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Ikeda T, Jin D, Takai S, Nakamura K, Nemoto E, Kojima S, Oku H. Blastocyst-like Structures in the Peripheral Retina of Young Adult Beagles. Int J Mol Sci 2024; 25:6045. [PMID: 38892233 PMCID: PMC11172769 DOI: 10.3390/ijms25116045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/26/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
In this immunohistological study on the peripheral retina of 3-year-old beagle dogs, excised retina specimens were immunostained with antibodies against nestin, Oct4, Nanog, Sox2, CDX2, cytokeratin 18 (CK 18), RPE65, and YAP1, as well as hematoxylin and DAPI, two nuclear stains. Our findings revealed solitary cysts of various sizes in the inner retina. Intriguingly, a mass of small round cells with scant cytoplasms was observed in the cavity of small cysts, while many disorganized cells partially occupied the cavity of the large cysts. The small cysts were strongly positive for nestin, Oct4, Nanog, Sox2, CDX2, CK18, and YAP1. RPE65-positive cells were exclusively observed in the tissue surrounding the cysts. Since RPE65 is a specific marker of retinal pigment epithelial (RPE) cells, the surrounding cells of the peripheral cysts were presumably derived from RPE cells that migrated intraretinally. In the small cysts, intense positive staining for nestin, a marker of retinal stem cells, seemed to indicate that they were derived from retinal stem cells. The morphology and positive staining for markers of blastocyst and RPE cells indicated that the small cysts may have formed structures resembling the blastocyst, possibly caused by the interaction between retinal stem cells and migrated RPE cells.
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Affiliation(s)
- Tsunehiko Ikeda
- Department of Ophthalmology, Osaka Kaisei Hospital, Osaka 532-0003, Osaka, Japan
- Department of Ophthalmology, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (E.N.); (S.K.); (H.O.)
| | - Denan Jin
- Department of Innovative Medicine, Graduate School of Medicine, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (D.J.); (S.T.)
| | - Shinji Takai
- Department of Innovative Medicine, Graduate School of Medicine, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (D.J.); (S.T.)
| | | | - Emika Nemoto
- Department of Ophthalmology, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (E.N.); (S.K.); (H.O.)
| | - Shota Kojima
- Department of Ophthalmology, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (E.N.); (S.K.); (H.O.)
| | - Hidehiro Oku
- Department of Ophthalmology, Osaka Medical and Pharmaceutical University, Takatsuki 569-8686, Osaka, Japan; (E.N.); (S.K.); (H.O.)
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Francis JM, Mowat FM, Ludwig A, Hicks JM, Pumphrey SA. Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs. Vet Ophthalmol 2024; 27:70-78. [PMID: 37986551 PMCID: PMC10842750 DOI: 10.1111/vop.13163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 11/03/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023]
Abstract
OBJECTIVE To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs. ANIMALS STUDIED One hundred and eighteen companion dogs. PROCEDURES Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade. RESULTS Age was strongly correlated with NS grade (p < .0001). Age-adjusted analysis of NS grade relative to refraction showed a mild but not statistically significant increase in myopia with increasing NS grade, with eyes with grade 3 NS averaging 0.58-0.88 D greater myopia than eyes without NS. However, the myopia of >1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade. CONCLUSIONS NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.
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Affiliation(s)
- Jenelle M Francis
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Freya M Mowat
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Allison Ludwig
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jacqueline M Hicks
- Department of Biostatistics, School of Public Health, Boston University, Boston, Massachusetts, USA
- Dr. Francis's current address is Animal Eye Clinic, Matthews, North Carolina, USA
| | - Stephanie A Pumphrey
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
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Salzman MM, Merten N, Panek WK, Fefer G, Mondino A, Westermeyer HD, Gruen ME, Olby NJ, Mowat FM. Age-associated changes in electroretinography measures in companion dogs. Doc Ophthalmol 2023:10.1007/s10633-023-09938-7. [PMID: 37302110 DOI: 10.1007/s10633-023-09938-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 05/17/2023] [Indexed: 06/13/2023]
Abstract
PURPOSE To determine the association between age and retinal full-field electroretinographic (ERG) measures in companion (pet) dogs, an important translational model species for human neurologic aging. METHODS Healthy adult dogs with no significant ophthalmic abnormalities were included. Unilateral full-field light- and dark-adapted electroretinography was performed using a handheld device, with mydriasis and topical anaesthesia. Partial least squares effect screening analysis was performed to determine the effect of age, sex, body weight and use of anxiolytic medication on log-transformed ERG peak times and amplitudes; age and anxiolytic usage had significant effects on multiple ERG outcomes. Mixed model analysis was performed on data from dogs not receiving anxiolytic medications. RESULTS In dogs not receiving anxiolytics, median age was 118 months (interquartile range 72-140 months, n = 77, 44 purebred, 33 mixed breed dogs). Age was significantly associated with prolonged peak times of a-waves (dark-adapted 3 and 10 cds/m2 flash p < 0.0001) and b-waves (cone flicker p = 0.03, dark-adapted 0.01 cds/m2 flash p = 0.001). Age was also significantly associated with reduced amplitudes of a-waves (dark-adapted 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.005) and b-waves (light-adapted 3 cds/m2 flash p < 0.0001, dark-adapted 0.01 cds/m2 flash p = 0.0004, 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.007) and flicker (light-adapted 30 Hz 3 cds/m2 p = 0.0004). Within the Golden Retriever breed, these trends were matched in a cross-sectional analysis of 6 individuals that received no anxiolytic medication. CONCLUSIONS Aged companion dogs have slower and reduced amplitude responses in both rod- and cone-mediated ERG. Consideration of anxiolytic medication use should be made when conducting ERG studies in dogs.
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Affiliation(s)
- Michele M Salzman
- Department of Surgical Sciences, Medical Sciences Center, School of Veterinary Medicine, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA
| | - Natascha Merten
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
- Department of Medicine (Geriatrics and Gerontology), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Wojciech K Panek
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Gilad Fefer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Alejandra Mondino
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Hans D Westermeyer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Margaret E Gruen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Freya M Mowat
- Department of Surgical Sciences, Medical Sciences Center, School of Veterinary Medicine, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
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Balicka A, Zwolska J, Szadkowski M, Trbolova A, Balicki I. Refractive errors in mixed breed dogs of different ages. VET MED-CZECH 2023; 68:11-16. [PMID: 38384993 PMCID: PMC10878259 DOI: 10.17221/106/2021-vetmed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/08/2022] [Indexed: 02/23/2024] Open
Abstract
The purpose of the study was to evaluate the occurrence and range of refractive errors in dogs of different ages. A total of 99 clinically healthy, mixed-breed mesocephalic dogs were included in the study and divided into three different age groups according to the current human/pet analogy chart: 40 adults (23 males, 17 females, 1-8 years old, 3-70 kg), 21 seniors (14 males, 7 females, 6-11 years old, 7-42 kg), and 38 geriatrics (22 males, 16 females, 8-13 years old, 5-45 kg). All the dogs underwent an ophthalmic examination, including Schirmer tear test, tonometry, biomicroscopy, and ophthalmoscopy. Neither eye drops nor pharmacological sedatives were administered before the autorefractometry. The refractive states were assessed bilaterally using a hand-held Retinomax 3 (Righton) autorefractor. The results underwent statistical analysis using Statistica v12 software (ANOVA and t-test). A P-value < 0.05 was considered as significant. Emmetropia, defined as a refractive state > -0.5 D and < +0.5 D, was found in 36% of the adult, 43% of the senior, and 38% of the geriatric patients. Anisometropia was found in 1% of the adult, 9.5% of the senior and 5.5% of the geriatric dogs when the refractive power of the two eyes differed ≥ 1.0 myopia ≤ -0.5 D and hyperopia ≥ +0.5 D were found in 23% and 41% of the adult eye globes as well as 24% and 33% in the senior dogs and 15% and 47% in the geriatric dogs, respectively. The maximal values of the myopia in the adult and geriatric dogs were -2.5 D and -2.75 D, respectively. The maximal values of the hyperopia in the adult and geriatric dogs were 1.75 D and 2.5 D, respectively. No statistically significant correlation was found between the groups. Ametropia is a common refractive state for dogs of different ages. The most frequent refractive state in ametropic mixed-bed dogs in all age groups is hyperopia.
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Affiliation(s)
- Agnieszka Balicka
- Small Animals Clinic, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovak Republic
| | - Jowita Zwolska
- Department and Clinic of Animal Surgery, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
| | - Mateusz Szadkowski
- Department and Clinic of Animal Surgery, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
| | - Alexandra Trbolova
- Small Animals Clinic, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovak Republic
| | - Ireneusz Balicki
- Department and Clinic of Animal Surgery, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
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McKenzie BA, Chen F, LaCroix-Fralish ML. The phenotype of aging in the dog: how aging impacts the health and well-being of dogs and their caregivers. J Am Vet Med Assoc 2022; 260:963-970. [DOI: 10.2460/javma.22.02.0088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aging is the single most important cause of disease, disability, and death in adult dogs. Contrary to the common view of aging as a mysterious and inevitable natural event, it is more usefully understood as a set of complex but comprehensible biological processes that are highly conserved across species. Although the phenotypic expression of these processes is variable, there are consistent patterns both within and between species.
The purpose of this feature is to describe the patterns currently recognized in the physical and behavioral manifestations of aging in the dog and how these impact the health and welfare of companion dogs and their human caregivers. Important gaps in our knowledge of the canine aging phenotype will be identified, and current research efforts to better characterize aging in the dog will be discussed. This will help set the context for future efforts to develop clinical assessments and treatments to mitigate the negative impact of aging on dogs and humans.
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Affiliation(s)
| | - Frances Chen
- Cellular Longevity Inc dba Loyal, San Francisco, CA
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Bognár Z, Piotti P, Szabó D, Le Nézet L, Kubinyi E. A novel behavioural approach to assess responsiveness to auditory and visual stimuli before cognitive testing in family dogs. Appl Anim Behav Sci 2020. [DOI: 10.1016/j.applanim.2020.105016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wielkiewicz RM. Myopia is an Adaptive Characteristic of Vision: Not a Disease or Defect. REVIEW OF GENERAL PSYCHOLOGY 2016. [DOI: 10.1037/gpr0000090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This article proposes that myopia (nearsightedness) is an adaptive characteristic of human vision. Most theories of the evolution of vision assume myopia is a disease or defect that would have resulted in decreased reproductive fitness in the absence of modern corrective lenses. In contrast, the present article argues that myopic individuals may have played important roles in hunter–gatherer groups such as making tools and weapons, and identifying medicinal plants, contributing to individual and group survival. This idea is called the “adaptive myopia hypothesis.” Evidence favoring this hypothesis is reviewed in the context of the metatheory of evolutionary psychology.
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Antioxidant supplementation increases retinal responses and decreases refractive error changes in dogs. J Nutr Sci 2016; 5:e18. [PMID: 27293555 PMCID: PMC4891559 DOI: 10.1017/jns.2016.5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/06/2016] [Accepted: 02/02/2016] [Indexed: 11/23/2022] Open
Abstract
The objective of the study was to examine whether a nutritional antioxidant supplementation could improve visual function in healthy dogs as measured by electroretinography (ERG) and autorefraction. A total of twelve Beagles, 6 to 8 years of age, with normal eyes upon indirect ophthalmoscopy and slit lamp biomicroscopy, were age and sex matched and randomly assigned to receive a feeding regimen for 6 months with or without a daily antioxidant supplementation. Portable, mini-Ganzfeld ERG and a Welch Allyn hand-held autorefractor were used to test retinal response and refractive error in the dogs at baseline and at the end of the supplementation period. All ERG a-wave amplitudes obtained were increased in the treatment group compared with those of dogs in the control group, with significant improvements in the scotopic high and photopic single flash cone ERG responses (P < 0·05 for both). For the b-wave amplitudes, all responses were similarly increased, with significant improvements in responses for the scotopic high light intensity stimulation (P < 0·05), and for photopic single flash cone and 30 Hz flicker (P < 0·01 for both) recordings. Change in refractive error was significantly less in the treatment group compared with that of the control group during the 6-month study (P < 0·05). Compared with the control group, the antioxidant-supplemented group showed improvement to varying degrees for retinal function and significantly less decline in refractive error. Dogs, like humans, experience retinal and lens functional decline with age. Antioxidant supplementation as demonstrated may be beneficial and effective in the long-term preservation and improvement of various functions of the canine eye.
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