Journal List > J Korean Ophthalmol Soc > v.51(12) > 1008703

Kim, Whang, Byun, Song, Na, and Joo: Comparison of Short Term Clinical Results Between Epi-LASIK and Femtosecond LASIK

Abstract

Purpose

To compare short-term clinical results of femtosecond LASIK with those of epi-LASIK.

Methods

Twenty subjects (40 eyes) underwent femtosecond LASIK and 20 subjects (40 eyes) underwent epi-LASIK for myopia with astigmatism. The results of each surgery were compared with regard to visual acuity, spherical equivalent, safety, efficacy, stability, predictability and high order aberration.

Results

Postoperative uncorrected visual acuities were 0.51 ± 0.11, 0.95 ± 0.08, and 0.97 ± 0.08 for epi-LASIK and 0.76 ±0.19, 0.97 ± 0.07, and 0.98 ± 0.06 for femtosecond LASIK at one week, one month, and two months after surgery, respectively. Femtosecond LASIK showed faster improvement in visual acuity. Postoperative spherical equivalents were −0.83 ± 0.24, −0.31 ± 0.19, and −0.27 ± 0.09 for epi-LASIK and −0.47 ± 0.21, −0.28 ± 0.15, and −0.25 ± 0.12 for femtosecond LASIK. Safety, efficacy, stability, and predictability showed no differences between the two groups. High order aberrations were increased significantly; however, no significant difference between the two groups was found.

Conclusions

Both epi-LASIK and femtosecond LASIK are effective for surgical correction of myopia with fast visual rehabilitation. In addition, epi-LASIK and femtosecond LASIK showed good safeties, efficacies, predictabilities, and stabilities.

References

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Figure 1.
Changes of uncorrected visual acuity at 1 week interval for postoperative 2 months after epi-LASIK and Femtosecond LASIK.* p value 0.05; t-test
jkos-51-1573f1.tif
Figure 2.
Changes of best corrected visual acuity at 1 week interval for postoperative 2 months after epi-LASIK and Femtosecond LASIK.* p value <0.05; t-test
jkos-51-1573f2.tif
Table 1.
Baseline characteristics of eyes for epi-LASIK and Femtosecond LASIK
Epi-LASIK* Femtosecond LASIK p value
Age, mean (yr) 24 ± 6.7 23 ± 5.7 0.829
Sex (male/female) 7/13 (20) 6/14 (20)
Preoperative UCVA 0.15 ± 0.12 0.14 ± 0.10 0.315
Preoperative BSCVA§ 0.98 ± 0.09 0.97 ± 0.13 0.256
Sphere (D) −5.05 ± 3.1 −5.35 ± 2.8 0.391
Cylinder (D) −2.32 ± 1.8 −2.55 ± 2.0 0.341
SE# (D) −5.87 ± 2.3 −6.12 ± 2.7 0.298
Pachymetry (µm) 552 ± 61.8 548 ± 53.4 0.385

* Epi-LASIK = Epipolis laser in situ keratomileusis

Femtosecond LASIK = Femtosecond laser in situ keratomileusis

UCVA = uncorrected visual acuity

§ BSCVA = best spectacle corrected visual acuity

D = diopter

# SE = spherical equivalent

t-test.

Table 2.
Mean uncorrected visual acuity after epi-LASIK and Femtosecond LASIK at postoperative 1 week and 1, 2 months
Epi-LASIK* Femtosecond LASIK p value
1 week 0.51 ± 0.14 0.76 ± 0.19 < 0.01
1 month 0.95 ± 0.08 0.97 ± 0.07 0.419
2 months 0.97 ± 0.08 0.98 ± 0.06 0.336

* Epi-LASIK = Epipolis laser in-situ keratomileusis

Femtosecond LASIK = Femtosecond laser in situ keratomileusis

t-test.

Table 3.
Mean spherical equivalents after epi-LASIK and Femtosecond LASIK at postoperative 1 week and 1, 2 months
Epi-LASIK* Femtosecond LASIK p value
1 wk −0.83 ± 0.24 −0.47 ± 0.21 0.007
1 mon −0.31 ± 0.19 −0.28 ± 0.15 0.237
2 mon −0.27 ± 0.09 −0.25 ± 0.12 0.342

* Epi-LASIK = Epipolis laser in situ keratomileusis

Femtosecond LASIK = Femtosecond laser in situ keratomileusis

t-test.

Table 4.
Safety, efficacy, and predictability of epi-LASIK and Femtosecond LASIK at postoperative 2 months (in percentage)
Epi-LASIK* Femtosecond LASIK p value
Safety (BSCVA)
Loss of 1 line 6 4 0.386
No loss 84 83
Gain of 1 line 10 13
Efficacy
≥ 20/20 82 90 0.183
Predictability
± 0.50 D§ 40 42 0.682
± 1.00 D 84 89 0.329
Stability
Δ SE (SE2mo-SE1mo) 0.04 0.03 0.728

* Epi-LASIK = Epipolis laser in situ keratomileusis

Femtosecond LASIK = Femtosecond laser in situ keratomileusis

BSCVA = best spectacle corrected visual acuity

§ D = diopter

t-test.

Table 5.
Total HOA, coma, trefoil, spherical aberration of epi-LASIK and Femtosecond LASIK patients at pre- and postoperative 2 months (RMS, in microns)
Epi-LASIK*
Femtosecond LASIK
Total HOA Coma Trefoil SA§ Total HOA Coma Trefoil SA
Preop 0.215 0.174 0.072 0.081 0.197 0.183 0.070 0.123
Postop at 2 mo 0.342 0.236 0.126 0.103 0.285 0.208 0.089 0.165
Changes(%) 159 136 175 127 145 114 127 134
p value <0.01 0.025 <0.01 0.034 0.017 0.038 0.012 0.045

* Epi-LASIK = Epipolis laser in-situ keratomileusis

Femtosecond LASIK = Femtosecond laser in situ keratomileusis

HOA = High order aberration

§ SA = Spherical aberration

t-test.

Table 6.
Flap thickness at postoperative 1 month according to intended flap thickness
Intended flap thickness (μm) n Mean (μm) Range (μm)
110 22 114.4 104–128
120 8 122.1 109–132
130 10 134.1 123–142
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