Quantification of metamorphopsia in patients with idiopathic macular hole after successful surgical treatment

Abstract

Objective To evaluate quantification of metamorphopsia in eyes with idiopathic macular hole (IMH) before and after surgical treatment, and investigate its relationship between postoperative visual acuity, the macular hole index (MHI), and the macular hole prognostic factor (HPF). Methods Thirty eyes of 30 patients, who underwent successful vitrectomy and internal limiting membrane (ILM) peeling for IMH and were followed up more than 6 months, were included in the study. The uncorrected visual acuity of the fellow eyes was better than 20/25 and there was no metamorphopsia in that eye. The macular hole closure was confirmed by optical coherence tomography (OCT) scans. Metamorphopsia was evaluated by metamorphopsia-charts (M-chart). OCT, best corrected visual acuity (BCVA) and metamorphopsia were obtained before and after surgery. Vertical (MV) and horizontal (MH) metamorphopsia, macular hole index (MHI, the ratio of the height to the diameter of the base) , and macular hole prognostic factor (HPF,the ratio of the height to the minimum diameter) were measured. The metamorphopsia score was the average value of MV and MH. SPSS 16. 0 statistical analysis software was used for data analysis. Results Preoperative MV and MH were (1.82±0.04)° and (1.81±0.04)°, respectively. Six months after surgery,the MV and MH were (0.17±0.03)° and (0.11±0.03)° respectively. There was significant difference between pre- and post-operative metamorphopsia results (Z=-0.788, P＜0.05). The metamorphopsia score at 6 months after surgery were positively correlated with the value of the postoperative BCVA (LogMAR) (r=0.540, P=0.004) and negatively correlated with the values of preoperative MHI and HPF (r=-0.676,-0.518; P＜0.05). Conclusions Successful vitrectomy and ILM peeling can improve metamorphopsia of IMH. Postoperative metamorphopsia was correlated with the postoperative BCVA and the preoperative macular hole contour. Key words: Retinal perforations/surgery; Retinal perforations/complications; Vision disorders; Vitrectomy