ObjectiveTo observe the changes of macular blood flow density in patients of macular telangiectasis type 1 (Mac-Tel type 1) with macular edema before and after the treatment of anti-VEGF.MethodsA retrospective clinical study. From January 2016 to December 2017, 14 Mac-Tel type 1 patients (14 eyes) diagnosed in Nanjing Medical University Eye Hospital were included in the study. There were 6 males (6 eyes) and 8 females (8 eyes), with the mean age of 35.3±9.3 years. All patients underwent BCVA and OCT angiography examinations. The BCVA examination was performed using the Snellen visual acuity chart, which was converted into logMAR visual acuity. All the patients were received anti-VEGF injection treatment once a month for 3 consecutive months. The OCTA scanning region in the macular area was 3 mm × 3 mm. Macular blood flow density in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), the vessel density within a 300 μm width ring surrounding the foveal avascular area (FD-300) and central macular thickness (CMT) were measured in all eyes. Paired samples t-test and Pearson correlation analysis were used in this study.ResultsAt the baseline, logMAR BCVA was 0.69±0.07, CMT was 468.43±26.59 μm, SCP blood flow density was (50.99±1.19)%, DCP blood flow density was (43.79±1.44)%, FD-300 was (50.73±1.16)%. Compared with the baseline, there were significant differences between logMAR BCVA, CMT, DCP blood flow density and FD-300 in 1 week, 1 month, 3 months after treatment and 2 months after cessation of treatment (logMAR BCVA: t=6.77, 13.30, 16.99, 9.51; P=0.00, 0.01, 0.00, 0.01. CMT: t=6.99, 15.88, 26.10, 6.50; P=0.00, 0.01, 0.01, 0.00. DCP: t=6.75, 8.61, 15.12, 7.63; P=0.00, 0.01, 0.01, 0.00. FD-300: t=11.86, 13.08, 14.36, 4.41; P=0.00, 0.01, 0.01, 0.03). There was no significant difference in blood flow density of SCP between baseline and 2 months after cessation of treatment (t=1.36, P=0.19), but there was significant difference at the other time points after treatment (t=5.50, 6.84, 6.27; P=0.00, 0.01, 0.01). The Pearson's correlation analysis showed that there was a significant positive correlation between FD-300 and CMT (r2=0.54, P=0.04).ConclusionsThere is no significant change in the SCP blood flow density in the patients of Mac-Tel type 1 with macular edema, while the DCP blood flow density decreased and FD-300 increased. After anti-VEGF treatment, DCP blood flow density increased and FD-300 decreased. FD-300 is positively correlated with CMT.