Outcomes of a New Trans-epithelial Photorefractive Keratectomy (Streamlight PRK) Compared to Conventional PRK Procedures

Myopia = -6 Diopters or Myopic Astigmatism = -4 Diopters Clinical Trial

Official title:

Outcomes of a New Trans-epithelial Photorefractive Keratectomy (Streamlight PRK) Compared to Conventional PRK Procedures

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04710082
• Other study ID #: TEPRK
• Status: Completed
• Phase: N/A
• Start date: June 1, 2020
• Est. completion date: June 30, 2021

Study information

• Verified date: July 2021
• Source: Assiut University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Photorefractive keratectomy (PRK) involves mechanical or alcohol assisted debridement of the epithelium that leads to potential basement membrane (BM) injury ,with resultant more significant haze and pain compared to laser assisted epithelial removal known as 2 step trans-epithelial PRK (PTK-PRK). Our study is focusing on comparing the outcomes of the conventional 2 step trans-epithelial PTK-PRK to the new single step trans-epithelial PRK (StreamLight PRK, Alcon lab, TX, USA).

Description:

Photorefractive keratectomy (PRK) is nowadays one of the commonest refractive procedures in laser vision correction (LVC). PRK differs from laser in situ keratomileusis (LASIK) in that it's a flapless procedure involving the removal of corneal epithelium with different techniques including manual removal , alcohol assisted removal or excimer laser assisted removal with phototherapeutic keratectomy (PTK). Mechanical or alcohol assisted debridement of the epithelium may lead to potential basement membrane (BM) injury ,with resultant more significant haze and pain compared to laser assisted epithelial removal known as 2 step trans-epithelial PRK (PTK-PRK).

Single step trans-epithelial PRK allows removing the epithelium and stroma in a single step with a single ablation profile.

Previous studies paid particular attention for comparing the 2 step PTK-PRK procedure or the new single step PRK procedure to the conventional PRK procedures involving epithelial removal whether manual or alcohol assisted.

The aim of this study is to focus on comparing the different outcomes of the new single step Trans-epithelial PRK (StreamLight Technology) versus the routine 2 step PTK-PRK in terms of postoperative vision, epithelial healing, pain scoring and haze evaluation.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: June 30, 2021
• Est. primary completion date: June 30, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

• Inclusion Criteria: Candidates for Laser vision correction (LVC) with

1. Myopia up to -6 diopters

2. Myopic astigmatism up to -4 diopters

3. Corneal thinnest location = 500 um and a residual stromal bed = 300um.

• Exclusion criteria

1. Patients not candidates for LVC.

2. Hyperopic patients.

3. Systemic disease that contraindicates LVC.

4. Intra- or post-operative complications.

Related Conditions & MeSH terms

• Astigmatism
• Myopia = -6 Diopters or Myopic Astigmatism = -4 Diopters

Intervention

Procedure:
• Photorefractive keratectomy (PRK)
Photorefractive keratectomy (PRK) is a surgical procedure used by ophthalmic surgeons to treat patients presented with refractive errors and involves corneal epithelial removal followed by application of excimer laser to correct different refractive errors including Myopia, Hyperopia and Astigmatism.

Locations

Country	Name	City	State
Egypt	TIBA eye center	Assiut

Sponsors (1)

Lead Sponsor	Collaborator
Assiut University

Country where clinical trial is conducted

Egypt, 

References & Publications (1)

Kaluzny BJ, Cieslinska I, Mosquera SA, Verma S. Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction. Medicine (Baltimore). 2016 Feb;95(6):e1993. doi: 10.1097/MD.0000000000001993. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Uncorrected distant visual acuity (UDVA)	Visual acuity measurement using Snellen's Acuity Chart and will be expressed as decimal notation	6 months
Primary	Postoperative Refraction (Spherical equivalent)	Measured by Topcon Auto-Keratorefractometer	6 months
Secondary	Epithelial healing duration	Time for the epithelium to heal reported in days after PRK procudre	2 weeks
Secondary	Postoperative pain	Verbal Rating Scale(a series of words commonly used to describe pain (0: no pain, 1: mild pain, 2: moderate pain, 3: severe pain, 4: disabling pain)	1 week
Secondary	Postoperative Haze	Corneal Haze scoring using slit lamp bio-microscopy according to Fantes scoring system: 0: No haze, completely clear cornea; 0.5: Trace haze seen with careful oblique illumination; Haze not interfering with visibility of fine iris details; Mild obscuration of iris details; Moderate obscuration of the iris and lens; Complete opacification of the stroma in the area of the scar, anterior chamber is totally obscured	3 months