Clinical characteristics of neovascularization on the optic disc in diabetic retinopathy

Objective To observe the clinical characteristics of diabetic neovascularization on the disc (DNVD). Methods The clinical data of 526 patients (1052 eyes) who were diagnosed as diabetes in Department of intern medicine, as diabetic retinopathy by ophthalmoscope and fundus fluorescein angiograph (FFA) was retrospectively reviewed. All patients were carried out with best corrected visual acuity (BCVA), slit-lamp microscope, ophthalmoscope and FFA after mydriasis. In which, who has neovascularization on the optic disc with ophthalmoscopy and FFA examination were included in this study. The relationship between the occurrence and development of DNVD and phase of DR, disease duration, the level of blood glucose and panretinal photocoagulation were analyzed. Results DNVD was found in 167/1052 eyes (15.87%). There were 91 eyes (54.49%) with BCVA<0. 1, 58 eyes (34. 73%) with BCVA<0. 4 but ≥0. 1,and 18 eyes(19.78%) with BCVA≥0. 4. Retinal neovascularization was located in the surface of disc surface or within 1PD from the optic disc;Those vessels filled early and rapidly, and with local strong fluorescence due to fluorescence leakage at middle and late stage of FFA examination. All 167 DNVD eyes are proliferative diabetic retinopathy (PDR) with 43 eyes (25.75%) in stage Ⅳ, 52 eyes (31.14%) in stage Ⅴ and 72 eyes (43. 11%) in stage Ⅵ. Of those DNVD eyes, there were 5 eyes (2. 99%) with course of diabetes <3 years, 12 eyes (7.19%) s<5 years but ≥3 years, 21 eyes (12. 57%)<10 but ≥5 years, 56 eyes (33. 53%)<15 but ≥10 years and 73 eyes (43. 71%)≥15 years. There were 15 eyes (8. 98%) with fasting blood glucose (FBG)<7. 0 mmol/L, 26 eyes (15.57%) with FBG< 9.0 but ≥7.0 mmol/L, 50 eyes (29. 94%) with FBG<12. 0 but ≥9. 0 mmol/L and 76 eyes (45.51%) with FBG ≥12.0 mmol/L; there were 28 eyes (16. 77%) with 2 hour postprandial blood glucose(2hPBG)<10. 0 mmol/L, 35 eyes (20. 96%) with 2hPBG<12. 0 but ≥10. 0 mmol/L, 42 eyes (25.15%) with 2hPBG <16.0 but ≥12.0 mmol/L and 62 eyes (50. 30%) with 2hPBG ≥16.0 mmol/L. The occurrence of DNVD and duration of diabetes, FBG and 2hPBG were all positively correlated (r= 0. 991, 0. 984, 0. 960, P= 0. 001, 0. 016, 0. 040) by the Person correlation analysis. 15 eyes (5.84%) of DNVD happened in 257 eyes who treated with PRP in severe nonproliferative diabetic retinopathy (NPDR), 152 eyes (19.12%) DNVD happened in 795 eyes who untreated with PRP in severe NPDR,the differences were statistically significant (χ~2 =25. 659,P<0. 01) between them. Conclusion DNVD happened commonly in DR, the occurrence of DNVD is intensive related with diabetic retinopathy stage, duration of diabetes, FBG and PBG. Key words: Diabetic retinopathy/complications;  Retinal neovascularization/etiology;  Fluorescein angiography