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IEOC/Acrivet Equine Ophthalmology Symposium

Hotel Terra, Teton Village Jackson Hole, Wyoming, USA

June 7-9, 2013

International Equine Ophthalmology Consortium PO Box 1311 Meridian ID 83680 | 208-466-2519 | office@equineophtho.org

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IEOC/Acrivet Equine Ophthalmology Symposium

June 7-9, 2013 Terra Hotel, Teton Village | Jackson Hole, Wyoming, USA

The goal of this symposium is to share, with a small group of dedicated clinicians and scientists, current clinical and basic research on equine ophthalmology. Abstract and case presentations, along with social events, will facilitate the development of multi-centered collaborative research.

This symposium is sponsored by:

Exhibitors

Acrivet (Sponsor) 9067 S 1300 W Ste 104 Salt Lake City UT 84088

Ph: 801-256-9800 Fx: 801-562-3268

Contact: Joyce Wickham j.wickham@acrivet.com

Meds for Vets Pharmacy 585 West 9400 South #100

Sandy, UT 84070 Contact: Jamie Swayt

jamers316@hotmail.com

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SYMPOSIUM PROGRAM Map of meeting space: Page 52 Time Room Event Presenter Title/Topic Friday, June 7 6:00pm-10:00pm

Village Commons

Welcome Reception (weather permitting, otherwise Murie Ballroom)

Saturday, June 8 8:00am-5:00pm Murie Foyer Exhibits open 8:00am-8:30am Murie Foyer Breakfast with Exhibitors 8:30am-8:45am Murie Ballroom Welcome and

Introduction Dr. Rachel Allbaugh

8:45am-9:45am Murie Ballroom State of The Art Lecture

Dr. Elizabeth Giuliano

Photodynamic Therapy for Equine Periocular Tumors

9:45am-10:00am

Murie Foyer Break with Exhibitors

10:00am-11:00am

Murie Ballroom State of the Art Lecture

Dr. Elizabeth Giuliano

Photodynamic Therapy for Equine Periocular Tumors (continued)

11:00am-12:00pm

Scientific Abstract Presentations

Moderator: Dr. Tammy Michau

15 minute presentations, 5 minute Q&A

11:00am-11:20am

Murie Ballroom Dr. Kathern Myrna PRODUCTION OF PARATHYROID HORMONE RELATED PROTEIN IN EQUINE OPHTHALMIC AND PERIOCULAR SQUAMOUS CELL CARCINOMA

11:20am-11:40am

Murie Ballroom Dr. Mary Utter OUTCOMES AND COMPLICATIONS ASSOCIATED WITH SUPERIOR AND INFERIOR SUBPALPEBRAL LAVAGE SYSTEMS PLACED IN 112 EQUINE EYES (2011-2012)

11:40am-12:00pm

Murie Ballroom Dr. Caryn Plummer

COMPOSITION AND ANTI-PROTEOLYTIC ACTIVITY OF AN EQUINE AMNIOTIC MEMBRANE HOMOGENATE

12:00pm-1:00pm

Murie Ballroom Patio

Lunch

1:00pm-2:40pm

Scientific Abstract Presentations

Moderator: Dr. Tammy Michau

15 minute presentations, 5 minute Q&A

1:00pm-1:20pm Murie Ballroom Dr. Wendy Townsend

EQUINE ULCERATIVE KERATITIS: COMPARISON OF HISTOLOGY, CYTOLOGY, AND MYCOTIC CULTURE WITH RESULTS OF POLYMERASE CHAIN REACTION USING UNIVERSAL FUNGAL PRIMERS

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Time Room Event Presenter Title/Topic 1:20pm-1:40pm Murie Ballroom Dr. Riccardo

Stoppini EQUINE KERATOMYCOSIS IN NORTHERN ITALY: 65 CASES (2002-2012)

1:40pm-2:00pm Murie Ballroom Dr. James Rushton

LINEAR KERATOPATHY, A DEGENERATIVE PROCESS?

2:00pm-2:20pm Murie Ballroom Dr. Nelson Pinto ANTERIOR UVEITIS, ENDOTHELIITIS AND PIGMENT DISPERSION IN 11 HORSES

2:20pm-2:40pm Murie Ballroom Dr. Brian Gilger TREATMENT OF IMMUNE MEDIATED KERATITIS IN HORSES WITH EPISCLERAL CYCLOSPORINE MATRIX IMPLANTS

2:40pm-3:00pm Murie Foyer Break with Exhibitors 3:00pm-4:45pm

Case Reports

Moderator: Dr. Erica Tolar

10 minute presentations, 5 minute discussion

3:00pm-3:15pm Murie Ballroom Dr. William Miller CORNEA 3:15pm-3:30pm Murie Ballroom Dr. Andrew

Matthews CORNEA

3:30pm-3:45pm Murie Ballroom Dr. Marjorie Neaderland

CORNEA

3:45pm-4:00pm Murie Ballroom Dr. Silvia Stadler CORNEA 4:00pm-4:15pm Murie Ballroom Dr. Mary Utter CORNEA 4:15pm-4:45pm Murie Ballroom Dr. Tim Knott PHOTOGRAPHY 5:15pm-5:30pm Hotel Lobby Board buses for Dinner at Dornan’s 6:00pm-8:00pm Dornan’s Dinner at Dornan’s 8:00pm-8:30pm Entrance to

Dornan’s Board buses for return trip to hotel with stop in Jackson Hole*

Sunday, June 9 8:00am-5:00pm Murie Foyer Exhibits open 8:00am-8:30am Murie Foyer Breakfast with Exhibitors 8:30am-8:45am Murie Ballroom Speaker

Introduction Dr. Rachel Allbaugh

8:45am-9:45am Murie Ballroom State of the Art Lecture

Dr. Dennis Brooks Complications of Ophthalmic Surgery in the Horse

9:45am-10:00am

Murie Foyer Break with Exhibitors

10:00am-11:00am

Murie Ballroom State of the Art Lecture

Dr. Dennis Brooks Complications of Ophthalmic Surgery in the Horse (continued)

*The buses will return to the hotel via downtown Jackson Hole and will stop to drop off anyone who would like to spend the remainder of the evening in town. Transportation back to the hotel will be your own responsibility.Taxis are available in town.

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Sunday, June 9 (continued) Time Room Event Presenter Title/Topic 11:00am-12:00pm

Scientific Abstract Presentations

Moderator: Dr. Tammy Michau

15 minute presentations, 5 minute Q&A

11:00am-11:20am

Murie Ballroom Dr. Riccardo Stoppini

DIODE LASER PHOTOABLATION TO CORRECT DISTAL NASOLACRIMAL DUCT ATRESIA IN AN ADULT HORSE

11:20am-11:40am

Murie Ballroom Dr. Rachel Allbaugh

ELECTRORETINOGRAPHIC EVALUATION OF EQUINE EYES WITH EXTENSIVE BULLET-HOLE FUNDIC LESIONS

11:40am-12:00pm

Murie Ballroom Dr. Brian Gilger COMMON EQUINE OCULAR FUNDUS LESIONS EVALUATED BY SD-OCT

12:00pm-1:00pm

Murie Ballroom Patio

Lunch .

1:00pm-1:20pm Murie Ballroom Dr. James Rushton

A 2 YEAR OPHTHALMIC HEALTH SURVEY OF 266 LIPIZZANERS WITH SPECIAL EMPHASIS ON HERPESVIRUS INDUCED FINDINGS

1:20PM-1:40PM

Murie Ballroom Dr. Claudia Hartley

UNILATERAL INTERNAL OPHTHALMOPLEGIA & DELAYED ONSET ABDUCENS PALSY IN A YEARLING THOROUGHBRED FOLLOWING HEAD TRAUMA – PRESENTATION & DIAGNOSIS

1:40pm-2:25pm

Case Reports

Moderator: Dr. Erica Tolar

10 minute presentations, 5 minute discussion

1:40pm-1:55pm Murie Ballroom Dr. Brian Gilger SURGERY/ANESTHESIA 1:55pm-2:10pm Murie Ballroom Dr. Wendy

Townsend ORBIT

2:10pm-2:25pm Murie Ballroom Dr. Brian Patterson

CONJUNCTIVA

2:25pm-2:40pm Murie Foyer Break with Exhibitors 2:40pm-4:30pm Murie Ballroom Roundtable Discussions 4:30pm-5:00pm Murie Ballroom IEOC Member Business Meeting IEOC Members only 5:00pm Adjourn 5:00pm-5:30pm TBA IEOC Board Meeting IEOC Board Members only

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SYMPOSIUM INDEX LISTED IN ORDER OF PRESENTATION Program schedule……………………………………………………………… Page 4 Saturday, June 8th State of the Art Lecturer, Dr. Elizabeth Giuliano…………………………….. Page 9 “Photodynamic Therapy for Equine Periocular Tumors” (Notes will be made available through a University of Missouri URL to all attendees.) Abstracts: Author Title K. Myrna “PRODUCTION OF PARATHYROID HORMONE Page 13

RELATED PROTEIN IN EQUINE OPHTHALMIC AND PERIOCULAR SQUAMOUS CELL CARCINOMA”

M. Utter “OUTCOMES AND COMPLICATIONS ASSOCIATED Page 14

WITH SUPERIOR AND INFERIOR SUBPALPEBRAL LAVAGE SYSTEMS PLACED IN 112 EQUINE EYES (2011-2012)”

C. Plummer “COMPOSITION AND ANTI-PROTEOLYTIC Page 15

ACTIVITY OF AN EQUINE AMNIOTIC MEMBRANE HOMOGENATE”

W. Townsend “EQUINE ULCERATIVE KERATITIS: COMPARISON Page 16

OF HISTOLOGY, CYTOLOGY, AND MYCOTIC CULTURE WITH RESULTS OF POLYMERASE CHAIN REACTION USING UNIVERSAL FUNGAL PRIMERS”

R. Stoppini “EQUINE KERATOMYCOSIS IN NORTHERN Page 17

ITALY: 65 CASES (2002-2012)” J. Rushton “LINEAR KERATOPATHY, A DEGENERATIVE Page 18

PROCESS?” N. Pinto “ANTERIOR UVEITIS, ENDOTHELIITIS AND Page 19

PIGMENT DISPERSION IN 11 HORSES”

B. Gilger “TREATMENT OF IMMUNE MEDIATED KERATITIS Page 20 IN HORSES WITH EPISCLERAL CYCLOSPORINE

MATRIX IMPLANTS”

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Case Reports: Author Topic B. Miller CORNEA Page 21 A. Matthews CORNEA Page 23 M. Neaderland CORNEA Page 26 S. Stadler CORNEA Page 29 M. Utter CORNEA Page 32 T. Knott PHOTOGRAPHY Page 35 Sunday, June 9th State of the Art Lecturer, Dr. Dennis Brooks, …………………………… Page 37 “Complications of Ophthalmic Surgery in the Horse” Abstracts: Author Title R. Stoppini “DIODE LASER PHOTOABLATION TO CORRECT Page 41

DISTAL NASOLACRIMAL DUCT ATRESIA IN AN ADULT HORSE”

R. Allbaugh “ELECTRORETINOGRAPHIC EVALUATION OF Page 42 EQUINE EYES WITH EXTENSIVE BULLET-HOLE FUNDIC LESIONS” B. Gilger “COMMON EQUINE OCULAR FUNDUS LESIONS Page 43 EVALUATED BY SD-OCT” J. Rushton “A 2 YEAR OPHTHALMIC HEALTH SURVEY OF Page 44 266 LIPIZZANERS WITH SPECIAL EMPHASIS ON HERPESVIRUS INDUCED FINDINGS” C. Hartley “UNILATERAL INTERNAL OPHTHALMOPLEGIA & Page 45 DELAYED ONSET ABDUCENS PALSY IN A YEARLING THOROUGHBRED FOLLOWING HEAD TRAUMA – PRESENTATION & DIAGNOSIS” Case Reports: Author Topic B. Gilger SURGERY/ANESTHESIA Page 46 W. Townsend ORBIT Page 48 B. Patterson CONJUNCTIVA Page 50

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State of The Art Lecturer Elizabeth Giuliano, DVM, MS, DACVO University of Missouri Dr. Giuliano received a Bachelor of Science from Cornell University in Ithaca, New York in 1991 and her DVM degree from the University of Wisconsin-Madison in 1996. Following graduation from veterinary school, she completed a small animal rotating internship at the Animal Medical Center in New York City in 1997 and remained in private practice in midtown Manhattan the following year. In 1998, she returned to the University of Wisconsin-Madison to complete a Comparative Ocular Pathology

Fellowship. Since July 1, 1999, Dr. Giuliano has been a member of the Veterinary Medical Teaching Hospital at the University of Missouri-Columbia where she completed a residency in veterinary ophthalmology and a Masters of Science degree. She is currently a tenured faculty member of the department of veterinary medicine and surgery at the University of Missouri and section head of their comparative ophthalmology service. Dr. Giuliano was elected to the ACVO Board of Regents in the Fall of 2011.

(Notes will be made available by the speaker through a University of Missouri URL.)

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NOTES

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NOTES

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SATURDAY SESSION ABSTRACTS & CASE REPORTS

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PRODUCTION OF PARATHYROID HORMONE RELATED PROTEIN IN EQUINE OPHTHALMIC AND PERIOCULAR SQUAMOUS CELL CARCINOMA (KE Myrna,1 DS Major, EW Howerth2) Department of Small Animal Medicine and Surgery;1 Department of Pathology;2 College of Veterinary Medicine, University of Georgia. Purpose. To characterize the expression of parathyroid hormone related protein (PTHrP) by equine ocular squamous cell carcinoma (SCC). Methods. Records from horses biopsied for periocular SCC at the University of Georgia VTH from January 2008 to February 2012 were reviewed. Biopsies from 15 horses with confirmed SCC were immunohistochemically stained with a commercially available rabbit anti-PTHrP antibody. Slides were independently graded by all authors at 10x magnification for stain intensity on a scale of 0-3 (0 = negative control, and 3 = positive control,) Please discuss your control samples. One sample was “pre-cancerous” with moderate lymphoid follicular hyperplasia. This sample is reported separately. Records were reviewed for signalment, lesion location, metastasis, recurrence and serum calcium. Results. The average age of horses was 14.1 years (range: 2-28 years). Breeds represented included Paint Horses (7/15, 46.7%), Quarter Horse (3/15, 20%) , Tennessee Walking Horses (3/15, 20%), and one Thoroughbred and Percheron (6.7% each). 3 samples received a grade of 1 and 11 samples received a grade of 2. The pre-cancerous sample was graded 1. Bony invasion was present in one horse, no evidence of metastasis or recurrence was noted in any patient. Total serum calcium (tCa) was available for 10 horses and ionized calcium (iCa) for 3 horses. Values were overall normal with three mild hypocalcemias and one mild hypercalcemia. Conclusions. Ophthalmic SCC in horses produces PTHrP. A pre-cancerous lesion demonstrated mild expression. Serum calcium levels were not significantly elevated Indicating that PTHrP expression by the tumor was not sufficient to cause a clinically detectable increase in serum calcium levels. University of Georgia Veterinary Ophthalmology Research Fund. None.

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OUTCOMES AND COMPLICATIONS ASSOCIATED WITH SUPERIOR AND INFERIOR SUBPALPEBRAL LAVAGE SYSTEMS PLACED IN 112 EQUINE EYES (2011-2012) (MA Hays, ML Utter, NM Scherrer) New Bolton Center, University of Pennsylvania. Purpose. To describe the outcomes and complications associated with superior and inferior subpalpebral lavage (SPL) systems in equine eyes. Method. A retrospective medical record search was used to generate a list of horses treated with ophthalmic medications using an SPL from January 2011 through December 2012 at University of Pennsylvania’s New Bolton Center. Age, sex, breed, diagnosis, SPL lid placement (superior or inferior), duration of treatment using the SPL, complications and outcome were determined for each affected horse. Veterinarians who had placed SPLs and owners who had used SPLs during the study period were surveyed regarding their experiences. Results. A similar number of SPLs were placed in superior (46%) and inferior (54%) lids. There was no difference in the rate of complications associated with superior versus inferior lid SPLs. There was no difference in the disease conditions being treated, in the duration of therapy, or in the outcomes between superior and inferior lid SPLs. Subjectively, veterinarians described inferior SPL placement as being technically less difficult than superior SPL placement, and owners reported less uncertainty associated with monitoring and using inferior SPLs than with monitoring and using superior SPLs. Conclusions. Inferior SPLs may be easier to place and maintain, and are associated with similar complication rates and outcomes, compared to superior SPLs. None.

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COMPOSITION AND ANTI-PROTEOLYTIC ACTIVITY OF AN EQUINE AMNIOTIC MEMBRANE HOMOGENATE. (CE Plummer, JK Coleman, H Sapp, DE Brooks, BC Martins) College of Veterinary Medicine, University of Florida. Purpose. To analyze a suspension of equine amniotic membrane (EAM) designed for topical application to the eye, and determine if any anti-proteolytic activity persists after processing. Methods. The EAM was collected from normal full term deliveries, separated from the chorion, washed in phosphate buffered saline (PBS, Gibco), denuded (epithelial component) with 5.37 mM EDTA, and placed in a bath of PBS and 1% antiobiotic-antimycotic solution (ABAM, Invitrogen) for 3 hours. The amnion was then sectioned, placed in sterile glass tubes and lyophilized. Samples were resuspended in 5 ml Dulbecco’s phosphate buffered saline (DPBS, Gibco), homogenized (BBX5M Bullet Blender, NextAdvance), and then centrifuged at 10,000 rpm for 15 minutes to remove debris. The EAM homogenate (EAMH) was then analyzed by western blot, gelatin zymography, and reverse zymography for the presence, and activity, of tissue inhibitors of matrix metalloproteinases (TIMPs), matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and pigment epithelium derived factor (PEDF). Results. Western blot showed that significant amounts of TIMP-4 and moderate amounts of TIMP-2 and PEDF were present, while MMP-2, MMP-9, TIMP-1, TIMP-3 and VEGF were absent. MMP-2 and MMP-9 were also negative by gelatin zymography; while reverse zymography showed strong TIMP-based inhibition of human MMP-2 and moderate inhibition of human MMP-9. Conclusions. The EAMH did have significant anti-proteolytic activity following lyophilization and homogenation. More importantly, the presence of TIMPs suggests indicates that it’s use may potentially decrease the activity of proteases present in ocular surface diseases of the horse. Supported by a University of Florida Consolidated Faculty Competition Grant. None.

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EQUINE ULCERATIVE KERATITIS: COMPARISON OF HISTOLOGY, CYTOLOGY, AND MYCOTIC CULTURE WITH RESULTS OF POLYMERASE CHAIN REACTION USING UNIVERSAL FUNGAL PRIMERS (WM Townsend,1 H Mohammad, 2

MN Seleem 2) Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University;1 Department of Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University.2

Purpose. To compare the results of histologic and cytologic evaluation, mycotic culture, and a polymerase chain reaction (PCR) assay on corneal samples from horses with ulcerative keratitis. Methods. Corneal samples were collected from horses with ulcerative keratitis for routine cytologic evaluation (Kimura spatula), aerobic and mycotic culture (culture swab), and a PCR assay (culture swab). In surgical cases, histologic evaluation was performed. The PCR assay used internal transcribed spacer 2 (ITS2) genetic region universal fungal primers. Amplified PCR products were sequenced and analyzed using the GenBank database nucleotide BLAST alignment program. Descriptive results are presented. Positive and negative controls were included in the PCR assay. Results. Four eyes were sampled for cytology, culture, and PCR. On cytologic examination, 1/4 (Case 3) had fungal hyphae visualized with morphology suggestive of Aspergillus sp., while 3/4 had no infectious agents noted. The cultures yielded no growth for 4/4. Histologically, numerous fungal hyphae were noted with morphology suggestive of Aspergillus sp. in the one case (Case 4) with histologic evaluation. PCR was positive in 4/4 with isolates identified as Cryptococcus albidus in Case 1, an uncultured Ascomycete in Case 2, and Aspergillus flavus in Cases 3 and 4. Conclusions. Mycotic culture was unrewarding. In the 2 cases with Aspergillus flavus detected using PCR, either cytologic or histologic evaluation had also suggested the involvement of Aspergillus spp. In the other 2 cases with fungi detected on PCR, there was no other evidence of fungal involvement and may represent true infections or environmental contaminants. None.

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EQUINE KERATOMYCOSIS IN NORTHERN ITALY: 65 CASES (2002-2012) (R Stoppini 1, L Barachetti 2) Equine Ophthalmology Practitioner, Brescia, Italy;1 Department of Veterinary Science and Public Health, University of Milan, Italy;2 Purpose. To review clinical data of 65 cases of keratomycosis in Northern Italy between 2002-2012, considering incidence, season, clinical findings, medical/surgical approach, scar formation and visual outcome. Methods. Keratomycosis cases were categorized according to lesion depth: group 1: < 1/3 depth (n=9); group 2: between 1/3 and 2/3 depth (n=20); group 3: >2/3 depth (n=36, including 7 cases with corneal rupture) and were confirmed by cytology, culture, or histopathology. Corneal scaring and secondary intraocular damage were graded. Results. Total incidence was 5.6% (65 cases out of 1156 horses referred for ophthalmic problems between 2002 and 2012). The majority of the cases were referred between June and November (84.6%). Fungal organisms were confirmed via cytology (24/30, 80%), culture (8/14, 57%), and histopathology (50/50, 100%). Medical therapy was used alone in 19 cases (29.2%) and surgical therapy in 46 cases (70.8%). Surgical procedures included: Keratectomy (6), Conjunctival Pedicle Graft (21), Amniotic Membrane Transplant (10), BioSISt® (6) or ACell® (1) with conjunctival pedicle graft, Penetrating Keratoplasty (2). Eight cases required a second surgical procedure. Scar formation was slight (n=21, 32.3%), moderate (n=25, 38.5%) or severe (n=19, 29.2%). Vision was considered complete (n=21, 32.3%), incomplete (n=30, 46.2%) or absent (n=14, 21.5%). Conclusions. In Northern Italy keratomycosis has a relatively high incidence and negatively influences visual outcome especially in cases involving the posterior cornea.

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LINEAR KERATOPATHY, A DEGERNATIVE PROCESS? (J Rushton1, A Tichy2, B Nell1) 1 Department of Companion Animals and Horses, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria 2 Department for Biomedical Sciences, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria

Purpose. To report increasing numbers of horses showing linear keratopathy, the symptoms of which may occur with progression of age, in a closed study population of Lipizzaners. Methods. A closed population of Lipizzaners in 3 different federal states in Austria underwent complete ophthalmic examination 4 times over a period of 2 years, with 6 month intervals. Findings consistent with linear keratopathy were recorded, and associated with factors such as gender, location, boarding in open boxes or freestalls, training or transfer from one location to another throughout the study period. Logistic regression was applied to determine the influence of age on ophthalmic findings. Results. On the first, second, third and fourth examination 0.8%, 3.1%, 4.4% and 4.8% of the study population were diagnosed with linear keratopathy. No further progression of the disease was evident, once it had been identified. There was no history of antecedent ocular problems and no further pathologies were found in horses with this finding. Statistical analysis did not reveal any influence of gender, location, boarding, training or transfer between locations on this finding. However there was a significant influence of age on the presence of linear keratopathy. Conclusion. Based on the results of this study, a degenerative process of Descemet´s membrane as the underlying cause for linear keratopathy in aging horses seems likely, despite the lack of histological proof of this theory. We therefore recommend to include degeneration of Descemet´s membrane to the list of differential diagnoses in cases of linear keratopathy.

Support: Grant by Spanish Riding School-Federal stud Piber and Veterinary University Vienna. NONE

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ANTERIOR UVEITIS, ENDOTHELIITIS AND PIGMENT DISPERSION IN 11 HORSES (N Pinto,1 R McMullen Jr,1 K Linder2, J Cullen2, BC Gilger1) College of Veterinary Medicine, North Carolina State University, Department of Clinical Sciences;1, Department of Pathology.2, Raleigh, NC USA. Purpose. To describe the clinical, histopathologic and immunohistochemical characteristics of concomitant anterior uveitis and corneal endothelial inflammation associated with iris pigment dispersion in the horse. Methods. Horses presenting to North Carolina State University Veterinary Teaching Hospital between 2007 and 2011, with evidence of pigmented keratic precipitates and corneal edema were considered for inclusion. Information recovered from the medical records included signalment, clinical signs, pre-referral treatment duration and response to therapy, ophthalmic examination findings, post-referral treatment, response to therapy, and outcome. Results. 14 eyes from 11 horses between 10 and 22 years of age were included. Blepharospasm, epiphora, and/or corneal opacification were the first clinical signs noted. Further examination revealed iridal depigmentation, pigmented keratic precipitates and retrocorneal membranes. Treatment included topical and/or systemic anti-inflammatories and antibiotics. The response to treatment was variable, and 5 of the 14 eyes were ultimately enucleated. Anti-inflammatory therapy alteration resulted in worsening of clinical signs. Histopathology changes included iridal pigment dispersion with variable degrees of lymphoplasmacytic infiltrate. All 5 enucleated eyes had retrocorneal fibrous membranes and variable lymphoplasmacytic corneal stromal infiltrate. Immunohistochemistry revealed that T-cells were predominant in the iris, corneal endothelium and retrocorneal membranes, which were reactive to anti-smooth muscle actin and anti-vimentin, but negative to anti-cytokeratin. Conclusions. Horses being treated for uveitis associated with iris pigment dispersion and secondary corneal endothelial inflammation require diligent and frequent follow up examinations in combination with aggressive local immune suppression. However, the disease cannot always be controlled, and enucleation may ultimately be necessary to ensure the horse’s comfort. Support: None COI: None.

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TREATMENT OF IMMUNE MEDIATED KERATITIS IN HORSES WITH EPISCLERAL CYCLOSPORINE MATRIX IMPLANTS (BC Gilger,1 AB Clode,1 R Stoppini,2 NH Pinto,1 J Hemstead,1 J Gerding,1 JH Salmon1) Department of Clinical Sciences, North Carolina State University, Raleigh, NC USA;1 Equine practice, Brescia, Italy2

Purpose. To describe the use of episcleral silicone-matrix cyclosporine implants (ESMC) in horses with IMMK. Methods. Retrospective study. ESMC implants (1.2 cm length, 30% wt/wt CsA in silicone; with approximately 2 ug/day steady-state release for at least 400 days) were made at NCSU. Results. Fifteen horses (18 eyes) received one or more ESMC implants for superficial stromal (n=5), mid stromal (n=2), or endothelial (n=5) IMMK. A further 3 horses received one or more ESMC implants for pigmentary keratouveitis (PK). Five of 7 horses with superficial or midstromal IMMK and 4 of 5 horses with endothelial IMMK were well controlled after placement of ESMC implants (mean follow-up 215 days). Long disease duration prior to implantation was associated with less inflammation control with the ESMC implants. Horses with PK were not controlled with ESMC implants alone, but instead required use of frequent other medications. ESMC implants were well tolerated by all horses with only an occasional loss of the device. Conclusions. Results from this preliminary uncontrolled retrospective study suggests that the EMSC implants were well tolerated and appeared efficacious, especially early in the disease process with superficial, midstromal, and endothelial IMMK. Further study is needed to determine the duration of efficacy, number of implants required, and better therapies for pigmentary keratouveitis.

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AUTHORS AND ADDRESSES: Racconi RA(1), Miller WW(2)

(1) Mississippi State University College of Veterinary Medicine, Mississippi State, MS 39760

(2) Advanced Animal Eye Care, 555 Trinity Creek Cove, Cordova, TN 38118

TOPIC AREA: Cornea CASE SUMMARY: A 4 year old Quarter horse gelding presented for progressive opacification of the right eye. Initially the owner reported the eye to be mildly uncomfortable. Historically only a rim of edema was observed in the inferior perilimbal cornea. Treatment with topical antibiotics, antifungals, osmotics, and steroids failed to alter the progression. Examination revealed diffuse corneal edema of approximately 60% of the corneal surface. No other abnormalities were observed in the right eye. The left eye was within normal limits. Endothelitis was the presumptive initial diagnosis. Since the disease had progressed despite prior therapy and because of the horse’s intense training schedule it was elected to perform a keratoleptynsis surgery. Surgery was uncomplicated with the horse discharged from the hospital 5 days after surgery. Reevaluations at 1, 3, and 6 months following surgery demonstrated a clearer cornea with minimal scar. The horse was able to return to training one month following surgery. KEY WORDS: Cornea, surgery, edema, keratoleptynsis DISCUSSION POINTS: Etiology of endothelitis Medical therapy following keratoleptynsis surgery Alternative therapies to surgery How can pigment be stopped from proliferating in the graft

Diffuse corneal edema affecting the right eye of a 4 year old Quarter horse gelding

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Right eye immediately post-op demonstrating keratoleptynsis graft.

Right eye 6 months post-op. demonstrates pigmentation of the graft but intraocular structures can be seen through all areas of the graft.

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AUTHORS AND ADDRESSES: Dr. A G Matthews EICON, Bents Cottage, Redcastle, Lunan Bay, Inverkeilor, Angus, UK, DD11 5SS Emma Scurrell Cytopath, PO Box 24, Ledbury, Herefordshire, UK, HR8 2YD TITLE: Duplication of Descemet’s Membrane in a Horse: A Case Report TOPIC AREA: Cornea CASE SUMMARY: Duplication of Descemet’s membrane following endothelial insult is reported in people, dogs and cats, but to date not in horses. This report involves the right eye of a part-TB mare, first seen as a 5 year old in 1995. The previous history was unknown. The eye presented with non-painful ventral corneal oedema and semi-translucent fibrous-like membranes draped across the posterior ventral cornea (Fig 1). The horse subsequently worked without incident and was re-presented in 2007. At this time the opacity and posterior membranes had extended geographically. Dense, focal posterior corneal opacities and well defined normally transparent ‘holes’ in the more general posterior opacity were evident in the temporal quadrants (Fig 2). In May 2009 acute endothelial decompensation occurred, resulting in complete corneal opacity refractory to medical therapy (Fig 3). The horse was euthanased in 2010 for unrelated reasons. Histologically the cornea showed extensive duplication of Descemet’s Membrane with dome-like extensions and evidence of endothelial attenuation (Fig 4). Chronic stromal fibrosis, mineralization, vascularisation, pigmentation and neutrophilic keratitis were present. There was no evidence of acute or historic uveitis. The cause and temporal sequence of the intraocular pathological events could not be established, although initiating historic blunt trauma was suspected. KEY WORDS: Duplication, Descemet’s membrane. DISCUSSION POINTS: Mechanisms underlying pathological duplication of Descemet’s membrane. The horse eye is subject to blunt trauma, keratouveitis and ‘endotheliopathies’ with some frequency, yet why is this pathological event previously unrecorded in the horse?

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Fig 1: Eye in 1995 at initial presentation.

Fig 2: Eye in 2007, showing the focal opacities on the posterior cornea and transparent ‘holes’ in the more diffuse opacity in the temporal quadrants.

Fig 3: Eye in 2008, acute endothelial decompensation.

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Fig 4: Duplication of Descemet’s membrane (H&E)

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AUTHOR AND ADDRESS: Marjorie Neaderland, DVM, DACVO Animal Eye Clinic, 123 West Cedar St., Norwalk, CT 06854 TOPIC AREA: Cornea TITLE: Malignant transformation of B cell lymphoma from IMMK CASE SUMMARY: 15 year old Oldenberg gelding was chronically treated for presumed bilateral IMMK with worsening of clinical signs in the right eye over 9 months. Mid stromal keratectomy was performed on the right eye. Small numbers of neutrophils, small lymphocytes and plasma cells were present with small sheets of large atypical mononuclear cells with abundant cytoplasm suggestive of neoplasia identified. Immunohistochemical and clonality staining revealed B cell lymphoma. CD3 for T cells stained small lymphocytes. MHC2, CD79a and CD20 stained the neoplastic appearing cells, molecular clonality analysis of IGH2 and IGH3 revealed clonal arrangements, consistent with an antigen presenting B cell lymphoma. The cornea was determined to be the only affected site after systemic diagnostics were performed. Treatment for corneal lymphoma was pursued with brachytherapy radiation, Xoft Axxent brachtherapy machine, delivering 6 Grey, 3 sessions over 6 weeks. Topical Mitomycin C treatment was performed post radiation to reduce post op corneal fibrovascular scarring (QID for one week, every other week for 3 cycles). Corneal clarity has significantly improved resulting in a currently comfortable and visual eye. KEY WORDS: Cornea, IMMK, B cell lymphoma, brachtherapy, Mitomycin C DISCUSSION POINTS: Immunohistochemical staining for IMMK keratectomies Brachytherapy for corneal disease Mitomycin C topical treatment for fibrovascular corneal scarring

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Figure 1: cornea pre op keratectomy

Figure 2: cornea 4 weeks post op keratectomy

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Figure 3: cornea 3 months post op radiation, 1 month post Mitomycin C

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AUTHORS AND ADDRESS: Stadler, S Pferdeklinik Tillysburg, Bruck bei Hausleiten 11, St. Florian 4490, Austria TOPIC AREA: Cornea CASE SUMMARY: A 12 year-old grey pony gelding was presented with an unilateral non-painful, diffuse chronic non-ulcerative superficial to midstromal corneal opacity affecting nearly the entire cornea with moderate signs of cellular infiltrate, one area of epithelial pigmentation and corneal vascularisation. The pony was treated with topical anti-inflammatory and immunosuppressive therapy (dexamethasone, cyclosporine 1%, bromfenac) several times and was treated surgically three times (superficial keratectomy, keratectomy and amnion-graft). Histopathology revealed infiltration of predominantly lymphocytes, stromal fibrosis, neovascularisation and keratin lamellae (pigment). Despite intensive and long-term immunmodulatory and surgical therapy this presumptively immune-mediated keratitis (IMMK) case has a strong tendency towards recurrence and refractoriness. KEY WORDS: Cornea Presumptively immune-mediated Recurrence and refractoriness to treatment DISCUSSION POINTS: Diagnosis: clinical presentation – histopathology Aetiopathogenesis – corneal pathology Therapy – topically – surgery Control of recurrence and refractoriness

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22.3.2011

14.9.2012

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21.1.2013

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AUTHORS AND ADDRESS: Utter, Mary Lassaline New Bolton Center, 382 W. Street Rd, Kennett Square, PA 19348 TOPIC AREA: Cornea TITLE: A-cell graft for keratomalacia CASE SUMMARY: A 9-year old Trakehner gelding was presented with a 15mm diameter melting corneal ulcer OS. Topical therapy prior to referral included an antibiotic, antifungal, anticollagenase and atropine, as well as a topical NSAID every four hours which was discontinued at admission. Corneal cultures grew Apergillus sp. (cultured prior to referral) and Pseudomonas sp. (cultured at admission). A keratectomy and A-cell graft were performed under general anesthesia to provide tectonic support for the globe. A complete temporary tarsorrhaphy placed postoperatively was left intact for 18 days. At the time of tarsorrhaphy removal, the cornea was fluorescein negative with no evidence of the A-cell graft present, and the horse was comfortable with a well dilated pupil on only 100mg flunixin twice daily. Eight other patients over the past eight months have received A-cell grafts for large keratectomies. Eight of nine A-cell grafts resulted in a good outcome. All surviving globes developed unanticipated ocular pain and corneal opacity approximately two weeks postoperatively, which resolved with anti-inflammatory therapy. A-cell may be a viable alternative for corneal grafting, with the advantage of commercial availability and shelf storage, but a period of keratouveitis may prolong healing. KEY WORDS: Keratomalacia, A-cell, transplant, graft DISCUSSION POINTS: Use of different biomaterials to serve different functions in corneal grafting (e.g., tectonic support, tissue replacement, cosmesis, optical clarity) Complications associated with different biomaterials Outcomes associated with different biomaterials

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Figure 1: Preoperative, severe keratomalacia is evident

Figure 2: Immediately postoperatively, A-cell graft is sutured in place.

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Figure 3: 18 days postoperatively.

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AUTHOR AND ADDRESS: Tim Knott, Rowe Referrals & The Equine Eye Clinic, Gloucestershire, UK timknott@equineeyeclinic.co.uk TITLE: Phoneoscopy – The Use of Smart Phone Cameras in Equine Ophthalmoscopy TOPIC AREA: Photography CASE SUMMARY: Using the built in camera on a smart phone without modification it is possible to record high resolution fundic images and video without the use of additional lenses or ophthalmoscopes. This technique relies on the small size of the smart phone camera lens and the close proximity of the LED light to the optical axis. The use of a camera application (e.g. The Iphone App Camera +, Tap Tap) which allows continuous illumination of the field of view is key to allowing fundic illumination, fundic photography or videography. The Iphone 4 or 4s can both be used to produce excellent fundic images. This technique can be applied to any smart phone camera where the LED camera light can be used continuously and is close enough to the camera lens. While the technique mirrors close direct ophthalmoscopy the iphone lens is considerably “wider angle” than the human eye resulting in a field of view in excess of that gained with a 20 dioptre indirect lens. Other techniques such as distant direct tapetal examination and the use of macro lenses to image the anterior segment and lens are also demonstrated.

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Equine fundus: Pigmentary retinopathy. Single

fundic image – captured with iPhone4S .

The LED is covered in 2-3 layers

of Micropore tape, the pupil dilated and the phone camera positioned close to the cornea.

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State of The Art Lecturer Dr. Dennis Brooks, DVM, PhD, DACVO University of Florida Dr. Brooks is the Ophthalmology Service Chief for the Department of Small Animal Clinical Sciences at the University of Florida College of Veterinary Medicine. He holds his DVM degree in veterinary science from the University of Illinois in Urbana, 1976-1980 and residency at UF, 1981-1985. He

holds a PhD in Glaucoma from UF in 1987 and is a Diplomate of American College of Veterinary Ophthalmologists board certified in 1984. His research interests include corneal transplantation in horses, eye problems in horses and glaucoma in all animals.

Complications of Ophthalmic Surgery in the Horse

Dennis E Brooks, DVM, PhD, Dip ACVO Professor of Ophthalmology

Department of Large Animal Clinical Sciences College of Veterinary Medicine

University of Florida 2015 SW 16 Ave

Gainesville, FL 32608 Office Phone: 352-392-2229 Fax: 352-294-9867

Email: brooksd@ufl.edu

Advances in the understanding of ophthalmic diseases of the horse and improved microsurgical technologies now allow for more complicated ophthalmic surgical procedures to be successfully performed on the horse eyelids, cornea, lens and vitreous, and for the successful treatment of equine glaucoma. A discussion of the common complications of selected ophthalmic surgical procedures in the horse can perhaps reduce their occurrence and minimize the degree of ocular dysfunction per occurrence. Indications, techniques and possible complications are discussed for the conditions listed (see complete notes online at this link: www.equineophtho.org/uploads/documents/ Brooks_2013IEOC_Complications_of_Ophthalmic_Surgery.pdf)

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EYELIDS Traumatic Eyelid Lacerations Entropion Laser as Alternative Surgical Technique for Eyelid Tumor Removal

NICTITANS

Nictitans or Third Eyelid Flaps Surgical Technique for Removal of the Third Eyelid

CORNEA

Corneal Lacerations Melting Ulcers and Keratectomy, Conjunctival Grafts, Amniotic Membrane Grafts Keratectomy Conjunctival Transplant Grafts Amniotic Membrane Grafts Penetrating Keratoplasty

Split Thickness Penetrating Keratoplasties

Posterior Lamellar Keratoplasty Deep Lamellar Endothelial Keratoplasty

LENS Cataract Surgery Equine Phacoemulsification Intracapsular Surgery for Cataract or Luxated Lens SURGICAL THERAPY FOR UVEITIS

Sustained release cyclosporine A delivery devices Pars Plana Vitrectomy for ERU

SURGICAL TREATMENT FOR GLAUCOMA

Transcleral Cyclophotocoagulation Gonioimplants Cyclocryosurgery Ciliary Body Ablation

GLOBE SURGERY Exenteration Evisceration and Intrascleral Prosthesis Implantation Enucleation Transpalpebral EnucleationTechnique Subconjunctival Enucleation Technique Intraorbital Prostheses

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SYNOPSIS Corneal transplantation, amniotic membrane transplantation, phacoemulsification cataract extraction, and laser glaucoma therapy are routine ophthalmic surgical procedures in horses. It is imperative to be aware of the indications, techniques and postoperative complications of these and other ophthalmic surgical procedures in horses. Meticulous and accurate anatomical repair can minimize postoperative complications to maintain positive visual outcomes in ophthalmic surgery of the horse.

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SUNDAY SESSION ABSTRACTS & CASE REPORTS

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DIODE LASER PHOTOABLATION TO CORRECT DISTAL NASOLACRIMAL DUCT ATRESIA IN AN ADULT HORSE (R Stoppini 1, S Tassan2) Equine Ophthalmology Practitioner, Brescia, Italy;1 Equine Practitioner, Milano, Italy;2 Purpose. To describe diode laser photoablation to correct unilateral distal nasolacrimal duct atresia. Methods. An 8 year-old, Hanoverian mare presented with unilateral chronic mucopurulent ocular discharge. The nasolacrimal duct (NLD) was normal on the right side, but the left nasal orifice was absent. Following sedation and local anesthesia, the left inferior lacrimal punctum was cannulated and irrigated. Dacryocystorhinography revealed distal NLD atresia. The horse was placed in stocks, sedated, and infraorbital and palpebral nerve blocks were performed. The proximal ventral nasolacrimal punctum was cannulated with a 1.7 mm Ø - 56 cm long, urinary catheter with the distal end trimmed and rounded. A 30-Watt, 980 nm diode laser (GAP Laser and Photonics, Solbiate Olona, Italy) was set at 18 Watts in continuous mode. A 600 µm diameter flexible bare quartz fiber was introduced until the tip was palpable through the nasal mucous membranes. The laser was activated and the quartz fiber gently advanced to create a new distal nasolacrimal orifice with minimum bleeding. The urinary catheter was replaced with a 1.1mm Ø feeding tube and sutured in place for 4 weeks. Therapy consisted of oral phenylbutazone for 2 days and topical tobramycin (4 times daily OS) for 15 days. Results. Creation of a distal nasolacrimal orifice was easily achieved. At the three-month postoperative re-evaluation the Jones test was positive, despite the inability to directly visualize the distal nasolacrimal orifice. Conclusions. The technique described was easily performed on the standing sedated horse, minimized bleeding, and was completed within 30 minutes.

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ELECTRORETINOGRAM EVALUATION OF EQUINE EYES WITH EXTENSIVE BULLET-HOLE FUNDIC LESIONS (RA Allbaugh, G Ben-Shlomo, and RD Whitley) Iowa State University College of Veterinary Medicine, Department of Veterinary Clinical Sciences, Ames, IA 50011, USA Purpose. To evaluate the impact of extensive bullet-hole nontapetal fundic lesions in horses on retinal function as measured by electroretinogram (ERG). Methods. Two horses with extensive bullet-hole lesions in both eyes had electroretinographic responses recorded bilaterally using a contact lens electrode and a mini-Ganzfeld electroretinographic unit. The horses’ pupils were dilated, they were sedated with intravenous detomidine, and an auriculopalpebral nerve block was performed. 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 min of dark adaptation. Consecutively, combined rod-cone response was evaluated bilaterally in response to high intensity light stimulus (3 cd.s/m2). Off-line analysis of the ERG 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 min of dark adaptation peaking at 469µv and 402µv for horse number 1 and 2 respectively. The b-wave amplitudes of the combined rod-cone response were OS- 459µv and OD- 392µv for horse number 1 and OS- 508µv and OD 608µv for horse number 2. Conclusions. Extensive bullet hole chorioretinal lesions do not appear to compromise outer retinal function. Further evaluation could be performed to evaluate structural changes to the retina and inner retinal function. None

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COMMON EQUINE OCULAR FUNDUS LESIONS EVALUATED BY SD-OCT (BC Gilger, N Pinto, AB Clode) Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA. Purpose. To determine the feasibility of use of a hand-held spectral domain optical coherence tomography (SD-OCT) instrument for examination of the equine ocular fundus. Methods. A SD-OCT instrument (Envisu SD-OCT, Bioptigen, Inc., Morrisville, NC) was used to image clinically normal horses and those with common retinal defects. Horses were tranquilized with detomidine, given palpebral nerve blocks, and dilated with 1.0% tropicamide HCL. The SD-OCT was used to create a series of tomographic and volumetric scans of the equine retina. A flexible tripod device (Grypton™ Portable Flexible Tripod, Targus USA, Anaheim, CA) was modified to stabilize the SD-OCT during measurement. Clinical retinal lesions imaged included presumed RPE coloboma, “bullet-hole” lesions, peripapillary depigmentation, and optic nerve lesions. Results. Despite the rapid scan rate of the Envisu OCT and use of the flexible tripod, horse and operator motion made scan acquisition difficult. However, with the SD-OCT we were able to identify individual retinal anatomic layers, measure thickness, and evaluate surface anatomy of the optic disc. Furthermore, we were able to visualize the tissue changes associated with common equine fundus lesions. Conclusions. Using the SD-OCT, we were able to non-invasively and in real-time generate high-resolution images of ocular posterior segment tissues in the horse. Despite motion artifacts, SD-OCT imaging of the equine retinal resulted in near histologic resolution of retinal pathology. Support: None COI: None

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AN 18 MONTH OPHTHALMIC HEALTH SURVEY OF 266 LIPIZZANERS WITH SPECIAL EMPHASIS ON HERPESVIRUS INDUCED FINDINGS (J Rushton1, A Tichy2, B Nell1)1Department of Companion Animals and Horses, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria; 2Department for Biomedical Sciences, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria

Purpose. The purpose of this study was to illustrate the course of equine ocular findings over a period of 18 months at 6 month intervals, and to associate them with the results of herpesvirus PCR. Methods. 266 Lipizzaners in 3 federal states of Austria underwent complete ophthalmologic examination 4 times. Blood samples, nasal- and conjunctival swabs were obtained at the same time and used for the detection of Gammaherpesviruses. The influence of herpesvirus infection and other contributing factors on ocular findings was determined using one-way ANOVA, and logistic regression. Results. In the first, second, third and fourth examination period 266, 261, 249 and 230 horses were included respectively. Ophthalmic findings consistent with herpesvirus infection included conjunctivitis with 118 (44.4%), 145 (55.6%), 151 (60.6%), and 170 (73.9%) cases for each respective examination and corneal pathologies with 53 (19.9%), 67 (25.7%), 83 (33.3%) and 83 (36.1%) cases respectively. Statistical analysis revealed a statistically significant decrease of positive herpesvirus PCR results with progressing age. The presence of corneal findings increased significantly over time and with progressing age. At the time of each examination 45.1%, 41.8%, 43.0%, and 57.0% of horses with conjunctival or corneal findings respectively were positive for Gammaherpesviruses. When inflammatory corneal diseases and conjunctivitis were correlated with PCR results, which had been obtained 6 months earlier 16.9%, 8.8%, and 13.9% of horses developed these findings between examinations. Conclusion. Based on the results of our study there is a significant influence of young age on herpesvirus infection. Corneal pathologies increased over time and with progressing age. Over all examination periods an average of 46.7% of horses had ocular findings consistent with herpesvirus induced infection and 13.2% of new cases with antecedent positive PCR results were identified between two examinations.

Support: Grant by Spanish Riding School-Federal stud Piber and Veterinary University Vienna. NONE

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UNILATERAL INTERNAL OPHTHALMOPLEGIA AND DELAYED ONSET ABDUCENS PARESIS DUE TO FRACTURE OF THE BASISPHENOID IN A YEARLING THOROUGHBRED FOLLOWING HEAD TRAUMA (C Hartley1, E Beltran1, J Stewart1, C Chiwitt1(2), E Curnow3, P Johnson1, A Holloway1, S Powell3, C Marr3) 1 Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, U.K.;(2) Current address: Willows Veterinary Centre and Referral Service, Highlands Road, Shirley, Solihull, West Midlands, B90 4NH, U.K.;3 Rossdales Equine Hospital, Cotton End Road, Exning, Newmarket, Suffolk, CB8 7NN, U.K. Purpose. To describe the presentation and diagnosis of unilateral internal ophthalmoplegia and delayed-onset abducens paresis in a yearling Thoroughbred (TB). Case report. Immediately following the head trauma the TB remained prone with marked right sided epistaxis, a fixed and dilated right pupil, and swollen left periocular tissues and superficial corneal ulceration. The following day he was admitted to Rossdales Equine Hospital (REH) for examination, skull radiography and further treatment. Lethargy and a hypermetric gait resolved quickly. Endoscopy revealed haemorrhage emanating from the right ethmoidal sinus, and submucosal haemorrhages of dorsal guttural pouches bilaterally. Skull and lateral cervical radiographs were unremarkable. A mild anaemia and hypoproteinaemia consistent with recent severe haemorrhage was present. Abnormal voluntary eye movements were present in the right eye (exaggerated globe movements medially and weakened lateral movements), but no strabismus or nystagmus. A marked enophthalmos, medial strabismus, and third eyelid protrusion developed in the right eye by 10months post-injury. Tertiary referral (Animal Health Trust (AHT)) for ophthalmological and neuro-ophthalmological assessment revealed no extraocular muscle restriction (forced duction tests), no pupillary constriction response to topical 0.1% pilocarpine, or globe movement response to topical 0.1% phenylephrine in the right eye. Normal corneal and facial sensation and palpebral reflexes were present. A menace response was bilaterally present and fundus examination was unremarkable. Excursions of the head (vestibulo-ocular reflex) could elicit a weakened lateral movement of the globe suggesting lateral rectus dysfunction due to abducens nerve (CN VI) paresis. Neurolocalisation was at the level of the right orbital fissure involving the oculomotor nerve (parasympathetic component) and abducens nerve. Ocular and orbital ultrasound did not identify any abnormalities, but relative sizes of extraocular muscles were difficult to compare due to strabismus. Computed tomography understanding sedation (REH) did not identify any significant abnormalities. Euthanasia was elected and magnetic resonance imaging (MRI) of cadaver, and post-mortem (PM) examination, was undertaken (AHT). MRI failed to identify any abnormalities in the orbit, skull, or brain. Post-mortem identified a small fracture of the rostral end of the right pterygoid process of the basisphenoid, which involved the medial part of the right orbital fissure. Conclusion. Fracture of the rostral end of the right pterygoid process of the basisphenoid is capable of causing internal ophthalmoplegia and delayed-onset abducens paresis in the horse as has been described in humans. Funding: None.

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AUTHOR AND ADDRESS: Brian Gilger, Alison Clode North Carolina State University College of Veterinary Medicine TITLE: Complications on recovery after general anesthesia TOPIC AREA: Surgery / Anesthesia CASE SUMMARY: A 25-year-old Arabian mare was presented after an 8-week history of a progressive corneal stromal abscess of the right eye. Because the horse had only been exposed to one antifungal medication prior to presentation and because of the owner’s wish to avoid anesthesia, aggressive antifungal medical therapy was initiated using topical voriconazole, oral fluconazole, and 3 subconjunctival injections of amphotericin B (separated by 48 hours each). After approximately one week, the stromal abscess had not responded to medical therapy and developed satellite lesions. Surgical removal of the abscess was then recommended. Following general anesthesia and a retrobulbar nerve block (10 cc lidocaine), a two-step PK/conjunctival pedicle flap (8 mm diameter) was performed without complication. The horse had a very rough recovery from anesthesia, despite giving romifidine and subsequently acepromazine. The horse was profoundly ataxic and after falling several times, she buckled her two front legs and fell directly forward onto her head into a wall of the recovery stall. The unconscious horse was placed in lateral recumbency, re-intubated, and ventilated. The left eye was noted to have rotary and horizontal nystagmus, marked mydriasis, and no direct PLR. The patient was given IV fluids, mannitol, and prednisolone injectable. No movement was noted following the fall, aside from inadvertent nystagmus and palpebral twitching. Blood gas values were normalized, however no return of spontaneous respiration was ever achieved. The horse was subsequently euthanized. No necropsy was performed. DISCUSSION POINTS: - Do ophthalmic patients routinely take longer to recover from anesthesia and have

rougher recoveries? - What role does retrobulbar nerve blocks have on recovery from general anesthesia? - Does use of neuromuscular blockades improve or worsen equine recoveries? - Should ropes and padded hoods be used for recovery of ophthalmic patients? - What percentage of morbidity and mortality is there in equine ophthalmic anesthesia

recoveries? What do you quote the client?

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AUTHOR AND AND ADDRESS: Townsend, Wendy Purdue University, 625 Harrison St., W. Lafayette, IN 47907-2026 TOPIC AREA: Orbit CASE SUMMARY: Case 1: A twenty-year-old Standardbred mare presented with exophthalmos OD of 8 months duration that had markedly increased over the previous 2 weeks. On presentation she was blind OD, visual OS. No other neurologic deficits were noted. The globe OD was markedly exophthalmic and could not be retropulsed. In the OD a corneal scar, marked retinal degeneration, and optic nerve head atrophy were noted. The globe OS was within normal limits. Venous congestion was noted along the right side of her head. Because of the venous congestion there was concern that the lesion within the orbit was very extensive. Therefore a CT scan was recommended without performing an ocular ultrasound or skull radiographs. Upon induction of general anesthesia the mare had a seizure. A CT scan revealed a mass of soft tissue density involving the right maxillary sinus, right conchal, and right frontal sinuses. The right eye was displaced due to extension of the mass into the retro-bulbar space. The mass disturbed the architecture of the ethmoturbinates and lysed the ventral aspect of the cribriform place leading to close contact with the rostral aspect of the brain. The mass filled the sphenopalatine sinuses, continued medially to the right temporomandibular joint, lysed the basisphenoid bone, and extended into the calvarium. A region of either tumor growth or recent hemorrhage was present within the brain. Due to the extensive and aggressive nature of the mass, the owner elected euthanasia. On necropsy a light red mass with multifocal dark red, black, and pale tan discolorations was noted extending from the cribriform plate. The mass was 12cm x5cm, moderately firm, with blood filled loculations. The final diagnosis was an ethmoid acinar adenoma. The globe was noted to have a chronic retinal detachment with severe loss of neurons of the inner nuclear and ganglion cell layers. KEY WORDS: Orbit, ethmoid adenoma, ethmoid hematoma, ethmoid adenocarcinoma DISCUSSION POINTS: Has anyone else ever had an ethmoid hematoma diagnosed? Ethmoid hematoma versus ethmoid adenoma versus ethmoid adenocarcinoma? Seizures after anesthetic induction with blindness as the only neurologic deficit noted on examination?

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Figure 1: Fundic examination OD with marked retinal degeneration, optic nerve atrophy, and depigmentation. This image was obtained with the RetCam Wide-field Digital Imaging System using the 130 degree lens (Clarity Medical Systems).

Figure 2: CT section demonstrating the invasion into the orbit, displacement of the globe, extension into the frontal and maxillary sinuses, and destruction of the turbinates.

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AUTHOR AND ADDRESS: Brian Patterson BVM&S Cert VOphthal MRCVS Ophthalmology Service B&W Equine Hospital Breadstone GL13 9HG, United Kingdom TOPIC AREA: Conjunctival pathology CASE SUMMARY: A case of bilateral follicular conjunctivitis in a fourteen year old Thoroughbred gelding is presented. The individual had no previous history of ocular pathology and was systemically well at the time of examination. Stable relocation and an undiagnosed mild respiratory infection preceded the development of ocular symptoms. Routine healthcare practices were considered good. Clinical symptoms were present for two months prior to referral and had been poorly responsive to topical corticosteroids. Conjunctival bacteriology and testing for EHV 2 and 5 failed to demonstrate pathogens. A histological diagnosis of follicular conjunctivitis was made on multiple biopsy samples collected under standing chemical restraint. Symptoms resolved with oral prednisolone therapy. KEY WORDS: Follicular conjunctivitis DISCUSSION POINTS: Unusual clinical presentation Failure of topical corticosteroids to resolve symptoms

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Hotel Terra Symposium Floor Plan