Comparison of Visual, Refractive and Aberration Measurements of INTACS versus Toric ICL Lens Implantation; A Four-year Follow-up

Med Hypothesis Discov Innov Ophthalmol. 2018 Spring;7(1):32-39.


This study was performed to evaluate the visual, refractive, and aberration measurement results of 2 implants, including Intacs Intracorneal Ring Segments (ICRS) and phakic Toric Implantable Collamer Lens (TICL), in patients with moderate Keratoconus (KCN). In this retrospective cross-sectional study, 30 patients with KCN with a mean age of 29.83 years were included in 2 groups, including the Intacs Intracorneal Ring Segments (ICRS) group and the phakic Toric Implantable Collamer Lens (TICL) group. Preoperative data as well as 6-month, 1-, 2-, 3- and 4-year follow-up data after the operation were collected and analyzed with the SPSS software (ver. 23.0, SPSS, Inc., Chicago, IL), using the paired t-test, independent t-test, repeated measures Analysis of Variance (ANOVA), and one-way ANOVA. This study included 30 patients with KCN with a mean age of 29.83 years and range of 25 to 35 years, including 17 males with a mean age of 30.11 years and 13 female with a mean age of 29.25 years. Except for preoperative Uncorrected Distance Visual Acuity (UCDVA), Spherical Equivalent (SE) and astigmatism, there was a significant difference between the 2 groups regarding other variables. The TICL group had a significantly better UCDVA and Best Corrected Distance Visual Acuity (BCDVA) in all post-operative follow-ups, and SE and astigmatism values were significantly lower in all post-operative follow-ups when compared with the ICRS group. There was a significant reduction in corneal and total coma as well as internal trefoil aberrations (P<0.01, P<0.01, and P=0.014, respectively) in the ICRS group, and TICL led to a significant reduction in internal trefoil aberration with P<0.03. Comparison of the 2 groups revealed a significant difference in corneal spherical (P<0.01) and total coma (P=0.02) aberrations and no significant differences in other HOA. Both ICRS and TICL are useful in patients with moderate KCN. However, TICL appears to have more stable and predictable vision results.

Keywords: Higher-order aberrations; Intacs intracorneal ring segments; Keratoconus; Phakic toric Lens.