Hyperopia is one of the commonest refractive errors encountered in ophthalmology practice. Laser in situ keratomileusis (LASIK) has been widely used to correct hyperopia especially with the advent of femtosecond laser technology allowing larger flap creation suitable for peripheral hyperopic ablations with resultant predictable, effective, and safe refractive outcomes. However, the encountered LASIK flap complications encouraged many surgeons to assess efficiency and safety of surface ablation techniques such as photorefractive keratectomy (PRK) to correct hyperopia.
Although the initial refractive results of conventional manual or alcohol assisted PRK for hyperopia were encouraging, the frequently encountered post-PRK complications including undercorrection, overcorrection and regression of the hyperopic error had downgraded the conventional PRK as a preferred procedure for hyperopic correction. Transepithelial PRK provides an alternative technique to uniformly remove the epithelium using the excimer laser to minimize the potential complications caused by mechanical or alcohol assisted epithelial removal in conventional PRK. Advances in transepithelial PRK technology have allowed refractive surgeons to remove the epithelium followed by stromal laser ablation in a single step instead of performing the procedure in 2 separate steps known as phototherapeutic keratectomy-photorefractive keratectomy (PTK-PRK). Most of the previous studies paid particular attention to investigate the accuracy and safety of single-step transepithelial PRK in correcting myopia and myopic astigmatism. The aim of the current study is to evaluate the visual and refractive outcomes of the single-step transepithelial PRK procedure in correcting moderate hyperopia and hyperopic astigmatism.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Single-step transepithelial Photorefractive keratectomy (PRK) is a corneal refractive surgical procedure utilized to correct myopia, hyperopia and astigmatism where excimer laser is used in a single step to remove the corneal epithelium followed by stromal laser ablation to correct the patient's refractive error.
TIBA eye center
Asyut, Egypt
Visual acuity
Uncorrected and corrected distance visual acuity (UDVA,CDVA) measurement using logMAR distant charts.
Time frame: 12 months
Cycloplegic refraction
Cycloplegic sphere, cylinder and refractive spherical equivalent (SEQ) were measured with auto-keratorefractometer (KR-8900:Topcon, Korea republic)
Time frame: 12 months
Keratometry and corneal asphericity
Postoperative keratorefractive changes in mean keratometry (Km) and Q value were recorded using pentacam (Oculus GmbH, Germany)
Time frame: 12 months
Post-PRK haze
Post-PRK haze was evaluated using slit lamp based on Fantes et al. scale: Grade 0: No haze, completely clear cornea Grade 0.5: Trace haze seen with careful oblique illumination Grade 1: Haze not interfering with the visibility of fine details of the iris Grade 2: Mild obstruction of iris details Grade 3: Moderate obstruction of the iris and lens Grade 4: Complete opacification of the stroma in the area of the scar, anterior chamber is totally obscured.
Time frame: 12 months
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