Clinical trial NCT05261685: Single-step Transepithelial PRK for Hyperopia
Official title: Twelve-Month Outcome of Single-step Transepithelial Photorefractive Keratectomy for Moderate Hyperopia and Hyperopic Astigmatism
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Moderate Hyperopia
Keywords: Single-step PRK
StreamLight PRK
Hyperopia
Photorefractive keratectomy
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2022-03-02
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

* Patients with moderate hyperopia with a hyperopic cycloplegic spherical equivalent between +2 and + 4.5 diopters D.
* A steep keratometry (Ks) ≤ 46 D.
* Minimum pachymetry of 500 μm with a calculated residual stromal bed exceeding 350 μm after epithelial and stromal ablation.

Exclusion Criteria:

* Patients not candidate for corneal refractive surgery,
* Steep cornea (Ks \> 46 D) with an expected postoperative keratometry \> 48 D,
* Large angle kappa as estimated by Chord mu \> 0.25 mm,
* Hyperopic amblyopia whether unilateral or bilateral with CDVA less than 0.2 . logMAR acuity,
* Recent contact lens wear, dry eye disease and autoimmune disorders.

Primary outcomes:
measure: Visual acuity
timeFrame: 12 months
measure: Cycloplegic refraction
timeFrame: 12 months
Secondary outcomes:
measure: Keratometry and corneal asphericity
timeFrame: 12 months
measure: Post-PRK haze
timeFrame: 12 months
Other outcomes:
Locations:
city: Assiut
country: Egypt
facility: TIBA eye center
Study officials:
affiliation: Assiut University
name: Mahmoud Abdel-Radi
role: PRINCIPAL_INVESTIGATOR
References:
citation: Adib-Moghaddam S, Arba-Mosquera S, Walter-Fincke R, Soleyman-Jahi S, Adili-Aghdam F. Transepithelial Photorefractive Keratectomy for Hyperopia: A 12-Month Bicentral Study. J Refract Surg. 2016 Mar;32(3):172-80. doi: 10.3928/1081597X-20160121-01.