Authors: Wang Ruina, Guo Hongliang, Ma Ting, Liang Houcheng, Long Tan
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The incidence of myopia is gradually increasing, and how to choose a better corrective method of myopia for the best visual demand is very important.
This study was to compare visual quality of implantable collamer lens (ICL) implantation with femtosecond laser in situ keratomileusis (FS-LASIK) for moderate and high myopia using double-pass optical quality analysis system (OQAS).
A non-randomized controlled clinical trail was performed.Fifty-two eyes with -4.00 to -9.00 D of 26 consecutive patients were included in NO.1 Hospital of Xi’an from January 2015 to January 2016.Twenty-four eyes of 12 patients with the corneal thickness <500 μm received ICL implantation as ICL group and 28 eyes of 14 patients which corneal thickness was ≥500 μm underwent FS-LASIK surgery as FS-LASIK group.The demography was matched between the two groups (all at P>0.05). All the patients were followed-up for 3 months after surgery.The preoperative best corrected distance visual acuity (BCDVA), spherical equivalent (SE), postoperative uncorrected distance visual acuity (UCDVA), BCDVA and SE were examined and compared between two groups.The parameters from OQAS were evaluated and intergrouply compared, including the objective scattering inders (OSI), modulation transfer function (MTF) cut off frequency, Strehl ratio and OQAS values under the contrast of 100%, 20% and 9%(OV100, OV20, OV9).
The postoperative BCDVA was not significantly different from preoperative UCDVA in both ICL group and FS-LASIK group (-0.04±0.10 vs. 0.05±0.12; -0.07±0.12 vs.0.00±0.12) (t=3.128, 2.358, both at P>0.05). No statistically significant differnces were found in SE, UCDVA and BCDVA after operation between ICL group and FS-LASIK group (t=1.292, 0.900, -0.653, all at P>0.05). OQAS examination showed that MTF cut off, OSI, Strehl ratio, OV100 were not significantly different after operation between ICL group and FS-LASIK group (t=-2.032, -1.440, -0.224, all at P>0.05). The postoperative OV20 and OV9 were 0.82±0.14 and 0.80±0.21 in the ICL group, which were significantly higher than those in the FS-LASIK group(0.59±0.15 and 0.47±0.13)(t=4.105, 4.702, both at P<0.05).
Both ICL implantation and FS-LASIK provide good optical and visual quality for moderate to high myopic eyes, and ICL appears to have a better visual quality in comparison with FS-LASIK under the contrasts of 20% and 9%.