Validation of M-CHARTS for Quantitative Assessment of Metamorphopsia Following Rhegmatogenous Retinal Detachment Repair.

Abstract

To validate the quantitative assessment of metamorphopsia in rhegmatogenous retinal detachment(RRD) using M-CHARTS by determining its correlation with subjective reporting of metamorphopsia with a validated metamorphopsia questionnaire(modified MeMoQ). Research Ethics Board approved, prospective observational study carried out at St. Michael's Hospital, Toronto, Canada. Patients with primary, unilateral RRD and healthy controls were included. Metamorphopsia at 3-months was assessed with modified MeMoQ and M-CHARTS. 100 patients(50 with RRD,50 controls) were included. 70%(35/50) of the RRD group had metamorphopsia with M-CHARTS and 80%(40/50) with MeMoQ. The modified MeMoQ and total M-CHARTS scores were significantly higher in patients with RRD compared to controls(p<0.0001). Cronbach's alpha reliability coefficient was 0.934 in the RRD group. Horizontal, vertical, and total M-CHARTS scores were significantly correlated with MeMoQ scores(rs=0.465,p=0.0007;rs=0.405,p=0.004;rs=0.475,p=0.0005,respectively). M-CHARTS was 72.7% sensitive and 94.6% specific for detection of metamorphopsia(positive score≥0.2), with an area under the ROC curve=0.801. A stronger correlation was found in patients who scored ≥0.2 on the M-CHARTS and reported metamorphopsia with the MeMoQ(rs=0.454,p=0.001). We have validated M-CHARTS as a tool to quantitatively assess metamorphopsia in patients with RRD, which is significantly correlated with patient-reported outcomes using the metamorphopsia questionnaire(MeMoQ). A total score of ≥0.2 with M-CHARTS was more strongly correlated with MeMoQ.