Page 89 - JSOM Winter 2024

personnel from both sanctioned and unsanctioned contact lens Measurements for CDVA, UDVA, MR, pachymetry, procedure
wear may be avoidable with refractive surgery. type, and ablation depth/ lenticule thickness were acquired
from examination forms.
Beyond clinical outcomes, the success of refractive surgery is
also measured by the patient’s perception of their visual quality Statistical Analysis
and overall satisfaction. The patient’s perspective encompasses Univariate and bivariate analyses were performed using
how the improvement in vision aligns with their expectations STATA 15 (StataCorp, College Station, TX). Summary statis-
and how it impacts their daily life. Questionnaires serve as an tics included measures of central tendency and dispersion for
essential tool, offering feedback from patients on how they feel quantitative variables as well as frequencies and percentages
before and after refractive surgery. When objective measures for qualitative variables. The sample was sufficiently large to
such as visual acuity are combined with patient expectations perform parametric rather than non-parametric tests for con-
and satisfaction, a holistic representation of a patient’s defini- tinuous variables.
tion of surgical outcomes and success is produced.
First, refractive surgery types (LASIK, PRK, and SMILE)
While studies have reported LASIK versus PRK QOV out- were compared on patient and preoperative characteristics
comes, this study aims to assess PROs of LASIK, PRK, and using one-way ANOVA tests with the Bonferroni method for
SMILE in the context of advancing technology, differing surgi- pairwise comparisons, chi-square test, or Fisher exact test as
cal procedures, and basic visual outcomes. appropriate. Second, paired comparisons in outcomes mea-
sured before and after surgery were performed for LASIK,
PRK, and SMILE groups separately using paired t tests. Third,
Methods
differences in PROs from before and following surgery were
The study was reviewed and deemed exempt from full re- compared between LASIK, PRK, and SMILE groups using
view by the Department of Research Programs at Fort Belvoir one-way ANOVA tests with the Bonferroni method for pair-
Community Hospital (FBCH, known as Alexander T. Augusta wise comparisons. Finally, postoperative patient satisfaction
Military Medical Center since 2023), Fort Belvoir, Virginia. A was compared among the three refractive surgery groups using
retrospective review of medical records was performed among one-way ANOVA tests with the Bonferroni method for pair-
patients who underwent refractive surgery. The surgeries wise comparisons. Two-sided statistical tests were performed
took place at the former Walter Reed Army Medical Center’s at α=0.05.
Center for Refractive Surgery or the current FBCH’s War-
fighter Refractive Eye Surgery Program and Research Center Results
( WRESP-RC) between 2004 and 2019.
Overall, the study comprised 750 eyes of 375 participants:
Since the SMILE procedure became available at the WRESP-RC LASIK (118 eyes, 15.7%), PRK (550 eyes, 73.3%), and SMILE
in March of 2017, the number of patients who underwent (82 eyes, 10.9%). Most participants were men (73.6%) with
SMILE was limited compared to those who underwent alter- a mean age of 33.9 (SD 8.2) years. Over half (65.7%) had a
native procedures available earlier, including LASIK and PRK. history of contact lens wear. Participants had a mean manifest
Patients who underwent ICL were excluded from this study as sphere of –3.11 (SD 1.69) diopters (D), cylinder of –.64 (SD
the standard operating procedures differed for ICL patients in 62) D, and MSE of –3.43 (SD 1.69) D. CDVA was 20/20 or
this population. better in 99.5% of eyes preoperatively. Baseline characteristics
by type of treatment are presented in Table 1.
To be study-eligible, patients who underwent a myopic refrac-
tive procedure must have completed both a preoperative and a Visual outcomes for each treatment type are shown in Table
6-month postoperative assessment using the Quality of Vision 2 and Figure 1. Per Table 2, all treatments significantly im-
and Patient Satisfaction questionnaire derived from Schall- proved UDVA, and there was a significant difference in post-
6
horn and colleagues. SMILE is currently approved to treat operative CDVA between PRK and SMILE (P=.001). Figure
myopia with astigmatism; therefore, hyperopic patients were 1 displays preoperative CDVA and postoperative UDVA.
excluded from the study. The efficacy index (a ratio of mean postoperative UDVA to
mean preoperative CDVA) was 0.92 (95% CI 0.90–0.95) for
Data collection LASIK, 0.95 (95% CI 0.94–0.96) for PRK, and 0.95 (95%
The “Quality of Vision and Patient Satisfaction Before and Af- CI 0.91–0.99) for SMILE with no significant difference be-
ter Refractive Surgery” Questionnaire includes validated Likert tween groups (P=.204). The safety index, the ratio of mean
scales (‘Far vision,’ ‘Glare,’ ‘Night vision,’ ‘Driving difficulty,’ postoperative CDVA to mean preoperative CDVA, was 1.03
‘Symptoms,’ ‘Bothered by,’ and ‘Limitation because of vision’). (95% CI 1.01–1.06) for LASIK, 1.04 (95% CI 1.03–1.06) for
Item responses are coded as 1-3, 1-4, or 1-5, in addition to PRK, and 1.00 (95% CI 0.97–1.03) for SMILE, which was not
dichotomous (‘yes’ or ‘no’) items focused on wearing contact significantly different between groups (P=.066). There was a
lenses or glasses for far vision and motor vehicle operation. significant difference in attempted cylinder correction between
treatment groups (P<.001) and 6-month postoperative MSE
Medical records were also reviewed for patient demographics, (P=.022) (Supplemental Table 1).
vision correction history (glasses or contact lens), preoperative
characteristics (uncorrected distance visual acuity (UDVA), Significant changes in the QOV and Patient Satisfaction scores
corrected distance visual acuity (CDVA), manifest refraction from preoperative baseline are shown in Table 3. Of the scales
(MR), manifest spherical equivalent (MSE), pachymetry, comparing LASIK, PRK, and SMILE, there was an overall sig-
procedure type, ablation depth, and postoperative character- nificant difference in postoperative driving difficulty between
istics (UDVA, CDVA, manifest refraction, MSE and PROs). groups (P=.025).

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