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Functional alterations of retinal neurons and vascular involvement progress simultaneously in the Psammomys obesus model of diabetic retinopathy
Author(s) -
Dellaa Ahmed,
Mbarek Sihem,
Kahloun Rim,
Dogui Mohamed,
Khairallah Moncef,
Hammoum Imane,
RayanaChekir Narjess Ben,
Charfeddine Ridha,
Lachapelle Pierre,
ChaouachaChekir Rafika Ben
Publication year - 2021
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.25114
Subject(s) - photopic vision , scotopic vision , retina , erg , diabetic retinopathy , retinal , electroretinography , biology , ophthalmology , diabetes mellitus , retinopathy , endocrinology , medicine , neuroscience
To investigate the progression of diabetic retinopathy (DR) in a new diurnal animal model, we monitored clinically the DR in Psammomys obesus ( P . obesus ) during 7 months using electroretinography (ERG) and imaging techniques. After the onset of DR, all ERG components decreased progressively. In scotopic conditions, by 3‐months of disease progression, the diabetic P . obesus displayed a significant decrease in amplitude of b‐max, b‐wave responses, and mixed b‐waves. While mixed a‐wave decreased between 4 and 7 months. Significant differences of OP2 appeared following 1 month of disease. In photopic conditions, we noticed a decrease in the a‐wave at 2 months, while it took more than 5 months in b‐wave amplitude. The photopic negative response (PhNR) and the i‐wave amplitudes decreased following 4 and 5 months. OP1 and OP2 were the first to be altered and a significant decrease in the amplitude started after 3 months. Finally, 30 Hz‐flicker and photopic S‐cone were impaired after 2 and 3 months, respectively. The assessment of the eye fundus of the retina revealed an abnormal vascular architecture appeared at Months 6 and 7. In addition, we noticed exudates in the superior periphery of the retina at the same stage. The retina thickness showed a significant reduction at Month 7. Our results indicate that the clinical correlates of human DR are present in diabetic P . obesus . The depressed of ERGs, disruption of retinal architecture, and the appearance of exudates may reflect vascular and neuronal damage throughout the retina as are seen in the advanced stages of human DR.