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.
Retrospective analysis of complications associated with retrobulbar bupivacaine in dogs undergoing enucleation surgery.
Vet Anaesth Analg. 2020 May 06;:
Authors: Bartholomew KJ, Smith LJ, Bentley E, Lasarev MR
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.
PMID: 32653165 [PubMed - as supplied by publisher]
Wound leakage rates of ex vivo uniplanar versus biplanar phacoemulsification clear corneal incisions in dogs.
Vet Ophthalmol. 2019 Dec 04;:
Authors: Snyder K, Terhaar H, Bentley E, Miller PE
OBJECTIVE: The purpose of this study was to compare the leakage rates of perilimbal uniplanar and biplanar clear corneal incisions in dogs when subjected to increased intraocular pressure (IOP) both from within the eye and via external pressure.
PROCEDURE: Uniplanar clear corneal incisions were created in eight freshly enucleated canine eyes using a 3.2 mm straight slit knife while 8 fellow eyes received a biplanar clear corneal incision consisting of an approximately 300 μm deep groove followed by a 3.2 mm straight slit knife entry into the anterior chamber. Both wounds were reapposed using three simple interrupted 8-0 polyglactin 910 sutures. Eyes were cannulated with two 25 g needles: One connected to a pressure transducer, and the other connected to a reservoir of isotonic saline. The IOP at which the wound leaked was recorded when the intraocular pressure was increased internally by raising the height of the fluid bag, and again when the cornea was externally compressed. Kaplan-Meier survival curves compared incision types for each method of increasing IOP and were evaluated using Mantel-Cox log-rank analysis.
RESULTS: Both wound types resisted leakage at IOP in the physiologically achievable range and no significant differences were observed between clear corneal incisions when pressure was applied externally (P = .353) or was increased from within the globe (P = .615).
CONCLUSION: Ex vivo uniplanar and biplanar clear corneal incisions in dogs are equally strong, with no significant differences in leakage rates when IOP is increased internally or externally.
PMID: 31799807 [PubMed - as supplied by publisher]
Factors affecting publication in peer-reviewed journals of abstracts presented from 2008 to 2012 ACVO meetings.
Vet Ophthalmol. 2018 Apr 14;:
Authors: Bentley E, Koester M, Bdolah-Abram T, Yair N, Ofri R
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%.
PMID: 29656563 [PubMed - as supplied by publisher]
Genomic, Recombinational and Phylogenetic Characterization of Global Feline Herpesvirus 1 Isolates.
Virology. 2018 Mar 29;518:385-397
Authors: Lewin AC, Kolb AW, McLellan GJ, Bentley E, Bernard KA, Newbury SP, Brandt CR
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.
PMID: 29605685 [PubMed - as supplied by publisher]
Cavernous sinus syndrome in dogs and cats: case series (2002-2015).
Open Vet J. 2018;8(2):186-192
Authors: Jones AM, Bentley E, Rylander H
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.
PMID: 29911023 [PubMed]
Protozoal infections of the cornea and conjunctiva in dogs associated with chronic ocular surface disease and topical immunosuppression.
Vet Ophthalmol. 2015 Jun 3;
Authors: Beckwith-Cohen B, Gasper DJ, Bentley E, Gittelman H, Ellis AE, Snowden KF, Shock BC, Yabsley MJ, Dubielzig RR
OBJECTIVE: To describe five cases of protozoal keratitis or conjunctivitis in dogs with chronic preexisting ocular surface disease treated with long-term immunosuppression.
ANIMALS STUDIED: Five dogs that developed corneal or conjunctival mass lesions.
PROCEDURES: The database of the Comparative Ocular Pathology Laboratory of Wisconsin was searched for canine cases diagnosed with corneal or conjunctival protozoal infection. Five cases were identified, and tissues were examined using routine and special histochemical stains: immunohistochemical labels for Neospora caninum, Toxoplasma gondii, and Leishmania spp., and tissue sample PCR for Leishmania spp., Trypanosoma cruzi, tissue coccidia (i.e., T. gondii/Sarcocystis/Neospora), piroplasms, trichomonads, and Acanthamoeba. Electron microscopy was performed for two cases, and serology for N. caninum and T. gondii was available for three cases.
RESULTS: Preexisting ocular diseases included keratoconjunctivitis sicca and pigmentary keratitis (n = 4) and pyogranulomatous meibomian adenitis (n = 1). All dogs were treated with tacrolimus or cyclosporine for at least 1.2 years. Dogs were presented with fleshy corneal or conjunctival masses that were clinically suspected to be neoplastic (n = 4) or immune mediated (n = 1). Histologic examination revealed granulomatous inflammation with intralesional protozoal organisms. Amoeba (n = 2), T. gondii (n = 2), or Leishmania mexicana (n = 1) were identified using molecular techniques. Serological tests were negative.
CONCLUSIONS: Protozoal keratitis and conjunctivitis without systemic involvement appears rare and may be associated with chronic preexisting ocular surface disease treated with long-term immunosuppression. Based upon clinical appearance, lesions could be confused with neoplasia. This is the first report of amoebic keratoconjunctivitis in dogs and of L. mexicana in dogs in the United States.
PMID: 26037023 [PubMed - as supplied by publisher]
Cavernous sinus syndrome in a Holstein bull.
Vet Ophthalmol. 2015 Mar;18(2):164-7
Authors: Jacob SI, Drees R, Pinkerton ME, Bentley EM, Peek SF
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.
PMID: 24256077 [PubMed - in process]
Outcome of iridociliary epithelial tumour biopsies in dogs: a retrospective study.
Vet Rec. 2015 Feb 7;176(6):147
Authors: Beckwith-Cohen B, Bentley E, Dubielzig RR
To evaluate the outcome of eyes with a confirmed iridociliary epithelial tumour (ICET) following biopsy. Forty-two specimens were selected from the Comparative Ocular Pathology Laboratory of Wisconsin database, including 11 globes enucleated following ICET biopsy and 31 iridociliary biopsies with a confirmed ICET. Histopathology was performed for all specimens. When identified, the corneal surgical wound was examined in enucleated globes. Tumour type and margins were determined for biopsy specimens and follow-up was obtained when possible. Biopsies were performed for diagnosis, debulking or excision. 30/31 biopsies had dirty margins, and iridociliary adenomas were indistinguishable from adenocarcinomas by biopsy. Upon biopsy submission 5/23 biopsies were reported as incisional and 18/23 as excisional. Follow-up information was obtained for 14/18 of those reported as excisional. 8/14 had documented recurrence within 5.0±5.6 months and 6/14 had no recurrence at 21.5±13.6 months postoperatively. Three enucleated globes were diagnosed with iridociliary adenocarcinomas and eight with iridociliary adenomas. The corneal surgical wound was sampled in 8/11 globes. There was a synechia to the surgical wound in 3/8 globes, and in 3/8 globes there were neoplastic cells within or adjacent to the surgical wound. The postoperative success of ICET excision is highly variable; complete excision is rarely achieved and recurrence is common. Biopsy effects on ocular tissues may result in synechia and other surgical complications. ICET can be diagnosed by biopsy, but adenomas are indistinguishable from adenocarcinomas.
PMID: 25319595 [PubMed - indexed for MEDLINE]
Comparison of carprofen and tramadol for postoperative analgesia in dogs undergoing enucleation.
J Am Vet Med Assoc. 2014 Dec 15;245(12):1375-81
Authors: Delgado C, Bentley E, Hetzel S, Smith LJ
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.
PMID: 25459482 [PubMed - in process]
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
Authors: Hendrix DV, Bentley E, Rohrbach BW
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.
PMID: 24131796 [PubMed - indexed for MEDLINE]
Long-term outcome of sudden acquired retinal degeneration syndrome in dogs.
J Am Vet Med Assoc. 2013 Nov 15;243(10):1425-31
Authors: Stuckey JA, Pearce JW, Giuliano EA, Cohn LA, Bentley E, Rankin AJ, Gilmour MA, Lim CC, Allbaugh RA, Moore CP, Madsen RW
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.
PMID: 24171371 [PubMed - indexed for MEDLINE]
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
Authors: Gallhoefer NS, Bentley E, Ruetten M, Grest P, Haessig M, Kircher PR, Dubielzig RR, Spiess BM, Pot SA
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.
PMID: 23865880 [PubMed - indexed for MEDLINE]
Feline ocular tumors following ciliary body ablation with intravitreal gentamicin.
Vet Ophthalmol. 2013 Jul;16 Suppl 1:188-90
Authors: Duke FD, Strong TD, Bentley E, Dubielzig RR
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.
PMID: 23701585 [PubMed - indexed for MEDLINE]
Canine ocular tumors following ciliary body ablation with intravitreal gentamicin.
Vet Ophthalmol. 2013 Mar;16(2):159-62
Authors: Duke FD, Strong TD, Bentley E, Dubielzig RR
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.
PMID: 22812389 [PubMed - indexed for MEDLINE]
Systemic hypertension and hypertensive retinopathy following PPA overdose in a dog.
J Am Anim Hosp Assoc. 2013 Jan-Feb;49(1):46-53
Authors: Ginn JA, Bentley E, Stepien RL
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.
PMID: 23148140 [PubMed - indexed for MEDLINE]
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
Authors: Tsai S, Bentley E, Miller PE, Gomes FE, Vangyi C, Wiese A, Almazan A, Li H, Conforti P, Lee SS, Robinson MR
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.
PMID: 22050644 [PubMed - indexed for MEDLINE]
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
Authors: Clark JS, Bentley E, Smith LJ
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.
PMID: 22050712 [PubMed - indexed for MEDLINE]
Ocular lesions associated with systemic hypertension in dogs: 65 cases (2005-2007).
J Am Vet Med Assoc. 2011 Apr 1;238(7):915-21
Authors: Leblanc NL, Stepien RL, Bentley E
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.
PMID: 21453181 [PubMed - indexed for MEDLINE]
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
Authors: Myrna KE, Bentley E, Smith LJ
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.
PMID: 20632790 [PubMed - indexed for MEDLINE]
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
Authors: Pot SA, Liliensiek SJ, Myrna KE, Bentley E, Jester JV, Nealey PF, Murphy CJ
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.
PMID: 19875665 [PubMed - indexed for MEDLINE]