Low energy SMILE gives better short term UCVA compared to higher energy SMILE

Session Details

Session Title: Small Lenticule Extraction

Session Date/Time: Tuesday 25/09/2018 | 08:00-10:30

Paper Time: 08:57

Venue: Room A3, Podium 3

First Author: : A.Viljanen FINLAND

Co Author(s): :                        

Abstract Details

Purpose:

This study compares low energy (LE) and higher energy (HE) small incision lenticle extraction (SMILE) results on UCVA, BCVA and refraction change.

Setting:

In this retrospective two center study, 344 eyes of LE and 324 eyes of SE SMILEs included 6 months follow-up. Subjects had mean age of 32/33 (LE/HE) years, 63/55 (LE/HE) % females. Subgroups of baseline SEQ -0.75 - -3, -3.01 - -6 and -6.01 - -10 dioptria were analyzed.

Methods:

VisuMax (Carl Zeiss) laser energy settings were adjusted from 33-30 to 23-20 energy corresponding from 165-150 nJ to 115-100 nJ. Spot and track distance for lenticule cut was 4.4 µm, and side cut 1.5 µm. Fast mode was used. A 10 % nomogram to compensate for under correction was used in both energy levels. Operations were done within 1.5 years before and after energy change. Parameters are UCVA, BCVA and attended refractive change minus achieved refractive change after laser treatment. Follow-up visits were 1 and 6 months. Linear mixed model was used in statistical analysis.

Results:

The attended vs achieved refractive change was equal in 1 month and 6 months in all subgroups and within 0.20 dioptria (p ns. for all). In the subgroup of SEQ -0.75 D to -3 D, LE SMILE UCVA was statistically better compared to HE SMILE at 1 month (LE -0.07 vs SE -0.04 LogMAR, p < 0.05). In other subgroups, UCVA did not differ between energy levels. At 1 month, BCVA was within 1 ETDRS letter between energy levels in all subgroups. At 6 months, UCVA and BCVA were equal in both energy levels in all baseline SEQ groups.

Conclusions:

Low energy SMILE gives better short term UCVA in small refraction corrections compared to higher energy SMILE. BCVA was equal in both energy levels and in all refraction groups. Low energy SMILE did not change lasers refractive results, as attended vs achieved refractive change was unchanged. Low energy SMILE was safe with no retreatments or complications reported.

Financial Disclosure:

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