Effects of optical zone in LASIK with high myopia on the postoperative contrast sensitivity

Session Details

Session Title: Presented Poster Session: Presbyopia

Session Date/Time: Saturday 05/09/2015 | 15:00-16:30

Paper Time: 15:50

Venue: Poster Village: Pod 2

First Author: : T.Yonekawa JAPAN

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

Abstract Details

Purpose:

The contrast sensitivity has been reported to decrease after laser in situ keratomileusis (LASIK). We investigate influence of optical zone (OZ) in LASIK with high myopia (Spherical power:-6.00～-8.00D)on the postoperative contrast sensitivity and uncorrected visual acuity (UCVA).

Setting:

Inouye Eye Hospital, Tokyo, Japan

Methods:

The subjects were 66 eyes of 46 patients who underwent LASIK at our clinic. The subjects were randomly divided into two groups by OZ: 6.5mm group (33eyes, mean age: 30.6 years old, mean spherical equivalent: -6.69±0.44D) and 6.0mm group (33eyes, mean age: 37.7 years old, mean spherical equivalent: -6.91±0.57D). The target refractive correction was emmetropia in all cases. The contrast sensitivity was measured with a contrast-glare tester (CGT-1000™: TAKAGI, JAPAN), and analyzed using Area Under the Log Contrast Sensitivity Function (AULCSF). AULCSF and mean UCVA were analyzed statistically between the 2 groups (Mann–Whitney U Test).

Results:

At 3 months postoperatively, AULCSF (glare off) was 1.57 in 6.5mm group and 1.58 in 6.0mm group respectively. There are no difference between two groups in contrast sensitivity without glare (P=0.7000). However, AULCSF (glare on) was 1.56 in 6.0mm group and 1.47 in 6.0mm group respectively. The difference between two groups was statistically significant (P=0.0161). UCVA was -0.11±0.12 (logarithm of the minimum angle of resolution: log MAR) in 6.5mm group, and -0.08±0.14 (log MAR) in 6.0mm group respectively. There are no difference between two groups (P=0.2600).

Conclusions:

OZ in LASIK may significantly affect the postoperative glare contrast sensitivity. Larger OZ is preferable for the high myopic patients than smaller one.

Financial Disclosure:

NONE