Characteristics of subretinal particles detected after pars plana vitrectomy for rhegmatogenous retinal detachment

BACKGROUND: To determine the incidence and characteristics of the multiple subretinal particles (SRPs) present after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). METHODS: The medical records of 224 eyes of 224 patients that underwent PPV for RRD were reviewed. The presence of SRPs in the subretinal fluid blebs and the presence of subretinal deposits were determined by optical coherence tomography (OCT) and fundus autofluorescence (FAF). The characteristics of the FAF and infrared reflectance (IR) images of a scanning laser ophthalmoscope in eyes with SRPs (SRPs group) were compared to that of eyes without SRPs (control group). RESULTS: SRPs were observed in 27 eyes (12%), and they were completely resolved in 20 eyes (74%) after 6 months. The incidence of macula-off RRD (85%) and preoperative precipitates (41%) were significantly higher in the SRPs group than that in the control group (64%, P = 0.046; 12%, P = 0.002). The axial length was significantly shorter in the SRPs group than that in the control group (25.04 ± 1.54 mm, 26.00 ± 1.78 mm, P = 0.012). The preoperative and postoperative best-corrected visual acuity were not significantly different between the two groups (P = 0.702, P = 0.337). The subretinal fluid bleb determined by OCT were hyperfluorescent in the FAF images in 24 eyes (89%), and the subretinal deposits were hypofluorescent with solid appearance by OCT other than fluid in 3 eyes (11%). The hypofluorescent subretinal deposits in the FAF images were bright in the IR images in 2 eyes. CONCLUSIONS: The SRPs consist of lipofuscin-related hyperfluorescent subretinal fluid and the subretinal deposits containing bright IR melanin particles of proliferating retinal pigment epithelial cells. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12886-023-02865-w.