Differential distribution of fibrovascular proliferative membranes in 25-gauge vitrectomy for proliferative diabetic retinopathy

AIM:To analyze the distribution of fibrovascular proliferative membranes(FVPMs)in proliferative diabetic retinopathy(PDR)patients that treated with pars plana vitrectomy(PPV),and to evaluate the outcomes separately.METHODS:This was a retrospective and cross-sectional study.Consecutive 25-gauge(25-G)PPV cases operated for PDR from May 2018 to April 2020.According to the FVPMs images outlined after operations,subjects were assigned into three groups:arcade type group,juxtapapillary type group,and central type group.All patients were followed up for over one year.General characteristics,operation-related variables,postoperative parameters and complications were recorded.RESULTS:Among 103 eyes recruited,the FVPMs distribution of nasotemporal and inferiosuperioral was significantly different(both P<0.01),with 95(92.23%)FVPMs located in the nasal quadrants,and 74(71.84%)in the inferior.The eyes with a central FVPM required the longest operation time,with silicon oil used in most patients,generally combined with tractional retinal detachment(RD)and rhegmatogenous RD,the worst postoperative bestcorrected visual acuity(BCVA)and the highest rates of recurrent RD(all P<0.05).FVPM type,age of onset diabetes mellitus,preoperative BCVA,and combined with tractional RD and rhegmatogenous RD were significantly associated with BCVA improvement(all P<0.05).Compared with the central type group,the arcade type group had higher rates of BCVA improvement.CONCLUSION:FVPMs are more commonly found in the nasal and inferior mid-peripheral retina in addition to the area of arcade vessels.Performing 25-G PPV for treating PDR eyes with central FVPM have relatively worse prognosis.

Osteopontin expression in vitreous and proliferative retinal membranes of patients with proliferative vitreous retinopathy

AIM: To analyze osteopontin (OPN) expression in vitreous and proliferative retinal membranes of patients with proliferative vitreous retinopathy (PVR). METHODS: A total of 54 vitreous fluid samples were obtained between 2009 and 2010, which contained 45 with PVR (group A) and 9 without PVR (group B). Enzyme-linked immunosorbent assay was applied to quantify the OPN concentrations in vitreous fluid. Four samples of proliferative retinal membrane were also obtained at the time of vitrectomy, and their contents of OPN were measured by Real-time RT-PCR. RESULTS: The OPN levels in the vitreous fluid were 778.48+/- 62.06ng/mL in group A and 452.99 32.52ng/mL in group B. The vitreous OPN levels in group A were significantly higher than those in group B and to rise by time in the early stages of PVR. The average OPN levels in the proliferative retinal membranes (F =0.14) were also higher than those in the retinal pigment cells (F =0) using Real-time RT-PCR. CONCLUSION: The high vitreous and proliferative retinal membrane OPN levels in PVR suggest that OPN might promote the development of PVR. The vitreous OPN concentrations are rising by the time in the early phases of PVR.