Aims/Key Questions: The hypothesis is: Diluted baby shampoo is more disruptive and
deleterious to the human tear film and ocular surface than Blephaclean solution. It is
expected that there will be a clinically meaningful difference (approximately 30%) in the
non-invasive tear-break up time after the application of baby shampoo compared to
Blephaclean.
Potential outcomes: To raise awareness that the safety profile of baby shampoo is
insufficient to make it a professional and ethical recommendation for daily lid hygiene.
Recruitment: All subjects will be recruited from the staff and student population of the
Faculty of Health and Human Sciences, Plymouth University as well as patients of The Centre
for Eyecare Excellence (CEE) and Well-being centre (WBC) at Plymouth University. The
recruitment will be carried out via email, flyers and direct invitation. After the first
contact, the information sheet, as well as the informed contents, will be sent, or a printed
version will be given to all potential subjects.
Design: This prospective study is a two-visit, prospective, cross-sectional, double-blinded
and randomized controlled trial. The basic population is described as a healthy UK population
with diverse ethnic backgrounds and physiological variation. The principal investigator will
carry out the data collection at the Peninsula Allied Health Centre, CEE or WBC (Plymouth
University). Ethical approval was grantet. This study conforms to the ethical principles of
the Declaration of Helsinki, ICH guidelines for Good Clinical Practice (GCP) and Plymouth
University's Principles for Research Involving Human Participants.
Sample size calculations were performed for detecting differences between two dependent
not-normally distributed means. A maximum effect size (NIK-BUT difference after the
application of baby shampoo compared to Blephaclean) of 0.4 is expected with alpha=0.05 and
beta=0.20 (80% power). A sample size of 52 will be required. If considering potential
dropouts, the study will aim to recruit 60 subjects. The effect size was calculated based on
the distribution of the NIK-BUT in healthy eyes (Abdelfattah et al. 2015).
Primary outcome measure: The non-invasive Keratograph (tear film) break-up time (NIK-BUT) is
defined as the primary outcome parameter for the present study. The NIKBUT is defined as the
interval between the last complete blink and the first appearance of a dry spot, or
disruption in the tear film detected automatically by the Keratograph 5M (in seconds).
Randomisation Method: The choice of the eye side, as well as the first cleansing product,
will be randomised to minimise investigator bias. Block-wise randomisation is chosen to
guarantee an equal group size. The block size is calculated with m = 2n (n means a number of
possible groups) per group.
Subject History & Study Eligibility (Fig. 1 - 1 & 2): Before determining study eligibility
for each subject, the information sheet and the informed content will be handed out to the
patient subject again. During recruitment potential subjects will also be given the
information sheet. This will ensure that the participant has had sufficient time to
understand the study and make an informed decision about participating in the study. Eligible
subjects will be allowed to continue. Non-eligible subjects will be dismissed at this time.
Subjects will have procedures performed on both eyes. Testing order was designed to
sequentially administer the least invasive test to the most invasive test. This methodology
will ensure that a previous procedure will have a minimal effect on all subsequent
assessments.
Visual Acuity with height and low contrast: The investigator will measure the subject's
visual acuity (VA) on a calibrated LogMAR chart at 100% contrast and FrACT for low contrast
VA. If the patient is unable to read the 6/12 letters monocular, the investigator will
pinhole over the patient's unaided or presenting refractive error correction to determine the
subject's visual potential. After finishing both eyes separately, the visual acuity will be
examined binocularly with the same procedure.
Questionnaires: Subjects will be asked to complete the OSDI and McMonnies questionnaires.
Tear film & ocular surface assessment: The tear film will be examined with the Oculus
Keratograph 5M from Oculus Optikgeräte GmbH (following K5M). This will include automatic
assessments of the Non-Invasive Keratograph Break-Up time (NIKBUT), the tear meniscus height,
lipid layer assessment, tear flow and bulbar (conjunctival) redness. Additionally, the K5M
will also be used to assess corneal and conjunctiva staining. For assessing bulbar and
palpebral conjunctival staining a sterile Lissamine green strip will be wet with sterile
saline and applied to the superior bulbar conjunctiva.
Lid cleansing procedure: One investigator will prepare the products such that the principal
investigator and the participant are masked. The Principal investigator will apply the
product to the upper and lower lid areas and margins, using standard techniques. One eye will
be treated using Blephaclean the other eye will be treated using baby shampoo, randomised for
visit 1 and visit 2. The Principal investigator needs to apply and gently massage foam from
one bottle onto the periocular skin of the closed superior and inferior eyelids of the
designated eye with clean fingertips for one minute before rinsing with water, and to take
care to avoid the transfer of residual products to the fellow eye during cleansing and
drying. The Principal investigator has to avoid direct contact with the ocular surface, and
to clean their hands prior to using the second treatment for the fellow eye, in order to
prevent cross contamination.