ON and OFF Electroretinography and Contrast Sensitivity in Duchenne Muscular Dystrophy

Author(s)

Salgueiro Barboni, Mirella Telles ^{[1, 2]} ; Nagy, Balazs Vince ^{[3, 1, 2]} ; de Araujo Moura, Ana Laura ^{[1, 2]} ; Damico, Francisco Max ^{[1, 2, 4]} ; da Costa, Marcelo Fernandes ^{[1, 2]} ; Kremers, Jan ^[5] ; Ventura, Dora Fix ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Nucleo Neurociencias & Comportamento, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Psicol, Dept Psicol Expt, Sao Paulo - Brazil

^[3] Budapest Univ Technol & Econ, Dept Mechatron Opt & Engn Informat, Budapest - Hungary

^[4] Univ Sao Paulo, Fac Med, Dept Oftalmol, Sao Paulo - Brazil

^[5] Univ Hosp Erlangen, Dept Ophthalmol, Erlangen - Germany

• Document type: Journal article
• Source: INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE; v. 54, n. 5, p. 3195-3204, MAY 2013.
• Web of Science Citations: 10

Abstract

PURPOSE. The study investigated possible asymmetric dysfunction of the ON and OFF visual mechanisms in DMD (Duchenne muscular dystrophy) patients associated with specific genetic alterations. METHODS. Nineteen DMD patients and 7 heterozygous DMD carriers were tested, as well as 19 age-matched controls. Full-field ERGs were recorded using mesopic (1 cd/m(2)) and photopic (250 cd/m(2)) sawtooth luminance modulations as stimuli: rapid increase and ramping decrease (to isolate ON responses) or rapid decrease and ramping increase (for OFF responses). In addition, a psychophysical study comprised contrast sensitivity tests using two checkerboard stimuli at either higher (ON) or lower (OFF) luminance relative to the background: 0.3 cycles per degree (cpd) presented for 33 ms (low spatial frequency, short duration) and 2 cpd presented for 1500 ms (high spatial frequency, long duration). RESULTS. A significant ERG amplitude reduction, relative to controls, was detected in the DMD patients in the mesopic positive peaks for both ON and OFF stimuli, as well as for the photopic ON stimulus (P < 0.05). Contrast sensitivity was significantly lower in the DMD patients (P < 0.05) relative to controls for the ON stimuli. Neither the ERG nor the contrast sensitivities were altered in the carriers. CONCLUSIONS. This study suggests that there are ON and OFF ERG alterations when both rods and cones contribute to the ERG responses in DMD patients. When only cones are activated there is an asymmetrical ERG alteration, also revealed by the contrast sensitivity measurements. (AU)

• FAPESP's process: 08/58731-2 - Vision as a sensitive indicator of conditions threatening retinal and central nervous system function
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 07/55125-1 - Electrophysiological and psychophysical evaluation of ON and OFF visual pathways in Duchenne muscular dystrophy young patients
• Grantee: Mirella Telles Salgueiro Barboni
• Support Opportunities: Scholarships in Brazil - Doctorate