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

Completed

• Conditions: Ophthalmopathy; Myopia; Keratopathy

• Registration Number: NCT04917562
• Lead Sponsor: Centre Hospitalier Régional Metz-Thionville

Brief Summary

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.

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 Timeline

• Study Start: 2018-01-01
• Primary Completion: 2020-01-01
• Study Completion: 2020-01-01
• Status Verified: 2021-05
• Study First Submitted: 2021-05-21
• Study First Submitted QC: 2021-06-01
• Study First Posted: 2021-06-08
• Last Update Submitted: 2023-04-12
• Last Update Posted: 2023-04-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 38

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 & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Postoperative best spectacle corrected visual acuity (BSCVA) at month 1	Month 1	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)
Postoperative best spectacle corrected visual acuity (BSCVA) at month 3	Month 3	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)
Postoperative uncorrected visual acuity (UCVA) at week 1	Week 1	Postoperative uncorrected visual acuity (UCVA) (logMAR)
Postoperative best spectacle corrected visual acuity (BSCVA) at week 1	Week 1	Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)
Postoperative uncorrected visual acuity (UCVA) at month 1	Month 1	Postoperative uncorrected visual acuity (UCVA) (logMAR)
Postoperative uncorrected visual acuity (UCVA) at month 3	Month 3	Postoperative uncorrected visual acuity (UCVA) (logMAR)

Secondary Outcome Measures

Name	Time	Method
Visual acuity efficacy index	3 months	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.
Predictability	3 months	Predictability was defined as the percentage of eyes having reached target refraction (± 0.5D) at the end of follow-up (3 months).
Postoperative corneal haze measurement at month 1	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
Patient sex	Before surgery	Sex ratio Men/Women (percent)
Preoperative Myopia	Before surgery	Myopia (Diopters)
Postoperative corneal haze measurement at week 1	Week1	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
Visual acuity safety index	3 months	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.
Postoperative corneal haze measurement at month 3	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
postoperative spherical equivalent	3 months	Percent of postoperative spherical equivalent D (SD)
Preoperative Keratometry	Before surgery	Keratometry (dipoters)
Preoperative total ablation thickness	Before surgery	Total ablation thickness (µm)
Postoperative refractive astigmatism at +/- 0.5D of target	3 months	Percent of eyes within +/- 0.5D of target
Postoperative refractive astigmatism at +/- 1.0D of target	3 months	Percent of eyes within +/- 1.0D of target
Complications	Up to 3 months	Percent of postoperative infections or epithelial healing
Patient age	Before surgery	Age (years)
Preoperative Astigmatism	Before surgery	Astigmatism (Diopters)
Preoperative Spherical equivalence	Before surgery	Spherical equivalence (Diopters)
Preoperative best spectacle corrected visual acuity	Before surgery	BSCVA (logMAR)
Preoperative central corneal thickness	Before surgery	central corneal thickness (µm)
Preoperative optical and transition zones	Before surgery	Optical and transition zones (mm)

Trial Locations

Locations (1)

Centre Hospitalier Metz Thionville; 🇫🇷 Metz, France