To evaluate macular function and structure before and after epimacular membrane surgery and to estimate the usefulness of pattern ERG test parameters in predicting the postoperative visual acuity.
We evaluated 32 eyes of 32 patients (mean age 70.8 ± 6.7 years) before and 12 months after successful 25G pars plana vitrectomy with epimacular membrane removal and internal limiting membrane peeling. Distance best-corrected visual acuity (DBCVA—logMAR), foveal thickness (optical coherence tomography—OCT) and macular function [pattern electroretinogram—PERG (ISCEV standard): amplitudes (A) of P50- and N95-waves, implicit time (IT) of P50-wave] were assessed. To estimate the differences between the mean values of considered characteristics, the t test or Wilcoxon matched pair test was used. Correlation between preoperative data of PERG and preoperative and final DBCVA were investigated using Pearson correlation analysis. A receiver operating characteristic curve was constructed to obtain a cutoff value allowing prediction of visual prognosis. We tried to obtain the P50 and N95 amplitudes cutoff value in prediction of good visual outcome (DBCVA of 0.3 or less).
Twelve months after surgery, mean of DBCVA significantly increased in comparison with preoperative value (0.31 ± 0.12 vs. 0.6 ± 0.15; p < 0.001) and 23/32 eyes (72 %) achieved visual improvement of two and more Snellen lines. In OCT test, the significant reduction in foveal thickness mean (313.34 ± 47.01 vs. 509.03 ± 93.88 µm; p < 0.001) was obtained. In PERG test, the significant increase in the mean amplitudes of P50- (AP50) and N95 (AN95)-waves as well as significant decrease in the mean implicit time (IT) of P50-wave were achieved (AP50: 3.41 ± 1.48 vs. 2.38 ± 1.23 µV; p < 0.001; AN95: 5.46 ± 1.72 vs. 3.75 ± 1.48 µV; p < 0.001; IT P50: 55.00 ± 3.60 vs. 56.75 ± 5.78 ms; p < 0.001). Twelve months postoperatively, DBCVA was significantly correlated with preoperative IT P50 (r = 0.39; p = 0.027), AP50 (r = −0.68; p < 0.001) and AN95 (r = −0.73; p < 0.001).
Removal of idiopathic epimacular membranes with internal limiting membrane peeling not only provided increase in visual acuity and reduction in foveal thickness but also caused improvement of innermost retinal layer function in macular region. Pattern ERG test might be a valuable tool in predicting the postoperative visual acuity.
McCarty DJ, Mukesh BN, Chikani V et al (2005) Prevalence and associations of epiretinal membranes in the visual impairment project. Am J Ophthalmol 140:228–294 CrossRef
Hood DC, Frishman LJ, Saszik S, Viswanathan S (2002) Retinal origin of the primate multifocal ERG: implications for the human response. Invest Ophthalmol Vis Sci 43:1673–1685 PubMed
Maffei L, Fiorentini A (1981) Electroretinographic responses to alternative gratings before and after section of the optic nerve. Science 211(4485):953–955 CrossRef
Holder EG (2001) Pattern electroretinography (PERG) and an integrated approach to visual pathway diagnosis. Prog Retinal Eye Res 20(4):531–561 CrossRef
Otto T, Bach M (1997) Retest variability and diurnal effects in the pattern electroretinogram. Doc Ophthalmol 92(4):311–323 CrossRef
- Assessment of macular function, structure and predictive value of pattern electroretinogram parameters for postoperative visual acuity in patients with idiopathic epimacular membrane
- Springer Berlin Heidelberg
Neu im Fachgebiet Augenheilkunde