المؤلفون: Bulcsú Dékány, Erika Tátrai, Arnold Szabo, Gabor Mark Somfai, Fanni Pálya, Zoltán Zsolt Nagy, Petra Soltész, Anikó Somogyi, Rozina I. Hajdú, Anna Enzsoly, Attila Oláh, Akos Kusnyerik, Csaba Mátyás, Zsolt Turóczi, Ákos Lukáts, Tamás Radovits, Klaudia Szabó, Dániel S. Veres, Irén Szalai

المصدر: Investigative Ophthalmology & Visual Science

مصطلحات موضوعية: Blood Glucose, Male, Opsin, genetic structures, Rats, Sprague-Dawley, chemistry.chemical_compound, cones, 0302 clinical medicine, Thyroid, Diabetic retinopathy, Middle Aged, Cone Opsins, Photoreceptor outer segment, medicine.anatomical_structure, Retinal Cone Photoreceptor Cells, Female, Adult, Thyroid Hormones, medicine.medical_specialty, 030209 endocrinology & metabolism, Retina, Diabetes Mellitus, Experimental, opsin expression, Young Adult, 03 medical and health sciences, Internal medicine, Diabetes mellitus, medicine, Animals, Humans, Aged, Glycated Hemoglobin, Diabetic Retinopathy, Color Vision, business.industry, Retinal, medicine.disease, eye diseases, Rats, Rats, Zucker, Cross-Sectional Studies, Diabetes Mellitus, Type 1, Endocrinology, Diabetes Mellitus, Type 2, chemistry, Case-Control Studies, 030221 ophthalmology & optometry, sense organs, business, Hormone

الوصف: Purpose In diabetic subjects, early visual functional alterations such as color vision deficiencies (CVDs) are known to precede clinically apparent diabetic retinopathy. Prominent photoreceptor outer segment degeneration and an increase in the number of retinal dual cones (co-expressing S- and M-opsins simultaneously) have been described in diabetic rat models, suggesting a connection with the development of CVDs. As cone opsin expression is controlled by thyroid hormones, we investigated the diabetic retina in association with thyroid hormone alterations. Methods In rat models of type 1 and 2 diabetes, dual cones were labeled by immunohistochemistry, and their numbers were analyzed in relation to free triiodothyronine (fT3) and free thyroxine (fT4) levels. Quantification of dual cones was also performed in human postmortem retinas. Additionally, a cross-sectional case-control study was performed where thyroid hormone levels were measured and color vision was assessed with Lanthony desaturated D15 discs. Results A higher number of dual cones was detectable in diabetic rats, correlating with fT4 levels. Dual cones were also present in postmortem human retinas, with higher numbers in the three diabetic retinas. As expected, age was strongly associated with CVDs in human patients, and the presence of diabetes also increased the risk. However, the current study failed to detect any effect of thyroid hormones on the development of CVDs. Conclusions Our results point toward the involvement of thyroid homeostasis in the opsin expression changes in diabetic rats and human samples. The evaluation of the possible clinical consequences warrants further research.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::866f76c024f4e82df2b6f230d5bb7d51Test
https://doi.org/10.1167/iovs.62.6.20Test

المؤلفون: Shin Yoshitake, Yoko Dodo, Sotaro Ooto, Akihito Uji, Noriyuki Unoki, Kazuaki Miyamoto, Tomoaki Murakami, Shigeta Arichika, Nagahisa Yoshimura

المصدر: Investigative Ophthalmology & Visual Science. 55:8513-8522

مصطلحات موضوعية: Adult, Male, Optics and Photonics, medicine.medical_specialty, Erythrocytes, Young Adult, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Diabetes mellitus, Ophthalmology, Humans, Medicine, Stage (cooking), Analysis of Variance, Diabetic Retinopathy, Cardiac cycle, business.industry, Lasers, Reproducibility of Results, Retinal Vessels, Retinal, Diabetic retinopathy, Blood flow, Middle Aged, medicine.disease, eye diseases, Sensory Systems, Capillaries, Scanning laser ophthalmoscopy, Ophthalmoscopy, Diabetes Mellitus, Type 1, Diabetes Mellitus, Type 2, chemistry, Regional Blood Flow, Case-Control Studies, Hemorheology, Female, business, Blood Flow Velocity

الوصف: PURPOSE Adaptive optics scanning laser ophthalmoscopy (AO-SLO) is a noninvasive technique that allows for the direct monitoring of erythrocyte aggregates in retinal capillaries. We analyzed the retinal hemorheologic characteristics in normal subjects, diabetic patients without diabetic retinopathy (NDR), and diabetic patients with nonproliferative diabetic retinopathy (NPDR), using spatiotemporal (ST) blood flow images to visualize blood corpuscle trajectory. METHODS AO-SLO images of the parafoveal capillary network were acquired for three groups: 20 healthy volunteers, 17 diabetic patients with NDR (8 type 1 and 9 type 2 patients), and 10 diabetic patients with NPDR (4 type 1 and 6 type 2). The erythrocyte aggregate velocity assigned to a relative cardiac cycle and the elongation rate of the erythrocyte aggregate were calculated. RESULTS Careful observation revealed that flow velocity fluctuations were found with higher frequency in diabetic patients than in normal subjects. The total average velocities were 1.26 ± 0.22 mm/s in the normal group, 1.31 ± 0.21 mm/s in the NDR group, and 1.63 ± 0.35 mm/s in the NPDR group. The average velocities of the NPDR group were higher than those in the normal (P = 0.001) and NDR (P = 0.009) groups. The average elongation rates of the 3 groups were 0.67 ± 0.20, 0.39 ± 0.19, and 0.33 ± 0.11, respectively. Elongation rate differed significantly between the normal and NDR (P = 0.003) groups as well as the normal and NPDR (P = 0.001) groups. CONCLUSIONS AO-SLO can be used to detect retinal hemorheologic changes in the early stages of diabetic retinopathy.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::54ca0c1700cd79ba7df096eee897abbfTest
https://doi.org/10.1167/iovs.14-15121Test