目的： 探讨糖尿病(diabetes mellitus，DM)患者在出现糖尿病视网膜病变(diabetic retinopathy，DR)之前黄斑区视功能状态。

方法：选择来我院眼科行眼部检查无视力改变及眼底异常的DM患者70例140眼(20～<30岁8例16眼，30～<40岁18例36眼，40～<50岁24例48眼，50岁以上20例40眼)； 正常人80例160眼(20～<30岁20例40眼，30～<40岁20例40眼，40～<50岁20例40眼，50岁以上20例40眼)作为对照组。采用MP-1微视野计对正常组和DM组行眼底成像和黄斑部微视野检查，记录受检眼黄斑20°范围内视网膜平均光敏感度(MS)、2°和4°固视稳定性及固视点位置。

结果： 20～30岁中，DM组和正常组黄斑20°范围内MS值分别为15.32±1.82、19.41±0.32dB； 30～40岁中，糖尿病组和正常组MS值分别为14.93±2.11、18.92±0.73dB； 40～50岁中，MS值分别为14.55±2.84、18.21±0.53dB； 50岁以上组， MS值分别为13.21±2.25、17.14±1.21dB； 同一年龄段，两组比较差异均有统计学意义(P<0.05)。所有受检者均为中心固视。正常组共160眼，固视稳定眼124眼(77.5%)，固视相对不稳定眼36眼(22.5%)； 糖尿病组共140眼，固视稳定眼109眼(77.9%)，固视相对不稳定眼31眼(22.1%)，两组固视稳定率比较，差异无统计学意义(χ²=0.00549，P>0.05)。

结论： DM患者在出现视网膜形态学改变之前，黄斑区视功能已受到损害，其20°范围内视网膜光敏感度已受到损害； 但其固视位置及固视稳定性相对正常人而言尚无明显改变。

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.