Abstract
Abstract: :
Purpose:To evaluate the responses from the macula in the affected and unaffected fellow eyes of patients with macular holes using the Functional Fundus Imaging System (FFIS) developed at our institution and the multifocal electroretinogram (mfERG). Methods:We recruited 10 patients (mean age = 70 years) with macular holes at various stages. We measured local visual acuity thresholds at 27 discrete locations within 18° in diameter using the FFIS and local ERG responses within 40° in diameter using the mfERG (VERIS, 103-scaled hexagons). Results:The FFIS acuity thresholds were significantly elevated within 18° in the affected eyes compared to an age-similar normally sighted control group (t's ranging from -2.9 to -5.7, p < 0.01). In contrast, no statistically significant differences were found in the fellow eyes when compared to a control group. The mfERG amplitudes were affected mainly in the central 6° in affected eyes. In the central 2°, 4 out of 10 affected eyes showed non-detectable ERG signals. The remaining 6 eyes showed statistically significantly decreased amplitudes, but not delayed implicit times, when compared to the control group (t = 4.0, p < 0.01). Of interest, the fellow eyes showed marginally significantly decreased amplitudes in the central 2° when compared to normal controls (t = 1.9, p = 0.068). Conclusion:Both local psychophysical and electrophysiological testing consistently demonstrated retinal dysfunction extending beyond the site of the macular holes. This observation is in accord with a previous study showing perifoveal retinoschisis or edema using optical coherence tomography. Interestingly, marginally significant ERG amplitude reductions in the fellow eyes may reflect subclinical functional impairment of the fovea.
Keywords: 461 macular holes • 395 electroretinography: clinical • 511 perimetry