Abstract:AIM: To observe the clinical effect of Toric intraocular lens(Toric IOL)implantation in the correction of corneal astigmatism, and vector analysis of residual astigmatism and corneal astigmatism.
METHODS: A retrospective case observation study. A total of 63 patients with 77 eyes who underwent phacoemulsification combined with Toric IOL implantation in our hospital from September 2018 to October 2019 were selected. LogMAR uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), residual astigmatism of subjective refraction were observed after operation in 1wk, 1mo, and 3mo. And after dilated pupil, the Toric IOL axis position was measured by OPD-scanⅢ, and compared with the target axis position(LAD).
RESULTS: The median(interquartile range)of UCDVA at 1wk, 1mo, and 3mo after operation were 0.22(0.15, 0.40), 0.30(0.15,0.40),and 0.30(0.15, 0.40), which were better than those of UCDVA \〖0.82(0.60, 1.22)\〗 and BCDVA \〖0.52(0.30, 0.70)\〗 before operation(P<0.008). The residual astigmatism was 0.75(0.50, 1.00), 0.75(0.38, 1.00), 0.50(0.25, 1.00)D, respectively, which was significantly lower than that of preoperative corneal astigmatism \〖2.19(1.73, 2.69)D\〗(P<0.008). At 3mo after surgery, the proportion of UCDVA(LogMAR)≤0.301 was 69%; the proportion of residual astigmatism ≤0.75D was 73%. The median LAD at 1wk, 1mo, and 3mo after surgery were 2.0°, 2.0°, and 3.0°; 81%, 82%, 77% were less than 5°. The maximum LAD value is 11°. Astigmatism vector analysis: preoperative corneal astigmatism was 2.31±0.80D, centroid value was 1.44D@177°±1.99D; Predicted postoperative residual astigmatism was 0.14±0.17D, centroid value was 0.02D@58°±0.22D; residual astigmatism at 3mo after operation was 0.69±0.53D, centroid value was 0.05D@142°±0.88D.
CONCLUSION: Toric IOL can effectively correct corneal astigmatism in patients with cataract and has good rotational stability. Astigmatism vector analysis can directly show the difference between predicting postoperative astigmatism and actual residual astigmatism, which is helpful to analyze and optimize the measurement of corneal astigmatism, calculation of IOL degree, surgical design, postoperative observation.