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

PURPOSE

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).

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Retinal Displacement after Scleral Buckle versus Combined Buckle and Vitrectomy for Rhegmatogenous Retinal Detachment: ALIGN Scleral Buckle versus Pars Plana Vitrectomy with Scleral Buckle

PURPOSE

To assess the risk of retinal displacement after scleral buckle (SB) versus pars plana vitrectomy with SB (PPV-SB).

DESIGN

Multicenter prospective nonrandomized clinical trial.

METHODS

The study took place at VitreoRetinal Surgery in Minneapolis, Minnesota, Sankara Nethralaya in Chennai, India, and St. Michael's Hospital in Toronto, Canada from July 2019 to February 2022. Patients who underwent successful SB or PPV-SB for fovea-involving rhegmatogenous retinal detachment with gradable postoperative fundus autofluorescence (FAF) imaging were included in the final analysis. Two masked graders assessed FAF images 3 months postoperatively. Metamorphopsia and aniseikonia were assessed with M-CHARTs and the New Aniseikonia Test, respectively. The primary outcome was the proportion of patients with retinal displacement detected with retinal vessel printings on FAF in SB versus PPV-SB.

RESULTS

Ninety-one eyes were included in this study, of which 46.2% (42 of 91) had SB and 53.8% (49 of 91) underwent PPV-SB. Three months postoperatively, 16.7% (7 of 42) in the SB group and 38.8% (19 of 49) in the PPV-SB group had evidence of retinal displacement (difference = 22.1%; odds ratio = 3.2; 95% confidence interval [CI], 1.2-8.6; P = 0.02) on FAF. The statistical significance of this association increased after adjustment for extent of retinal detachment, baseline logarithm of the minimum angle of resolution, lens status, and sex in a multivariate regression analysis (P = 0.01). Retinal displacement was detected in 22.5% (6 of 27) of patients in the SB group with external subretinal fluid drainage and 6.7% (1 of 15) of patients without external drainage (difference = 15.8%; odds ratio = 4.0; 95% CI, 0.4-36.9; P = 0.19). Mean vertical metamorphopsia, horizontal metamorphopsia (MH), and aniseikonia were similar between patients in the SB and PPV-SB groups. There was a trend to worse MH in patients with retinal displacement versus those without retinal displacement (P = 0.067).

CONCLUSIONS

Scleral buckle is associated with less retinal displacement compared with PPV-SB, indicating that traditional PPV techniques cause retinal displacement. There is a trend toward increased risk of retinal displacement in SB eyes that underwent external drainage compared with SB eyes without drainage, which is consistent with our understanding that the iatrogenic movement of subretinal fluid, such as that which occurs intraoperatively during external drainage with SB, may induce retinal stretch and displacement if the retina is then fixed in the stretched position. There was a trend to worse MH at 3 months in patients with retinal displacement.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.