The postoperative contrast sensitivity threshold of LASIK in preoperative test factors

Session Details

Session Title: Presented Poster Session: Refractive Surgery New Techniques/Instrumentation/Devices II

Venue: Poster Village: Pod 2

First Author: : T.Yonekawa JAPAN

Co Author(s): :    S. Tamaoki   K. Shimamoto   H. Uozato   T. Hatada   K. Inoue   T. Tsuru        

Abstract Details

Purpose:

The contrast sensitivity (CS) has been reported to decrease after laser in situ keratomileusis (LASIK).　We reported the influence of optical zone (OZ) on the postoperative CS after LASIK for high myopia (Yonekawa et al, ESCRS 2015 and 2016) using the Area Under the Log Contrast Sensitivity Function (AULCSF). In this retrospective study, we investigate the post-LASIK CS threshold for the following factors: ablation depths, spherical equivalents (SE), mesopic pupil diameters (MPD).

Setting:

Inouye Eye Hospital, Tokyo, JAPAN

Methods:

The subjects were 224 eyes of 121patients. The subjects were divided into 2 groups based on the corneal thickness and predicted ablation depth according to OZ: 6.5mm (148 eyes) and 6.0mm (76 eyes). CS was measured with glare ON and OFF using a contrast-glare tester (CGT-2000™: TAKAGI, JAPAN), and calculated AULCSF. AULCSF was examined, every 10μm of the ablation depth (26μm to 115μm), every 1 Diopter (D) of the SE (-1.38D to -10.13D) and every 1mm of the MPD (3.27mm to 8.39mm), and the threshold of CS change was calculated respectively, and statistically analyzed (Mann-Whitney U test).

Results:

CS was significantly reduced when the ablation depth was more than 90 μm at 6.0mm (OFF) groups (P = 0.0024). There was no significant difference in CS in SE between the 2 groups (P> 0.0500) . CS was significantly decreased when the preoperative MPD was more than 8.0mm at 6.0mm (ON) groups (P = 0.0249).

Conclusions:

It is important to evaluate the effects of the ablation depth and preoperative mesopic pupil diameter to prevent CS decrease after LASIK.

Financial Disclosure:

None