The comparison of corneal higher-order aberration and surgically induced astigmatism between the clear corneal incision and the limbus tunnel incision of posterior chamber implantable collamer lens implantation

BackgroundThis study aimed to compare the corneal high-order aberrations and surgically induced astigmatism between the clear corneal incision and limbus tunnel incision for posterior chamber implantable collamer lens (ICL/TICL) implantation.MethodsA total of 127 eyes from 73 myopic patients underwent ICL V4c implantation, with 70 eyes receiving clear corneal incisions and 57 eyes receiving limbus tunnel incisions. The anterior and back corneal surfaces were measured and the Root Mean Square of all activated aberrations (TRMS) was calculated, including higher-order aberration (HOA RMS), spherical aberration Z40, coma coefficients (Coma RMS) Z3-1 Z31, and surgically induced astigmatism (SIA). The measurements were taken preoperatively and postoperatively at 1 day, 1 week, and 1, 3, and 6 months. In this study, the corneal higher-order aberration was estimated as the Zernike coefficient calculated up to 5th order. The measurements were taken at a maximum diameter of 6.5 mm using Pentacam.ResultsOne week after the operation, the corneal back Z31 of the clear corneal incision group was 0.06 +/- 0.06, while the limbus tunnel incision group showed a measurement of 0.05 +/- 0.06 (p = 0.031). The corneal back Z40 of the clear corneal incision group was -0.02 +/- 0.25, compared to -0.04 +/- 0.21 in the limbus tunnel incision group (p = 0.01). One month after the operation, the corneal back SIA of the clear corneal incision group was 0.11 +/- 0.11, compared to 0.08 +/- 0.11of the limbus tunnel incision group (p = 0.013), the corneal total SIA of the clear corneal incision group was 0.33 +/- 0.30, compared to 0.15 +/- 0.16 in the limbus tunnel incision group (p = 0.004); the clear corneal incision group exhibited higher levels of back astigmatism and total SIA than the limbus tunnel incision in the post-operation one month period. During the 6- month post-operative follow-up period, no significant difference in Z31, Z40, and other HOA RMS data was observed between the two groups. The total SIA of the corneal incision group and the limbus tunnel incision group were 0.24 +/- 0.14 and 0.33 +/- 0.32, respectively (p = 0.393), showing no significant difference between the two groups 6 months after the operation.ConclusionOur data showed no significant difference in the high-order aberration and SIA between clear corneal incision and limbus tunnel incision up to 6 months after ICL-V4c implantation.