AbstractPurpose To determine the changes of neurons and Muller cells functional activity in idiopathic macular holes (MH).Methods 7 patients (59‐70years) with a full‐thickness MH (3rd stage by Gass, 6‐8 months duration) were examined. Optical coherent tomography (Stratus3000 OCT, Carl Zeiss) used to detect the maximum size of the MH, total macular volume (TMV) and foveal thickness (FT). The central and general macular sensitivity (Sc within 3° from the fixation point, and Sg) were tested with microperimetry (macula 12°, MP1 Nidek). The cone ERG, photopic flicker ERGs (FERG) at 8.3, 10, 12, 30Hz were recorded (RETIport/scan21, Roland Consult), and glial indices were calculated as the ratio of amplitudes of the ERG b‐wave and every FERG.Results The best corrected visual acuity was 0.23±0.09, FT=345±12μ; TMV=7.3±0.1mm3; the maximum hole size 581±62μ. Sc =7.9±1.1dB; Sg=12.2±1.3dB. In MH, a moderate reduction of a‐ and b‐wave amplitudes was noted up to 67% and 88.3% of the norm. The b/a ratio was to 50% higher than in control, reflecting a violations in the outer/post‐receptor retina interface. The amplitude of 24Hz‐FERG (but not the 8.3‐12Hz FERG) showed a sharp reduction (up to 31.4%), indicating to a drastic violation of the bipolar cell activity. The less significant depression in the single‐flash ERG b‐wave may reflect the compensatory hyperactivity of Muller cells, which masks the true reduction of bipolar cells activity. Glial indices increased more than two times at 24Hz, testifying a violation of cone bipolar and Muller cells interaction.Conclusion MH is associated with the reduction in the function of photoreceptor and bipolar cells, sharp increase in Muller cell activity and interaction of cone bipolar and Muller cells.