This is a prospective, comparative, randomized, controlled, single-blind, single-surgeon, single-center PMCF clinical study whereby participants undergoing refractive surgery for correction of ametropia will receive a transepithelial PRK (tPRK) and conventional PRK treatment in the contralateral eye. To avoid bias in the clinical outcomes, the two PRK treatment options are randomized to the eyes of the patients based on ocular dominance. In addition, a 1:1 randomization is applied within the tPRK group to eyes with and without end-treatment laser polishing. Both procedures, standard PRK and tPRK, are performed in a one-step procedure. The main difference between the procedures is, that in conventional PRK, the epithelium will be removed using alcohol, whereas in tPRK procedures, the epithelium will be removed by laser ablation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
39
Transepithelial Photorefractive keratectomy (tPRK) with laser ablation of the corneal epithelium and stroma in a single-step procedure using the B+L Teneo 317 Model 2 Excimer Laser.
Transepithelial Photorefractive keratectomy (tPRK) using the B+L Teneo 317 Model 2 Excimer Laser with end-treatment laser polishing using a fixed thickness of the additional layer of 5 μm.
Conventional Photorefractive keratectomy (PRK) with alcohol-assisted epithelium ablation. Then the aspheric ablation profile will be performed using the B+L Teneo 317 Model 2 Excimer Laser.
Asian Eye Institute
Makati City, Philippines
Absolute refractive predictability
Absolute refractive predictability is the absolute difference between intended and achieved Manifest Refraction Spherical Equivalent (MRSE) between eyes
Time frame: 3 months follow up
Monocular Uncorrected Distance Visual Acuity (UDVA) under photopic light conditions
The visual acuity measurements will be assessed using Clinical Trial Suite (M\&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions.
Time frame: 3 months follow up
Monocular Uncorrected Distance Visual Acuity (UDVA) under mesopic light conditions
The visual acuity measurements will be assessed using Clinical Trial Suite (M\&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under mesopic light conditions.
Time frame: 3 months follow up
Monocular Corrected Distance Visual Acuity (CDVA) under photopic light conditions
The visual acuity measurements will be assessed using Clinical Trial Suite (M\&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under photopic light conditions. Corrected means spectacle corrected.
Time frame: 3 months follow up
Monocular Corrected Distance Visual Acuity (CDVA) under mesopic light conditions
The visual acuity measurements will be assessed using Clinical Trial Suite (M\&S Technologies, Niles, IL, USA) at 4 m in LogMAR scale under mesopic light conditions. Corrected means spectacle corrected.
Time frame: 3 months follow up
Monocular Contrast Sensitivity
The contrast sensitivity test consists in assessing the possibility to distinguish the alternation of white and grey fringes of difference contrast with difference frequency. Contrast sensitivity will be assessed under photopic and mesopic light conditions using Clinical Trial Suite (M\&S Technologies, Niles, IL, USA) device at 2.5 m.
Time frame: 3 months follow up
Halo Photic phenomena
The amount and disturbance of photic halo side effects will be assessed by the Halo Simulator: With this software tool the particant mimics the individual vision perception by adjusting a typical night scene image with the intensity and size of halo. The simulator utilizes a numerical scale to quantify the size and intensity of halos, ranging from 0 (none), 25 (mild), 50 (moderate), 75 (severe) to 100 (very severe).
Time frame: 3 months follow up
Glare Photic phenomena
The amount and disturbance of photic glare side effects will be assessed by the Glare simulator: With this software tool the particant mimics the individual vision perception by adjusting a typical night scene image with the intensity and size of glare. The simulator utilizes a numerical scale to quantify the size and intensity of glare, ranging from 0 (none), 25 (mild), 50 (moderate), 75 (severe) to 100 (very severe).
Time frame: 3 months follow up
Corneal pain
The epithelial healing process after photorefractive keratectomy treatment often comes along with the perception of some corneal pain. To assess the pain level, the participants will receive a self-administered pain questionnaire to fill out every day from the day of the surgery until they return for the 6-9 days follow up visit. An 11-point scale will be used to rate the self-reporting of pain, where 0 is 'None' and 10 is the highest level of 'Severe'. Higher scores indicate higher level of pain.
Time frame: 3 months follow up
Visual perception scale
To assess the visual perception level, the participants will receive a self-administered visual perception questionnaire to fill out every day from the day of the surgery until they return for the 6-9 days follow up visit. A 4-point scale will be used to rate the self-reporting of visual perception, with 1 = 'Clear' and 4 = 'Very Poor' vision. Higher scores indicate poorer visual perception.
Time frame: 3 months follow up
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