Condition category
Eye Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Some people find wearing contact lenses can be uncomfortable, especially at the end of the day. At present, we do not know whether changes to the eye or to the contact lens are the most important factors in governing this discomfort. This project aims to improve our understanding in this area by assessing the effect of lens replacement and lens manipulation on the comfort of contact lenses.

Who can participate?
Adults who currently use daily disposable soft contact lenses and have used them for at least six months and have symptoms of discomfort at the end of the day

What does the study involve?
Volunteers will attend a clinic for six visits over four days. They will wear their habitual contact lenses during the course of the study. On day 1, volunteers will attend the clinic for an initial visit in which the investigator will confirm that they match the inclusion and exclusion criteria and will do an examination of the front surface of the eye. On days 2 and 3, volunteers will attend the clinic in the morning and 5 hours later. The investigator will randomly assign an intervention to each eye. In the morning, comfort scores will be collected before and after lens application. Volunteers will then leave the clinic and will be asked to wear their contact lenses in the normal way for at least 12 hours during which time they will provide comfort scores via SMS. Volunteers will return to the clinic 5 hours after lens application and the investigator will either replace the lens or manipulated the lens on-eye. The contact lens will not be manipulated in any way in the control group. Comfort scores will be collected at this time. Volunteers will then be asked to continue wearing their lenses and to provide comfort scores via SMS until they remove their lenses. On day 4, volunteers will attend the clinic for an exit visit in which they will receive an examination of the front surface of the eye and will then leave the study.

What are the possible benefits and risks of participating?
Benefits may include a thorough anterior eye examination and advice on contact lenses. All lens care products have the potential of causing serious injury to the eye. Due to the nature and duration of the study, the risks are judged to be similar to those of normal contact lens wear since subjects. It is possible that the following may occur with the use of contact lens products: pain, abrasion of the eyes, sensations of itching, burning or stinging, excessive tear production, unusual secretions, redness, reduced sharpness of vision, blurred vision, sensitivity to light or dry eyes. In rare instances, corneal ulcers, scarring, the growth of blood vessels into the cornea, temporary or permanent decreased vision, iritis and infections of the eye requiring treatment might occur. Major side effects from the use of diagnostic dye sodium fluorescein are very rare, but there are three reports of anaphylaxis following topical instillation of fluorescein. Anaphylaxis can result in death but none of the reported cases to date has been fatal. Other rare side effects from the topical use of sodium fluorescein can include slight stinging on instillation and temporary blurred vision.

Where is the study run from?
Eurolens Research at the University of Manchester (UK)

When is the study starting and how long is it expected to run for?
From February 2013 to March 2014

Who is funding the study?
Investigator initiated and funded

Who is the main contact?
Miss Maria Navascues-Cornago

Trial website

Contact information



Primary contact

Miss Maria Navascues-Cornago


Contact details

Eurolens Research
Carys Bannister Building
University of Manchester
Dover Street
M13 9PL
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effect of three interventions on contact lens comfort in symptomatic wearers: a randomised single-blind study


Study hypothesis

To investigate the effect of replacing the lens with the same or with a new lens and performing a scleral swish part way through the day on comfort in symptomatic daily disposable soft contact lens wearers.

Ethics approval

University of Manchester Committee on the Ethics of Research on Human Beings, 07/06/2013, ref: 13009

Study design

Interventional randomised controlled single-blind single-centre trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet


Contact lens comfort


Subjects will attend the clinic on two study days. On each day, subjects attended the clinic in the morning without any lenses in situ (and not having worn lenses beforehand on the day). A new pair of their habitual daily disposable lenses was applied directly from the packaging solution and worn for at least 12 hours. Comfort scores were recorded before lens application and 6 minutes post-application using the 0 to 100 grading scale. Automated short message service (SMS) text messages via mobile phone were sent to subjects every hour following lens application requesting a comfort score using the same scale. Five hours after lens application, the investigator performed one of three interventions on each eye together with a control:
1. Replacement of the existing lens with a new lens: the existing lens will be removed and a new, fresh contact lens will be re-applied directly from the packaging solution
2. Removal of the existing lens and re-application of the same lens: the existing lens will be removed and placed in a lens case containing 0.9% sterile saline (Eye Care solutions, Crest Medical Ltd, Warrington, UK) and then re-applied
3. A scleral swish: the contact lens will be slid off the cornea onto the temporal conjunctiva; subjects will then be asked to fully blink five times, and then the lens will be slid back onto the cornea
4. No action (control): the contact lens will not be manipulated in any way

The interventions will be randomly assigned to each eye (i.e., each eye will receive a different intervention) and subjects will be masked to whether the re-applied lens is a new lens or the same lens. The investigator will generate the randomisation scheme using the web site (, which creates random permutations of interventions for a situation where subjects are to receive all of the interventions in random order.

Intervention type



Drug names

Primary outcome measure

1. Contact lens comfort score will be measured with an annotated vertical analogue comfort scale of 0 (causes pain, cannot be tolerated) and 100 (excellent, cannot be felt) and recorded on paper before lens application, 5 hours post-application, and 6 minutes post-intervention
2. Comfort scores at 6 minutes post-application and at every hour following lens application will be collected through SMS messaging using the same scale; only SMS comfort scores received within 30 minutes from the target time will be included in the analysis

Secondary outcome measures


Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. At least 18 years old and capacity to volunteer
2. Understand rights as a research subject
3. Willing and able to 
sign a statement of informed consent
4. Willing and able to follow the protocol
5. Agree not to participate in other clinical research for the duration of this study
6. Wear daily disposable soft contact lenses and have worn them for at least 6 months
7. Symptomatic according to method by Young et al (Characterizing contact lens-related dryness symptoms in a cross-section of UK soft lens wearers. Contact Lens and Anterior Eye 2011; 34: 64–70)
8. Willing to wear contact lenses for at least 12 hours a day
9. Having a mobile phone

Participant type

Healthy volunteer

Age group




Target number of participants


Participant exclusion criteria

1. Systemic or ocular disorder that might affect ocular health
2. Grade 2 or greater of any anterior ocular clinical signs
3. Use of any topical medication, such as eye drops or ointment
4. Previous cataract or corneal refractive surgery
5. Corneal distortion resulting from previous hard or rigid lens wear or keratoconus
6. Pregnant or lactating
7. Diabetes
8. Infectious disease (e.g., hepatitis)
9. Immunosuppressive disease (e.g., HIV)
10. History of severe allergic reaction or anaphylaxis (a serious form of hypersensitivity that can, in rare cases, result in death)
11. Unacceptable lens fit (grade –2 or +2 on a –2 to +2 grading scale)
12. Participation in other clinical trial or research within 2 weeks before starting this study

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Eurolens Research, University of Manchester
M13 9PL
United Kingdom

Sponsor information


University of Manchester

Sponsor details

Oxford Road
M13 9PL
United Kingdom

Sponsor type




Funder type

Not defined

Funder name

Investigator initiated and funded

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The results of this study are intended to be published in a scientific journal in the near future (to be confirmed at a later date)

Intention to publish date

Participant level data

Not expected to be available

Basic results (scientific)

Publication list

2015 results in:

Publication citations

Additional files

Editorial Notes