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Liebold F, Adler W, Jansen S, Klussmann JP, Meyer M, Nehrlich L, Schmitz J, Vingerhoets A, Heindl LM, Hinkelbein J. Evaluation of colour vision impairment during acute hypobaric hypoxia in aviation medicine: a randomized controlled trial. J Physiol Sci 2024; 74:6. [PMID: 38311742 PMCID: PMC10840265 DOI: 10.1186/s12576-024-00898-4] [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: 09/16/2023] [Accepted: 01/18/2024] [Indexed: 02/06/2024]
Abstract
The digitization of aircraft cockpits places high demands on the colour vision of pilots. The present study investigates colour vision changes upon acute exposure to hypobaric hypoxia. The digital Waggoner Computerized Color Vision Test and the Waggoner D-15 were performed by 54 healthy volunteers in a decompression chamber. Respective altitude levels were sea level, 10,000 or 15,000 ft for exposure periods of 15 and 60 min, respectively. As for 60 min of exposure a significant decrease in colour perception was found between subjects at 15,000 ft as compared to the control group as well as between subjects at 15,000 ft as compared to subjects at 10,000 ft. No significant difference was found in the comparison within the 15,000 ft groups across time points pre-, peri-, and post-exposure. Thus, pilots appear to experience only minor colour vision impairment up to an exposure altitude of 15,000 ft over 60 min of exposure.
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Affiliation(s)
- F Liebold
- Department of Anaesthesiology und Intensive Care Medicine, University Hospital and Faculty of Medicine Cologne, Cologne, Germany.
- Department of Anaesthesiology und Intensive Care Medicine, University Hospital and Faculty of Medicine Leipzig, Liebigstraße 20, 04103, Leipzig, Germany.
| | - W Adler
- Institute for Medical Informatics, Biometry and Epidemiology (IMBE), Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - S Jansen
- Department of Otorhinolaryngology, University Hospital and Faculty of Medicine Cologne, Cologne, Germany
| | - J P Klussmann
- Department of Otorhinolaryngology, University Hospital and Faculty of Medicine Cologne, Cologne, Germany
| | - M Meyer
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Essen, University of Duisburg-Essen, Duisburg, Germany
| | - L Nehrlich
- Department of Anaesthesiology und Intensive Care Medicine, University Hospital and Faculty of Medicine Cologne, Cologne, Germany
| | - J Schmitz
- Department of Anaesthesiology und Intensive Care Medicine, University Hospital and Faculty of Medicine Cologne, Cologne, Germany
- Department of Sleep and Human Factor, German Aerospace Centre, Linder Höhe, 51147, Cologne, Germany
| | - A Vingerhoets
- Department of Medical and Clinical Psychology, Tilburg University, Tilburg, Netherlands
| | - L M Heindl
- Department of Ophthalmology, University Hospital and Faculty of Medicine Cologne, Cologne, Germany
| | - J Hinkelbein
- Johannes Wesling Klinikum Minden, University Hospital, Ruhr University Bochum, Bochum, Germany
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Tsai LT, Chen CC, Hou CH, Liao KM. Achromatic and chromatic contrast discrimination in patients with type 2 diabetes. Sci Rep 2023; 13:7420. [PMID: 37156848 PMCID: PMC10167204 DOI: 10.1038/s41598-023-34407-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 04/28/2023] [Indexed: 05/10/2023] Open
Abstract
Effects of type 2 diabetes on achromatic and chromatic contrast sensitivity (CS) are still controversial. In this study, we aimed to investigate CS in patients without diabetic retinopathy (no-DR) and in those with non-proliferative DR (NPDR) and proliferative DR (PDR) using psychophysical methods with transient and sustained achromatic stimuli and color patches. Achromatic CS was measured with the pulsed pedestal (PP) paradigm (7, 12, and 19 cd/m2) and pedestal-△-pedestal (P-△-P) paradigm (11.4, 18, and 28.5 cd/m2). A chromatic discrimination paradigm that assesses protan, deutan, and tritan color vision was adopted. Forty-two patients (no-DR n = 24, NPDR n = 12, PDR = 6; male n = 22, mean age = 58.1 y/o) and 38 controls (male n = 18, mean age = 53.4 y/o) participated. In patients, mean thresholds were higher than in controls and linear trends were significant in most conditions. For the PP paradigm, differences were significant in the PDR and NPDR groups in the 7 and 12 cd/m2 condition. For the P-△-P paradigm, differences were only significant in the PDR group in the 11 cd/m2 condition. Chromatic contrast loss was significant in the PDR group along the protan, deutan and tritan axes. The results suggest independent involvements of achromatic and chromatic CS in diabetic patients.
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Affiliation(s)
- Li-Ting Tsai
- School of Occupational Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Ophthalmology, National Taiwan University Hospital, Taiwan College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chien-Chung Chen
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Chiun-Ho Hou
- Department of Ophthalmology, National Taiwan University Hospital, Taiwan College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kuo-Meng Liao
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Zhong-Xiao Branch, Taipei City Hospital, Taipei, Taiwan.
- Department of Endocrine and Metabolism, Zhong-Xiao Branch, Taipei City Hospital, No. 87, Tongde Rd., Nangang Dist., Taipei, 11556, Taiwan.
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Banerjee A, Pandurangan K, Joe A, Sachidanandam R, Sen P. Comparison of broadband and monochromatic photopic negative response in eyes of patients with diabetes with no diabetic retinopathy and different stages of diabetic retinopathy. Indian J Ophthalmol 2021; 69:3241-3248. [PMID: 34708780 PMCID: PMC8725145 DOI: 10.4103/ijo.ijo_988_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Purpose: To evaluate the change in broadband (W/W), red on blue (R/B), and blue on yellow (B/Y) photopic negative response (PhNR) in patients with diabetes mellitus with no diabetic retinopathy (no DR) and different stages of DR and compare it with age-matched controls. This study was performed to provide a single PhNR protocol that can be used for early diagnosis of DR. Methods: It was a cross-sectional case-control study done in a hospital setup. Patients with diabetes with no DR and different stages of DR with no other associated ocular pathologies were included. Age-matched controls with no retinal pathologies were also included for comparison. All subjects underwent detailed ophthalmic examination and W/W, R/B, and B/Y electroretinography. Fifty control eyes and 52 treatment naïve eyes of 52 patients with diabetes [no DR = 11, mild nonproliferative diabetic retinopathy (NPDR) =11, moderate NPDR = 10, severe NPDR = 9, and proliferative DR = 11] were included in the study. Results: On comparing the ERG responses in patients with diabetes and age-matched controls, a significant reduction (P < 0.05) was noted in the amplitudes of a-wave (39.78 ± 11.34 μV vs. 67.28 ± 12.88 μV), b-wave (116.25 ± 45.25 vs. 134.39 ± 28.78 μV), W/W PhNR (33.86 ± 17.33 vs. 67.18 ± 15.99 μV), R/B PhNR (28.77 ± 15.85 vs. 53.48 ± 14.15 μV), and B/Y PhNR (55.04 ± 32.63 vs. 104.79 ± 24.37 μV). Posthoc analysis revealed that all the eyes in the diabetic group, including those with no DR, had a significantly reduced PhNR amplitude (P < 0.05) when compared with controls. PhNR was found to reduce in amplitude with increasing severity of DR (P < 0.05), with more significance in B/Y. Receiver operating characteristic showed highest area under the curve in B/Y PhNR (94%, P < 0.001), with maximum sensitivity and specificity of 88% and 87%, respectively. Conclusion: Changes in the amplitude and implicit time of ERG can reflect the severity of DR. PhNR amplitudes, especially B/Y PhNR, appear to be significantly reduced even in eyes with no DR.
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Affiliation(s)
- Aniruddha Banerjee
- Department of Optometry; Department of Vitreo-Retinal Services, Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Karthika Pandurangan
- Department of Optometry, Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Amose Joe
- Department of Optometry; Department of Vitreo-Retinal Services, Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Ramya Sachidanandam
- Department of Optometry; Department of Vitreo-Retinal Services, Medical Research Foundation, Chennai, Tamil Nadu, India
| | - Parveen Sen
- Department of Vitreo-Retinal Services, Medical Research Foundation, Chennai, Tamil Nadu, India
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Krásný J, Magera L, Pluhovský P, Čeledová J, Holubová L. PRE-RETINOPATHY OF TYPE 1 DIABETES IN THE CONTEXT OF FUNCTIONAL, STRUCTURAL AND MICROCIRCULATORY CHANGES IN THE MACULAR AREA. CESKA A SLOVENSKA OFTALMOLOGIE : CASOPIS CESKE OFTALMOLOGICKE SPOLECNOSTI A SLOVENSKE OFTALMOLOGICKE SPOLECNOSTI 2021; 77:170-182. [PMID: 34507493 DOI: 10.31348/2021/20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM The authors assessed the development of intraocular changes in type 1 diabetes (T1DM) from the onset of the disease leading to diabetic retinopathy (DR). The quote: “There must be an intermediate stage between the physiological intraocular finding and the diabetic retinopathy itself “, (prof. Jan Vavřinec). METHODS A two-year study (2018 and 2019) was conducted at the Department of Ophthalmology of the Teaching Hospital Kralovske Vinohrady in Prague (Czech Republic). There were 54 patients aged 17-42 years, the detection of T1DM ranged between the 1st and 14th year of life, with a duration of 12-35 years. Individual patients were always examined simultaneously by three methods: CS (contrast sensitivity), SD-OCT (spectral domain optical coherence tomography) and OCT-A (optical coherence tomography-angiography). We examined 106 eyes once and in a comprehensive manner. RESULTS We have shown that there is an intermediate stage between the physiological finding on the retina and DR, so-called diabetic pre-retinopathy (DpR). Subsequent redistribution of the observed into two DpR subgroups was derived from the size of the FAZ, either with its smaller area or with a larger area determining the microvascularity of the central area of the retina. The results of both other methods were assigned to these values. For SD-OCT, the depth of the fovea (the difference between the central retinal thickness and the total average retinal thickness) was determined, which was affected by the increased the macular cubature. In all patients it was on average 10.3 μm3. The retina in the central area was significantly strengthened compared to the healthy population at the level of significance p 0,001. We divided the actual DpR into an image: DpR1 in 26.5 % of eyes - condition with an average shallower fovea only by 21.5 μm below the level of the surrounding retina and an average narrower FAZ: 0.165 mm2 and with a more significant decrease in CS; DpR2 in 40.5 % of eyes - condition with average deeper fovea by 42 μm, i.e., more significantly and average larger FAZ: 0.325 mm2 with lower decrease of CS. At the same time, other changes in microvascularity were noted, such as disorders in the sense of non-perfusion in the central part of the retina of various degrees. This finding differed significantly from changes in already established (non-proliferative) NPDR in 36 % of eyes, when a significant decrease in CS with normal visual acuity was found 4/4 ETDRS. Statistical differences in CS between DpR1 and DpR2 and NPDR were determined - always p 0.001. The average depth of the fovea was NPDR: 29.5 μm. NPDR had the largest average FAZ: 0.56 mm2. Also significant were the most significant changes in non-perfusion and especially the presence of microaneurysms. CONCLUSIONS These three non - invasive methods helped to monitor the dynamics of the development of ocular changes in T1DM of better quality than the determination of visual acuity and ophthalmoscopic examination. Increased retinal volume induced hypoxia of visual cells with subsequent dual autoregulatory mechanism conditioning two types of diabetic pre-retinopathy before the onset of DR.
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Tonade D, Kern TS. Photoreceptor cells and RPE contribute to the development of diabetic retinopathy. Prog Retin Eye Res 2021; 83:100919. [PMID: 33188897 PMCID: PMC8113320 DOI: 10.1016/j.preteyeres.2020.100919] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/26/2022]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness. It has long been regarded as vascular disease, but work in the past years has shown abnormalities also in the neural retina. Unfortunately, research on the vascular and neural abnormalities have remained largely separate, instead of being integrated into a comprehensive view of DR that includes both the neural and vascular components. Recent evidence suggests that the most predominant neural cell in the retina (photoreceptors) and the adjacent retinal pigment epithelium (RPE) play an important role in the development of vascular lesions characteristic of DR. This review summarizes evidence that the outer retina is altered in diabetes, and that photoreceptors and RPE contribute to retinal vascular alterations in the early stages of the retinopathy. The possible molecular mechanisms by which cells of the outer retina might contribute to retinal vascular damage in diabetes also are discussed. Diabetes-induced alterations in the outer retina represent a novel therapeutic target to inhibit DR.
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Affiliation(s)
- Deoye Tonade
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Veterans Administration Medical Center Research Service, Cleveland, OH, USA; Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Veterans Administration Medical Center Research Service, Long Beach, CA, USA.
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González-Casanova J, Schmachtenberg O, Martínez AD, Sanchez HA, Harcha PA, Rojas-Gomez D. An Update on Connexin Gap Junction and Hemichannels in Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22063194. [PMID: 33801118 PMCID: PMC8004116 DOI: 10.3390/ijms22063194] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/06/2021] [Accepted: 03/10/2021] [Indexed: 01/10/2023] Open
Abstract
Diabetic retinopathy (DR) is one of the main causes of vision loss in the working age population. It is characterized by a progressive deterioration of the retinal microvasculature, caused by long-term metabolic alterations inherent to diabetes, leading to a progressive loss of retinal integrity and function. The mammalian retina presents an orderly layered structure that executes initial but complex visual processing and analysis. Gap junction channels (GJC) forming electrical synapses are present in each retinal layer and contribute to the communication between different cell types. In addition, connexin hemichannels (HCs) have emerged as relevant players that influence diverse physiological and pathological processes in the retina. This article highlights the impact of diabetic conditions on GJC and HCs physiology and their involvement in DR pathogenesis. Microvascular damage and concomitant loss of endothelial cells and pericytes are related to alterations in gap junction intercellular communication (GJIC) and decreased connexin 43 (Cx43) expression. On the other hand, it has been shown that the expression and activity of HCs are upregulated in DR, becoming a key element in the establishment of proinflammatory conditions that emerge during hyperglycemia. Hence, novel connexin HCs blockers or drugs to enhance GJIC are promising tools for the development of pharmacological interventions for diabetic retinopathy, and initial in vitro and in vivo studies have shown favorable results in this regard.
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Affiliation(s)
- Jorge González-Casanova
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago 8910060, Chile;
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile;
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Helmuth A. Sanchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Paloma A. Harcha
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (A.D.M.); (H.A.S.); (P.A.H.)
| | - Diana Rojas-Gomez
- Escuela de Nutrición y Dietética, Facultad de Medicina, Universidad Andres Bello, Santiago 8370146, Chile
- Correspondence: ; Tel.: +56-2-26618559
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Maguire J, Parry NRA, Kremers J, Murray IJ, McKeefry D. Human S-cone electroretinograms obtained by silent substitution stimulation. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2018; 35:B11-B18. [PMID: 29603933 DOI: 10.1364/josaa.35.000b11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/27/2017] [Indexed: 06/08/2023]
Abstract
We used triple silent substitution stimuli to characterize human S-cone electroretinograms (ERGs) in normal trichromats. Short-wavelength-cone (S-cone) ERGs were found to have different morphological features and temporal frequency response characteristics compared to ERGs derived from L-cones, M-cones, and rod photoreceptors in normal participants. Furthermore, in two cases of retinal pathology, blue cone monochromatism (BCM) and enhanced S-cone syndrome (ESCS), S-cone ERGs elicited by our stimuli were preserved and enhanced, respectively. The results from both normal and pathological retinae demonstrate that triple silent substitution stimuli can be used to generate ERGs that provide an assay of human S-cone function.
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Dellaa A, Benlarbi M, Hammoum I, Gammoudi N, Dogui M, Messaoud R, Azaiz R, Charfeddine R, Khairallah M, Lachapelle P, Ben Chaouacha-Chekir R. Electroretinographic evidence suggesting that the type 2 diabetic retinopathy of the sand rat Psammomys obesus is comparable to that of humans. PLoS One 2018; 13:e0192400. [PMID: 29420665 PMCID: PMC5805270 DOI: 10.1371/journal.pone.0192400] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 01/23/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose Type 2 diabetic retinopathy is the main cause of acquired blindness in adults. The aim of this work was to examine the retinal function of the sand rat Psammomys obesus as an animal model of diet-induced type 2 diabetes when subjected to a hypercaloric regimen. Materials and methods Hyperglycemia was induced in Psammomys obesus by high caloric diet (4 kcal/g). The visual function of control (n = 7) and diabetic (n = 7) adult rodents were followed up during 28 consecutive weeks with full-field electroretinogram(ERG) recordings evoked to flashes of white light according to the standard protocol of the International Society for Clinical Electrophysiology of Vision protocol (ISCEV). Results Twenty-eight weeks following the induction of diabetes, results revealed significantly reduced and delayed photopic and scotopic ERG responses in diabetic rats compared to control rats. More specifically, we noted a significant decrease in the amplitude of the dark-adapted 0.01ERG (62%), a- and b-wave amplitudes of the dark-adapted 3.0 ERG (33.6%, 55.1%) and the four major oscillatory potentials components (OP1-OP4) (39.0%, 75.2%, 54.8% and 53.7% respectively). In photopic conditions, diabetic rats showed a significant decrease in a- and b-wave (30.4%, 43.4%), photopic negative response (55.3%), 30 Hz flicker (63.7%), OP1-OP4(51.6%, 61.8%, 68.3% and 47.5% respectively) and S-cone (34.7%). Significantly delayed implicit times were observed for all ERG components in the diabetic animals. Results obtained are comparable to those characterizing the retinal function of patients affected with advanced stage of diabetic retinopathy. Conclusion Psammomys obesus is a useful translational model to study the pathophysiology of diabetic retinopathy in order to explore new therapeutic avenues in human patients.
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Affiliation(s)
- Ahmed Dellaa
- Laboratory of Physiopathology, Food and Biomolecules of the Higher Institute of Biotechnology Sidi Thabet, Manouba University, BiotechPole Sidi Thabet, Ariana, Tunisia
- Faculty of Sciences of Bizerte, Carthage University, Bizerte, Tunisia
| | - Maha Benlarbi
- Laboratory of Physiopathology, Food and Biomolecules of the Higher Institute of Biotechnology Sidi Thabet, Manouba University, BiotechPole Sidi Thabet, Ariana, Tunisia
| | - Imane Hammoum
- Laboratory of Physiopathology, Food and Biomolecules of the Higher Institute of Biotechnology Sidi Thabet, Manouba University, BiotechPole Sidi Thabet, Ariana, Tunisia
| | - Nouha Gammoudi
- Department of functional explorations of the nervous system, University Hospital of Sahloul, Sousse, Tunisia
| | - Mohamed Dogui
- Department of functional explorations of the nervous system, University Hospital of Sahloul, Sousse, Tunisia
| | - Riadh Messaoud
- Department of Ophthalmology, University Hospital of Fattouma Bourguiba, Monastir, Tunisia
| | - Rached Azaiz
- UNIMED Pharmaceutical Industry, industrial area Kalaa Kebira, Sousse, Tunisia
| | - Ridha Charfeddine
- UNIMED Pharmaceutical Industry, industrial area Kalaa Kebira, Sousse, Tunisia
| | - Moncef Khairallah
- Department of Ophthalmology, University Hospital of Fattouma Bourguiba, Monastir, Tunisia
| | - Pierre Lachapelle
- Department of Ophthalmology, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Rafika Ben Chaouacha-Chekir
- Laboratory of Physiopathology, Food and Biomolecules of the Higher Institute of Biotechnology Sidi Thabet, Manouba University, BiotechPole Sidi Thabet, Ariana, Tunisia
- * E-mail:
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Bavinger JC, Dunbar GE, Stem MS, Blachley TS, Kwark L, Farsiu S, Jackson GR, Gardner TW. The Effects of Diabetic Retinopathy and Pan-Retinal Photocoagulation on Photoreceptor Cell Function as Assessed by Dark Adaptometry. Invest Ophthalmol Vis Sci 2016; 57:208-17. [PMID: 26803796 PMCID: PMC4877135 DOI: 10.1167/iovs.15-17281] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose The pathophysiology of vision loss in persons with diabetic retinopathy (DR) is complex and incompletely defined. We hypothesized that retinal pigment epithelium (RPE) and rod and cone photoreceptor dysfunction, as measured by dark adaptometry, would increase with severity of DR, and that pan-retinal photocoagulation (PRP) would exacerbate this dysfunction. Methods Dark adaptation (DA) was measured in subjects with diabetes mellitus and healthy controls. Dark adaptation was measured at 5° superior to the fovea following a flash bleach, and the data were analyzed to yield cone and rod sensitivity curves. Retinal layer thicknesses were quantified using spectral-domain optical coherence tomography (OCT). Results The sample consisted of 23 controls and 73 diabetic subjects. Subjects with moderate nonproliferative diabetic retinopathy (NPDR) exhibited significant impairment of rod recovery rate compared with control subjects (P = 0.04). Cone sensitivity was impaired in subjects with proliferative diabetic retinopathy (PDR) (type 1 diabetes mellitus [T1DM]: P = 0.0047; type 2 diabetes mellitus [T2DM]: P < 0.001). Subjects with untreated PDR compared with subjects treated with PRP exhibited similar rod recovery rates and cone sensitivities. Thinner RPE as assessed by OCT was associated with slower rod recovery and lower cone sensitivity, and thinner photoreceptor inner segment/outer segment layer was associated with lower cone sensitivity. Conclusions The results suggest that RPE and photoreceptor cell dysfunction, as assessed by cone sensitivity level and rod- and RPE-mediated dark adaptation, progresses with worsening DR, and rod recovery dysfunction occurs earlier than cone dysfunction. Function was preserved following PRP. The findings suggest multiple defects in retinoid function and provide potential points to improve visual function in persons with PDR.
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Affiliation(s)
- J Clay Bavinger
- Department of Ophthalmology and Visual Sciences W. K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Grace E Dunbar
- Department of Ophthalmology and Visual Sciences W. K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Maxwell S Stem
- Department of Ophthalmology and Visual Sciences W. K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Taylor S Blachley
- Department of Ophthalmology and Visual Sciences W. K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, United States
| | - Leon Kwark
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Sina Farsiu
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States 3Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
| | | | - Thomas W Gardner
- Department of Ophthalmology and Visual Sciences W. K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, United States
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Pardue MT, Barnes CS, Kim MK, Aung MH, Amarnath R, Olson DE, Thulé PM. Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes. Transl Vis Sci Technol 2014; 3:6. [PMID: 24959388 DOI: 10.1167/tvst.3.3.6] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/28/2014] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To evaluate the utility of low luminance stimuli to functionally probe inner retinal rod pathways in the context of diabetes mellitus in both rat and human subjects. METHODS Inner retinal dysfunction was assessed using oscillatory potential (OP) delays in diabetic rats. Scotopic electroretinograms (ERGs) in response to a series of increasing flash luminances were recorded from streptozotocin (STZ)-treated and control Sprague-Dawley rats after 7, 14, 20, and 29 weeks of hyperglycemia. We then evaluated OP delays in human diabetic subjects with (DR) and without (DM) diabetic retinopathy using the International Society for Clinical Electrophysiology in Vision (ISCEV) standard scotopic protocol and two additional dim test flashes. RESULTS Beginning 7 weeks after STZ, OP implicit times in diabetic rats were progressively delayed in response to dim, but not bright stimuli. In many diabetic subjects the standard ISCEV dim flash failed to illicit measureable OPs. However, OPs became measurable using a brighter, nonstandard dim flash (Test Flash 1, -1.43 log cd s/m2), and exhibited prolonged implicit times in the DM group compared with control subjects (CTRL). CONCLUSIONS Delays in scotopic OP implicit times are an early response to hyperglycemia in diabetic rats. A similar, inner retinal, rod-driven response was detected in diabetic human subjects without diabetic retinopathy, only when a nonstandard ISCEV flash intensity was employed during ERG testing. TRANSLATIONAL RELEVANCE The addition of a dim stimulus to standard ISCEV flashes with assessment of OP latency during ERG testing may provide a detection method for early retinal dysfunction in diabetic patients.
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Affiliation(s)
- Machelle T Pardue
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA ; Neuroscience Program, Emory University, Atlanta, GA
| | - Claire S Barnes
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moon K Kim
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moe H Aung
- Neuroscience Program, Emory University, Atlanta, GA
| | - Raj Amarnath
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA
| | - Darin E Olson
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
| | - Peter M Thulé
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
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McKeefry D, Kremers J, Kommanapalli D, Challa NK, Murray IJ, Maguire J, Parry NRA. Incremental and decremental L- and M-cone-driven ERG responses: I. Square-wave pulse stimulation. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2014; 31:A159-A169. [PMID: 24695165 DOI: 10.1364/josaa.31.00a159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electroretinograms (ERGs) elicited by transient, square-wave L- and M-cone isolating stimuli were recorded from human trichromatic (n=19) and dichromatic (n=4) observers. The stimuli were generated on a four primary LED stimulator and were equated in terms of cone modulation (cone contrast=0.11) and retinal illuminance (12,000 trolands). L- and M-cone isolated ERGs had waveforms similar to those observed for luminance responses. However, M-cone ERGs exhibited a phase reversal in their responses to onset and offset stimuli relative to the L-cone responses. This on-off response reversal was observed in trichromats but not dichromats. Simultaneous counterphase and inphase combinations of L- and M-cone isolating stimuli generated responses that reflected chromatic and luminance processing, respectively. We conclude that L- and M-cone specific ERGs provide a measure of how photoreceptors contribute to postreceptoral mechanisms.
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Attenuation of S-cone function at high altitude assessed by electroretinography. Vision Res 2014; 97:59-64. [DOI: 10.1016/j.visres.2014.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/24/2014] [Accepted: 02/10/2014] [Indexed: 11/21/2022]
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Plasma levels of IL-17, VEGF, and adrenomedullin and S-cone dysfunction of the retina in children and adolescents without signs of retinopathy and with varied duration of diabetes. Mediators Inflamm 2013; 2013:274726. [PMID: 24347823 PMCID: PMC3852315 DOI: 10.1155/2013/274726] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/06/2013] [Accepted: 10/12/2013] [Indexed: 11/30/2022] Open
Abstract
The study objective was to assess chosen biochemical parameters of blood and bioelectric function of the retina in patients with T1DM. The study group consisted of 41 patients with T1DM with no signs of diabetic retinopathy. The control group included 21 pediatric patients. We performed (1) S-cone ERG testing with retina response stimulation in both eyes at the luminance of 0.1, 0.2, and 0.5 (cd × s/m2) with the 440 nm blue flash and light application of the amber background (300 ph cd/m2, 495 nm wavelength), (2) anthropometric measurements, (3) biochemical investigations: IL-17, VEGF, and ADM by the ELISA method. A comparison of the ERG results with biochemical investigations indicates a likely correlation between the worsening of retinal bioelectric function and VEGF levels growing with diabetes duration. We showed a negative correlation between ADM and HbA1c and described possible causes of ADM reduction observed in subgroup I. We demonstrated the presence of bioelectric retinal dysfunction already before the diagnosis of diabetic retinopathy, which provides new possibilities in the diagnosis of preclinical chronic complications of diabetes. The changes observed in the levels of IL-17, ADM, and VEGF suggest their involvement in the diabetic pathogenesis of eye diseases.
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Changes in frequency-doubling perimetry in patients with type I diabetes prior to retinopathy. BIOMED RESEARCH INTERNATIONAL 2013; 2013:341269. [PMID: 24319681 PMCID: PMC3844182 DOI: 10.1155/2013/341269] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 11/18/2022]
Abstract
PURPOSE To evaluate the ability of frequency-doubling technology (FDT) perimetry in detecting visual field defects in young adults with type I diabetes prior to retinopathy or with minor retinovascular changes. METHODS This comparative cross-sectional study included 30 healthy subjects and 73 age-matched patients with type I diabetes mellitus. All subjects underwent a full ocular examination including an FDT with the threshold C-20-5 strategy. Only one eye per subject was randomly included in the statistical analysis. FDT results and time to perform the test were compared between the groups. RESULTS The mean age was 27.1 years in the control group and 26.6 years in the diabetic group (P = 0.875). The mean period from the onset of diabetes was 12.6 ± 6.7 years, while minimal retinovascular changes were observed in 18 eyes. Mean deviation of FDT did not differ between the groups. Although global indices of FDT were within normal limits, pattern standard deviation of FDT was higher in the diabetic group (P = 0.035). The area under the receiver operating characteristic curve was 0.647 for pattern standard deviation of FDT (standard error = 0.052; P = 0.017). CONCLUSION FDT can detect retinal dysfunctions in diabetic patients prior to the onset of significant vascular complications.
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McFarlane M, Wright T, Stephens D, Nilsson J, Westall CA. Blue flash ERG PhNR changes associated with poor long-term glycemic control in adolescents with type 1 diabetes. Invest Ophthalmol Vis Sci 2012; 53:741-8. [PMID: 22222270 PMCID: PMC3880360 DOI: 10.1167/iovs.11-8263] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To investigate the relationship between long-term glycemic control and photopic negative response (PhNR) changes in the blue flash ERG in adolescents with type 1 diabetes (T1D) without diabetic retinopathy (DR). METHODS After light adaptation, ERG responses to 1.60 cd·s/m(2) blue (420 nm) flashes (blue flash ERG) and 3.0 cd·s/m(2) white flashes (LA 3.0 ERG) were recorded in 22 patients (age range, 12 to 19 years) and 28 age-similar control subjects. The primary outcome measure was the amplitude of the PhNR. Secondary outcome measures were the amplitude and implicit time of the a-wave and b-wave. Multiple regression analyses were conducted with glycated hemoglobin (HbA(1c)) values and the time since diagnosis of T1D as covariates. RESULTS Blue flash ERG PhNR amplitudes were reduced (P = 0.005) in patients compared with control subjects. Multiple regression analysis demonstrated that a 1-unit increase in HbA(1c) was associated with a 15% decrease in the blue flash ERG PhNR amplitude (r = 0.61, P = 0.003). Compared with controls blue flash ERG a-waves (P = 0.03) and b-waves (P = 0.02) were delayed in patients but were not significantly associated with HbA(1c) or time since diagnosis of T1D. None of the ERG measures in the LA 3.0 ERG were significantly different in patients compared with controls. CONCLUSIONS Poorer long-term glycemic control is associated with worsening inner retinal dysfunction involving short-wavelength cone pathways of adolescents with T1D and no clinically visible DR. Future studies are warranted to determine whether changes in the blue flash ERG PhNR are a predictive marker of subclinical DR.
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Affiliation(s)
- Michelle McFarlane
- Ophthalmology and Vision Sciences and, The Hospital for Sick Children, Toronto, Ontario, Canada
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Affiliation(s)
- Francesco Boscia
- Department of Ophthalmology and Otolaryngology, University of Bari, Bari, Italy.
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Alvarez Y, Chen K, Reynolds AL, Waghorne N, O'Connor JJ, Kennedy BN. Predominant cone photoreceptor dysfunction in a hyperglycaemic model of non-proliferative diabetic retinopathy. Dis Model Mech 2010; 3:236-45. [PMID: 20142328 DOI: 10.1242/dmm.003772] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Approximately 2.5 million people worldwide are clinically blind because of diabetic retinopathy. In the non-proliferative stage, the pathophysiology of this ocular manifestation of diabetes presents as morphological and functional disruption of the retinal vasculature, and dysfunction of retinal neurons. However, it is uncertain whether the vascular and neuronal changes are interdependent or independent events. In addition, the identity of the retinal neurons that are most susceptible to the hyperglycaemia associated with diabetes is unclear. Here, we characterise a novel model of non-proliferative diabetic retinopathy in adult zebrafish, in which the zebrafish were subjected to oscillating hyperglycaemia for 30 days. Visual function is diminished in hyperglycaemic fish. Significantly, hyperglycaemia disrupts cone photoreceptor neurons the most, as evidenced by prominent morphological degeneration and dysfunctional cone-mediated electroretinograms. Disturbances in the morphological integrity of the blood-retinal barrier were also evident. However, we demonstrate that these early vascular changes are not sufficient to induce cone photoreceptor dysfunction, suggesting that the vascular and neuronal complications in diabetic retinopathy can arise independently. Current treatments for diabetic retinopathy target the vascular complications. Our data suggest that cone photoreceptor dysfunction is a clinical hallmark of diabetic retinopathy and that the debilitating blindness associated with diabetic retinopathy may be halted by neuroprotection of cones.
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Affiliation(s)
- Yolanda Alvarez
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Belfield, Dublin D4, Ireland
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Bibliography. Current world literature. Neuro-ophthalmology. Curr Opin Ophthalmol 2006; 17:574-5. [PMID: 17065928 DOI: 10.1097/icu.0b013e32801121a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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