Ten year outcome of photorefractive keratectomy and laser in situ keratomileusis for myopia and myopic astigmatism
Session Details
Session Title: Surface Photoablation
Session Date/Time: Monday 12/09/2016 | 14:30-16:30
Paper Time: 14:30
Venue: Hall C1
First Author: : B.Bubała-Stachowicz POLAND
Co Author(s): : D. Wygledowska-Promienska E. Mrukwa-Kominek
Abstract Details
Purpose:
The aim of the study was to determine the safety, functional outcome and refractive stability of laser correction for refractive errors including photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK). A comparative analysis of changes in the outer surface of the cornea during a ten-year period after the above mentioned interventions was also performed.
Setting:
Patients with myopia and myopic astigmatism were qualified for photorefractive keratectomy and laser-assisted in situ keratomileusis based on the subjective and objective examinations. The analysis included 100 eyes of 54 patients (28 women and 26 men) divided into two groups depending on the type of surgical treatment.
Methods:
Group I comprised 50 eyes operated on with PRK including 25 eyes with a spherical equivalent of up to -6.00D (group I a) and 25 eyes with a spherical equivalent of more than -6.00D (group Ib). Group II comprised 50 eyes after LASIK including 25 eyes with a spherical equivalent of up to -6.00D (group IIa) and 25 eyes with a spherical equivalent of more than -6.00D (group IIb). All patients were examined prior to the procedure; follow-up examinations were performed at 1, 3, 6 and 12 months of surgery and at 10 years after laser correction of refractive errors.
Results:
The refractive stability rates were as follows: group IA – 1.0; group IIA-1.03; group IB-1.01; group IIB-1.13. UDVA was 0.12, 0.09, 0.10 and 0.03 in groups IA, IB, IIA and IIB, respectively. At 10 years of the procedure, the respective values of UDVA were 0.99, 0.95, 0.99 and 0.86. Before the keratorefractive interventions, the mean best-corrected visual acuity was 0.99 in both groups and remained stable throughout the entire observation period. During a 10-year observation period, the safety index was 1.1 in group IA, 1.01 in group IB, 1.02 in group IIA and 1.0 in group IIB. The efficacy index (postoperative UDVA / preoperative CDVA) was 0.96, 0.96, 0.94 and 0.86 in groups IA, IB, IIA and IIB, respectively.
Conclusions:
PRK and LASIK have been confirmed to be safe procedures. Also, refractive stability rates turned out to be quite high during a 10-year observation period. The examination of corneal structure using confocal microscopy revealed that, at 10 years after surgery, patients who had presented with high-degree refractive errors still had changes in the corneal epithelium and stroma, the magnitude of which seemed to be associated with ablation depth during surgery. This observation concerns both patients after PRK and LASIK. Patients who underwent PRK and LASIK exhibited a significant uncorrected distance visual acuity improvement over the entire observation period.
Financial Disclosure:
NONE
