An observational study in Keratoconus, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Recruiting at 1 site in China. Open to participants aged 10 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-12-09.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Observational
The purpose of this observational study was to understand the differences in clinical features and mechanisms of keratoconus between children and adults. The main questions it aimed to answer as follows: (1) to understand the characteristics of keratoconus in Chinese children. (2) to observe corneal stromal cells at the cytological level using in vivo corneal laser confocal microscopy and explore the pathogenesis.
Keratoconus is a progressive and asymmetric corneal dilation disease, in which the cornea presents as a conical protrusion, leading to irregular astigmatism, progressive myopia, corneal thinning, and subsequent visual impairment. If left untreated, acute corneal edema may occur in the late stage, resulting in a sharp decline in vision. This disease is a binocular disease and can occur unilaterally first. The incidence rate of the general population is 1/2000. Most of the diseases described in the literature began in adolescence, and about 90% of the patients were diagnosed at the age of 10. Some literature reported that the youngest patient was 4 years old, and the disease generally remained stable until about 40 years old.
Currently, research on pediatric keratoconus mainly includes the prevalence and morphological characteristics, as well as the progression of corneal collagen cross-linking surgery. The younger onset age of KC is often associated with rapid progression and late stage disease diagnosis. Scholars have observed that 88% of children develop KC after one year of diagnosis, and advocate for early corneal collagen cross-linking treatment for these children's eyes. However, the reasons for the onset and progression of keratoconus in children at a young age are not yet clear.
Due to the young age of onset and unclear reasons for the progression of pediatric keratoconus in clinical practice, as well as insufficient research on pediatric keratoconus in recent years, the clinical characteristics of pediatric keratoconus are still lacking, and the pathogenesis of pediatric keratoconus is still unclear. Therefore, this study aims to compare pediatric keratoconus with adult keratoconus, extract the characteristics of pediatric keratoconus, and use a live corneal laser confocal microscope to observe the stromal cellular structure inside pediatric keratoconus, in order to provide some clinical reference for the pathological understanding of pediatric keratoconus.
313 studies on the registry are indexed under Keratoconus; 56 are open to participants now.
This study's planned enrollment of 160 is above the median of 130 across 97 observational studies indexed under Keratoconus.
Browse Keratoconus studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Consistently enrolled subjects aged between 10 and 50 years old with keratoconus and myopic astigmatism who visited the refractive clinic from April 2023 to April 2024
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
① Patients with keratoconus who visit the refractive clinic.
Clinical non-inflammatory or traumatic corneal thinning and corneal astigmatism.
Aged between 10 and 50 years old, no gender restrictions.
Exclusion Criteria:
① There is a history of contact lens wearing in the last four weeks.
poor fixation and can not cooperate with the examination. ③ History of eye trauma and surgery (including corneal collagen cross-linking surgery).
History of other related eye diseases: corneal disease, glaucoma, retinal choroid disease, etc..
⑤ severe eye diseases affecting imaging such as dry eye, conjunctivitis and pterygium.
⑥ Any systemic disease affecting eye morphology and refractive interstitium.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Other: Observation
Other: Observation
Other: Observation
Other: Observation
Observe the clinical natural changes of eye parameters of the subjects.
Thinnest corneal thickness
Measurement of the thinnest point corneal thickness using the Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
Kmax
Measurement of the maximum keratometry from the anterior corneal surface using the Pentacam Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
ISV
Measurement of the index of surface variance of corneal front surface using the Pentacam Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
IVA
Measurement of the index of vertical asymmetry of the corneal anterior surface using the Pentacam Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
IHA
Measurement of the index of height asymmetry of the corneal anterior surface using the Pentacam Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
IHD
Measurement of the index of height decentration the corneal anterior surface using the Pentacam Three-Dimensional Anterior Segment Analyzer.
Time frame: 1 year
CBI
Measurement of the corvis biomechanical index of cornea using the Corneal Biomechanical Analyzer.
Time frame: 1 year
TBI
Measurement of the tomographical biomechanical index of cornea using the Corneal Biomechanical Analyzer.
Time frame: 1 year
SPA1
Measurement of the stiffness parameter at the first applanation of cornea using the Corneal Biomechanical Analyzer.
Time frame: 1 year
SSI
Measurement of the stress-strain index of cornea using the Corneal Biomechanical Analyzer.
Time frame: 1 year
Corneal stromal cell density
Measurement of the corneal stromal cell density using in vivo corneal confocal microscopy.
Time frame: 1 year
Mutations in collagen related genes
The expressions and mutations in collagen related genes(COL4A3, COL4A4 COL5A1, COL6A2, TGFBI, LOX, MMP9, TIMP1) using the DNA Sequencing Technology.
Time frame: 1 year
Frame best corrected visual acuity
Measurement of best-corrected visual acuity of eye using visual charts.
Time frame: 1 year
Spherical power
Measurement of myopic refraction of eye using subjective refraction methods.
Time frame: 1 year
Cylindrical power
Measurement of astigmatism of eye using subjective refraction methods.
Time frame: 1 year
Axial length
Measurement of axial length of eye using IOL-Master 700.
Time frame: 1 year
Plan to share: Yes — We will share our Study protocol, Statistical analysis plan, Informed consent form, Clinical study report.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: The IPD and supporting information will be permanently available (start date) on December 30, 2025.
Access criteria: Any non-commercial scholars and institutions can apply to access the IPD and supporting information.
Started Apr 2023 (actual). Primary completion is estimated for Apr 2025, 23 months after the start.
Of 33 non-industry observational studies under Keratoconus, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 204. This study's planned 23 months is close to that.
Counting every sponsor, half of 36 studies reached it within 30 months; a quarter within 13 and three quarters within 95.
How these figures are worked out, and which studies are left out of them.
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