AIM: To investigate the macular function of patients with diabetes mellitus(DM)who had no diabetic retinopathy(DR).

METHODS: Totally 140 eyes of 70 subjects with diabetes who had no vision disorders and fundus abnormalities(DM group)and 160 eyes of 80 normal subjects(control group)were examined. In DM group, from 20 to 30 were 8 patients(16 eyes), from 30 to 40 were 18 patients(36 eyes), from 40 to 50 were 24 patients(48 eyes), over 50 were 20 patients(40 eyes). In control group, there were 20 people in each age stages. Retinal imaging and macular microperimetry were measured by MP-l Microperimeter. The mean retinal light sensitivity(MS)in the central 20°, fixation stability and fixation position in the central 2° and 4° were recorded.

RESULTS: With the ages from 20 to 30, the MS of DM group and control group were 15.32±1.82, 19.41±0.32dB; from 30 to 40, the MS were 14.93±2.11, 18.92±0.73dB; from 40 to 50, the MS were 14.55±2.84, 18.21±0.53dB; over 50 years, the MS were 13.21±2.25, 17.14±1.21dB; respectively,the difference was all statistically significant between the two groups with the same age(P>0.05). All subjects were central fixation. Among 160 eyes of control group, fixation was stable in 124 eyes(77.5%), relative unstable in 36 eyes(22.5%); among 140 eyes of DM group, fixation was stable in 109 eyes(77.9%), relative unstable in 31 eyes(22.1%), the difference was statistically significant(χ²=0.00549, P>0.05).

CONCLUSION: The macular function and the MS in the central 20° had been damaged before fundus morphological abnormalities were detected in patients with diabetes. However, compared with control group, the fixation position and fixation stability did not changed significantly in patients with diabetes.