Participants, procedures, and parameters
dry eye disease, lens wear, epilepsy, bulbar redness, Johnson & Johnson Vision, glaucoma, photosensitive epileptic seizures
SYSTEMIC DISEASE, DRY EYE, EPILEPSY, EAR CONDITION, FLASHING LIGHT, EYE, DRY EYE, GLAUCOMA, EAR CONDITIONS, DISEASES
Dry eye patients were consecutively recruited from the Dry Eye Clinic of University Eye Hospital Düsseldorf, Germany. Healthy study participants were recruited through public notices on the campus of the Heinrich-Heine University Düsseldorf, Germany. The general inclusion criteria were a minimum age of 18 years and informed consent, while exclusion criteria were a history of epilepsy, contact lens wear within 30 min before measurements, or ocular surgery within the last 4 weeks. The reason to define epilepsy as an exclusion criterion was that the flashing light of the LipiView® diagnostic device (TearScience Inc., Morrisville, NC, USA) was considered a possible trigger for photosensitive epileptic seizures. For the healthy group, inclusion criteria included a McMonnies questionnaire score of ≤ 14.5, with exclusion criteria of an established diagnosis of DED, systemic or ocular diseases directly relate to DED, use of any regularly applied eyedrops (e.g., treatment of glaucoma) or any other eyedrops with 2 h before the examination. The McMonnies dry eye questionnaire is a self-administered screening tool for dry eye disease which has been validated for use in the general population with good sensitivity and specificity [After informed consent had been given in the written form, participants completed the McMonnies questionnaire, the OSDI questionnaire, and a medical history questionnaire, whereupon fulfillment of inclusion or exclusion criteria was checked. The medical history form recorded gender, age, preexisting ocular and systemic diseases, previous eye surgery, and use of spectacles. Spectacle wearers were instructed to continue to wear these throughout the entire data collection period.Upon inclusion, the order of mask wear conditions (FFP2-mask/surgical mask/no mask) was randomized using sealed envelopes.Surgical masks (Paul Hartmann AG, Heidenheim, Germany) consisted of a three-layer nonwoven fabric and a micro-germ filter complying with category II of the EU Regulation 2016/425 [Examinations were performed after 30 min of each mask wear condition as specified by the prespecified random order. Patients were asked to sit alone in a separate room during the mask-wearing period (Table Possible mask wear and measurement sequencesRandomassignmentThe following examinations were performed in a darkened room following the same protocol and sequence after 30 min in the morning between 8 and 12 AM. The right eye was always examined first; all examinations were done once per cycle. The lipid layer thickness was measured by interferometry (LipiView®, Johnson & Johnson Vision, Santa Ana, CA, USA) followed by an examination of non-invasive tear film break-up time (first breakup) (NIBUT), tear meniscus height, and bulbar redness using the Oculus Keratograph 5 M (Oculus Optikgeräte GmbH, Wetzlar, Germany).All procedures performed met the ethical standards of the institutional research commission of the Heinrich-Heine University of Düsseldorf as well as the Helsinki Declaration of 1964 and its later amendments. The trial was registered with the DRKS (German Clinical Trials Register) (trial number: DRKS00024427) and approved by the Ethics Committee of the Heinrich-Heine University Düsseldorf on March 1st, 2021 (trial number: 2020–1219).