To investigate the correlation between dyslipidemia with retinal microangio-pathy and neuronal degeneration in diabetic patients.

Prospective cohort study. 111 patients 62 males and 49 females, average age (55.05±10.65) years with diabetic mellitus (DM) and diabetic retinopathy(DR) were enrolled during April 2016 to June 2017 in Beijing Tongren Hospital. According to the Diabetes Association guidelines on DM and DR, patients were divided into DM, non-proliferative DR and proliferative DR (PDR) groups. All patients underwent routine ophthalmologic examinations and swept source optical coherent tomography(OCT)-optical coherent tomography angiography (OCTA). Serum fasting blood glucose, glycated hemoglobin, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglyceride(TG) were determined by biochemical examination. The area of foveal avascular zone (FAZ) and the average thickness of the retinal nerve fiber layer(RNFL), ganglion cell layer (GCL+ ) and ganglion cell complex (GCC) were obtained by quantitative analysis of OCT and OCTA. The age, DM duration, serum levels of glycated hemoglobin, TG, TC and LDL-C of patients were described by mean±standard deviation. One-way ANOVA was used for comparison among three groups. The risk factors such as age, sex, DM duration, glycated hemoglobin, TG, TC, LDL-C levels and other factors on DM and DR patients were analyzed by Logistic regression. The area of FAZ and the average thickness of RNFL, GCL+ , GCC were described by mean±standard deviation. Independent sample t testing was used for comparison between groups.

DM duration of DM group, NPDR group and PDR group was (7.92±6.06) years, (12.72±5.87) years and (12.25±7.12) years, respectively, and the DM duration of PDR and NPDR groups were longer than the DM group. The difference was statistically significant (F=5.46, P<0.05). The content of TC in three groups was (4.42±1.02) mmol/L, (4.66±1.18) mmol/L, and (5.15±1.33) mmol/L. The content of LDL-C in three groups was (2.48±0.97) mmol/L, (2.85±1.01) mmol/L and (3.24±0.99) mmol/L. Compared to the DM group, the serum of TC and LDL-C in PDR group was significantly higher (F=3.08, 4.38, P<0.05 ). The content of TG in three groups was (1.91±1.33) mmol/L, (1.50±1.11) mmol/L and (1.62±1.05) mmol/L; the difference among three groups is not statistically significant (F=1.07, P>0.05). The results of Logistic regression analysis showed that DM duration and the content of LDL-C were risk factors for DR progression (OR=1.10, 1.69; P<0.05). The area of FAZ and the average thickness of RNFL, GCL+ , GCC in high TC group were (413.27±180.85)mm², (41.25±20.05)μm, (81.18±18.65)μm and (125.84±34.51)μm , respectively. Those of normal TC group were (327.03±103.36) mm², (35.26±12.92)μm, (77.50±11.28)μm and (114.96±17.12)μm, respectively. Compared to the normal TC group, the area of FAZ and the average thickness of RNFL and GCC of high TC group were significantly higher (t=2.59, 2.26, 2.06; P<0.05). The area of FAZ and the average thickness of RNFL, GCL+ , GCC of high LDL-C group were (393.74±169.71) mm², (39.80±19.76)μm, (79.13±18.37)μm and (128.43±32.53)μm. Those of normal LDL-C group were (324.20±100.91) mm², (35.77±13.08)μm, (78.50±11.36)μm and (115.32±15.056)μm. Compared to the normal LDL-C group, the area of FAZ and the average thickness of RNFL and GCC of high LDL-C group were significantly higher (t=2.31, 1.53, 2.55; P<0.05). The area of FAZ and the average thickness of RNFL, GCL+ , GCC of high TG group were (371.95±169.92) mm², (36.05±14.29)μm, (79.52±14.32)μm and (118.11±21.34)μm. Those of normal TG group were (348.73±116.99) mm², (38.15±15.54)μm, (78.42±14.09)μm and (118.60±25.73)μm. There was no significant difference between two groups (t=0.80, 0.77, 0.42, 0.11; P>0.05).

LDL-C is an independent risk factor for progression of DR. Dyslipidemia may aggravate retinal microangiopathy and retinal neuron degeneration in micro-vasculopathy in diabetic patients.