Changes in OCTA-related parameters and their impact on retinal sensitivity after ILM flap inversion surgery in patients with IMH

Abstract

Objective: To analyze the changes in optical coherence tomography angiography(OCTA)-related parameters before and after idiopathic macular hole (IMH) internal limiting membrane (ILM) flap inversion surgery and assess their impact on retinal sensitivity. Methods: A retrospective case series study was conducted, collecting clinical data of 30 patients (30 eyes) diagnosed with IMH who underwent vitrectomy combined with ILM flap inversion surgery at Shanxi Eye Hospital, affiliated with Shanxi Medical University, between January 2020 and December 2021. Visual acuity and best-corrected visual acuity were examined preoperatively and at 1, 3, and 6 months postoperatively. Microperimetry measured retinal sensitivity (RS), and OCTA measured retinal thickness (RT) as well as vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Statistical analysis was performed using t-tests, repeated measures analysis of variance, and Pearson correlation analysis. Results: Thirty patients with IMH (30 eyes) were included, with 3 males (3 eyes) and 27 females (27 eyes). The mean age was (62.5±3.0) years, and the follow-up time was (96.3±1.3) days, with a 100% closure rate of macular holes postoperatively. RT in the macular was significantly lower at 1, 3, and 6 months postoperatively compared to preoperative values (F=46.21, P<0.001). The RT in the upper macular region showed statistically significant differences at different time points (P<0.001). VD in the SCP layer showed no significant differences between the upper and lower macular regions at various time points (F=3.21, P=0.601). VD in the upper region of the DCP layer increased at 1, 3, and 6 months postoperatively (P<0.001). RS in the macular was higher at 1, 3, and 6 months postoperatively compared to preoperative values (F=52.01, P<0.001). RS in the lower macular region increased at 3 and 6 months postoperatively (P<0.001), while in the upper region, it increased only at 6 months postoperatively (P<0.001). There was a positive correlation between RS and RT at 1 and 3 months postoperatively, but not at 6 months postoperatively in the upper macular region (r=0.40, P=0.071). In the lower macular region, there was a positive correlation between RS and RT at 1 and 3 months postoperatively (P<0.001). There was no correlation between RS in the upper macular region at 6 months postoperatively and preoperative RT (r=0.43, P=0.072), but there was a positive correlation with RT at 3 months postoperatively (r=0.58, P=0.041). Conclusions: After idiopathic macular hole internal limiting membrane flap inversion surgery, the OCTA-related parameters have changed. There are transient changes in deep vascular parameters and thinning of the retinal layers at the ILM inversion site, leading to decreased sensitivity.