Predictive value of pattern VEP, pattern ERG and hole size in macular hole surgery.

OBJECTIVE: To describe pattern-reversal visual evoked response (PRVEP) and pattern electroretinogram (PERG) parameters in eyes with macular hole and their value for predicting postoperative visual outcome. METHODS: Prospectively we studied 27 eyes (27 patients) with a full-thickness macular hole. Preoperatively the hole and rim were measured and the PRVEP and PERG were recorded. The preoperative parameters were correlated with postoperative visual outcome. RESULTS: The macular hole was closed in 26 of 27 eyes. Sixteen eyes (59%) had an increase in visual acuity (VA) of two lines or more, 10 eyes (37%) remained within one line of preoperative VA and 1 eye (4%) had a decrease in VA of two lines. Duration of symptoms was negatively correlated with preoperative VA (R=-0.547, P=0.0038) and postoperative VA (R=-0.519, P=0.0065) and positively correlated with hole area (R=0.533, P=0.0061) and rim area R=0.633, P=0.0009). Only the PRVEP P100 latency of the 10' check size and the PERG N35 latency were significantly associated with visual outcome (P=0.022 and P=0.042 respectively). CONCLUSIONS: There was no association of either hole or rim size with postoperative visual outcome. Preoperative electrophysiology, however, is useful as a prognostic tool. Utilization is limited to the use of latency parameters of the response and is dependent on the check size of the stimulus.

Prognostic value of pattern reversal visual-evoked potentials in idiopathic epiretinal membrane.

BACKGROUND: Prognostically favorable factors for epiretinal membrane removal have been described in the literature by several authors. Little information, however, is available about the objective assessment of the preoperative macular function. This study reports the results of idiopathic epiretinal membrane removal and the prognostic value of preoperative, pattern reversal visual-evoked potentials (PRVEPS) in recovery of visual acuity (VA). METHODS: In 60 patients (60 eyes) with idiopathic epiretinal membrane we performed PRVEP examination preoperatively. All eyes were operated on by standard three-port vitrectomy with membrane removal. Two eyes were excluded because of postoperative complications. Follow-up VA was compared with preoperative VA for the 58 study eyes and correlated with preoperative PRVEP parameters. RESULTS: The mean preoperative VA was 0.2, the mean postoperative VA, 0.4. The PRVEP was recordable in 74%, 67% and 36% of cases for check sizes of 17, 10 and 7 arcmin respectively. Twenty patients (50%) had an increase in VA of two lines or more, in 25 patients (43%) VA remained within one line of the preoperative value, and in 4 patients (7%) VA decreased by two lines or more. The mean preoperative VA was not significantly different between the group with an improved VA and the group that did not benefit from membrane removal. Of the PRVEP parameters, only the N80 latency for the 17' check size was significantly associated with postoperative visual outcome. CONCLUSION: The PRVEP is applicable as a predictor for visual outcome in cases of epiretinal membrane removal. For the 17' pattern size we found a significant association of the combination of recordability and delayed N80 latency with visual outcome.

Pattern reversal visual evoked potentials in eyes with macular holes and their fellow eyes.

PURPOSE: To investigate whether the pattern reversal visual evoked potential can be useful in the diagnosis and management of macular hole patients. METHODS: The pattern reversal visual evoked potential was measured in 66 patients with a macular hole and in 43 healthy control subjects. Check sizes of 34', 17' and 10' were applied. RESULTS: Results showed that, for the check sizes of 34', 17' and 10', eyes with a macular hole had significantly prolonged N80 and P100 latencies and a significantly reduced P100 amplitude as compared to their fellow eyes. Furthermore, for the 10' check size, the fellow eyes appeared to have a significantly reduced P100 amplitude in comparison with the control eyes, whereas N80 and P100 latencies of the fellow eyes of the macular hole patients were not prolonged. CONCLUSION: Significant pattern reversal visual evoked potential alterations were shown in eyes with macular holes and fellow eyes for small check sizes.

Pattern-reversal visual evoked potentials in patients with epiretinal membrane.

PURPOSE: To determine the extent of pattern-reversal visual evoked potential parameter alteration by epiretinal membranes and to investigate the use of pattern-reversal visual evoked potential in the estimation of macular function in eyes with epiretinal membrane and in the fellow eyes. METHODS: In both eyes of 162 patients with epiretinal membrane, 92 of primary and 70 of secondary origin, pattern-reversal visual evoked potentials were recorded. Check sizes of 17', 10', and 7' (minutes of arc) were used. Parameters investigated were N80 and P100 latencies and P100 amplitude. RESULTS: No significant difference was detected between eyes with epiretinal membrane of primary and secondary origin regarding visual acuity and the pattern-reversal visual evoked potential parameters for the different check sizes. Compared with the fellow eyes, the eyes with epiretinal membrane had a significantly reduced visual acuity, prolonged N80 and P100 latencies, and a reduced P100 amplitude for the different check sizes. Compared with a separate control group (N = 20) with patients 50 to 59 years old, eyes with epiretinal membrane (N = 9) showed the same features as in the total group, but only for the 17' and 10' check sizes. The fellow eyes (N = 9) showed a significant reduction of the P100 amplitude (P < .05) for the pattern sizes of 17' and 10', but no difference in visual acuity or pattern-reversal visual evoked potential latency was found. CONCLUSIONS: In eyes with epiretinal membrane, pattern-reversal visual evoked potential latencies are prolonged, and amplitude is reduced. Relationships between clinical parameters and pattern-reversal visual evoked potential parameters require further study.