Mチャート®を用いた黄斑上膜術後の変視量の変化の検討

Use of M-charts® in the evaluation of metamorphopsia after surgical removal of epiretinal membrane

要約　目的：黄斑上膜の除去術後の変視症の変化をMチャート^®で評価した報告。対象と方法：過去9か月間に黄斑上膜の除去術を行った23例23眼を対象とした。変視症は術後3か月までMチャート^®で定量的に評価した。視力はlogMARで判定した。結果：平均視力は術前0.29，術後3か月で0.16で，有意差があった（p＜0.05）。変視量の平均は，垂直方向が術前0.75，術後3か月で0.41，水平方向が術前0.92，術後3か月で0.49と，いずれも有意に改善した（p＜0.05）。垂直方向の変視量には，術前値と術後3か月値に相関があった（相関係数0.66，p＜0.05）。水平方向の変視量には，術前値と術後3か月値に相関があった（相関係数0.45，p＜0.05）。結論：黄斑上膜の除去術では，変視症が術後3か月で改善し，その術前値と術後3か月値に有意な相関があった。黄斑上膜の手術は変視症が増強する前に実施することが望ましい。

Abstract.　Purpose：To report changes in metamorphopsia after surgery for epiretinal membrane evaluated by M-charts^®. Cases and Method：This study was made on 23 eyes of 23 patients who received surgery for epiretinal membrane during the past 9 months. Amount of metamorphopsia was evaluated by M-charts^® up to 3 months after surgery. Visual acuity was evaluated as logMAR. Results：Visual acuity averaged 0.29 before and 0.16 three months after surgery. The difference was significant（p＜0.05）. Vertical metamorphopsia averaged 0.75 before and 0.41 three months after surgery. Horizontal metamorphopsia averaged 0.92 and 0.49 respectively. The differences were significant（p＜0.05）. Positive correlation was present in the amount of vertical metamorphopsia（r＝0.66,p＜0.05）and in that of horizontal one（r＝0.45,p＜0.05）. Conclusion：Metamorphopsia improved 3 months after surgery for epiretinal membrane. Early surgery is advocated as the amount of improvement is quantitatively correlated with the presurgical value.