ObjectiveTo evaluate the correlation between macular microstructure changes and visual outcome before and after scleral buckling for macular-off primary rhegmatogenous retinal detachment (RRD). MethodsA total of 43 eyes in 43 patients with RRD were enrolled in this retrospective study. All patients underwent scleral buckling and the retina was successfully reattached. Best corrected visual acuity (BCVA) and spectral domain optical coherence tomography (SD-OCT) were measured for all patients before and at 3 days, 1, 3 and 6 months after surgery. The height of subretinal fluids (SRF), the thickness of retinal neurosensory layer in foveal, and the thickness of outer nuclear layer (ONL) were measured. The microstructure changes of external limiting membrane (ELM), junction line and intermediate line of photoreceptor inner segment/outer segment (IS/OS) were observed. The correlation between morphologic changes in the macular foveal and BCVA on 6 months after surgery were also analyzed. ResultsThe mean preoperative BCVA was 1.18±0.93. The detached retinas had 3 types of SD-OCT images, including normal foveal contour without edema, diffuse edema with ONL cystoids cavities, diffuse edema with ONL cystoids cavities and wave-like ONL. The mean preoperative SRF height was (885.05±493.28) μm. The preoperative mean thickness of retinal neurosensory layer in foveal and ONL in the RRD eyes were thinner than the healthy fellow eyes (t=2.642, 1.895;P < 0.05). The fluids and cystoids cavities were absorbed, retina reattached in all the RRD eyes at 3 days after surgery. SRF had been detected in 100.0%, 93.0%, 77.8%, 46.5% RRD eyes on 3 days, 1 month, 3 months and 6 months after surgery, with heights of (219.00±117.02), (163.51±72.83), (101.27±64.47), (55.69±21.15) μm respectively. There were 3 patterns of residual SRF: diffuse, subfoveal multi-bleb, subfoveal single bleb. Compared with the healthy fellow eyes, there were significant differences in the mean thickness of foveal neurosensory layer (t=-10.658, -8.550, -6.955) and ONL thickness (t=-6.240, -5.424, -3.326, -3.323) at 3 days, 1 month, 3 months and 6 months after surgery(P < 0.05), except for the thickness of foveal neurosensory layer at 6 months after surgery (t=-2.186, P=0.570). The reattached retinas had 4 types of SD-OCT images, including: (1) disrupted ELM, IS/OS line and intermediate line; (2) intact ELM with disrupted IS/OS line and intermediate line; (3) intact ELM and IS/OS line with disrupted intermediate line; (4) intact ELM, IS/OS line and intermediate line. The mean postoperative BCVA at different time points were better than preoperative BCVA (t=-3.12, -4.89, -5.03, -4.53; P < 0.05). The postoperative BCVA of eyes with intact IS/OS was different from that of eyes with disrupted IS/OS at 6 months after surgery (t=2.609, P < 0.05). The preoperative SRF height, thickness of foveal neurosensory layer and ONL were correlated with the BCVA at 6 months after surgery (r=0.817, 0.028, 0.521; P < 0.05). ConclusionsMacular-off RRD eyes had SRF, thinner foveal neurosensory layer and ONL before and after scleral buckling. The disruption of ELM, IS/OS junction line and intermediate line can be seen in most of RRD patients. The thinner foveal neurosensory layer and ONL were correlated with the slow recovery of postoperative BCVA.