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Michalak SR, Kim S, Park S, Casanova MI, Bowman MAW, Ferneding M, Leonard BC, Good KL, Li JY, Thomasy SM. Topical Ripasudil for the Treatment of Primary Corneal Endothelial Degeneration in Dogs. Transl Vis Sci Technol 2022; 11:2. [PMID: 36048012 PMCID: PMC9440609 DOI: 10.1167/tvst.11.9.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to evaluate the tolerability and efficacy of topical rho-kinase inhibitor ripasudil in the treatment of primary corneal endothelial degeneration (PCED) in dogs. Methods Twenty-one eyes of 12 client-owned, PCED-affected dogs received topical ripasudil 4 times daily. Ophthalmic examination, ultrasonic pachymetry (USP), Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal microscopy were performed at baseline and 1, 3, 6, and 12 months. Effects of treatment on corneal thickness, corneal edema extent, and endothelial cell density (ECD) were evaluated by repeated-measures ANOVA or Friedman test. Individual eyes were classified as improved, progressed, or stable at 12 months using clinical response criteria. Kaplan-Meier curves and log-rank test were used to compare ripasudil-treated eyes to age-, breed/size-, and disease stage-matched historical controls. Results During treatment, 12 dogs developed conjunctival hyperemia, 4 demonstrated reticular bullous epithelial edema, and 2 developed corneal stromal hemorrhage. No adverse event necessitated permanent cessation of ripasudil. Central corneal thickness measured by USP significantly progressed from baseline to 12 months. Corneal thickness by FD-OCT, ECD, and edema extent did not differ over time. Considered individually, 5 eyes improved, 8 remained stable, and 8 progressed. The log-rank test found less edema progression in ripasudil-treated eyes compared to historical controls. Conclusions Ripasudil was well-tolerated in PCED-affected dogs. Response to therapy varied; 62% of eyes showed improved or stable disease whereas 38% progressed. Ripasudil-treated eyes progressed more slowly than historical controls. Translational Relevance Topical ripasudil offered a therapeutic benefit in a subset of patients using a canine model of endothelial degeneration, which may guide future trials in humans.
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Affiliation(s)
- Sarah R Michalak
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Soohyun Kim
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Sangwan Park
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - M Isabel Casanova
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Morgan A W Bowman
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Michelle Ferneding
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Brian C Leonard
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Kathryn L Good
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Jennifer Y Li
- Department of Ophthalmology & Vision Science, School of Medicine, University of California Davis, Davis, California, USA
| | - Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, California, USA.,Department of Ophthalmology & Vision Science, School of Medicine, University of California Davis, Davis, California, USA
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Jeong Y, Kang S, Ahn J, Kim S, Kim H, Park J, Seo K. Assessment of corneal and limbal epithelial thickness by spectral-domain optical coherence tomography in brachycephalic and non-brachycephalic dogs. Vet Ophthalmol 2022; 26 Suppl 1:89-97. [PMID: 35904513 DOI: 10.1111/vop.13016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 07/12/2022] [Accepted: 07/21/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the variance in corneal epithelial thickness (CET) and limbal epithelial thickness (LET) according to the age and skull type by using spectral-domain optical coherence tomography (SD-OCT) in normal dogs. ANIMALS AND PROCEDURES This study used an eye each from 46 dogs (24 brachycephalic and 22 non-brachycephalic dogs) assessed to have clear corneas. Each dog was classified according to age into groups 1 (0-5 years), 2 (6-10 years), and 3 (>11 years). OCT imaging was performed on the central cornea for CET and perpendicular to the quadrant of the limbus for LET. The average of the maximum LET (maxLET) value was measured in four eye quadrants. RESULTS Corneal epithelial thickness was not significantly different according to age in brachycephalic and non-brachycephalic dogs. Visualization of the limbal invagination was better when the maxLET was thick. Nasal and temporal maxLETs were significantly thicker than superior and inferior maxLETs in non-brachycephalic dogs. In brachycephalic dogs, there was a significant decrease in nasal maxLET with age (rs = -0.489, p = .015). Significant differences between brachycephalic and non-brachycephalic dogs were observed in nasal maxLET (p = .024) and temporal maxLET (p = .011). CONCLUSIONS Invagination was better visualized in the nasal and temporal limbal quadrants of non-brachycephalic dogs compared with brachycephalic dogs, and the maxLETs of the regions were thicker than those of the brachycephalic dogs. CET and LET measurements using SD-OCT can help in clinical assessment and research on ocular surface diseases in dogs.
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Affiliation(s)
- Youngseok Jeong
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Junyeong Ahn
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Sol Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Hyelin Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Jisoo Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
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Occelli LM, Pirie CG, Petersen‐Jones SM. Non‐invasive optical coherence tomography angiography: A comparison with fluorescein and indocyanine green angiography in normal adult dogs and cats. Vet Ophthalmol 2022; 25 Suppl 1:164-178. [DOI: 10.1111/vop.12973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 01/08/2023]
Affiliation(s)
- Laurence M. Occelli
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
| | - Chris G. Pirie
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
| | - Simon M. Petersen‐Jones
- Department of Small Animal Clinical Sciences College of Veterinary Medicine Michigan State University East Lansing Michigan USA
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Jeong Y, Kang S, Shim J, Lee E, Jeong D, Park S, Lee S, Kim SA, Seo K. The feasibility of clinical evaluation for anterior uveitis through spectral-domain optical coherence tomography in dogs. Vet Ophthalmol 2021; 25 Suppl 1:111-121. [PMID: 34793607 DOI: 10.1111/vop.12955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 11/05/2021] [Accepted: 11/05/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the clinical application of spectral-domain optical coherence tomography (SD-OCT) for anterior uveitis in dogs. ANIMALS AND PROCEDURES Client-owned dogs presenting with anterior uveitis and clinically healthy dogs were enrolled in this study. Included eyes were divided into 5 groups by flare grade and 3 groups by cell grade through slit-lamp biomicroscopy. Each eye was examined using SD-OCT following slit-lamp biomicroscopy. The ratio of aqueous signal intensity to air signal intensity, which is called the aqueous-to-air relative intensity (ARI) index, was used to evaluate the flare grade. Cell number, central corneal thickness (CCT), and the presence of keratic precipitates (KPs) were analyzed on SD-OCT. The OCT parameters, including ARI index, cell number, and CCT, were compared to the slit-lamp clinical flare and cell grade. RESULTS Thirty-six eyes with anterior uveitis and 27 healthy eyes were enrolled. The ARI index showed a significant correlation with clinical flare grade (rs = 0.811, p < .001). In multiple regression analysis, the ARI index and CCT showed a significant negative correlation (r = -0.258, p = .044). The number of cells on SD-OCT significantly increased with cell grade on slit-lamp biomicroscopy (rs = 0.653, p < .001). The clinical flare grade and CCT were significantly correlated in the partial correlation analysis after controlling for age (partial correlation coefficient = 0.471, p = .002). KPs were observed in 61% of the eyes with flare using SD-OCT (22/36 eyes). CONCLUSIONS Spectral-domain optical coherence tomography could provide quantitative information, including the ARI index, cell counts, and CCT in dogs. SD-OCT is an auxiliary modality for slit-lamp biomicroscopy when evaluating anterior uveitis in dogs.
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Affiliation(s)
- Youngseok Jeong
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Jaeho Shim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Eunji Lee
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Dajeong Jeong
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sanghyun Park
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Songhui Lee
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Su An Kim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
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Guresh AM, Horvath SJ, Gemensky-Metzler A, Miller E, Yildiz V, Myers JV, Newbold GM. The effect of central corneal thickness on intraocular pressure values using various tonometers in the dog. Vet Ophthalmol 2021; 24 Suppl 1:154-161. [PMID: 33616274 DOI: 10.1111/vop.12873] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To compare intraocular pressure readings from three different tonometers, the Tono-Pen AVIA® (TP), TonoVet® (TV) and TonoVet Plus® (TV+) and to determine how measurements from each tonometer are affected by central corneal thickness (CCT). ANIMALS Ninety dogs. PROCEDURES Normal dogs and dogs with ocular disease were selected for study inclusion. Central corneal thickness measurements were gathered with the Pachette 4 ultrasonic pachymeter, and IOP measurements were gathered with the three tonometers in random order. ANOVA or Wilcoxon tests were utilized for overall group comparisons. Linear regression analyses were utilized to determine the association between IOP and CCT. RESULTS When comparing tonometers to each other, for all dogs, readings from the TV+were significantly different compared to the TV (p = <.0001) and TP (p = <.0001); however, there was no significant difference between the TV and the TP (p = .999). Linear regression did not find any significant correlation between corneal thickness and IOP readings with any tonometer when looking at normal dogs or when including dogs with ocular abnormalities. DISCUSSION This study did not find a significant correlation between an increase in CCT and increase in IOP reading in any tonometer comparison amongst normal and dogs with ocular abnormalities. The TV+produced consistently and significantly higher readings, but measurements did not exceed the expected IOP range in normal dogs. For consistency, the same tonometer should be used when monitoring IOP over time.
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Affiliation(s)
- Andrew M Guresh
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - Stephen J Horvath
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - Anne Gemensky-Metzler
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - Eric Miller
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - Vedat Yildiz
- Department of Medicine, Center for Biostatistics, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - John V Myers
- Department of Medicine, Center for Biostatistics, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
| | - Georgina M Newbold
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, USA
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Di Pietro S, Giannetto C, Falcone A, Piccione G, Congiu F, Staffieri F, Giudice E. Dexmedetomidine and Tear Production: Evaluation in Dogs as Spontaneous Model for Ocular Surface Disorders. Vet Sci 2021; 8:vetsci8020028. [PMID: 33669215 PMCID: PMC7919802 DOI: 10.3390/vetsci8020028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 02/07/2021] [Accepted: 02/13/2021] [Indexed: 12/30/2022] Open
Abstract
Simple Summary The general anesthesia or sedation reduces both the tear production and the stability of tear film that protect corneal surface, predisposing itself to the exposure keratopathy. The aim of the present study was to evaluate the effects of intramuscular dexmedetomidine (DEX) on canine tear production, measured by standardized Schirmer Tear Test 1 (STT-1) strips, for the 8 h following sedation, in dogs. A significant effect of time on canine tear production was found, highlighting that dexmedetomidine sedative protocol significantly affects tear production in dogs. It is recommended to treat the canine eyes with tear substitutes to protect ocular surface health and the welfare of the dogs. The ocular lubrication should be performed during and up to 12 h after sedation. The present report could provide preliminary information to better understand the effect of DEX on the tear film dynamics. Abstract Tear film provides lubrication and protection to the ocular surface. The sedation reduces tear production, often leading to perioperative exposure keratopathy. The aim of the present study was to report the effects of intramuscular dexmedetomidine on canine tear production, measured by STT-1, for an experimental period of 8 h after sedation. Ten dogs who underwent sedation for routine radiologic assessment were recruited for the study. In all animals, tear production in right and left eyes was measured 15 min before sedation (T0: basal values) and 20 min (T20), 1 h (T1), 2 h (T2), 4 h (T4) and 8 h (T8) after drug administration. Analysis of variance and post hoc Bonferroni test (p < 0.05) were performed. A significant effect of time on canine tear production was found. The tear production returned to basal values at T8. So, it is recommended to treat the canine eyes with tear substitutes during and up to 12 h after sedation.
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Affiliation(s)
- Simona Di Pietro
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
- Correspondence: ; Tel.: +39-0906-766-758; Fax: +39-0906-766-979
| | - Claudia Giannetto
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
| | - Annastella Falcone
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
| | - Giuseppe Piccione
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
| | - Fulvio Congiu
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
| | - Francesco Staffieri
- Department of Emergency and Organ Transplantation, University of Bari, 70124 Bari, Italy;
| | - Elisabetta Giudice
- Department of Veterinary Sciences, University of Messina, Viale Palatucci, 98168 Messina, Italy; (C.G.); (A.F.); (G.P.); (F.C.); (E.G.)
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Sebbag L, Mochel JP. An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface. Med Res Rev 2020; 40:2566-2604. [PMID: 32735080 DOI: 10.1002/med.21716] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/01/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022]
Abstract
Preclinical animal studies provide valuable opportunities to better understand human diseases and contribute to major advances in medicine. This review provides a comprehensive overview of ocular parameters in humans and selected animals, with a focus on the ocular surface, detailing species differences in ocular surface anatomy, physiology, tear film dynamics and tear film composition. We describe major pitfalls that tremendously limit the translational potential of traditional laboratory animals (i.e., rabbits, mice, and rats) in ophthalmic research, and highlight the benefits of integrating companion dogs with clinical analogues to human diseases into preclinical pharmacology studies. This One Health approach can help accelerate and improve the framework in which ophthalmic research is translated to the human clinic. Studies can be conducted in canine subjects with naturally occurring or noninvasively induced ocular surface disorders (e.g., dry eye disease, conjunctivitis), reviewed herein, and tear fluid can be easily retrieved from canine eyes for various bioanalytical purposes. In this review, we discuss common tear collection methods, including capillary tubes and Schirmer tear strips, and provide guidelines for tear sampling and extraction to improve the reliability of analyte quantification (drugs, proteins, others).
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Affiliation(s)
- Lionel Sebbag
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.,Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Jonathan P Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
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Comprehensive Clinical, Diagnostic, and Advanced Imaging Characterization of the Ocular Surface in Spontaneous Aqueous Deficient Dry Eye Disease in Dogs. Cornea 2020; 38:1568-1575. [PMID: 31369464 DOI: 10.1097/ico.0000000000002081] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE To perform a comprehensive clinical, diagnostic, and imaging characterization of the ocular surface in West Highland White Terriers (WHWTs) diagnosed with aqueous deficient dry eye (ADDE) disease. METHODS Six ADDE-affected and 13 ADDE-unaffected WHWT dogs were enrolled and underwent clinical assessment and disease scoring, tear osmolarity, phenol red thread test, Schirmer tear test, tear film breakup time, fluorescein staining, Rose bengal and lissamine green vital dye staining, meibometry, corneal esthesiometry, ultrasound pachymetry, optical coherence tomography, in vivo confocal microscopy, and conjunctival biopsy. Subjective assessment of their condition was provided by owner-reported surveys. RESULTS ADDE-affected WHWT dogs had higher median clinical disease (conjunctiva: 5.75 vs. 0.00; cornea: 14.00 vs. 5.00; total: 17.50 vs. 5.00), vital staining (Rose bengal: 2.25 vs. 1.50; lissamine green: 2.00 vs. 1.00), and histologic disease (conjunctiva: 2 vs. 0) scores when compared with the controls. In addition, ADDE-affected WHWTs had significantly lower phenol red thread test (5.0 vs. 17.5, mm/15 s), Schirmer tear test (3 vs. 20, mm/min), tear film breakup time (3.6 vs. 13.9, s) values and higher area under the curve values for meibometry (394 vs. 245, meibometry units [MU]). There were no significant differences in other tear film tests performed. Advanced imaging revealed decreased tear meniscus height (optical coherence tomography) and variable pigment deposition within corneal epithelial cells (in vivo confocal microscopy). CONCLUSIONS This comprehensive assessment of ADDE-affected WHWTs depicts the ocular surface changes associated with quantitative lacrimal gland dysfunction. Importantly, ADDE-affected WHWTs may prove a valuable naturally occurring ADDE model for investigating underlying pathophysiological mechanisms and the development of novel therapeutics.
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Armour MD, Askew TE, Eghrari AO. Endothelial keratoplasty for corneal endothelial dystrophy in a dog. Vet Ophthalmol 2019; 22:545-551. [PMID: 30972947 DOI: 10.1111/vop.12670] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/19/2019] [Accepted: 03/27/2019] [Indexed: 08/09/2023]
Abstract
OBJECTIVE To assess the efficacy of an endothelial keratoplasty procedure at defined intervals to 1 year postoperatively for the treatment of corneal endothelial dystrophy (CED) in a canine patient. PROCEDURE A dog diagnosed with CED with progressive corneal edema underwent an endothelial keratoplasty. The patient was examined pre- and postoperatively with slit lamp biomicroscopy and ultrasonic pachymetry. RESULTS Mean central corneal thickness (CCT) measured with pachymetry was >1400 μm preoperatively and decreased postoperatively to 725 μm. The transplanted donor tissue became transparent 2 weeks postoperatively and incorporated with the recipient cornea. The graft remained transparent throughout the duration of the postoperative period evaluated in this study (2 weeks postoperatively to 1 year). The canine patient was comfortable pre- and postoperatively. CONCLUSIONS Endothelial keratoplasty is a potential therapeutic option for canine cases with progressive corneal thickening due to CED. As this is a single case study, further investigation into the use of endothelial keratoplasty to treat CED is warranted. Moreover, canine patients with CED might serve as a surgical model for human patients with Fuchs' Endothelial Corneal Dystrophy.
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Affiliation(s)
- Micki D Armour
- Armour Veterinary Ophthalmology, Washington, District of Columbia
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11
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Shrader SM, Mowry RN. Histomorphometric evaluation of the Göttingen minipig eye. Vet Ophthalmol 2019; 22:872-878. [DOI: 10.1111/vop.12665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/28/2019] [Accepted: 02/28/2019] [Indexed: 12/29/2022]
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Topical Rho-Associated Kinase Inhibitor, Y27632, Accelerates Corneal Endothelial Regeneration in a Canine Cryoinjury Model. Cornea 2019; 38:352-359. [PMID: 30516555 DOI: 10.1097/ico.0000000000001823] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Corneal endothelial cell regeneration varies by species, with nonhuman primates (NHPs) and rabbits displaying low and high proliferative capacities, respectively. Recent studies report that topical application of rho-associated kinase (ROCK) inhibitors accelerates corneal endothelial wound healing in animal models and human patients with endothelial dysfunction. This study determines the regenerative capacity of canine corneal endothelial cells in vivo and their response to a topical ROCK inhibitor, Y27632, after transcorneal freezing. METHODS Right eyes of 6 beagles underwent transcorneal freezing; 10 mM ROCK inhibitor Y27632 or vehicle control was applied topically to both eyes at least 4 times daily for 56 days. Endothelial cell density was evaluated by in vivo confocal microscopy, and corneal thickness was measured by Fourier-domain optical coherence tomography (FD-OCT) and ultrasound pachymetry. RESULTS Transcorneal freezing induced severe central corneal edema in dogs, with restoration of transparency occurring within 4 weeks. Y27632 significantly decreased corneal thickness by FD-OCT and ultrasound pachymetry in the acute phase and significantly increased endothelial cell density at days 28 and 42 post-cryoinjury, suggesting faster restoration of endothelial cell recovery. CONCLUSIONS Canine corneal endothelial function recovers at a similar rate as NHPs but more slowly than rabbits after cryoinjury. Faster corneal endothelial wound healing was observed by in vivo confocal microscopy and FD-OCT in dogs treated with Y27632 versus vehicle controls. Thus, a canine cryoinjury model may be a useful alternative to NHPs in detecting a response to therapies directed at endothelial regeneration.
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Hoehn AL, Thomasy SM, Kass PH, Horikawa T, Samuel M, Shull OR, Stewart KA, Murphy CJ. Comparison of ultrasonic pachymetry and Fourier-domain optical coherence tomography for measurement of corneal thickness in dogs with and without corneal disease. Vet J 2018; 242:59-66. [PMID: 30503546 DOI: 10.1016/j.tvjl.2018.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 11/17/2022]
Abstract
Several ultrasonic and Fourier-domain optical coherence tomography (FD-OCT) pachymeters are used to measure corneal thickness in canine patients and research subjects. This study assessed the reliability of and consistency between two ultrasonic pachymetry (USP) devices, Pachette 3 and Accupach VI, as well as automated and manual measurements obtained using FD-OCT in dogs with and without corneal disease. Corneal thickness measurements were compiled from 108 dogs and analyzed using mixed effects linear regression, with Bonferonni adjustments for post-hoc comparisons, to determine the effects of age, weight and disease state. Data are presented as predicted mean±standard error. Canine corneal disease can result in marked increases in thickness that frequently exceed the upper limits of measurement of some pachymetry devices developed for human use. In this study, the corneas of dogs with endothelial disease or injury frequently exceeded the upper limits of quantitation of 999 and 800μm for the Accupach VI and automated FD-OCT pachymeters, respectively. Using values <800μm, the Pachette 3 generated significantly greater values for central corneal thickness (CCT) than the Accupach VI, manual FD-OCT and automated FD-OCT at 625±7.0, 615±7.2, 613±7.2, and 606±7.4μm respectively (P<0.001). Of the two devices where measurements >1000μm were obtained, manual FD-OCT demonstrated less variability than the Pachette 3. Corneal thickness increased linearly with age and weight with an increase of 6.9±1.8μm/year and 1.6±0.8μm/kg body weight (P<0.005 and P=0.038, respectively).
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Affiliation(s)
- A L Hoehn
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - S M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, 4610 X St., Sacramento, CA 95817, USA.
| | - P H Kass
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - T Horikawa
- Animal Eye Center, 5175 Pacific St., Rocklin, CA 95677, USA
| | - M Samuel
- Eye Care for Animals, 21160 W. Capitol Drive Suite B, Pewaukee, WI 53072, USA
| | - O R Shull
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - K A Stewart
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - C J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, 4610 X St., Sacramento, CA 95817, USA
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Samuel M, Thomasy SM, Calderon AS, Kass PH, Collins K, Murphy CJ. Effects of 5% sodium chloride ophthalmic ointment on thickness and morphology of the normal canine cornea. Vet Ophthalmol 2018; 22:229-237. [PMID: 29927055 DOI: 10.1111/vop.12582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the effect of 5% sodium chloride ophthalmic ointment (5% NaCl) on thickness and morphology of the normal canine cornea using ultrasonic pachymetry (USP), in vivo confocal microscopy (IVCM), and Fourier-domain optical coherence tomography (FD-OCT). METHODS Five healthy laboratory Beagles received ophthalmic examinations including USP, IVCM, and FD-OCT prior to and at fixed intervals following treatment. The right and left eyes were treated with 5% NaCl and artificial tears ophthalmic ointment (AT), respectively, every 2 hours for 4 treatments/d (days 2-9), and then hourly for 7 treatments/d (day 10). Treatment groups were statistically compared using mixed-effects linear regression. RESULTS Treatment with 5% NaCl resulted in a 12 μm decrease in corneal thickness from baseline (P < .001), while there was no significant difference in corneal thickness between values obtained at baseline and following treatment with AT (P = .82). Epithelial cell density significantly increased from baseline (530 ± 52 cells/mm2 ) to 577 ± 43 and 567 ± 15 cells/mm2 with 5% NaCl and AT, respectively (P = .003 and .005, respectively). However, keratocyte cell density in the anterior and posterior stroma and endothelial cell density did not significantly differ following treatment with 5% NaCl or AT ointment (P > .05). CONCLUSIONS Short-term topical treatment with 5% NaCl decreased corneal thickness in normal dogs with no observable changes in corneal morphology or signs of ocular toxicity.
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Affiliation(s)
| | - Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA.,Department of Ophthalmology & Vision Science, UC Davis Eye Center, School of Medicine, University of California, Davis, CA, USA
| | - Allison S Calderon
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Philip H Kass
- Department of Population Health and Reproduction, School of Veterinary Medicine and School of Medicine, University of California, Davis, CA, USA
| | | | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA.,Department of Ophthalmology & Vision Science, UC Davis Eye Center, School of Medicine, University of California, Davis, CA, USA
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15
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de Oliveira JK, Montiani-Ferreira F, Williams DL. The influence of the tonometer position on canine intraocular pressure measurements using the Tonovet ® rebound tonometer. Open Vet J 2018; 8:68-76. [PMID: 29721435 PMCID: PMC5918127 DOI: 10.4314/ovj.v8i1.12] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 02/21/2018] [Indexed: 12/17/2022] Open
Abstract
The objective of this study was to assess the variability of readings made using the Tonovet® rebound tonometer for measurement of intraocular pressure (IOP) in the peripheral cornea and in angulated positions on the canine corneal surface. Forty-six client-owned dogs admitted for ophthalmic evaluation at the Queen's Veterinary School Hospital, University of Cambridge were included in the study. IOP readings were taken at a variety of locations and using the tonometer at a number of different angles to the cornea: 1) Perpendicularly at center of the cornea (CC); 2) At the center of the cornea but with the tonometer positioned at four angles, and 3) At four different points on the peripheral cornea. All values were compared with the values recorded at the recommended CC position. IOP values were significantly underestimated in seven positions, with median and interquartile range from 12.1 ± 4 mmHg (nasal on periphery) to 15 ± 5 mmHg (laterally angled at center), varying between 0 mmHg to 2.9 mmHg from the CC value. While dorsally angled in the central cornea were not significantly different from those at CC (p = 0.09). Median values were lower for measurements in peripheral positions when compared to angled central positions. These results demonstrate that angling the tonometer or measuring in peripheral regions can result in small but statistically significant underestimation of IOP values.
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Affiliation(s)
- Juliana Kravetz de Oliveira
- Department of Veterinary Medicine, Federal University of Paraná, Rua dos Funcionários, 1540, Curitiba, Paraná, Brazil
| | - Fabiano Montiani-Ferreira
- Department of Veterinary Medicine, Federal University of Paraná, Rua dos Funcionários, 1540, Curitiba, Paraná, Brazil
| | - David L Williams
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES UK
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16
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Shull OR, Reilly CM, Davis LB, Murphy CJ, Thomasy SM. Phenotypic Characterization of Corneal Endothelial Dystrophy in German Shorthaired and Wirehaired Pointers Using In Vivo Advanced Corneal Imaging and Histopathology. Cornea 2018; 37:88-94. [PMID: 29077583 PMCID: PMC5799001 DOI: 10.1097/ico.0000000000001431] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE To evaluate corneal morphology using ultrasonic pachymetry (USP), Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal microscopy (IVCM) in 2 related canine breeds-German shorthaired pointers (GSHPs) and German wirehaired pointers (GWHPs)-with and without corneal endothelial dystrophy (CED). This condition is characterized by premature endothelial cell degeneration leading to concomitant corneal edema and is similar to Fuchs endothelial corneal dystrophy. METHODS Corneas of 10 CED-affected (4 GSHP and 6 GWHP) and 19 unaffected, age-matched (15 GSHP and 4 GWHP) dogs were examined using USP, FD-OCT, and IVCM. A 2-sample t test or Mann-Whitney rank-sum test was used to statistically compare parameters between both groups. Data are presented as mean ± SD or median (range). RESULTS Central corneal thickness determined using USP was significantly greater in CED-affected than in unaffected dogs at 1179 (953-1959) and 646 (497-737) μm, respectively (P < 0.001). Central epithelial thickness was found to be significantly decreased in CED-affected versus unaffected dogs at 47 ± 7.1 and 55 ± 7.1 μm, respectively (P = 0.011), using FD-OCT. With IVCM, corneal endothelial density was significantly less (P < 0.001) in 5 dogs with CED versus 19 unaffected controls at 499 ± 315 versus 1805 ± 298 cells/mm, respectively. CED-affected dogs exhibited endothelial pleomorphism and polymegethism, whereas CED-unaffected dogs had regular hexagonal arrangement of cells. CONCLUSIONS GSHPs and GWHPs with CED exhibit marked differences in corneal morphology when compared with age-matched control dogs. These 2 CED-affected breeds represent spontaneous, large animal models for human Fuchs endothelial corneal dystrophy.
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Affiliation(s)
- Olivia R. Shull
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | | | - Lola B. Davis
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
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17
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Comparison of central corneal thickness in dogs measured by ultrasound pachymetry and ultrasound biomicroscopy. Vet J 2017; 232:13-14. [PMID: 29428083 DOI: 10.1016/j.tvjl.2017.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 11/23/2022]
Abstract
Ultrasound pachymetry (UP) is currently the most common technique used to evaluate central corneal thickness (CCT). New devices which allow assessment of CCT without corneal contact have been compared, but there are discrepancies among instruments. The aim of this study was to compare CCT measurements obtained by UP and ultrasound biomicroscopy (UBM) in 28 eyes of 14 healthy Beagles dogs. Mean CCT±standard deviation (SD) were 552±63μm for UP and 551±55μm for UBM. UBM showed both a fixed and proportional bias when compared to ultrasound pachymetry, but this was not considered to be clinically important. Measured CCT did not differ between UP and UBM (P=0.796). The intra-class correlation coefficient indicated a strong agreement between methods (0.990). The CCT measurements between left (548±61μm) and right (555±59μm) eyes did not differ (P=0.760). Male dogs had higher CCT measurements than female dogs (P=0.038).
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18
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Jeong S, Kang S, Park S, Park E, Lim J, Nam T, Seo K. Comparison of corneal thickness measurements using ultrasound pachymetry, ultrasound biomicroscopy, and digital caliper in frozen canine corneas. Vet Ophthalmol 2017; 21:339-346. [DOI: 10.1111/vop.12509] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Seowoo Jeong
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Seonmi Kang
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Sangwan Park
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Eunjin Park
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Jaegook Lim
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Taekjin Nam
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine and Research Institute for Veterinary Science; Seoul National University; 1 Gwanak-ro Gwanak-gu Seoul 08826 Korea
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19
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Schlesener BN, Scott EM, Vallone LV. An unusual case of feline acute corneal hydrops: atypical disease presentation and possible in vivo
detection of Descemet's membrane detachment in the cat's unaffected eye. Vet Ophthalmol 2017; 21:426-431. [DOI: 10.1111/vop.12527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Brittany N. Schlesener
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; 4474 Texas A&M University College Station TX 77843-4474 USA
| | - Erin M. Scott
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; 4474 Texas A&M University College Station TX 77843-4474 USA
| | - Lucien V. Vallone
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; 4474 Texas A&M University College Station TX 77843-4474 USA
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20
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Wolfel AE, Pederson SL, Cleymaet AM, Hess AM, Freeman KS. Canine central corneal thickness measurements via Pentacam-HR®
, optical coherence tomography (Optovue iVue®
), and high-resolution ultrasound biomicroscopy. Vet Ophthalmol 2017; 21:362-370. [DOI: 10.1111/vop.12518] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Allison E. Wolfel
- Department of Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins CO 80523 USA
| | - Samantha L. Pederson
- Department of Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins CO 80523 USA
| | - Allison M. Cleymaet
- Department of Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins CO 80523 USA
| | - Ann M. Hess
- Department of Statistics; College of Natural Sciences; Colorado State University; Fort Collins CO 80523 USA
| | - Kate S. Freeman
- Department of Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins CO 80523 USA
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21
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Thomasy SM, Cortes DE, Hoehn AL, Calderon AC, Li JY, Murphy CJ. In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy. Invest Ophthalmol Vis Sci 2017; 57:OCT495-503. [PMID: 27454658 PMCID: PMC4968913 DOI: 10.1167/iovs.15-18885] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Boston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED. Methods The corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range). Results Mean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively. Conclusions Corneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Dennis E Cortes
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Alyssa L Hoehn
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Allison C Calderon
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Jennifer Y Li
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, United States
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States 2Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, Uni
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22
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Di Y, Li MY, Qiao T, Lu N. Edge detection and mathematic fitting for corneal surface with Matlab software. Int J Ophthalmol 2017; 10:336-342. [PMID: 28393021 DOI: 10.18240/ijo.2017.03.02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 12/08/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To select the optimal edge detection methods to identify the corneal surface, and compare three fitting curve equations with Matlab software. METHODS Fifteen subjects were recruited. The corneal images from optical coherence tomography (OCT) were imported into Matlab software. Five edge detection methods (Canny, Log, Prewitt, Roberts, Sobel) were used to identify the corneal surface. Then two manual identifying methods (ginput and getpts) were applied to identify the edge coordinates respectively. The differences among these methods were compared. Binomial curve (y=Ax2+Bx+C), Polynomial curve [p(x)=p1xn+p2xn-1 +....+pnx+pn+1] and Conic section (Ax2+Bxy+Cy2+Dx+Ey+F=0) were used for curve fitting the corneal surface respectively. The relative merits among three fitting curves were analyzed. Finally, the eccentricity (e) obtained by corneal topography and conic section were compared with paired t-test. RESULTS Five edge detection algorithms all had continuous coordinates which indicated the edge of the corneal surface. The ordinates of manual identifying were close to the inside of the actual edges. Binomial curve was greatly affected by tilt angle. Polynomial curve was lack of geometrical properties and unstable. Conic section could calculate the tilted symmetry axis, eccentricity, circle center, etc. There were no significant differences between 'e' values by corneal topography and conic section (t=0.9143, P=0.3760 >0.05). CONCLUSION It is feasible to simulate the corneal surface with mathematical curve with Matlab software. Edge detection has better repeatability and higher efficiency. The manual identifying approach is an indispensable complement for detection. Polynomial and conic section are both the alternative methods for corneal curve fitting. Conic curve was the optimal choice based on the specific geometrical properties.
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Affiliation(s)
- Yue Di
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai 200062, China
| | - Mei-Yan Li
- Department of Ophthalmology, Eye & ENT Hospital Fudan Unversity, Fenyang Road 83, Shanghai 200031, China
| | - Tong Qiao
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai 200062, China
| | - Na Lu
- Department of Radiology, Huashan Hospital North, Fudan University, 108 Luxiang Road, Shanghai 201907, China
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23
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Vallone LV, Enders AM, Mohammed HO, Ledbetter EC. In vivo
confocal microscopy of brachycephalic dogs with and without superficial corneal pigment. Vet Ophthalmol 2016; 20:294-303. [DOI: 10.1111/vop.12416] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Lucien V. Vallone
- Department of Clinical Sciences; College of Veterinary Medicine; Cornell University; Ithaca NY 14853 USA
| | - Andrew M. Enders
- Department of Clinical Sciences; College of Veterinary Medicine; Cornell University; Ithaca NY 14853 USA
| | - Hussni O. Mohammed
- Department of Population Medicine and Diagnostic Sciences; College of Veterinary Medicine; Cornell University; Ithaca NY 14853 USA
| | - Eric C. Ledbetter
- Department of Clinical Sciences; College of Veterinary Medicine; Cornell University; Ithaca NY 14853 USA
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