Clinical observation of intraocular lens calculation in eyes with previous radial keratotomy / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

@#AIM: To evaluate the accuracy of the Barrett True K intraocular lens(IOL)calculation formulas in eyes with previous radial keratotomy(RK).<p>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.<p>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(<i>P</i><0.05). There was no significant difference in absolute refractive error between the two methods(<i>P</i>>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(<i>P</i><0.05).<p>CONCLUSION: Barrett True K online formula applied to cataract patients after RK can achieve satisfactory refractive status.