Abstract:

Objective To evaluate the expression of neuroglobin (NGB) in aqueous, vitreous, fibrous proliferation membrane and serum of patients with proliferative diabetic retinopathy (PDR). Design Clinical case control study. Participants Thirty patients who were diagnosed as PDR were divided into 3 groups equally according severity of the disease: IV, V, and VI. The control group consisted of 10 patients with idiopathic macular hole. Methods We collected aqueous, vitreous, fibrous proliferation membrane or internal limiting membrane during vitrectomy. Serum was collected before operation. The level of NGB in the aqueous, vitreous and serum was determined quantitatively using ELISA method. The expression level of NGB in the fibrous proliferation membrane or internal limiting membrane was determined using immunohistochemistry method. Main Outcome Measures The level of NGB in serum aqueous, vitreous, fibrous proliferation membrane and internal limiting membrane of patients. Results In PDR groups, the level of NGB in serum, aqueous and vitreous was significantly higher than in the idiopathic macular hole group (F=494.433, 143.923, 2568.291; all P<0.001). The  NGB level in serum and vitreous was lower in PDR4 group than in PDR5 group (t=-9.766, -27.578; both P<0.001), lower in PDR4 group than in PDR6 group(t=-29.678, -26.419; both P<0.001), lower in PDR5 group than in PDR6 group (t=-15.117, -3.231; P<0.001, P=0.003 respectively). The level of NGB in aqueous in PDR4, PDR5 and PDR6 groups was not significantly different (all P>0.05). The positive rates of NGB expression in fibrous proliferation membrane in the IMH group, PDR4 group, PDR5 group, PDR6 group were 0, (6.12±2.12)％, (13.43±2.05)％, (16.39±2.46)％ respectively. The differences between any two PDR groups were statistically significant. It was lower in PDR4 group than in PDR5 group (t=-21.552, P<0.001), lower in PDR4 group than in PDR6 group(t=-25.059, P<0.001),lower in PDR5 group than in PDR6 group (t=-7.238, P<0.001). Conclusions The level of NGB in serum, aqueous, vitreous and fibrous proliferation membrane of PDR patients significantly increased compared to the control group, and increased with the severity of the disease. (Ophthalmol CHN, 2017, 26: 323-327)

Key words: neuroglobin, proliferative diabetic retinopathy, fibrous proliferation membrane, ELISA, immunohistochemistry