lesions in the subcortical white matter in two dogs. MRI exams were performed in 5/6 dogs and revealed unilateral, variably sized, striatocapsular lesions consistent with nonhemorrhagic infarctions. Diagnostic imaging (6/6) and postmortem examinations (2/6) suggested that SCI resulted from lesions in the vascular territories of the rostral choriodal (6/6) and lenticulostriate arteries (2/6). Diseases predisposing to infarction were not identified in 5/6 dogs. Improvements in mentation, behavior, proprioceptive deficits, and hemiparesis were seen in surviving dogs, but persistent, symptomatic sensory deficits were noted during the follow-up period., Conclusions: SCI should be considered as a differential diagnosis for dogs with acute onset, nonprogressive homonymous hemianopia, contralateral GP deficits or hemiparesis, and facial hypalgesia. MRI is the preferred modality for the antemortem imaging diagnosis of SCI. Although partial recovery occurred in all surviving dogs, visual and facial sensory disturbances persisted.

Objective: To assess the efficacy and kinetics of a continuous infusion modality for topical ophthalmic drug delivery via subpalpebral lavage in horses., Animals Studied: Five ophthalmically normal horses, Procedures: A constant-rate continuous delivery pump was used to apply 0.01% fluorescein solution to the eyes of five ophthalmically normal horses via subpalpebral lavage. Fluorescein was applied at a rate of 0.14 mL/h for 72 h. Tear samples were collected from the ventral conjunctival fornix at regular intervals via capillary tube and tear fluorescein concentrations were determined via spectral assay. Laboratory studies to evaluate the procedures used in the study also were performed., Results: Overall mean tear film fluorescein concentration was approximately 20% of the applied concentration of fluorescein. However, tear film fluorescein concentrations varied considerably between horses and over time. Dilution varied from 0.62% to 60% of the applied concentration. Air pockets sporadically appeared in subpalpebral lavage tubing lines, resulting in discontinuous topical application of fluorescein., Conclusions: Constant-rate delivery of ophthalmic medications using a continuous infusion pump may provide a valuable method of topical drug delivery if tear film dilution of drugs is taken into account.

Objective: To determine the effect of oral hydrocortisone on intraocular pressure (IOP) in ocular normotensive dogs., Animals Studied: Seventeen ocular normotensive dogs. Procedures Dogs were randomly assigned to treatment (n = 9) and control (n = 8) groups. Dogs in the treatment group received hydrocortisone, 3.3 mg/kg PO every 8 h, and dogs in the control group received gelatin capsule placebo PO every 8 h for 5 weeks. Applanation tonometry was performed on both eyes of all dogs prior to treatment and then once weekly for 5 weeks during hydrocortisone treatment., Results: No significant effect of treatment was noted for right (P = 0.1013) or left (P = 0.1157) eyes during the treatment period, nor was there significant interaction of treatment by week for the right (P = 0.9456) or left (P = 0.3577) eyes. A significant rise in IOP over the treatment period was noted in both right (P < 0.0001) and left (P = 0.0006) eyes of both groups, but was unrelated to treatment., Conclusion: Orally administered hydrocortisone does not significantly increase IOP in nonglaucomatous dogs when administered over a 5-week period.

Objective: To evaluate the effect of topical ophthalmic 10% phenylephrine on systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), pulse rate (PR) and electrocardiogram (ECG) in dogs., Animals Studied: Nine clinically normal dogs., Procedure: Arterial catheters were placed in the dorsal pedal artery of awake dogs and ECG leads were attached. After a 15-min acclimatization period, baseline PR, SAP, DAP and MAP were recorded every 5 min for 20 min. Two treatment groups (eight dogs each) were studied. Group I: one drop of phenylephrine was placed in each eye once. Group II: one drop of phenylephrine was placed in each eye three times at 5-min intervals. Following treatment, PR, SAP, DAP and MAP were recorded every 5 min for 90 min. The mixed procedure of the SAS system was used to perform a repeated measures analysis of variance to test for linear and quadratic trends across time., Results: Group I: There was a significant quadratic decrease in PR across time (P = 0.0051). Systolic arterial pressure increased linearly with time (P = 0.0002), MAP increased linearly with time (P = 0.0131), and DAP increased linearly with time (P = 0.0001). Group II: There was a significant quadratic decrease in PR across time (P = 0.0023). There was a significant quadratic increase in SAP (P = 0.0324), MAP (P = 0.0103) and DAP (P = 0.0131) across time., Conclusions: Topical ophthalmic application of 10% phenylephrine in normal dogs results in elevation of arterial blood pressure and reflex bradycardia.

Objectives: To determine the presence of feline leukemia virus (FeLV) in the corneas of FeLV-infected cats., Animals Studied: Thirty-four random source cats., Procedures: Seventeen cats were found positive for FeLV serum p27 antigen by enzyme-linked immunosorbent assay (ELISA). Twelve ELISA positive cats were also positive on peripheral blood samples by immunofluorescent antibody (IFA) testing. Seventeen ELISA negative cats served as negative controls. Full thickness corneal specimens were collected from the left cornea of all cats and analyzed for FeLV proviral DNA and gp70 antigen by polymerase chain reaction (PCR) and immunohistochemical (IHC) testing, respectively., Results: Eleven (64.7%) positive corneal PCR results were obtained from 17 ELISA positive cats. Of 12 cats that were both ELISA and IFA positive on peripheral blood, 10 (83.3%) had positive corneal PCR results. All corneal tissues from ELISA negative cats were PCR negative. IHC staining of corneal sections revealed the presence of FeLV gp70 in corneal tissues of nine (52.9%) ELISA positive cats. Of the 12 cats that were both ELISA and IFA positive on peripheral blood, eight (66.7%) had positive corneal IHC results. Positive IHC staining was localized to the corneal epithelium. Corneal tissues of all ELISA negative cats and all IFA negative cats were negative on IHC testing., Conclusions: FeLV antigens and proviral DNA are present in corneal tissues of some FeLV-infected cats. Screening corneal donors for FeLV infection is warranted.

OBJECTIVE: To determine the effect of topical 1% ophthalmic atropine sulfate on intraocular pressure (IOP) in ocular normotensive horses. Animals Studied Eleven clinically healthy horses. Procedures IOP was measured bilaterally twice daily, at 8 AM and 4 PM, for 5 days. No medication was applied for the first 2 days of the study. Thereafter, one eye of each horse was treated with 0.1 mL of topical 1% atropine sulfate ointment twice daily (7 AM and 7 PM) for 3 days. The contralateral eye served as a control. In eight of the horses, an additional IOP reading was taken 3 days following cessation of the atropine treatment. RESULTS: There was no significant difference in the IOP of control vs. treatment eyes in the pretreatment period, days 1 and 2 (P = 0.97 and 0.55, respectively). During the treatment period, treated eyes of 10 of the horses had significantly lower IOP than control eyes (P = 0.03). The mean IOP reduction in treated eyes, relative to untreated eyes, was 11.2%. One horse had a significant rise in IOP in the treated eye compared to the remaining study animals. The IOP of control eyes did not vary significantly over the observation period (P = 0.27). There was no significant variation in IOP between the 8 AM and 4 PM measurement (P = 0.9). CONCLUSIONS: Topical 1% atropine sulfate causes a small, but significant decline in IOP in most ocular normotensive horses. Because topical atropine may elevate IOP in some horses, it should be used with caution in the treatment of glaucoma in this species.