A study analyzing macular microvasculature features after vitrectomy using OCT angiography in patients with idiopathic macular epiretinal membrane

Abstract

Background: To evaluate postoperative changes in retinal capillary plexus and to assess contributing factors in postoperative visual improvement using optical coherence tomography angiography (OCT-A) in patients with idiopathic epiretinal membrane (iERM) post membrane removal. Methods: Patients scheduled for vitrectomy and membrane peel for iERM were enrolled. 35 subjects were included for this study. OCT-A was used to measure the FAZ related parameters and the superficial and deep capillary plexus layers using 3 mm × 3 mm scans. Measurements were taken before surgery and at every post-surgical follow-up. The unaffected fellow eyes were used as controls. Evaluated factors included: BCVA, vessel density (VD) and retinal thickness (RT) in five regions, FAZ area, FAZ perimeter (PERIM), acircularity index (AI) and foveal vessel density (FD). Results: Compared with the control group, the foveal vessel density (FVD) in superficial capillary plexus (SCP) was greater in the epi-retinal membrane group (P < 0.0001), whereas both groups had comparable parafoveal vessel density (PRVD) in SCP (p > 0.05). After surgery there was a reduction in the PRVD in SCP. The FVD in DCP increased and the PRVD in DCP decreased at baseline (p < 0.001). After surgery there was an increase in PRVD in DCP. By 6 months post-op, the PRVD had no statistically significant difference compared with the control group (p > 0.05). Dvalue of LogMAR BCVA was positively correlated with pre-op LogMAR BCVA (p < 0.0001), FVD in SCP (p < 0.001). It was negatively correlated with FAZ area (P < 0.001) and PERIM (P < 0.05). Conclusions: Vitrectomy and membrane removal led to the decrease of VD in SCP and the increase of PRVD in DCP. Patients with a more severe iERM may receive greater visual improvement with surgery. Trial registration: Trial registration number (TRN) and date of registration. ChiCTR2000031289, retrospectively registered, 2020.03.26.

Effect of Foveal Pit Restoration in Foveal Avascular Zone after Surgery for Idiopathic Epiretinal Membrane

“…In addition, the preoperative FAZ area was significantly correlated with the postoperative FAZ area. These results are consistent with previous reports [13][14][15].…”

Macular Perfusion Impairment in Von Hippel-Lindau Disease Suggests a Generalized Retinal Vessel Alteration

“…However, our results cannot be easily compared when different OCTA commercial software is used and the ICP is partially incorporated into the other plexuses. Moreover, in the present study we excluded VHL eyes with any lesion and/or changes at the posterior pole, including the epiretinal membrane, that seems to increase macular flow [ 25 ].…”

“…Therefore, the presence of tiny clinically undetectable RHs, visible just with fluorescein angiography, cannot be excluded. Another limitation is that genotype-phenotypes correlation was not performed [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Therefore, we cannot exclude that the genotype of VHL germline mutation may differently influence retinal vascular development and perfusion.…”

Epiretinal membrane: A review

“…Unlike fovea plana and foveal hypoplasia in which the FAZ may also be absent, ERMs do not have macular‐foveal capillaries that cross the fovea. Following ERM peeling, there is a reduction in the vessel density of the SCP but increase in the parafoveal vessel density of the DCP 107 . This re‐organisation of the macular capillary plexuses correlates with postoperative VA 108 and microperimetry results 109 …”