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

Centre Hospitalier Régional Metz-Thionville38 enrolled

Overview

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.

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

Conditions

Ophthalmopathy Myopia Keratopathy

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Locations (1)

Centre Hospitalier Metz Thionville

Metz, France

Outcomes

Primary Outcomes

Postoperative uncorrected visual acuity (UCVA) at week 1

Postoperative uncorrected visual acuity (UCVA) (logMAR)

Time frame: Week 1

Postoperative best spectacle corrected visual acuity (BSCVA) at week 1

Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)

Time frame: Week 1

Postoperative uncorrected visual acuity (UCVA) at month 1

Postoperative uncorrected visual acuity (UCVA) (logMAR)

Time frame: Month 1

Postoperative uncorrected visual acuity (UCVA) at month 3

Postoperative uncorrected visual acuity (UCVA) (logMAR)

Time frame: Month 3

Postoperative best spectacle corrected visual acuity (BSCVA) at month 1

Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)

Time frame: Month 1

Postoperative best spectacle corrected visual acuity (BSCVA) at month 3

Postoperative best spectacle corrected visual acuity (BSCVA) (logMAR)

Time frame: Month 3

Secondary Outcomes

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.

Data from ClinicalTrials.gov

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Time frame: 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.

Time frame: 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).

Time frame: 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

Time frame: Week1

Postoperative corneal haze measurement at month 1

Time frame: Month 1

Postoperative corneal haze measurement at month 3

Time frame: Month 3

postoperative spherical equivalent

Percent of postoperative spherical equivalent D (SD)

Time frame: 3 months

Postoperative refractive astigmatism at +/- 0.5D of target

Percent of eyes within +/- 0.5D of target

Time frame: 3 months

Postoperative refractive astigmatism at +/- 1.0D of target

Percent of eyes within +/- 1.0D of target

Time frame: 3 months

Complications

Percent of postoperative infections or epithelial healing

Time frame: Up to 3 months

Patient sex

Sex ratio Men/Women (percent)

Time frame: Before surgery

Patient age

Age (years)

Time frame: Before surgery

Preoperative Myopia

Myopia (Diopters)

Time frame: Before surgery

Preoperative Astigmatism

Astigmatism (Diopters)

Time frame: Before surgery

Preoperative Spherical equivalence

Spherical equivalence (Diopters)

Time frame: Before surgery

Preoperative best spectacle corrected visual acuity

BSCVA (logMAR)

Time frame: Before surgery

Preoperative Keratometry

Keratometry (dipoters)

Time frame: Before surgery

Preoperative central corneal thickness

central corneal thickness (µm)

Time frame: Before surgery

Preoperative optical and transition zones

Optical and transition zones (mm)

Time frame: Before surgery

Preoperative total ablation thickness

Total ablation thickness (µm)

Time frame: Before surgery