Session Title: Vitreoretinal Surgery II
Session Date/Time: Friday 18/09/2015 | 08:00-10:00
Paper Time: 09:28
First Author: : H.Yetik TURKEY
Co Author(s): : C. Dogan S. Sirop A. Sarici
PURPOSE:To evaluate and compare the anatomic and functional (visual acuity -VA) results of pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) removal for refractory diffuse diabetic macular edema (DME)
Multicenter, prospective, non-masking, randomised, interventional case series study performed in Surp Pırgic Armenian Hospital and Cerrahpasa Medical Faculty.
A total of 14 cases with a mean age of 64,428±3,776 (58-70) years and having bilateral refractory diffuse diabetic macular edema unresponsive to all other treatment modalities including laser, anti-VEGFs and steroid injections for at least last 1 year was included. One eye of each patient was randomly assigned to pars plan vitrectomy without (PPV Group) and the fellow eye with ILM removal (PPV+ILM Group). All patients were followed up for a mean 13,143±2,033 (10-17) months. Visual acuity (Va) and central macular thickness (CMT) measured by OCT (Zeiss Cirrus HD) were evaluated and in-group and inter-group comparisons of preoperative and first week, 6 and 12 months' postoperative values were performed.
Mean preoperative Va of PPV vs PPV+ILM Groups was 0,052±0,029(0,025-0,1) and 0,057±0,025(0,025-0,1) respectively, without statistically significant difference (p=0,600). Mean postoperative Va at 6. and 12.months was 0,054±0,022(0,025-0,1) and 0,068±0,048(0,025-0,2) for PPV and 0,28±0,067(0,2-0,4) and 0,32±0,098(0,1-0,4) for PPV+ILM Group, respectively with a high statistically significant difference (p=0.00) at both 6. and 12.months. Mean preoperative CMT values of PPV vs PPV+ILM Groups were 604,21±63,03(496-690)µm and 601,50±48,07(510-700)µm respectively without statistical significant difference (p=0,899). Mean postoperative CMT values at 1 week, 6. and 12.months were 362,64-±55,93 (268-450)µm, 428,571±130,241(286-680)µm and 494,86±172,12 (270-750)µm for PPV and 314,79±36,00 (269-390)µm, 302,57±52,92 (236-400)µm and 284,14±66,55 (210-450)µm for PPV+ILM Group with a statistically significant difference between the groups. At in-group comparison of PPV Group despite the presence of statistically significant difference in CMTs at 1.week (p=0,000), 6.(p=0,000) and 12.months(p=0,0345) there wasn't a statistically significant difference in Va levels at neither 6. (p=0,853) nor 12.months (p=0,295). In PPV+ILM Group there was a high statistical significance(p=0,000) for each parameter compared including Va levels at 6. and 12.months vs. preoperative and CMTs at 1.week, 6. and 12.months vs. preoperative levels.
Pars plana vitrectomy with or without ILM removal is successful to relieve macular edema anatomically in refractory diffuse DME. But without ILM removal, despite a significant decrease in central macular thickness no significant increase in Va can be achieved at 6. or 12.months and furthermore for some cases, months after the surgery DME may recur more significantly than the preoperative level. Therefore probably mainly depending upon the more significant decrease in VEGF production by Müller Cells stimulated by ILM removal itself, to achieve a both anatomical and functional success, ILM peeling should be added to PPV procedure as the mainstay of the surgery in refractory DMEs. Otherwise in terms of functional outcome PPV without ILM peeling seems useless for the cases having similar ocular features of the study cases.