Background The aim of this study was to assess the retinal and choroidal microvasculature features using optical coherence tomography angiography (OCTA) in patients with retinitis pigmentosa (RP). Methods This study was a meta-analysis of relevant published studies that were included after a comprehensive search of PubMed, Embase, Cochrane Library, and Web of Science databases. Mean difference (MD) with a 95% confidence interval was used to assess continuous variable outcomes. Heterogeneity was evaluated using the chi-squared test based on the values of P and I2. Results Seven studies were included in this meta-analysis. The vessel density values measured in the superficial and deep foveal zones of RP patients using OCTA were significantly lower than the recorded values in the control groups (MD = −3.58, P=0.04; MD = −4.93, P=0.02, respectively). The superficial and deep parafoveal vessel density values measured with OCTA were also significantly lower in RP patients than in control groups (MD = −9.09, P < 0.00001; MD = −10.74, P < 0.00001, respectively); for choriocapillaris vessel density, there was no statistically significant difference between RP patients and controls (MD = −1.33, P=0.09). The deep foveal avascular zone (FAZ) was significantly larger in RP patients than in controls (MD = 0.15, P=0.01), whereas there was no significant difference in the superficial foveal avascular zones in the two groups (MD = 0.08, P=0.11). Conclusions We showed that retinal and choroidal vessels were attenuated in RP patients. Additionally, we revealed that the FAZ was larger in RP patients, especially the deep FAZ. OCTA may become a useful modality in the diagnosis and monitoring of patients with RP.

Background. The aim of this meta-analysis was to compare morphological and functional outcomes between vitrectomy with the inverted internal limiting membrane (ILM) flap technique and vitrectomy with internal limiting membrane peeling in highly myopic eyes with macular hole- (MH-) induced retinal detachment (MHRD). Methods. The PubMed, Web of Science, Embase, and Cochrane Library databases were comprehensively searched from inception to November 10, 2019, for published studies comparing the two techniques for the treatment of MHRD. The outcomes in the collected articles included the postoperative MH closure rate, retinal reattachment rate, and best-corrected visual acuity (BCVA). Review Manager (version 5.3) was used for analyses. Results. In total, seven retrospective studies comparing the inverted ILM flap technique with ILM peeling for the treatment of MHRD were included. The MH closure rate was significantly higher in the inverted ILM flap group than in the ILM peeling group at 6 and 12 months after initial surgery (OR = 15.39; 95% CI: 6.68 to 35.43;P<0.00001 and OR = 12.58, 95% CI: 3.51 to 45.08; P=0.0001), while the retinal reattachment rate was similar in both groups at 6 months after initial surgery (OR = 2.40; 95% CI: 0.89 to 6.50; P=0.08). Besides, the postoperative BCVA was significantly better in the inverted ILM flap group than in the ILM peeling group at 12 months after initial surgery (MD = −0.35; 95% CI: −0.52 to −0.18; P<0.0001). Conclusions. Thus, the MH closure rate and postoperative BCVA may be better with the inverted ILM flap technique than with ILM peeling for myopic MHRD, while the postoperative retinal reattachment rate appears to be similar with both techniques. Therefore, in the future, vitrectomy with the inverted ILM flap technique should be preferred over standard ILM peeling technique for the treatment of MHRD in highly myopic eyes.