目的：评估Barrett True K公式应用于放射状角膜切开术(RK)术后的白内障患者的屈光准确性。

方法：选取2017-02/2019-02在我院确诊为RK屈光手术后的白内障患者22例42眼，术前分别用两种方法计算人工晶状体屈光度：(1)选取术眼角膜中央直径3mm区域最小的前表面K值，应用SRK/T公式计算，目标屈光度设为-1.0D；(2)用Barrett True K在线计算公式，选择RK术后模式，目标屈光度设为-1.0D。术后3mo检查术眼屈光状态，对比两种方法计算的屈光误差。

结果：术后3mo，Barrett公式法屈光误差为0.61(-0.37， 0.88)D，明显低于传统公式法的0.35(-0.25， 0.63)D(P<0.05)； 屈光误差绝对值比较无差异(P>0.05)。传统公式法屈光误差在±0.5、±1.0、±2.0D的范围的分别占21%、45%、90%，Barrett公式法屈光误差在±0.5、±1.0、±2.0D的范围的分别占31%、74%、100%(P<0.05)。

结论：Barrett True K在线公式应用于RK术后的白内障患者可达到较满意的屈光状态。

METHODS: From February 2017 to February 2019, 42 eyes of 22 cataract patients with previous RK were selected in our hospital. Two methods were used to calculate IOL refraction before surgery: 1)Selected the smallest anterior surface K value in the area of 3mm central corneal diameter, used SRK/T formula, the target refraction was set at -1.0D; 2)Used Barrett True K on-line calculation formula, the mode of RK was selected and the target refraction was set at -1.0D. Three months after operation, the refractive state of the eyes was examined and the refractive errors calculated by the two methods were compared.

RESULTS: The average refractive error of Barrett formula method was 0.61(-0.37, 0.88)3mo after operation, which was significantly lower than that of traditional formula method 0.35(-0.25, 0.63)D(P<0.05). There was no significant difference in absolute refractive error between the two methods(P>0.05). The refractive errors of traditional formula method in the range of ±0.5D, ±1.0D, ±2.0D accounted for 21%, 45%, 90% respectively. The refractive errors of Barrett formula method in the range of ±0.5D, ±1.0D, ±2.0D accounted for 31%, 74%, 100% respectively(P<0.05).

CONCLUSION: Barrett True K online formula applied to cataract patients after RK can achieve satisfactory refractive status.