Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03987880 |
Other study ID # |
PiXLMYOP-II |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
January 22, 2018 |
Est. completion date |
October 15, 2020 |
Study information
Verified date |
December 2020 |
Source |
Umeå University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
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.
Description:
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.