Abstract:AIM: To compare phacoemusification combined Toric intraocular lens implantation(Toric-IOL)with spherical intraocular lens implantation combined peripheral corneal relaxing incisions(PCRIs)for astigmatism correction in elderly patients before having cataract surgery.
METHODS: This randomized prospective clinical study comprised eyes with more than 0.75 diopter(D)of preexisting corneal astigmatism. Totally 54 patients(54 eyes), 27 males and 27 females, with mean age 70.04±9.08 years, were enrolled consecutively to group A(n=30)(0.75D-1.50D)and group B(n=24)(1.75D-2.50D)according to the corneal astigmatism. In each group patients were randomized to undergo Toric-IOL implantation or PCRLs in the steep axis with spherical IOL implantation. Uncorrected visual acuity(UCVA), best-corrected visual acuity(BCVA), error of vector(|EV|), surgery induced refraction correction(|SIRC|)and correction rat(CR)were measured 1 month and 6 months postoperatively.
RESULTS: Six months postoperatively, all 54 eyes got the BCVA≥0.6. Patients underwent PCRIs and Toric-IOL with BCVA≥0.8 were 86.7% vs 93.3%(P>0.05)in group A and 75% vs 91.7%(P=0.59)in group B respectively. UCVA, |EV|, |SIRC| and CR in patients underwent PCRIs and Toric-IOL were not significantly different by 0.70±0.21 vs 0.76±0.17(P=0.81), 0.48±0.22 vs 0.37±0.19(P=0.13), 0.87±0.30 vs 0.92±0.38(P=0.71),0.75±0.16 vs 0.78±0.19(P=0.56)respectively in group A; It were significantly different by 0.50±0.15 vs 0.78±0.11(P<0.01), 1.17±0.36 vs 0.54±0.33(P<0.01), 1.08±0.27 vs 1.68±0.32(P <0.01), 0.51±0.13 vs 0.81±0.14(P <0.01)respectively in group B. Difference of UCVA and |EV| between 1 month and 6 months were not significant in patients in group A, but were significant in group B, regardless of PCRIs or Toric-IOL surgery. In group A,UCVA and |EV| measured 1 month and 6 months post-operation were 0.77±0.23 vs 0.70±0.21(P=0.09),0.50±0.23 vs 0.48±0.22(P=0.58)respectively in PCRIs patients and 0.77±0.223 vs 0.76±0.17(P=0.81), 0.40±0.18 vs 0.37±0.19(P=0.55)respectively in Toric-IOL patients. In group B, UCVA and |EV| measured 1 month and 6 months post-operation were 0.63±0.17 vs 0.50±0.15(P<0.01), 0.81±0.34 vs 1.17±0.36(P<0.01)respectively in PCRIs patients and 0.81±0.12 vs 0.78±0.11(P=0.08), 0.48±0.31 vs 0.54±0.33(P<0.01)respectively in Toric-IOL patients.
CONCLUSION: Toric-IOL implantation and PCRIs were both safe and effective for astigmatism correction in elderly patients before having cataract surgery. The efficacy and stability of astigmatism correction were equal in low astigmatic patients. Toric-IOL implantation achieved an enhanced effect over PCRIs in higher astigmatic patients. Both of the surgeries had the refractive regression after 6 months and PCRIs regressed more obviously.
