方法：临床病例对照研究。选择2016-10/2017-12在青岛市市立医院眼科中心符合入组条件的超声乳化白内障患者82例87眼，分为非糖尿病组和糖尿病组。依据术前HbA1c水平，将糖尿病组分为高HbA1c值组(HbA1c>7.0%)和正常HbA1c值组(HbA1c≤7.0%)。其中非糖尿病组(4%≤HbA1c≤6.0%)28例30眼，高HbA1c组28例29眼和正常HbA1c组26例28眼。运用频域光相干断层扫描(SD-OCT)检查各组患者术前1d，术后1d，1wk，1、3mo时黄斑中心凹视网膜厚度(CST)、黄斑总容积(CV)和黄斑中心凹脉络膜厚度(SFCT)，采用多因素重复测量方差分析其变化，Pearson相关分析探究其与HbA1c值的相关性； 同时比较各组患者术后黄斑水肿(PCME)发生率； 进一步分析糖尿病患者HbA1c值与术后最佳矫正视力(CDVA)的关联性。

结果：非糖尿病组、高HbA1c组和正常HbA1c组患者白内障术后1wk时CST分别为239.03±11.55、254.38±26.44、247.07±19.51μm，术后1mo时CST分别为241.00±11.15、271.55±61.05、248.64±38.28μm(F=3.001，P=0.048)； 其中高HbA1c值组和正常HbA1c值组比较有差异(P<0.05)，且两组患者术后1wk，1mo时HbA1c值与CST之间在P=0.01水平上呈正相关关系(r_术后1wk=0.338，r_术后1mo=0.297)。三组患者术后发生PCME分别为0例、5眼(17%)和1眼(4%)。非糖尿病组、高HbA1c组和正常HbA1c组患者术后1wk时CDVA分别为0.07±0.06、0.12±0.10、0.09±0.08，术后1mo时CDVA分别为0.03±0.06、0.11±0.15、0.11±0.09，术后3mo时CDVA分别为0.02±0.04、0.08±0.12、0.06±0.06(F=3.272，P=0.045)； 其中高HbA1c值组和正常HbA1c值组比较无差异(P>0.05)，两组患者HbA1c值与术后1wk，1、3mo(r_术后1wk=0.425，r_术后1mo=0.235，r_术后3mo=0.332)CDVA(LogMAR)在P=0.01水平上两者显著相关且呈正相关关系。三组患者白内障术后CV、SFCT的组间变化趋势大致相同，其变化程度的组间无差异。

结论：糖尿病患者术前HbA1c水平与超声乳化白内障术后黄斑区视网膜和脉络膜结构有一定的相关性； 术前HbA1c>7.0%的患者术后发生黄斑水肿的风险增加。同时，糖尿病患者术前HbA1c水平与白内障术后最佳矫正视力密切相关； 术前HbA1c值越高的患者术后视力提高越欠佳。

METHODS: It is a prospective randomized clinical trial. According to the patient's history, the subjects were divided into the non-diabetes group and the diabetic group. According to the level of HbA1c before operation, the diabetic group was divided into the high HbA1c group(HbA1c>7.0%)and the normal HbA1c group(HbA1c≤7.0%). All 87 eyes from 82 patients who met the criteria from October 2016 to December 2017 in the Department of Ophthalmology at Qingdao Municipal Hospital were enrolled in this study. There were 30 eyes from 28 patients in the non-diabetes group(4%≤HbA1c≤6.0%), 29 eyes from 28 patients in the high HbA1c group and 28 eyes from 26 patients in the normal HbA1c group. Spectral-domain optical coherence tomography(SD-OCT)was used to examine central subifield thickness(CST), central volume(CV)and subfoveal choroidal thickness(SFCT)at 1d before surgery, 1d after surgery, 1wk after surgery, 1mo after surgery and 3mo after surgery. The variance analysis and Pearson correlation analysis were used to analyze the changes and the correlation with HbA1c value. At the same time, the incidence of macular edema after surgery(PCME)was compared among the groups, and the relationship between HbA1c and postoperative corrected distance visual acuity(CDVA)in diabetes patients was also analyzed.

RESULTS: In non diabetic group, high HbA1c group and normal HbA1c group, CST was 239.03+11.55μm, 254.38+26.44μm, 247.07+19.51μm at 1wk after cataract surgery. Their CST was 241.00±11.15μm, 271.55±61.05μm, 248.64±38.28μm at 1mo after cataract surgery(F=3.001, P=0.048). Besides, there was a positive correlation between HbA1c and CST at 1wk and 1mo after operation in the two groups at P=0.01 level(r_1wk=0.338, r_1mo=0.297)(P<0.05). The postoperative macular cystoid edema in non-diabetic group, high HbA1c group and normal HbA1c group were 0, 5(5 eyes, 17%)and 1(1 eye, 4%)respectively. In non diabetic group, high HbA1c group and normal HbA1c group, CDVA was 0.07±0.06, 0.12±0.10, 0.09±0.08 at 1wk after cataract surgery. Their CDVA was 0.03±0.06, 0.11±0.15, 0.11±0.09 at 1mo after cataract surgery. Their CDVA was 0.02±0.04, 0.08±0.12, 0.06±0.06 at 3mo after cataract surgery(F=3.272, P=0.045). The differences among three groups in the CDVA were statistically significant at 1wk, 1mo and 3mo after surgery. There was no significant difference between the high HbA1c group and the normal HbA1c group(P>0.05). However, CDVA(LogMAR)of the two groups was positively correlated with HbA1c at P=0.01 level(r_1wk=0.425, r_1mo=0.235, r_3mo=0.332). There was no statistically significant difference in the changes of CV and SFCT among the three groups, and the trend of changes among these groups was approximately the same.

CONCLUSION: There is a close relationship between the microscopic structure of macula and HbA1c before phacoemulsification in diabetic patients. The risk of macular edema increased in patients with hba1c >7.0% before surgery. The best corrected visual acuity of diabetes patients after surgery was significantly related to the hba1c value before surgery. The higher the hba1c value before surgery, the poorer the improvement of vision after surgery. The level of HbA1c before surgery in diabetic patients is related to the anatomical structure of macular after cataract surgery. The risk of macular edema after surgery is increased in patients with high HbA1c(HbA1c>7.0%)before surgery. Meanwhile, the preoperative HbA1c of diabetic patients is closely related to CDVA after cataract surgery. The higher the preoperative HbA1c value, the worse the CDVA in diabetics after surgery.