Optical coherence tomography and focal macular electroretinogram in eyes with epiretinal membrane and macular pseudohole.

PURPOSE

To determine the morphology of macular pseudoholes (MPHs) and the relationship of morphology to macular function.

DESIGN

Observational case series.

METHODS

Optical coherence tomography (OCT) was performed on 42 eyes of 42 consecutive patients with an epiretinal membrane (ERM) and an MPH. The diameters of the MPH, and the thickness of the foveal and parafoveal retina were measured. Of these 42 eyes, focal macular electroretinograms (FMERGs) were recorded from 22 eyes of 22 patients with a 15 degree stimulus; FMERGs were also recorded with a 5 degree stimulus from 9 eyes of these 22 eyes.

RESULTS

In 42 eyes, the mean +/- Standard deviation (SD) diameter (437.7 +/- 172.8 microm) and geometrical shape of the MPHs were not significantly correlated with the visual acuity. The MPHs were divided into 2 types from the OCT images at the base of MPHs; group A had normal thickness (100-199 microm; n = 29), and group B (n = 13) had thicknesses of >or= 200 microm, or thickness < 100 microm, or irregular base. The visual acuity in group A (logarithm of the minimum angle of resolution [log MAR] mean +/- SD:.083 +/-.144) was significantly better than group B (log MAR,.407 +/-.212, P <.0001). There was a significant reduction in the amplitude of all components of FMERGs elicited by the 15 degree stimulus in the affected eyes (mean +/- SE, A-wave: 1.26 +/-.12 microv, B-wave: 3.07 +/-.27 microv, oscillatory potentials: 1.23 +/-.25 microv) compared with the normal fellow eyes (A-wave: 1.58 +/-.13 microv, B-wave: 4.14 +/-.27 microv, oscillatory potentials: 2.35 +/-.29 microv). A significant correlation was found between the relative amplitudes of the B-wave elicited by the 5 degree stimulus and the visual acuity (r =.918, P =.0005).

CONCLUSIONS

In eyes with an ERM and an MPH, the visual acuity is generally correlated with the OCT images. Macular function of eyes with an MPH resembles eyes with an ERM without an MPH. The effect of the ERM appears to be different on the base and parafovea of the MPHs.