Photorefractive Intrastromal Corneal Crosslinking as a Treatment for Low Grade Myopia

2019-06-21 03:48:32 | BioPortfolio


To assess the improvement in refractive error and the corneal endothelial safety with a customized corneal crosslinking treatment regimen for low grade myopia. The study compares two treatment protocols, a 4.0-mm central ring-shaped zone with a 3.5-mm central ring-shaped zone in high oxygen environment without corneal epithelial debridement.


The study design is a prospective, single-masked intraindividually comparing randomized controlled trial, conducted at the Department of Clinical Sciences / Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study includes healthy men and women with low grade myopia, aged between 18-35 years and involves 27 participants with a myopia of -0.5 to -2.5 diopters (D) and astigmatism of ≤0.75D. All participants are treated with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on), after topical riboflavin. Both eyes are treated and randomized to receive ultraviolet (UV) light according to PiXL 4.0 mm treatment zone in one eye and PiXL 3.5 mm treatment zone in the other, which is masked to the participant. For myopia <0.75D, 10 J/cm^2 is used and for higher levels of myopia 15J/cm^2 is used. Throughout the treatment, humidified oxygen is continuously delivered around the eye using an oxygen mask to achieve an oxygen concentration of ≥95 percentage. All participants are informed about the procedures and provide oral and written consent before inclusion in the study.

At baseline, each eye is examined with slit-lamp microscopy, subjective refraction, determination of uncorrected (UCVA), low contrast visual acuity at 2.5 percentage and 10 percentage contrast and best corrected (BSCVA) visual acuities using the LogMAR fast protocol and intraocular pressure (IOP) using Goldmann applanation tonometry. Under standardized, mesopic light conditions each eye is evaluated by keratometry readings, central corneal thickness and after treatment also the depth of demarcation lines, extracted from Schemipflug camera measurements, Pentacam HR® (Oculus, Inc. Lynnwood, WA). Central corneal endothelial photographs are taken with the Topcon SP-2000P specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands), from which the corneal endothelial cell count is manually calculated from a cluster of 25 cells from each photograph. Total ocular wavefront is measured with iTrace (Tracey Technologies, Inc.).

All the above mentioned examinations are reassessed at 1, 3 and 6 and 12 months after treatment. At 1 day and 1 week after treatment, solely UCVA, Auto refractor measurements, slit-lamp examination and a subjective comparison of discomfort and visual performance in each eye are evaluated.

Study Design




4.0 mm treatment, 3.5 mm treatment


Department of Clinical Sciences/Ophthalmology, Umeå University
901 85


Active, not recruiting


Umeå University

Results (where available)

View Results


Published on BioPortfolio: 2019-06-21T03:48:32-0400

Clinical Trials [1201 Associated Clinical Trials listed on BioPortfolio]

Evaluating NeuroVision's Neural Vision Correction (NVC) Myopia Treatment

The purpose of the present study is to carry out a trial to evaluate the clinical efficacy of the NeuroVision Low Myopia Treatment. The specific questions to be answered are: 1. ...

Safety and Efficacy Study of 0.5%, 0.1% & 0.01% Atropine Treatment to Both Eyes In Treatment of Myopia In Children

The purpose of this study is to find an optimal dose of atropine for preventing the rapid progression of myopia in children by comparing the efficacy, safety and functional impact of binoc...

Study of the MEL 80 Excimer Laser Using LASIK in the Treatment of Moderate to High Myopia

The purpose of this study is to determine whether the MEL 80 Excimer Laser is effective in the treatment of moderate to high myopia (nearsightedness), when used as part of the Laser In Sit...

Low-Dose Atropine for Treatment of Myopia

Study Objectives The objectives for this randomized trial are: 1. To determine the efficacy of daily low-dose atropine (0.01%) for slowing myopia progression over a two-year...

Effect of Using Myopia Prediction Algorithm on Myopia School-aged Children

In this study, the investigators aim to perform a prospective, randomized controlled study to compare the myopia development between myopia children using myopia prediction algorithm and m...

PubMed Articles [29180 Associated PubMed Articles listed on BioPortfolio]

A prospective evaluation of photorefractive intrastromal cross-linking for the treatment of low-grade myopia.

To evaluate photorefractive intrastromal cross-linking (PiXL) treatment for low-grade myopia, comparing three treatment protocols.

Multifocal spectacles in childhood myopia: Are treatment effects maintained? A systematic review and meta-analysis.

We evaluate the impact of duration on the treatment effect of multifocal spectacle lenses used to inhibit myopia progression in children. A systematic literature search identified randomized controlle...

Myopia Control: Why Each Diopter Matters.

Reducing the incidence or prevalence of any disease by 40% is of huge public health significance. Slowing myopia by 1 diopter may do just that for myopic maculopathy-the most common and serious sight-...

Effects of scleral collagen crosslinking with different carbohydrate on chemical bond and ultrastructure of rabbit sclera: Future treatment for myopia progression.

Myopia is the most common ocular disorder and is mainly caused by axial elongation of the sclera. If the stiffness of sclera increased, it can inhibit myopia progression. The aim of this study is to c...

PM2.5 and NOx exposure promote myopia: clinical evidence and experimental proof.

Myopia is caused by complex genetic and environmental factors. However, information regarding the effect of long-term exposure to air pollutants on the risk of development of myopia is lacking. We col...

Medical and Biotech [MESH] Definitions

Procedures, surgery, or other treatment without consent of person or persons receiving treatment.

Withholding or withdrawal of a particular treatment or treatments, often (but not necessarily) life-prolonging treatment, from a patient or from a research subject as part of a research protocol. The concept is differentiated from REFUSAL TO TREAT, where the emphasis is on the health professional's or health facility's refusal to treat a patient or group of patients when the patient or the patient's representative requests treatment. Withholding of life-prolonging treatment is usually indexed only with EUTHANASIA, PASSIVE, unless the distinction between withholding and withdrawing treatment, or the issue of withholding palliative rather than curative treatment, is discussed.

A vasodilator that also has bronchodilatory action. It has been employed in the treatment of angina pectoris, in the treatment of asthma, and in conjunction with ultraviolet light A, has been tried in the treatment of vitiligo. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1024)

A treatment method in which patients are under direct observation when they take their medication or receive their treatment. This method is designed to reduce the risk of treatment interruption and to ensure patient compliance.

Excessive axial myopia associated with complications (especially posterior staphyloma and CHOROIDAL NEOVASCULARIZATION) that can lead to BLINDNESS.

More From BioPortfolio on "Photorefractive Intrastromal Corneal Crosslinking as a Treatment for Low Grade Myopia"

Quick Search

Relevant Topics

Women's Health
Women's Health - key topics include breast cancer, pregnancy, menopause, stroke Follow and track Women's Health News on BioPortfolio: Women's Health News RSS Women'...

Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...

Searches Linking to this Trial