Abnormal focal macular electroretinogram in eye with idiopathic epimacular membrane Original Reearch Article

PURPOE: To tudy the functional tate of the retina beneath an epimacular membrane by mean of focal macular electroretinography. METHOD: Focal macular electroretinogram of 30 conecutive patient (age 25 to 75 year) with unilateral idiopathic epimacular membrane were recorded propectively. The amplitude and implicit time of the a and b wave and the ocillatory potential (O1, O2, O3) recorded from the eye with idiopathic epimacular membrane were compared with thoe of the normal fellow eye. REULT: There wa a tatitically ignificant reduction in the amplitude of the a wave (P < .001), the b wave (P < .001), and the ocillatory potential (O1 + O2 + O3; P < .001) of the affected eye. The reduction of the b-wave amplitude wa ignificantly greater than that of the a wave, reulting in a lower b/a wave ratio (P = .003) in the affected eye. The reduction in the amplitude of the ocillatory potential wa ignificantly greater than that of the other two component (P < .001). The implicit time were ignificantly prolonged for the a wave (P < .001), the b wave (P = .004), and O3 (P < .001). There wa a ignificant correlation between relative b-wave amplitude (affected/normal fellow eye) and the viual acuity (r = −0.50, P = .007). Thee finding were imilar to thoe we reported for eye with aphakic cytoid macular edema. CONCLUION: The focal macular electroretinogram in eye with epimacular membrane dicloed abnormalitie that were imilar to thoe of eye with cytoid macular edema. Thi ugget that the epimacular membrane probably induced damage to the neuron in the inner retinal layer. Dyfunction of thee neuron i one poible caue of viual impairment in thi dieae.