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.

Pathophysiology of Secondary Macular Hole in Rhegmatogenous Retinal Detachment

Purpose

To describe the pathophysiology of secondary macular hole (MH) in rhegmatogenous retinal detachment (RRD).

Methods

A retrospective cohort of 360 consecutive primary fovea-off RRDs presenting to St. Michael's Hospital, Toronto, from January 2012 to September 2022 were included. Preoperative OCT was assessed for bacillary layer detachment (BALAD) abnormalities. Histological sections of normal eyes were assessed to inform OCT interpretations. Primary outcome measure was the progression of BALAD to full-thickness MH (FTMH).

Results

Of the 360 patients, 22.5% (n = 81) had BALAD abnormalities at presentation. Eight percent (29/360) had associated MH, of which 79.3% (23/29) were a BALAD-lamellar hole and 20.7% (6/29) were FTMH. After reattachment, 62% of MHs persisted (18/29), of which 83% (15/18) had BALAD-lamellar holes that subsequently progressed to FTMH in a mean of 8.1 ± 3.2 days. BALAD-lamellar holes had significantly worse postoperative visual acuity (P < 0.001) when compared with other BALAD abnormalities (58/81) or with the rest of the cohort (279/360). OCT spectrum from BALAD to FTMH includes (1) cleavage planes extending from Henle fiber layer into the BALAD; (2) central outer nuclear layer thinning; (3) Müller cell cone loss with tissue remnants at the foveal walls; (4) retinal tissue operculum close to BALAD-MH; and (5) progressive thinning or degradation of the posterior band of BALAD-lamellar hole leading to FTMH. Histological specimens identified foveal regions of low mechanical stability.

Conclusions

BALAD plays a crucial role in the pathophysiology of MH in RRDs, which forms owing to sequential changes in four critical areas: RPE-photoreceptor interface, myoid zone, Henle fiber layer, and Müller cell cone with surrounding tissue. Timely management of fovea-off RRD with BALAD may be prudent to avoid the progression to BALAD-lamellar hole, subsequent FTMH, and worse functional outcomes.

Morphologic Stages of Rhegmatogenous Retinal Detachment Assessed Using Swept-Source OCT

PURPOSE

To describe the sequential morphologic changes after rhegmatogenous retinal detachment (RRD) utilizing a novel, objective, and clinically relevant staging system based on swept-source OCT (SS-OCT) and determine its association with the duration of fovea-off and postoperative visual acuity (VA).

DESIGN

Prospective cohort study.

SUBJECTS

Consecutive patients with primary fovea-involving RRD referred to St. Michael's Hospital, Toronto, Canada, from January 2020 to April 2022.

METHODS

All patients underwent SS-OCT and ultrawide-field SS-OCT at baseline. Primary RRDs with breaks above the 8- and 4-o'clock meridians were included. Patients with vision loss for ≥ 3 months, proliferative vitreoretinopathy grade C or worse, a demarcation line, previous vitrectomy, or other retinal pathology were excluded. The staging was based on an assessment of outer retinal morphology on successive SS-OCT scans from the peripheral break to the most posterior aspect of the RRD, following its direction of progression.

MAIN OUTCOME MEASURES

Sequential outer retinal morphologic changes observed using SS-OCT and associated VA at 3 months after surgery.

RESULTS

Forty-nine eyes were included. The mean age (standard deviation [SD]) was 61.2 (15.2) years. The mean presenting logarithm of the minimum angle of resolution (SD) acuity was 1.09 (0.75). All stages observed on a high-definition horizontal 51-line scan were reported. Outer retinal changes occurred in 5 stages: (1) separation of the neurosensory retina from the retinal pigment epithelium (42/49, 85.7%); (2) thickening of inner and outer segments of photoreceptors (45/49, 91.8%); (3) outer retinal corrugation formation: (3a) low-frequency (44/49, 93.6%) and (3b) high-frequency outer retinal corrugations (42/49, 85.7%); (4) loss of the definition of outer retinal corrugations, with concurrent thickening of inner and outer segments (26/49, 53.1%); and (5) patchy (moth-eaten) or complete loss of inner and outer segments (17/49, 34.7%). The mean duration of fovea-off by stage in the parafovea (SD) was 2 (1.4), 2.3 (1.2), 11.4 (8.1), and 12 (13.3) days for stages 3a, 3b, 4, and 5, respectively. There was a statistically significant association between increasing stage of RRD and longer duration of foveal involvement (P = 0.001) and, most importantly, between increasing stage and worse VA at 3 months after surgery (P = 0.011).

CONCLUSIONS

This novel staging system describes the sequential morphologic changes in RRD using SS-OCT. Increasing stage of RRD was associated with worse VA at 3 months after surgery.

FINANCIAL DISCLOSURE(S)

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