Refractive Transepithelial Photo-keratectomy (T-PKR) in High Myopia (TEPEHERKAHM)

Refractive Transepithelial Photo-keratectomy (T-PKR) Without Addition of Mitomycin-C in High Myopia: a Retrospective Study of 69 Eyes

The aim of this study is to evaluate the anatomical and refractive parameters following a single-step transepithelial photo-refractive keratectomy (T-PRK) without the addition of mitomycin-C for the treatment of high myopia of 6 diopters or more.

Study Overview

• Status: Completed
• Conditions: Myopia; Ophthalmopathy; Keratopathy

Detailed Description

In this retrospective study, 69 high myopic eyes of 6 diopters or more were treated in 38 patients by Trans-PRK with the SCHWIND Amaris 500E® excimer laser platform without the use of mitomycin-C. Several outcomes are measured in treated patients, such as postoperative uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), efficacy, safety and predictability of the procedure, as well as corneal haze measurement. The patients are followed-up for 3 months.

• Study Type: Observational
• Enrollment (Actual): 38

Contacts and Locations

Study Locations

• France
  • Metz, France, 57085
    • Centre Hospitalier Metz Thionville

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This is a retrospective study conducted on the eyes of patients with high myopia (less than or equal to -6 diopters) associated or not with astigmatic less than 3 diopters operated by Trans-PRK with the SCHWIND Amaris 500E platform (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany) in the CHR Metz-Thionville between January 1, 2018 and January 1, 2020

Description

Inclusion Criteria:

• age ≥18 years,
• myopic sphere of -6 diopters or more,
• astigmatism less than 3 diopters,
• stable myopia not progressing for more than one year

Exclusion Criteria:

• age <18 years,
• myopic sphere less than -6 diopters,
• astigmatism greater than 3 diopters,
• progressive myopia (variation of more than 0.5 diopters over one year),
• abnormal corneal topography or the presence of manifest keratoconus,
• pre-existing eye pathology,
• history of eye surgery,
• active inflammatory or infectious eye disease,
• dermatological disease or systemic connectivitis

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative uncorrected visual acuity (UCVA) at week 1	Postoperative uncorrected visual acuity (UCVA) (logMAR)	Week 1
Postoperative best spectacle corrected visual acuity (BSCVA) at week 1	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)	Week 1
Postoperative uncorrected visual acuity (UCVA) at month 1	Postoperative uncorrected visual acuity (UCVA) (logMAR)	Month 1
Postoperative uncorrected visual acuity (UCVA) at month 3	Postoperative uncorrected visual acuity (UCVA) (logMAR)	Month 3
Postoperative best spectacle corrected visual acuity (BSCVA) at month 1	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)	Month 1
Postoperative best spectacle corrected visual acuity (BSCVA) at month 3	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)	Month 3

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual acuity efficacy index	The efficacy of the procedure was defined by the proportion of eyes with uncorrected visual acuity at 3 months greater than or equal to Log MAR 0.1 (or 8/10 on a decimal scale). The efficacy index was defined as the ratio between the mean uncorrected visual acuity at 3 months and the best corrected visual acuity preoperatively. A threshold of 80% was required to consider the surgery successful.	3 months
Visual acuity safety index	The safety of the procedure was defined as the proportion of eyes that lost 2 or more lines of visual acuity compared to the best preoperative corrected visual acuity. The safety index was defined as the ratio between the best corrected visual acuity 3 months postoperatively and the best corrected visual acuity preoperatively. An 80% threshold was chosen to consider the procedure safe.	3 months
Predictability	Predictability was defined as the percentage of eyes having reached target refraction (± 0.5D) at the end of follow-up (3 months).	3 months
Postoperative corneal haze measurement at week 1	Corneal haze assessment was performed at each follow-up visit and reported on the Fantes scale; Grade 0: absence of corneal haze.; Grade 1: corneal fog that does not prevent the visibility of details of the iris; Grade 2: slight fading of details of the iris; Grade 3: pronounced erasure of details of the iris and lens; Grade 4: complete opacification of the stroma preventing access to the anterior chamber	Week1
Postoperative corneal haze measurement at month 1	Corneal haze assessment was performed at each follow-up visit and reported on the Fantes scale; Grade 0: absence of corneal haze.; Grade 1: corneal fog that does not prevent the visibility of details of the iris; Grade 2: slight fading of details of the iris; Grade 3: pronounced erasure of details of the iris and lens; Grade 4: complete opacification of the stroma preventing access to the anterior chamber	Month 1
Postoperative corneal haze measurement at month 3	Corneal haze assessment was performed at each follow-up visit and reported on the Fantes scale; Grade 0: absence of corneal haze.; Grade 1: corneal fog that does not prevent the visibility of details of the iris; Grade 2: slight fading of details of the iris; Grade 3: pronounced erasure of details of the iris and lens; Grade 4: complete opacification of the stroma preventing access to the anterior chamber	Month 3
postoperative spherical equivalent	Percent of postoperative spherical equivalent D (SD)	3 months
Postoperative refractive astigmatism at +/- 0.5D of target	Percent of eyes within +/- 0.5D of target	3 months
Postoperative refractive astigmatism at +/- 1.0D of target	Percent of eyes within +/- 1.0D of target	3 months
Complications	Percent of postoperative infections or epithelial healing	Up to 3 months
Patient sex	Sex ratio Men/Women (percent)	Before surgery
Patient age	Age (years)	Before surgery
Preoperative Myopia	Myopia (Diopters)	Before surgery
Preoperative Astigmatism	Astigmatism (Diopters)	Before surgery
Preoperative Spherical equivalence	Spherical equivalence (Diopters)	Before surgery
Preoperative best spectacle corrected visual acuity	BSCVA (logMAR)	Before surgery
Preoperative Keratometry	Keratometry (dipoters)	Before surgery
Preoperative central corneal thickness	central corneal thickness (µm)	Before surgery
Preoperative optical and transition zones	Optical and transition zones (mm)	Before surgery
Preoperative total ablation thickness	Total ablation thickness (µm)	Before surgery

Collaborators and Investigators

• Sponsor: Centre Hospitalier Régional Metz-Thionville
• Investigators: Principal Investigator: Jean Marc Perone, MD, CHR Metz Thionville Hopital de Mercy

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2018
• Primary Completion (Actual): January 1, 2020
• Study Completion (Actual): January 1, 2020

Study Registration Dates

• First Submitted: May 21, 2021
• First Submitted That Met QC Criteria: June 1, 2021
• First Posted (Actual): June 8, 2021

Study Record Updates

• Last Update Posted (Actual): April 13, 2023
• Last Update Submitted That Met QC Criteria: April 12, 2023
• Last Verified: May 1, 2021

More Information

Terms related to this study

• Keywords: efficacy; mitomycin-C; corneal haze; high myopia; transepithelial photorefractive keratectomy; predictibility
• Additional Relevant MeSH Terms: Refractive Errors; Eye Diseases; Myopia
• Other Study ID Numbers: 2021-03-Obs-CHRMT

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No