方法：研究遵循统一的调查流程及方法。由经过培训的眼科医师整群抽取四川甘孜州两个藏族聚居点的中老年人145例290眼及居住地地域近似的2个彝族聚居地136例272眼进行眼科检查、问卷调查并睑结膜囊分泌物接种于血琼脂培养基上，培养48h后进行细菌分离鉴定，并对两组受检人群的结果进行比较。

结果：藏族和彝族受检者的人口基线特征比较差异无统计学意义(P>0.05)。藏族中老年人结膜囊细菌培养阳性率为50.7%，彝族为69.9%，差异有统计学意义(P<0.05)。藏族结膜囊多种细菌共存者占11.6%，彝族为2.6%； 藏族人群中多种细菌共存的构成比明显高于彝族(P<0.05)。藏族结膜囊中棒状杆菌培养的阳性率为15.9%，彝族的为22.4%，差异有统计学意义(P<0.05)； 藏族结膜囊中表皮葡萄球菌培养的阳性率为26.6%，彝族人群为26.1%，差异无统计学意义(P>0.05)。

结论：藏族中老年人结膜囊细菌培养阳性率低于彝族，藏族和彝族中老年人结膜囊的细菌大多为单一菌株，但藏族人多种菌株共存的现象比彝族更为多见。藏族人与彝族人结膜囊细菌菌属有一定的区别。

METHODS: This survey study was performed as the standardized training and protocol. A total of 290 eyes of 145 individuals from Tibetan nationality and 272 eyes of 136 individuals in Ganzi Tibetan Autonomous Prefecture received questionnaire survey and ophthalmological examination. The secretion of the inferior palpebral conjunctival sac was embrocated and inoculated on blood plate for 48-72 hours. The bacteria was separated and identified.

RESULTS: All the examinee finished the survey and examination with a good compliance. No significant difference was found in the demography between these two groups of population. The multiple bacterial positive rate in conjunctival sac was 50.7% in Tibetan nationality and that of Yi nationality was 69.9% with a considerably difference between them(P<0.05). The multiple bacterial species were simultaneously detected in 11.6% in Tibetan nationality population and 2.6% Yi nationality, showing evidently difference(P<0.05 ).The positive rate of corynbaccterium in conjunctival sac of Tibetan nationality was statistically lower than that of Yi nationality(P<0.05), but there was no statistical difference in the positive rate of staphylococcus epidemics between two groups(P>0.05).

CONCLUSION: The bacteria positive rate in conjunctiva sac is considerably difference in the population between Tibetan nationality and Yi nationality. The simple bacterial species is found in majority people in two groups of subjects. The positive rate of multiple bacterial strains coexistence is more than the Yi nationality. The bacterial strains is different between Tibetan nationality and Yi nationality.