Dr. Bentley is a Board Certified Veterinary Ophthalmologist and a Clinical Professor at the School of Veterinary Medicine, University of Wisconsin-Madison. Her clinical and research interests include corneal wound healing, particularly in spontaneous models of recurrent erosions. She has additional training in clinical trials, with an interest in effective management of pain in clinical patients. Other research interests are ocular imaging, with a focus on high resolution ultrasound, and glaucoma.
Effect of intraocular pressure (IOP), volume and location on the distribution of aqueous solutions injected into the suprachoroidal (SC) space
Investigative Ophthalmology & Visual Science, 63(7), pp.4152-F0144
Limited betadine preparation prior to nonhuman primate intravitreal dosing decreases adverse reactions in control animals
Investigative Ophthalmology & Visual Science, 63(7), pp.310-F0113
Retrospective analysis of complications associated with retrobulbar bupivacaine in dogs undergoing enucleation surgery
Vet Anaesth Analg. 2020 Sep;47(5):588-594. doi: 10.1016/j.vaa.2020.04.007. Epub 2020 May 6.
OBJECTIVE: To investigate complications associated with, and without, bupivacaine retrobulbar local anesthesia in dogs undergoing unilateral enucleation surgery.
STUDY DESIGN: Retrospective, observational study.
ANIMALS: A total of 167 dogs underwent unilateral enucleation surgery via a transpalpebral approach.
METHODS: Records from 167 dogs that underwent unilateral enucleation surgery that did (RB) or did not (NB) include retrobulbar bupivacaine anesthesia were reviewed, including anesthetic record, daily physical examination records, surgery report, patient discharge report and patient notes within 14 days of the surgery. Specific complications and severity were compared between RB and NB using the Wilcoxon rank-sum test. A 'complication burden' (0-5) comprising five prespecified complications was assigned and tested using rank-sum procedures. Statistical significance was set to 0.05.
RESULTS: Group RB included 97 dogs and group NB 70 dogs. Dogs in NB had a 17.0 percentage points (points) greater risk for a postoperative recovery complication (38.6% versus 21.6%; 95% confidence interval: 3.0-30.6 points; p = 0.017). There was inconclusive evidence that dogs in group RB had a lower risk of requiring perioperative anticholinergic administration (12.4% versus 22.9%; 10.5 points; p = 0.073). Other complications were similar between groups RB and NB with risks that differed by <10 points. The risk of hemorrhage was similar between groups RB (22.7%) and NB (20.0%) with no significant difference in the level of severity (p = 0.664).
CONCLUSIONS AND CLINICAL RELEVANCE: In this retrospective study, the use of retrobulbar bupivacaine for enucleation surgery in dogs was not associated with an increased risk of major or minor complications.
Ocular distribution and efficacy after suprachoroidal injection of AU-011 for treatment of ocular melanoma
Investigative Ophthalmology & Visual Science, 61(7), pp.3615-3615
Genomic analysis for virulence determinants in feline herpesvirus type-1 isolates
Virus Genes. 2020 Feb;56(1):49-57. doi: 10.1007/s11262-019-01718-3. Epub 2019 Nov 27.
Feline herpesvirus type 1 (FHV-1) is a widespread cause of respiratory and ocular disease in domestic cats. A spectrum of disease severity is observed in host animals, but there has been limited prior investigation into viral genome factors which could be responsible. Stocks of FHV-1 were established from oropharyngeal swabs obtained from twenty-five cats with signs of infection housed in eight animal shelters around the USA. A standardized numerical host clinical disease severity scoring scheme was used for each cat from which an isolate was obtained. Illumina MiSeq was used to sequence the genome of each isolate. Genomic homogeneity among isolates was relatively high. A general linear model for fixed effects determined that only two synonymous single nucleotide polymorphisms across two genes (UL37/39) in the same isolate (from one host animal with a low disease severity score) were significantly associated (p ≤ 0.05) with assigned host respiratory and total disease severity score. No variants in any isolate were found to be significantly associated with assigned host ocular disease severity score. A concurrent analysis of missense mutations among the viral isolates identified three genes as being primarily involved in the observed genomic variation, but none were significantly associated with host disease severity scores. An ancestral state likelihood reconstruction was performed and determined that there was no evidence of a connection between host disease severity score and viral evolutionary state. We conclude from our results that the spectrum of host disease severity observed with FHV-1 is unlikely to be primarily related to viral genomic variations, and is instead due to host response and/or other factors.
Comparison of outcomes in cataractous eyes of dogs undergoing phacoemulsification versus eyes not undergoing surgery
Vet Ophthalmol. 2020 Mar;23(2):286-291. doi: 10.1111/vop.12724. Epub 2019 Nov 20.
OBJECTIVE: To compare outcomes of surgical intervention and nonsurgical management of canine cataracts.
METHODS: Records of patients examined for cataracts from January 2007 to February 2018 were divided into two groups: nonsurgical and surgical. The nonsurgical group was further subdivided based on whether the decision not to pursue surgery was elected by owners, or based on ophthalmologist's advice. Inclusion criteria included 6 months of follow-up. Success in the nonsurgical group was defined as a comfortable eye with no potentially painful complications, and success in the surgical group additionally required vision. Time-to-failure (complications) was assessed with Cox proportional hazards models.
RESULTS: A total of 72 eyes (41 dogs) were included in the nonsurgical group, and 126 eyes (67 dogs) were surgically treated. There was no difference in gender or age; however, the surgical group had significantly more diabetic eyes (56.3% vs 15.3%; P < .001) and patient eyes with longer follow-up times (median 37.6 months vs 22.1 months; P < .001) than the nonsurgical group. There was no statistically significant difference in complication rates between the nonsurgical group (15/72 [20.8%]) and the surgical group (23/126 [18.3%]; HR: 2.22 [0.97, 5.0]; P = .060). However, the complication rate in the ophthalmologist-led nonsurgical group was significantly greater than in the owner-led nonsurgical group (P = .019) and the surgical group (P = .002).
CONCLUSIONS: When using relevant outcomes, whether or not a cataractous eye has surgery does not affect long-term complications; additionally, nonsurgical eyes that are poor surgical candidates have a higher complication rate than eyes deemed suitable for phacoemulsification for which owners elected not to pursue cataract surgery.
Additional Evidence for <em>DDB2</em> T338M as a Genetic Risk Factor for Ocular Squamous Cell Carcinoma in Horses
Int J Genomics. 2019 Sep 15;2019:3610965. doi: 10.1155/2019/3610965. eCollection 2019.
Squamous cell carcinoma (SCC) is the most common periocular cancer in horses and the second most common tumor of the horse overall. A missense mutation in damage-specific DNA-binding protein 2 (DDB2, c.1012 C>T, p.Thr338Met) was previously found to be strongly associated with ocular SCC in Haflinger and Belgian horses, explaining 76% of cases across both breeds. To determine if this same variant in DDB2 contributes to risk for ocular SCC in the Arabian, Appaloosa, and Percheron breeds and to determine if the variant contributes to risk for oral or urogenital SCC, histologically confirmed SCC cases were genotyped for the DDB2 variant and associations were investigated. Horses with urogenital SCC that were heterozygous for the DDB2 risk allele were identified in the Appaloosa breed, but a significant association between the DDB2 variant and SCC occurring at any location in this breed was not detected. The risk allele was not identified in Arabians, and no Percherons were homozygous for the risk allele. High-throughput sequencing data from six Haflingers were analyzed to ascertain if any other variant from the previously associated 483 kb locus on ECA12 was more concordant with the SCC phenotype than the DDB2 variant. Sixty polymorphisms were prioritized for evaluation, and no other variant from this locus explained the genetic risk better than the DDB2 allele (P = 3.39 × 10-17, n = 118). These data provide further support of the DDB2 variant contributing to risk for ocular SCC, specifically in the Haflinger and Belgian breeds.
Cavernous sinus syndrome in dogs and cats: case series (2002-2015)
Open Vet J. 2018;8(2):186-192. doi: 10.4314/ovj.v8i2.12. Epub 2018 May 26.
The cavernous sinus (CS) is a paired venous sinus that runs along either side of the pituitary gland on the floor of the calvarium. Cavernous sinus syndrome (CSS) refers to deficits in more than one of the cranial nerves III, IV, V, and VI, as they are in close association in this region. The purpose of this study was to identify the presenting complaints, neurologic findings, diagnosis, and outcomes in dogs and cats with confirmed cavernous sinus syndrome (CSS). Medical records between 2002 and 2015 were reviewed. Inclusion criteria were neurologic signs consistent with CSS and advanced imaging and/or post-mortem examination. Thirteen dogs and 2 cats were included. Twelve dogs received advanced imaging. Post-mortem examination was performed on 2 cats and 3 dogs. Dogs were 6 -13 years (mean= 10.8 years) of age and comprised of several different breeds. Both cats were male neutered domestic shorthair, ages 3 and 14 years. Presenting complaints included mydriasis (N=4), behavior changes (N=3), hyporexia (N=3), ptosis (N=2), ataxia (N=2), pain (N=2), weakness (N=2), lethargy (N=2), and one each of epiphora, ocular swelling, polydipsia, seizures, facial muscle atrophy, dysphagia, and head tilt. Neurologic signs included ophthalmoparesis/plegia (N=13), reduced/absent pupillary light response (N= 11), mydriasis (N= 10), reduced/absent corneal sensation (N= 7), ptosis (N= 6), reduced facial sensation (N= 2), and enophthalmos (N=1). Thirteen patients had a mass lesion within the cavernous sinus, 6 of which were confirmed neoplastic via histopathology. Median survival time for the 4 patients treated with radiation therapy was 1035 days (range 150-2280). Median survival for the 4 patients that received medical treatment was 360 days (range 7-1260 days), and for the 5 non-treated patients 14 days (range 0-90 days). In conclusion mydriasis and ophthalmoplegia are common signs of CSS. A mass lesion within the CS is the most common cause. Survival time may be improved with radiation therapy.
Genomic, Recombinational and Phylogenetic Characterization of Global Feline Herpesvirus 1 Isolates
Virology. 2018 May;518:385-397. doi: 10.1016/j.virol.2018.03.018. Epub 2018 Mar 30.
Feline herpes virus type 1 (FHV-1) is widely considered to be the leading cause of ocular disease in cats and has been implicated in upper respiratory tract infections. Little, however is known about interstrain phylogenetic relationships, and details of the genomic structure. For the present study, twenty-six FHV-1 isolates from different cats in animal shelters were collected from eight separate locations in the USA, and the genomes sequenced. Genomic characterization of these isolates includied short sequence repeat (SSR) detection, with fewer SSRs detected, compared to herpes simplex viruses type 1 and 2. For phylogenetic and recombination analysis, 27 previously sequenced isolates of FHV-1 were combined with the 26 strains sequenced for the present study. The overall genomic interstrain genetic distance between all available isolates was 0.093%. Phylogenetic analysis identified four main FHV-1 clades primarily corresponding to geographical collection site. Recombination analysis suggested that interclade recombination has occurred.
Factors affecting publication in peer-reviewed journals of abstracts presented from 2008 to 2012 ACVO meetings
Vet Ophthalmol. 2018 Apr 14:147-152. doi: 10.1111/vop.12573. Online ahead of print.
PURPOSE: To examine variables that affect publication of ACVO meeting abstracts in peer-reviewed journals and compare results to ECVO publication rate (PR).
METHODS: Published papers were identified via online searches for abstracts from 2008 to 2012 ACVO/ECVO meetings. Variables analyzed (via Pearson's chi-Squared test) included the following: oral presentation/poster, type of abstract (clinical/basic science/case report), species, ocular tissue, nationality, funding, first/last/any author a diplomate, resident as first author, and author affiliation (private practice/university).
RESULTS: One hundred and eighty-six of 577 ACVO abstracts were published within 608 ± 479 days, with 103 published in Veterinary Ophthalmology. Significant factors included the following: nationality of first/last authors (P = .005); English as first language (P < .001); presentation type (P < .001, oral 40% PR, poster 22% PR); type of study (P = .037, clinical study 35% PR, basic science 30% PR, case report 16% PR); resident as first author (P < .001); diplomate as any author except first/last (P < .001); first author affiliation (P = .001, university 37% PR, practice 21% PR); last author affiliation (P = .003, university 36% PR, practice 22% PR); and species (P < .001, horses 53% PR, multiple species 50% PR, cats 35% PR, food animals 31% PR, exotics/wildlife 31% PR, dogs 27% PR, laboratory animals/in vitro 24%). Nonsignificant factors were as follows: diplomate as first/last author, funding, and ocular tissue. Presentation type, resident as first author, university affiliation of first author, and species had the greatest effect on publication probability. For the same period, ECVO PR was 87 of 299, which was not significantly different from ACVO PR (P = .342).
CONCLUSION: At 32%, ACVO PR for the study years is similar to ECVO PR of 29%.
The SPOTS system: an ocular scoring system optimized for use in modern preclinical drug development and toxicology
Journal of Ocular Pharmacology and Therapeutics, 33(10), pp.718-734
Retinal detachment postphacoemulsification in Bichon Frises: a retrospective study of 54 dogs
Vet Ophthalmol. 2016 Sep;19(5):373-8. doi: 10.1111/vop.12310. Epub 2015 Oct 2.
OBJECTIVE: To compare rates of retinal detachment (RD) postphacoemulsification in American Bichon Frises with and without prophylactic retinopexy.
PROCEDURES: Medical records of 54 Bichon Frises undergoing phacoemulsification with or without prophylactic retinopexy between 2003 and 2013 in one or both eyes were reviewed from five Midwestern university veterinary teaching hospitals. Inclusion criteria were preoperative ERG, at least 6 months of follow-up postphacoemulsification, and the absence of preexisting RD as determined by ophthalmic examination and/or ultrasound. Statistical analyses were performed using chi-squared test, and Wilcoxon rank-sum tests and Wilson confidence intervals with the P-value <0.05 were considered significant.
RESULTS: Phacoemulsification was performed without retinopexy in 79 eyes (42 dogs, non-PR group) and with prophylactic retinopexy in 23 eyes (12 dogs, PR group). Incidence of diabetes mellitus was 10/42 and 3/12 in the non-PR and the PR groups, respectively (P = 0.93). Intraocular lens implantation was performed in 40/42 non-PR dogs and 11/12 PR dogs (P = 0.63, 73/79 vs. 21/23 eyes). At final re-examination, RD occurred in 4/79 eyes without retinopexy, compared to 0/23 RD in the retinopexy group. There was no statistically significant difference in RD rates between the two groups (P = 0.27).
CONCLUSIONS: These data provide no statistical evidence to support prophylactic retinopexy in Bichon Frises. Due to the low rate of retinal detachment following phacoemulsification without prophylactic retinopexy, the procedure appears to offer limited benefit to offset cost, procedural risk, and risk of extended or repeated anesthesia in Bichon Frises.
Comparison of carprofen and tramadol for postoperative analgesia in dogs undergoing enucleation
J Am Vet Med Assoc. 2014 Dec 15;245(12):1375-81. doi: 10.2460/javma.245.12.1375.
OBJECTIVE: To compare analgesia provided by carprofen and tramadol in dogs after enucleation.
DESIGN: Randomized, masked clinical trial.
ANIMALS: 43 dogs.
PROCEDURES: Client-owned dogs admitted for routine enucleation were randomly assigned to receive either carprofen or tramadol orally 2 hours prior to surgery and 12 hours after the first dose. Dogs were scored for signs of pain at baseline (ie, before carprofen or tramadol administration) and at 0.25, 0.5, 1, 2, 4, 6, 8, 24, and 30 hours after extubation. Dogs received identical premedication and inhalation anesthesia regimens, including premedication with hydromorphone. If the total pain score was ≥ 9 (maximum possible score of 20), there was a score ≥ 3 in any of 5 behavioral categories (highest score possible per category was 3 or 4), or the visual analog scale (VAS) score was ≥ 35 (maximum possible score of 100) combined with a palpation score > 0, rescue analgesia (hydromorphone) was administered and treatment failure was recorded.
RESULTS: No differences were found in age, sex, or baseline pain scores between groups. Significantly more dogs receiving tramadol required rescue analgesia (6/21), compared with dogs receiving carprofen (1/22). Pain and VAS scores decreased linearly over time. No significant differences were found in pain or VAS scores between groups at any time point (dogs were excluded from analysis after rescue).
CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study suggested that carprofen, with opioid premedication, may provide more effective postoperative analgesia than tramadol in dogs undergoing enucleation.
Cavernous sinus syndrome in a Holstein bull
Vet Ophthalmol. 2015 Mar;18(2):164-7. doi: 10.1111/vop.12127. Epub 2013 Nov 21.
A 13-month-old Holstein bull was presented for right-sided exophthalmos. Ophthalmologic examination noted that the animal was visual in both eyes, but that the right pupil was persistently dilated and very sluggish to constrict when stimulated with a bright light and that normal ocular motility was absent. Fundic examination of the right eye was normal as was a complete ophthalmologic examination of the left eye. Radiographs at presentation did not reveal the presence of sinusitis or other skull abnormalities. Initial treatment comprised intravenous antibiotics and anti-inflammatories for orbital inflammation over a 14-day period. There was no perceptible change in the appearance or neuro-ophthalmologic examination of the right eye during hospitalization. The animal was discharged to the owner's care, but 3 weeks later was found recumbent with unilateral strabismus of the left eye and a fixed right pupil. Due to the inability to rise and rapid deterioration, humane euthanasia was performed, and a full postmortem examination, preceded by a MRI, was performed that identified abscesses extending bilaterally through the round foramina obliterating the cavernous sinus region, as well as abscessation of the right mandible, right trigeminal neuritis, right-sided sinusitis, and right-sided otitis media. Cavernous sinus syndrome should be considered in cattle with a combination of exophthalmos and neuro-ophthalmologic abnormalities involving cranial nerves III, IV, V, and VI, whose branches are located within the cavernous sinus.
Long-term outcome of sudden acquired retinal degeneration syndrome in dogs
J Am Vet Med Assoc. 2013 Nov 15;243(10):1425-31. doi: 10.2460/javma.243.10.1426.
OBJECTIVE: To investigate long-term outcomes and owner-perceived quality of life associated with sudden acquired retinal degeneration syndrome (SARDS) in dogs.
DESIGN: Survey study.
ANIMALS: 100 dogs with SARDS examined at 5 academic veterinary institutions from 2005 to 2010.
PROCEDURES: The diagnosis was based on documented acute vision loss, normal results of ophthalmic examinations, and evaluation of extinguished bright-flash electroretinograms. Primary owners of affected dogs completed a questionnaire addressing outcome measures including vision, systemic signs, and perceived quality of life for their dogs.
RESULTS: Age at diagnosis was significantly correlated with positive outcome measures; dogs in which SARDS was diagnosed at a younger age were more likely to have alleged partial vision and higher owner-perceived quality of life. Polyphagia was the only associated systemic sign found to increase in severity over time. Medical treatment was attempted in 22% of dogs; visual improvement was not detected in any. Thirty-seven percent of respondents reported an improved relationship with their dog after diagnosis, and 95% indicated they would discourage euthanasia of dogs with SARDS.
CONCLUSIONS AND CLINICAL RELEVANCE: Blindness and concurrent systemic signs associated with SARDS appeared to persist indefinitely, but only polyphagia increased in severity over time. Most owners believed their pets had good quality of life and would discourage euthanasia of dogs with SARDS.
Characteristics of residency training associated with first-time pass rate on the American College of Veterinary Ophthalmologists certifying examination
Vet Ophthalmol. 2014 Jul;17(4):233-40. doi: 10.1111/vop.12111. Epub 2013 Oct 17.
OBJECTIVE: The aim of this study was to examine the association of various aspects of veterinary ophthalmology residency training with the first-time pass rate (FTPR) of the American College of Veterinary Ophthalmologists (ACVO) examination, as well as the individual written, image recognition, animal examination, and surgical sections of the examination.
PROCEDURES: Program type, resident evaluations, cumulative surgery and case logs, and scores from ACVO examinations from 2007 to 2010 were evaluated.
RESULTS: Data were available for 71 candidates. The overall FTPR was 35% (n = 25). For the different sections of the examination, FTPRs were as follows: written (68%), image recognition (76%), intraocular surgery (80%), extraocular surgery (65%), and animal examination (75%). The overall FTPR among candidates from academic residency (AR) programs was 43% (20 of 47), while the FTPR of residents in private practice (PPR) programs was 21% (5 of 24; P = 0.07). The AR candidates were more likely to pass the written portion than PPR residents (P = 0.02), and AR candidates had significantly more time off clinics (median 25%) vs PPR residents (median 18%; P = 0.007). The AR residents also had a higher reported percentage of direct supervision than PPR residents (95% vs 76%, respectively). Although PPR residents did significantly more surgeries and examined significantly more dogs and cats, those from ARs examined significantly more equine, bovine, avian, camelid, and reptile species.
CONCLUSIONS: Overall, AR residents had a higher FTPR and were more likely to pass the written portion of the examination. Total case and surgery numbers were not associated with FTPR.
Comparison of ultrasonography and histologic examination for identification of ocular diseases of animals: 113 cases (2000-2010)
J Am Vet Med Assoc. 2013 Aug 1;243(3):376-88. doi: 10.2460/javma.243.3.376.
OBJECTIVE: To compare ultrasonographic and histologic examination findings for eyes of animals with ocular diseases.
DESIGN: Retrospective case series.
ANIMALS: 116 eyes of 113 animals examined at 2 facilities.
PROCEDURES: Diseased eyes of animals were examined by means of ultrasonography, removed via enucleation or exenteration, then histologically examined. Ultrasonographic images and histopathologic slides were evaluated, and diseases of eyes were identified with each of those methods and allocated to various categories. For each disease category, agreement between results of ultrasonography and those of histologic examination was assessed via determination of κ statistic values.
RESULTS: Tests had good agreement for identification of iris or ciliary body neoplasia. Overall, intraocular neoplasia was not detected via ultrasonography for only 2 of 31 eyes with histologically detected neoplasia. Hemorrhagic or inflammatory changes were misinterpreted as neoplasia for 8 of 37 (22%) eyes. Tests had moderate to acceptable agreement for identification of retinal detachment. Retinal detachment was not detected by means of ultrasonography for 14 of 38 (37%) eyes with that diagnosis determined via histologic examination at one of the facilities (primarily in eyes with intraocular hemorrhage); however, retinal detachment was not identified via histologic examination for 6 of 38 (16%) eyes with that diagnosis determined via ultrasonography at the other facility.
CONCLUSIONS AND CLINICAL RELEVANCE: Agreement between tests evaluated in this study was clinically satisfactory for identification of intraocular neoplasia. Typically, diseases were misdiagnosed via ultrasonography for eyes with poor image contrast. Because determination of ultrasonographic diagnoses of retinal detachment and intraocular neoplasm may be of prognostic importance, performance of additional ultrasonographic techniques may be indicated.
Feline ocular tumors following ciliary body ablation with intravitreal gentamicin
Vet Ophthalmol. 2013 Jul;16 Suppl 1:188-90. doi: 10.1111/vop.12066. Epub 2013 May 22.
Practitioners approach chemical ciliary body ablation (CBA) in cats with caution. In 1994, an academic letter proposed a potential link between intraocular gentamicin injections for glaucoma and the appearance of ocular tumors in cats (Veterinary and Comparative Ophthalmology, 4, 1994, 166). There is an historic perceived risk for the development of feline ocular post-traumatic sarcoma following gentamicin ciliary body ablation, and many clinicians refrain from chemical ablation in cats for this reason. A recent study discussed the possibility of a correlation between intravitreal gentamicin and tumor promotion in dogs (Veterinary Ophthalmology, 16, 2013, 159). We searched the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) database for cases of cats diagnosed with ocular tumors following ciliary body ablation. Of eight cases with historic gentamicin injection, five had malignant tumors: three post-traumatic sarcomas and two melanomas.
Systemic hypertension and hypertensive retinopathy following PPA overdose in a dog
J Am Anim Hosp Assoc. 2013 Jan-Feb;49(1):46-53. doi: 10.5326/JAAHA-MS-5692. Epub 2012 Nov 12.
A 4 yr old spayed female Labrador retriever was examined 4 hr after ingesting an overdose of phenylpropanolamine (PPA). Clinical signs included anxiety, piloerection, mucosal ulceration, cardiac arrhythmia, mydriasis, and hyphema. Clinicopathologic abnormalities included elevated creatine kinase (CK) and aspartate aminotransferase (AST), proteinuria, and pigmenturia. Ventricular tachycardia and severe systemic hypertension were documented. Hyphema and retinal detachment were documented oculus uterque (OU). Phenoxybenzamine, sotalol, and esmolol resolved the ventricular tachycardia, and blood pressure was controlled with nitroprusside. All clinicopathologic and cardiac abnormalities resolved within 7 days, and ocular changes resolved within 1 mo. Monitoring of blood pressure and rapid pharmacologic intervention were successful in controlling hypertension secondary to PPA overdose and minimizing retinal damage.
Canine ocular tumors following ciliary body ablation with intravitreal gentamicin
Vet Ophthalmol. 2013 Mar;16(2):159-62. doi: 10.1111/j.1463-5224.2012.01050.x. Epub 2012 Jul 19.
Iridociliary tumors are the second most common primary ocular tumor in dogs and are usually benign. A review of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) database in 2009 suggested a potential correlation between malignant iridociliary epithelial tumors and ciliary body ablation by intravitreal gentamicin injection for the treatment of glaucoma. The purpose of this case series was to determine whether there is evidence of such a correlation in the COPLOW collection. Mining of the COPLOW database revealed that a significant number (39.5%) of canine globes with a history of ciliary body ablation were subsequently diagnosed with primary ocular tumors at enucleation, most commonly iridociliary epithelial tumors and melanocytic tumors. It is possible that neoplasia was present but unrecognized at the time of ciliary body ablation. These tumors had a higher than expected incidence of malignancy. These cases underscore the importance of reserving ciliary body ablation with gentamicin for disease-free eyes.
Evaluation of topical nalbuphine or oral tramadol as analgesics for corneal pain in dogs: a pilot study
Vet Ophthalmol. 2011 Nov;14(6):358-64. doi: 10.1111/j.1463-5224.2011.00883.x. Epub 2011 Apr 19.
OBJECTIVE: To evaluate the effectiveness of topical nalbuphine or oral tramadol in the treatment of corneal pain in dogs.
ANIMALS STUDIED: Fourteen male Beagle dogs.
PROCEDURES: Dogs were divided into three treatment groups and sedated with dexmedetomidine (5 μ/kg IV). A 4 mm corneal epithelial wound was created in the right eye (OD) of all dogs. Sedation was reversed with atipamazole IM. All dogs received pre/post ophthalmic examinations. Post operatively, Group NB (n = 5) received topical 1% preservative-free nalbuphine OD q8 h and an oral placebo PO q8 h. Group TR (n = 5) received tramadol (4 mg/kg) PO q8 h and topical sterile saline OD q8 h. Group CNTRL (n = 4) received topical sterile saline OD q8 h and an oral placebo q8 h. All dogs received topical 0.3% gentamicin OD TID until healed. Dogs were pain scored using a pain scoring system modified from the University of Melbourne pain scale at 0, 1, 2, 4, and 6 h, then every 6 h by observers masked to treatment, until corneal wounds were healed. Treatment failure was recorded if cumulative pain scores were above a minimum threshold of acceptable pain and rescue analgesia of morphine (1.0 mg/kg IM) was administered subsequently.
RESULT: Four dogs in Group NB, one dog in Group TR, and two dogs in Group CNTRL required rescue analgesia. There was no significant difference in the incidence of treatment failure between groups (P = 0.184). Mean time to rescue was 9.16 h. All corneal wounds were healed by 84 h.
CONCLUSIONS: The results of this study suggest tramadol rather than nalbuphine should be further investigated for the treatment of corneal pain.
Gender differences in iridocorneal angle morphology: a potential explanation for the female predisposition to primary angle closure glaucoma in dogs
Vet Ophthalmol. 2012 Mar;15 Suppl 1:60-3. doi: 10.1111/j.1463-5224.2011.00956.x. Epub 2011 Oct 17.
OBJECTIVE: Female dogs have approximately twice the risk of males for developing primary angle closure glaucoma (PACG). The cause of this gender difference is unknown, but one theory proposes that the gender differences in iridocorneal angle morphology are involved in this risk differential.
PROCEDURES: Fifty beagles (25 males, 25 females) were included into this study and had normal baseline ophthalmic examinations. Normal dogs were selected so as to avoid any potentially confounding influence of goniodysgenesis. Standardized 20-MHz high-resolution ultrasound images of the iridocorneal angle were acquired from one eye of each dog with the scan plane perpendicular to the limbus in the superior temporal quadrant. Images were imported into ImageJ, and the angle opening distance (AOD) and angle recess area (ARA) were measured by a masked observer, and the analysis of variance method was used to compare differences.
RESULTS: The mean (±SD) AOD was significantly smaller for female dogs (0.847 ± 0.241 mm) vs. male dogs (1.058 ± 0.322 mm) P-value = 0.012. The mean (± SD) ARA tended to be smaller for female dogs (0.584 ± 0.278 mm) vs. male dogs (0.748 ± 0.385 mm), but this difference was not significant (P-value = 0.092).
CONCLUSIONS: Female dogs have a significantly smaller AOD vs. males. This difference may render the female iridocorneal angle more susceptible to closure and may partially explain the 2:1 female/male predisposition to PACG. Further studies using goniodysgenic dogs are warranted.
Effects of unilateral topical administration of 0.5% tropicamide on anterior segment morphology and intraocular pressure in normal cats and cats with primary congenital glaucoma
Vet Ophthalmol. 2011 Sep;14 Suppl 1(Suppl 1):75-83. doi: 10.1111/j.1463-5224.2011.00927.x.
OBJECTIVE: To determine the effects of topical 0.5% tropicamide on anterior segment morphology (ASM) and intraocular pressure (IOP) in normal and glaucomatous cats. ANIMALS USED: Normal cats and cats with inherited primary congenital glaucoma (PCG).
PROCEDURES: Control IOP curves were performed in untreated normal and PCG cats. In the first experiment, tropicamide was applied OD in eight normal and nine PCG cats. IOP and pupillary diameter (PD) were measured at 0, 30, and 60 min, then hourly until 8 h post-treatment. In a second experiment, six normal and seven PCG cats received tropicamide OD. High-resolution ultrasound images were obtained at 0, 1, 5, and 10 h post-treatment to measure ASM changes. IOP and PD were measured OD at 0, 1, 2, 3, 5, 7, and 9 h.
RESULTS: In untreated normal cats IOP OU decreased throughout the day. In PCG cats IOP OU had wide fluctuations over time. In normal cats IOP response varied in the treated eye but did not change significantly in untreated eyes. IOP significantly increased from baseline in both eyes of all treated PCG cats. Increases in IOP were associated with some ASM changes. Cats with PCG had a significantly smaller angle recess areas, diminished ciliary clefts and decreased iris-lens contact. ASM changes were not strongly correlated with IOP in all cats.
CONCLUSIONS: The ASM of PCG cats is markedly different from normal cats, and clinically significant increases in IOP OU occur in cats with PCG after tropicamide treatment. The mechanism for this increase remains unclear.
Ocular lesions associated with systemic hypertension in dogs: 65 cases (2005-2007)
J Am Vet Med Assoc. 2011 Apr 1;238(7):915-21. doi: 10.2460/javma.238.7.915.
OBJECTIVE: To characterize ocular findings in hypertensive dogs, determine prevalence of hypertension in dogs with ocular disease suggestive of hypertension, and examine possible relationships between degree of hypertension and ocular disease.
DESIGN: Retrospective case series.
ANIMALS: 65 dogs initially referred for blood pressure measurement (n = 22), ophthalmic examination (25), or both (18).
PROCEDURES: Medical records were reviewed to identify dogs examined at the teaching hospital that underwent a complete ophthalmic examination and blood pressure measurement within a 24-hour period between January 1, 2005, and December 31, 2007. Signalment, history, blood pressure measurements, ophthalmic examination findings, and any vasoactive drug treatments were recorded. Ocular lesions considered likely to be associated with systemic hypertension included retinal hemorrhage, retinal detachment, hyphema, tortuous vessels, and subretinal edema.
RESULTS: Of the 65 dogs, 42 were hypertensive (systolic blood pressure ≥ 160 mm Hg) and 23 were normotensive. Sixty-two percent (26/42) of hypertensive dogs had ≥ 1 type of ocular lesion identified. Retinal hemorrhage was the most common ocular lesion in hypertensive dogs (17/42 [40%]). The presence of ≥ 1 type of ocular lesion had moderate sensitivity and specificity of 62% and 61 %, respectively, for identification of hypertension. Fifteen of the 25 (60%) dogs referred for blood pressure measurement after initial ophthalmic examination were found to be hypertensive.
CONCLUSIONS AND CLINICAL RELEVANCE: Ocular lesions are common in dogs with systemic hypertension. Dogs with hypertension or diseases associated with hypertension should be monitored carefully for evidence of ocular target organ damage, and hypertension should be systematically ruled out in dogs with characteristic ocular lesions.
Subretinal Administration of Fluorescent Microspheres in the Minipig
Investigative Ophthalmology & Visual Science, 52(14), pp.1358-1358.
Effectiveness of injection of local anesthetic into the retrobulbar space for postoperative analgesia following eye enucleation in dogs
J Am Vet Med Assoc. 2010 Jul 15;237(2):174-7. doi: 10.2460/javma.237.2.174.
OBJECTIVE: To assess the efficacy of a retrobulbar bupivacaine nerve block for postoperative analgesia following eye enucleation in dogs.
DESIGN: Randomized controlled trial.
ANIMALS: 22 dogs.
PROCEDURES: Client-owned dogs admitted to the hospital for routine eye enucleation were enrolled with owner consent and randomly assigned to a treatment (bupivacaine hydrochloride) or control (saline [0.9% NaCl] solution) group. Baseline subjective pain scores were recorded. Anesthesia consisted of hydromorphone and midazolam preoperatively, thiopental or propofol for induction, and isoflurane in oxygen for maintenance. An inferior-temporal palpebral retrobulbar injection of either saline solution or bupivacaine was administered. Transpalpebral eye enucleation was performed. Pain scores were recorded at 0.25, 0.5, 1, 2, 4, 6, 8, and 24 hours after extubation (time 0) by observers masked to treatment groups. Dogs were given hydromorphone (0.2 mg/kg [0.09 mg/lb], IM or IV) as a rescue analgesic if the subjective pain score totaled >or= 9 (out of a maximum total score of 18) or >or= 3 in any 1 category.
RESULTS: 9 of 11 control dogs required a rescue dose of hydromorphone, but only 2 of 11 dogs in the bupivacaine treatment group required rescue analgesia. Mean time to treatment failure (ie, administration of rescue analgesia following extubation) was 0.56 hours (95% confidence interval, 0.029 to 1.095 hours) for the 11 dogs that received hydromorphone.
CONCLUSIONS AND CLINICAL RELEVANCE: Retrobulbar administration of bupivacaine in dogs in conjunction with traditional premedication prior to eye enucleation was an effective form of adjunctive analgesia and reduced the need for additional postoperative analgesics.
Biosynthetic corneal substitute implantation in dogs
Cornea. 2010 Aug;29(8):910-6. doi: 10.1097/ICO.0b013e3181c846aa.
PURPOSE: To assess integration of a biosynthetic corneal implant in dogs.
METHODS: Three normal adult laboratory Beagles underwent ophthalmic examinations, including slit-lamp biomicroscopy, indirect ophthalmoscopy, applanation tonometry, and Cochet-Bonnet aesthesiometry. Biosynthetic corneas fabricated from glutaraldehyde crosslinked collagen and copolymers of collagen and poly(N-isopropylacrylamide-co-acrylic acid-co-acryloxysuccinimide, denoted as TERP) were implanted into dogs by a modified epikeratoplasty technique. Ophthalmic examinations and aesthesiometry were performed daily for 5 days and then weekly thereafter for 16 weeks. Corneal samples underwent histopathological and transmission electron microscopy examination at 16 weeks.
RESULTS: Implants were epithelialized by 7 days. Intraocular pressure was within normal range throughout the study. Aesthesiometry values dropped from an average of 3.67 cm preoperatively to less than 1 mm for all dogs for the first postoperative weeks. By week 16, the average Cochet-Bonnet value was 1.67 cm, demonstrating partial recovery of functional innervation of the implant. No inflammation or rejection of the implant occurred, and minimal haze formation was noted. Light microscopy revealed thickened but normal epithelium over the implant with fibroblast migration into the scaffold. On transmission electron microscopy, the basement membrane was irregular but present and adhesion complexes were noted.
CONCLUSION: Biosynthetic corneal implantation is well tolerated in dogs, and the collagen-polymer hybrid construct holds promise for clinical application in animals and humans.
Nanoscale topography-induced modulation of fundamental cell behaviors of rabbit corneal keratocytes, fibroblasts, and myofibroblasts
Invest Ophthalmol Vis Sci. 2010 Mar;51(3):1373-81. doi: 10.1167/iovs.09-4074. Epub 2009 Oct 29.
PURPOSE: Keratocyte-to-myofibroblast differentiation is a key factor in corneal wound healing. The purpose of this study was to determine the influence of environmental nanoscale topography on keratocyte, fibroblast, and myofibroblast cell behavior.
METHODS: Primary rabbit corneal keratocytes, fibroblasts, and myofibroblasts were seeded onto planar polyurethane surfaces with six patterned areas, composed of anisotropically ordered grooves and ridges with a 400-, 800-, 1200-, 1600-, 2000-, and 4000-nm pitch (pitch = groove + ridge width). After 24 hours cells were fixed, stained, imaged, and analyzed for cell shape and orientation. For migration studies, cells on each patterned surface were imaged every 10 minutes for 12 hours, and individual cell trajectories and migration rates were calculated.
RESULTS: Keratocytes, fibroblasts, and myofibroblasts aligned and elongated to pitch sizes larger than 1000 nm. A lower limit to the topographic feature sizes that the cells responded to was identified for all three phenotypes, with a transition zone around the 800- to 1200-nm pitch size. Fibroblasts and myofibroblasts migrated parallel to surface ridges larger than 1000 nm but lacked directional guidance on submicron and nanoscale topographic features and on planar surfaces. Keratocytes remained essentially immobile.
CONCLUSIONS: Corneal stromal cells elongated, aligned, and migrated, differentially guided by substratum topographic features. All cell types failed to respond to topographic features approximating the dimensions of individual stromal fibers. These findings contribute to our understanding of corneal stromal cell biology in health and disease and their interaction with biomaterials and their native extracellular matrix.
Elevations in sex hormones in dogs with sudden acquired retinal degeneration syndrome (SARDS)
J Am Anim Hosp Assoc. 2009 Sep-Oct;45(5):207-14. doi: 10.5326/0450207.
Dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) commonly are presented with concurrent clinical, physical, and historical findings consistent with hyperadreno-corticism (HAC) at the time of vision loss. Thirteen dogs diagnosed with SARDS on the basis of complete ophthalmic examination and extinguished bright-flash electroretinogram were evaluated for steroid hormonal abnormalities. Signalment, case history, physical examination, and clinicopathological findings were recorded. Serum cortisol and sex-hormone concentrations were measured before and after adrenocorticotropic hormone (ACTH) stimulation. Clinical signs of HAC, systemic hypertension, and proteinuria were commonly found in dogs with SARDS. Elevations in one or more sex hormones were found in 11 (85%) of 13 dogs (95% confidence interval [CI] 65% to 100%); cortisol was elevated in nine (69%) of 13 dogs (95% CI 44% to 94%). A minority of dogs (three [23%] of 13; 95% CI 0.2% to 46%) exhibited only an increase in adrenal sex hormones. Only one dog had completely normal ACTH stimulation test results. Symptoms of HAC were associated with abnormal ACTH stimulation results. Routine ACTH stimulation testing to evaluate cortisol and sex hormones, blood pressure screening, and urinalysis are recommended in these animals.
Refractive states of eyes and association between ametropia and breed in dogs
Am J Vet Res. 2008 Jul;69(7):946-51. doi: 10.2460/ajvr.69.7.946.
OBJECTIVE: To assess the refractive state of eyes in various breeds of dogs to identify breeds susceptible to ametropias.
ANIMALS: 1,440 dogs representing 90 breeds.
PROCEDURES: In each dog, 1 drop of 1% cyclopentolate or 1% tropicamide was applied to each eye, and a Canine Eye Registration Foundation examination was performed. Approximately 30 minutes after drops were administered, the refractive state of each eye was assessed via streak retinoscopy. Dogs were considered ametropic (myopic or hyperopic) when the mean refractive state (the resting focus of the eye at rest relative to visual infinity) exceeded +/- 0.5 diopter (D). Anisometropia was diagnosed when the refractive error of each eye in a pair differed by > 1 D.
RESULTS: Mean +/- SD refractive state of all eyes examined was -0.05 +/- 1.36 D (emmetropia). Breeds in which the mean refractive state was myopic (< or = -0.5 D) included Rottweiler, Collie, Miniature Schnauzer, and Toy Poodle. Degree of myopia increased with increasing age across all breeds. Breeds in which the mean refractive state was hyperopic (> or = +0.5 D) included Australian Shepherd, Alaskan Malamute, and Bouvier des Flandres. Astigmatism was detected in 1% (14/1,440) of adult (> or = 1 year of age) dogs; prevalence of astigmatism among German Shepherd Dogs was 3.3% (3/90). Anisometropia was detected in 6% (87/1,440) of all dogs and in 8.9% (8/90) of German Shepherd Dogs.
CONCLUSIONS AND CLINICAL RELEVANCE: Refractive states of canine eyes varied widely and were influenced by breed and age. In dogs expected to have high visual function (eg, performance dogs), determination of refractive state is recommended prior to intensive training.
Expression of matrix metalloproteinase 2 and 9 in experimentally wounded canine corneas and spontaneous chronic corneal epithelial defects
Cornea. 2007 Dec;26(10):1213-9. doi: 10.1097/ICO.0b013e31814b8a28.
PURPOSE: To determine matrix metalloproteinase (MMP) 2 and MMP 9 expression in acute and chronic experimentally wounded canine corneas and keratectomy samples from canine patients with spontaneous chronic corneal epithelial defects (SCCEDs).
METHODS: Mechanical debridement was performed unilaterally in 25 healthy dogs for the acute wound study. Twenty-four hours (n = 8), 48 hours (n = 5), 72 hours (n = 3), or 1 week (n = 9) after wounding, the dogs were euthanized. Debridement was performed once weekly for 8 weeks for the chronic study (n = 8). Therapeutic superficial keratectomies (n = 16) were performed on SCCED patients. Gelatin zymography and immunohistochemistry were performed.
RESULTS: Acute wounds showed upregulation of MMP 9 at all time points. At 7 days after wounding, values diminished markedly but remained elevated above those of unwounded controls. SCCED and chronic wound samples showed a significant increase in MMP 9 compared with controls but were less than that of acute wounds. There was no significant difference between chronic wounds versus SCCED samples. Fellow control eyes showed significant upregulation of MMP 9 in tandem with wounded eyes. There was no significant difference in values for MMP 2 in wounded corneas or SCCED compared with those of controls. Immunhistochemistry localized MMP 9 to predominantly the epithelium with some staining of keratinocytes and stroma.
CONCLUSIONS: The dog exhibits similar MMP expression during corneal wound healing to that of other species. The lack of significant difference in MMP expression between SCCED and chronic wounds suggest that MMP 2 and 9 are not involved in the pathophysiology of SCCED and are more likely altered secondary to a chronic epithelial defect.
Use of capecitabine to prevent acute renal allograft rejection in dog erythrocyte antigen-mismatched mongrel dogs
Vet Surg. 2007 Jan;36(1):10-20. doi: 10.1111/j.1532-950X.2007.00230.x.
OBJECTIVE: To assess efficacy and toxicity of a capecitabine (CAP)-based regimen for preventing rejection of renal allografts in dog erythrocyte antigen (DEA)-mismatched mongrel dogs.
STUDY DESIGN: Prospective, pilot study.
ANIMALS: Eight healthy, unrelated, DEA mismatched, adult mongrel dogs.
METHODS: All dogs received CAP, starting at 50 mg/m2 PO b.i.d. 4 days preoperatively, increasing to 200 mg/m2 PO b.i.d. by the day of surgery. All dogs received cyclosporine-A (CsA) and prednisolone starting 2 days preoperatively. Standard heterotopic renal transplantation with native nephrectomy was performed. After 90 days, surviving dogs were euthanatized and histopathologic examination was performed.
RESULTS: Two of 8 dogs developed acute neurotoxicity leading to death or euthanasia within 5 days of surgery. For the 6 remaining dogs, there were no statistically significant changes in complete blood count or serum biochemical values. No opportunistic infections developed during the study period. Five of 6 dogs had no to minimal evidence of graft rejection. Two of 6 dogs developed superficial and pigmentary keratitis. Significant histopathologic findings in all dogs included mild lymphoplasmacytic gastroenteritis, steroid hepatopathy, and corneal epithelial thinning. One dog had moderate interstitial nephritis and pyelitis.
CONCLUSIONS: In this experimental model, a CAP-CsA-prednisolone immunosuppressive regimen was effective in preventing rejection of allografts in DEA-mismatched dogs. Severe, unpredictable neurotoxicity and variable ocular toxicity significantly limit clinical applications at this time.
CLINICAL RELEVANCE: A CAP-CsA-prednisolone protocol is an effective, oral immunosuppressive regimen for prevention of allograft rejection in DEA-mismatched mongrel dogs. For clinical application, identification of patients susceptible to toxic side effects would be necessary.
Development of a retrobulbar injection technique for ocular surgery and analgesia in dogs
J Am Vet Med Assoc. 2006 Jul 15;229(2):220-5. doi: 10.2460/javma.229.2.220.
OBJECTIVE: To develop and compare 3 techniques for retrobulbar injection of local anesthetic agents for ocular surgery and analgesia in dogs.
DESIGN: Prospective study.
ANIMALS: 17 dogs (including 9 cadavers).
PROCEDURES: Inferior-temporal palpebral (ITP), perimandibular, and combined superior-inferior peribulbar injection techniques were compared by assessing the distribution of latex after injection into the orbits of 5 canine cadavers; magnetic resonance imaging (MRI) evaluation of the distribution of contrast agent after injection in the retrobulbar space of 4 canine cadavers; and assessment of the efficacy and MRI evaluation of the anatomic distribution of injections of a lidocainecontrast agent mixture in 4 anesthetized, nonrecovery dogs. By use of the preferred technique (ITP), the ocular effects of lidocaine anesthesia were evaluated in 4 dogs; during a 2-week period after treatment, dogs underwent ophthalmic examination, Schirmer tear testing (STT), intraocular pressure (IOP) measurement, and Cochet-Bonnet esthesiometry.
RESULTS: Of the 3 techniques, the ITP technique was the preferred method for retrobulbar administration of anesthetic agent in dogs because it was efficacious (pupil dilation and central rotation of the globe achieved in all eyes), easiest to perform, and provided thorough coverage of the intraconal retrobulbar space without complication. During the 2-week follow-up period, the ITP injection did not significantly affect STT, IOP, or Cochet-Bonnet esthesiometry values in dogs.
CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, retrobulbar administration of anesthetic agents via the ITP technique is a potential alternative to systemic administration of neuromuscular blocking agents for ophthalmic surgery and provides the additional benefit of local ocular analgesia.
Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs
J Am Anim Hosp Assoc. 2006 May-Jun;42(3):207-11. doi: 10.5326/0420207.
The effect on intraocular pressure (IOP) from dogs pulling against a collar or a harness was evaluated in 51 eyes of 26 dogs. The force each dog generated while pulling against a collar or a harness was measured. Intraocular pressure measurements were obtained during application of corresponding pressures via collars or harnesses. Intraocular pressure increased significantly from baseline when pressure was applied via a collar but not via a harness. Based on the results of the study, dogs with weak or thin corneas, glaucoma, or conditions for which an increase in IOP could be harmful should wear a harness instead of a collar, especially during exercise or activity.
Safety evaluation of intravitreal administration of VEGF trap in cynomolgus monkeys for 13 weeks.
Investigative Ophthalmology & Visual Science, 47(13), pp.1751-1751.
Putative aqueous humor misdirection syndrome as a cause of glaucoma in cats: 32 cases (1997-2003)
J Am Vet Med Assoc. 2005 Nov 1;227(9):1434-41. doi: 10.2460/javma.2005.227.1434.
OBJECTIVE: To characterize the clinical and morphologic aspects of aqueous humor misdirection syndrome (AHMS) in cats and provide a hypothesis regarding its pathogenesis on the basis of detailed analysis of affected cats.
DESIGN: Retrospective study.
ANIMALS: 32 cats (40 eyes).
PROCEDURE: Medical records of cats in which AHMS was diagnosed from July 1997 to August 2003 were reviewed. In certain cats, results of additional diagnostic testing were also obtained, including A-scan, B-scan, and high-resolution ultrasonography; streak retinoscopy; video keratometry; and infrared neutralizing videoretinoscopy as well as results of analysis of flash-frozen sections and histologic examination of enucleated globes.
RESULTS: Cats had a uniformly shallow anterior chamber, intact lens zonules, and a narrowed approach to an open iridocorneal angle. Mean age of affected cats was 11.7 years (range, 4 to 16 years), and female cats were significantly more often affected than male cats. Clinical signs included mydriasis, decreased pupillary light reflex, decreased menace response, and blindness. Glaucomatous changes to the optic nerve, incipient cataracts, and eventual blindness were seen. Intraocular pressure was > or = 20 mm Hg (range, 12 to 58 mm Hg) in 32 of 40 eyes. Ultrasonography and histologic examination revealed a thickened anterior vitreal face interposed between the lens and ciliary body, partial ciliary cleft collapse, and cavitated vitreal regions. Various treatment modalities were used.
CONCLUSIONS AND CLINICAL RELEVANCE: AHMS affects older cats, especially females, and may result in glaucoma, vision loss, and signs of ocular pain. Topical administration of carbonic anhydrase inhibitors decreased intraocular pressure.
Evaluation of intra-and interobserver reliability and image reproducibility to assess usefulness of high-resolution ultrasonography for measurement of anterior segment structures of canine eyes
American journal of veterinary research, 66(10), pp.1775-1779.
26-Week Intravitreal Injection Toxicity Study with rhuFab VEGF in Cynomolgus Monkeys with an 8-Week Recovery
Association for Research in Vision and Ophthalmology Annual Meeting. Invest Ophthalmol Vis Sci., 44 – electronic abstract (2003).