Correlations Between Dark-Adapted Rod Threshold Elevations and ERG Response Deficits in Duchenne Muscular Dystrophy

Author(s)

Salgueiro Barboni, Mirella Telles ^{[1, 2]} ; Dias, Sarah Leonardo ^[1] ; Silva, Leonardo Aparecido ^[1] ; Damico, Francisco Max ^{[1, 3]} ; Vidal, Kallene Summer ^[1] ; Costa, Marcelo Fernandes ^[1] ; Nagy, Balazs Vince ^[4] ; Kremers, Jan ^[5] ; Ventura, Dora Fix ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Psychol, Dept Expt Psychol, Sao Paulo - Brazil

^[2] Semmelweis Univ, Dept Ophthalmol, Maria U 39, H-1085 Budapest - Hungary

^[3] Univ Sao Paulo, Fac Med, Dept Ophthalmol, Sao Paulo - Brazil

^[4] Budapest Univ Technol & Econ, Dept Mechatron Opt & Mech Engn Informat, Budapest - Hungary

^[5] Univ Hosp Erlangen, Sect Retinal Physiol, Erlangen - Germany

• Document type: Journal article
• Source: INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE; v. 62, n. 4 APR 2021.
• Web of Science Citations: 0

Abstract

PURPOSE. The purpose of this study was to characterize changes in the full-field flash electroretinogram (ERG) in association with psychophysical dark-adapted visual thresholds in patients with genetically characterized Duchenne muscular dystrophy (DMD) either lacking Dp427 (Up 30) or at least Dp260 in addition to Dp427 (Down 30). METHODS. Twenty-one patients with DMD and 27 age-similar controls participated in this study. Dark-adapted (0.01, 3.0, and 10 cd.s/m(2) flashes) and light-adapted (3.0 cd.s/m(2) flash) ERGs were recorded following International Society for Clinical Electrophysiology of Vision (ISCEV) standard protocols. Visual detection thresholds to 625-nm (cone function) and 527-nm (rod function) light-emitting diode (LED) flashes (2 degree diameter) were measured during a dark adaptation period after a 1-minute exposure to a bleaching light (3000 cd/m(2)). Initially, 8 minutes of interleaved 625-nm and 527-nm thresholds were measured. After an additional 5 minutes of dark-adaptation, a second set of threshold measurements to 527-nm stimuli was performed during the subsequent 6 minutes. RESULTS. Dark-adapted b-wave amplitude was significantly reduced to all strengths of flash and a-wave in response to the strong flash stimulus was delayed (15.6 vs. 14.7 ms, P < 0.05) in patients with Down 30 compared with controls. Dark-adapted cone thresholds did not differ among the groups (-2.0, -1.8, and -1.7 log cd/m(2) for Down 30, Up 30, and controls, respectively, P = 0.21). In contrast, dark-adapted rod thresholds were elevated (F( 2,36) = 8.537, P = 0.001) in patients with Down 30 (mean = -3.2 +/- 1.1 log cd/m(2)) relative to controls (mean = -4.2 +/- 0.3 log cd/m(2)). Dark-adapted b-wave amplitudes were correlated with dark-adapted rod sensitivity in patients with DMD (Spearman Rho = 0.943, P = 0.005). The changes were much smaller or absent in patients with intact Dp260. CONCLUSIONS. Dp260 is particularly required for normal rod-system function in dark adaptation. (AU)

• FAPESP's process: 14/26818-2 - Development and implementation of visual evaluation methods: clinical applications and animal models
• Grantee: Dora Selma Fix Ventura
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 17/16948-4 - Impact of different types of modification of the gene for dystrophin in the vision of patients with muscular dystrophy
• Grantee: Leonardo Aparecido Silva
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 15/22227-2 - Electrophysiological and psychophysical evaluation of visual functions: a comparative study in Alzheimer's disease, glaucomatous neuropathy and age-related macular degeneration
• Grantee: Kallene Summer Moreira Vidal
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 16/04538-3 - Dystrophin and the human visual system: study of the visual phenotypes of Duchenne muscular dystrophy patients
• Grantee: Dora Selma Fix Ventura
• Support type: Regular Research Grants