Changes in Metamorphopsia, Visual Acuity, and Central Macular Thickness after Epiretinal Membrane Surgery in Four Preoperative Stages Classified with OCT B-Scan Images

Abstract

Purpose. To observe the changes in metamorphopsia, visual acuity, and central macular thickness (CMT) in patients undergoing vitrectomy for idiopathic epiretinal membranes (iERM); all of which were preoperatively stratified into 4 stages according to the anatomical structure of the macula seen on the optical coherence tomography (OCT) b-scan images. Methods. A total of 108 eyes of 106 patients were included. We evaluated and classified the severity of each preoperative ERM based on OCT. Changes in the best-corrected visual acuity (BCVA), metamorphopsia, and CMT were studied by comparing the pre- and postoperative measurements. The follow-up time was at least 6 months. Results. There were 41 eyes at stage 2, 35 at stage 3, 32 at stage 4, and none at stage 1. BCVA and metamorphopsia significantly improved at the final visit in all patients (P<0.01). However, comparing the pre- and postoperative measurements at each stage, only the BCVA and CMT improved significantly for all stages (P<0.001). For stages 2 and 3 ERMs, the horizontal (MH) and vertical (MV) metamorphopsia scores decreased significantly after surgery (P<0.05). No significant difference was found in either MH or MV for stage 4 ERMs (P both >0.05). The preoperative BCVA, MH, and CMT had significant difference among the three stages (P<0.05). Similarly, the postoperative values in the three variables mentioned above also had significant difference among the three stages (P<0.05). For stage 2 ERMs, the baseline MH and MV were positively correlated with the baseline CMT. The MH and MV at the final follow-up also presented a significant positive correlation with the baseline CMT. For stage 3 ERMs, only the baseline MV showed significant correlation with the CMT. Conclusion. Categorization of the preoperative ERMs is a useful method to predict the postoperative improvement in metamorphopsia, which would aid in surgical decisions for patients with ERMs.

Influence of Preoperative Foveal Layers’ Thickness on Visual Function and Macular Morphology by Phacovitrectomy for Epiretinal Membrane

“…In Groups 1–3, a consistent stage-by-stage course of OCT-morphological macular changes in progression of ERM was presented, which was also described in publications by Fung et al [ 6 ] and Mao et al [ 21 ]. In Groups 4 and 5, a complementary tractive component is pathophysiologically mandatory.…”

“…Group 1: Completely or partially preserved foveolar depression Group 2: Isolated elevation of the foveola Group 3: Elevation of the foveola with an ectopy of INL and/or IPL (EIFL) Group 4: MLH of tractive genesis Group 5: VMT In Groups 1-3, a consistent stage-by-stage course of OCT-morphological macular changes in progression of ERM was presented, which was also described in publications by Fung et al [6] and Mao et al [21]. In Groups 4 and 5, a complementary tractive component is pathophysiologically mandatory.…”

Assessment of macular microvasculature features before and after vitrectomy in the idiopathic macular epiretinal membrane using a grading system: An optical coherence tomography angiography study

“…Anteroposterior forces cause the macula to thicken; thickening of the macula and loss of foveal depression are easily visualized with OCT. In our previous study (Mao et al 2019), we applied the classification method developed by Govetto and colleagues to the study of metamorphopsia caused by iERM. We found that the postoperative BCVA and central macular thickness (CMT) were significantly improved at all stages; however, the metamorphopsia of stage 2 and stage 3 iERM was improved after surgery, while that of stage 4 iERM was not.…”

Optical coherence tomography biomarkers for visual acuity in patients with idiopathic epiretinal membrane

“…At early stages of iERM there are commonly no symptoms, whereas in advanced cases of the disease, patients may complain of visual impairment, distortion, macropsia, or monocular diplopia affecting their quality of life. 4,5…”