Condition category
Eye Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aim:
Keratoconus is an eye disease in which the normally round cornea thins and begins to bulge into a conical shape. This cone shape deflects light as it enters the eye and therefore causes distortion of vision. This study intends to investigate the benefit of educational material to improve the patient’s knowledge of the disease.

Who can participate?
Everyone who was previously diagnosed with keratoconus, who is older than 18 years can participate in the study at the Eye clinic of Cantonal Hospital of Lucerne.

What does the study involve?
The interventional group of patients will watch an educational material and answer control questions about this material before the consultation with the eye doctor. The patients in the interventional as well as the control group will fill out a questionnaire assessing their keratoconus knowledge after the consultation.

Benefits and risks of participating?
There are no risks of participating but the benefit for the participants is a better understanding of the disease, which will help the participant to make decisions on treatment options together with the doctor.

Where is the study run from?
The special corneal clinic at the Eye Clinic of Cantonal Hospital of Lucerne (Switzerland)

When is the study starting and how long is it expected to run for?
October 2019 to December 2020

Who is funding the study?
The Eye Clinic of the Cantonal Hospital of Lucerne (Switzerland)

Who is the main contact?
Philipp Baenninger,

Trial website

Contact information



Primary contact

Dr Philipp Baenninger


Contact details

Augenklinik Luzerner Kantonsspital
+41 412053312

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

The effect of an educational intervention to improve knowledge of patients with keratoconus attending a pre-intervention consultation – a randomized controlled trial


Study hypothesis

Keratoconus is a progressive, ectatic corneal disease in which the normally round cornea thins and begins to bulge into a conical shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina and causes distortion of vision.
This study intends to investigate the benefit of an educational measure prior to a consultation with a physician regarding the knowledge of keratoconus. This will help us to further develop and design the information material for keratoconus patients. By improving the knowledge about keratoconus we hope to indirectly improve the decision making of keratoconus patients.

Ethics approval

Ethics approval pending from the ethics committee of the Cantonal Hospital Lucerne

Study design

Single-centre single-blinded randomized controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet.




Measurements and Randomization:
Potentially eligible patients treated at the corneal clinic of the LUKS will be informed about the existence of the study by the administrative staff of the clinic. If a patient is interested to take part, written informed consent will be sought for study inclusion and usage of clinical data. All participants will be informed that they have the right to withdraw from the study at any time without any disadvantage and without having to provide their reason for this decision. Subjects will not undergo any study specific procedures until they have provided written consent by signing the informed consent form, which will also be signed by the person obtaining the consent.

Participating patients will be randomized at the clinical trial centre (outside the hospital) using the Stata 16.0 randomization routines. Randomization will be made with a 1:1 allocation ratio and using blocks of 2 and 4. The randomization list will be kept at the trial centre (concealed) and caregivers at the consultation will be blinded to the allocation.

Prior to the consultation of the interventional group, standardized oral information about keratoconus will be provided via the multifaceted educational material. The time taken to digest the material and answer the control questions will not exceed 10 min.

Both groups will spend another 5 min to fill out the questionnaire assessing their keratoconus knowledge after the consultation.

The educational material shows different animated scenes giving the same standardized information on keratoconus as the treating ophthalmologist gives in regular face-to-face consultation. The material was developed in collaboration with members of the medical faculty of the University of Zurich and a group of clinical experts at the eye clinic of the LUKS in January 2020. The duration of the multifaceted educational intervention takes about 5 min.

Control intervention:
Patients randomized to the non-interventional group will receive a standard consultation representing best practice.

Intervention type



Drug names

Primary outcome measure

Knowledge on keratoconus as assessed by an assessment form containing six multiple-choice questions designed according to information gathered in the previous minimum keratoconus study. Distribution of baseline parameters will be assessed and parameters deviating 10% or more between groups will be entered as covariates for the efficacy analyses to reduce the risk for confounding. The effects of the intervention on the primary outcome will be estimated using regression modeling. The assessment form will be provided directly after the intervention or control material.

Secondary outcome measures

1. Stage of keratoconus
2. Previous treatments for keratoconus
3. Sex, age and highest level of education

These data will also be collected in the assessment form directly after the intervention or control material.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Previously diagnosed keratoconus on at least one eye
2. Signed written informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Inability to follow the procedures of the study due to i.e. language problems, psychological disorders, dementia etc
2. Aged <18 years
3. Enrolment of the investigator, his/her family members, employees and other dependent persons

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Augenklinik Luzerner Kantonsspital [Cantonal Hospital of Lucerne Eye Clinic]

Sponsor information


Augenklinik Luzerner Kantonsspital [Cantonal Hospital of Lucerne Eye Clinic]

Sponsor details

+41 412052835

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Augenklinik Luzerner Kantonsspital [Cantonal Hospital of Lucerne Eye Clinic]

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal

IPD sharing statement: The data that support the findings of this study are available from the corresponding author, Philipp Baenninger, upon reasonable request.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

13/01/2020: Internal review. 10/01/2020: Trial’s existence confirmed by Cantonal Hospital Lucerne.