Efficiency of vitrectomy in combination with internal limiting membrane peeling associated with the gas-air tamponade of the vitreous cavity at the advanced stage of proliferative diabetic retinopathy

摘要

Purpose. To evaluate the effectiveness of vitrectomy in combination with internal limiting membrane peeling associated with the gas-air tamponade of the vitreous cavity at the advanced stage of proliferative diabetic retinopathy. Material and methods. The study involved 52 patients (52 eyes) with diabetes mellitus of type 2, who underwent the vitreoretinal surgery with a preliminary antivasoproliferative therapy. In all cases, a traction syndrome was found only from the side of posterior hyaloid proliferative tissue with gliosis of degree II-III, without signs of an epiretinal membrane. In the first group of patients (n=28) the 27-Gauge vitrectomy was performed, with the removal of only posterior hyaloid proliferative tissue followed by a tamponade of the vitreous cavity with a gas-air mixture, and in the second group (n=24) a similar volume of vitreoretinal surgery combined with peeling of the internal limiting membrane was carried out. Results. In all patients, before the combined surgical treatment, the visual acuity averaged 0.06±0.02. Before the treatment in patients of both groups according to optical coherence tomography the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area averaged 25.38±3.11μm, in the fovea and parafovea – 457.41±36μm and 701.51±24μm, respectively. The mean value of the optical density of the macular pigment before the treatment was 0.094±0.01 du. After the performed vitreoretinal intervention, the visual acuity in patients of the group 1 improved up to 0.10±0.02 (p<0.05), in the group 2 – up to 0.25±0.05 (р1-2><0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p><0.05), due to the formation of a secondary epiretinal membrane, which occurred in >< 0.05), in the group 2 – up to 0.25±0.05 (р1-2<0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p><0.05), due to the formation of a secondary epiretinal membrane, which occurred in >< 0.05). Six months after vitrectomy, the thickness of zone «nerve fibers layer – internal limiting membrane» in the macular area in patients of the group 1 increased 1.6 times (p< 0.05), due to the formation of a secondary epiretinal membrane, which occurred in 39.2% cases (11/28), 54.5% of cases (6/11) showed traction macular edema, and diabetic macular edema (without epiretinal membrane) was detercted in 28.5% of cases (8/28). In the group 2 of patients, the «nerve fibers layer» zone decreased by 1.5 times (р1-2<0.05), the epiretinal membrane and the traction macular edema were not diagnosed in any case (0/24), but 5 patients (20.8%) had diabetic macular edema (5/24). >< 0.05), the epiretinal membrane and the traction macular edema were not diagnosed in any case (0/24), but 5 patients (20.8%) had diabetic macular edema (5/24).  According to the data of optical coherence tomography, the thickness of the retina in the fovea and parafovea after the combined surgical treatment in patients of the group 1 averaged 212.49±36μm and 365.74±28μm, in the group 2 – 190.11±24μm and 334.18±21μm, respectively (р1-2<0.05). The average value of macular pigment optical density after treatment was 0.109±0.01 du in the group 1 and 0.122 ± >< 0.05). The average value of macular pigment optical density after treatment was 0.109±0.01 du in the group 1 and 0.122 ± 0.01 du in the group 2.  Conclusion. Vitrectomy combined with peeling of the inner limiting membrane in patients with advanced proliferative diabetic retinopathy contributes to obtain a higher visual acuity minimizing a risk of secondary epiretinal membrane and diabetic macular edema.