Intense pulsed light therapy significantly relieves dry eye symptoms and improves tear film metrics in meibomian gland dysfunction through modulation of meibum quality and expressibility

AbstractPurpose : This is a prospective interventional trial to examine the effects and potential underyling mechanisms of IPL treatment in meibomian gland dysfunction-related dry eye disease. Methods : The study was conducted between July 2016 – November 2016 at the Lo Fong Siu Po Eye Centre, Grantham Hospital, Hong Kong SAR. Consecutive subjects with moderate to severe meibomian gland dysfunction and on at least one lubricating eyedrop were recruited. Subjects underwent two courses of intense pulsed light therapy from a Lumenis M22 device (wavelength 590 nm, triple pulsed, energy 11-13 J/cm2) fifteen days apart. Baseline, 1-week and 1-month post-treatment parameters were measured and compared between groups, including: Ocular Surface Disease Index (OSDI) Dry eye Symptom Questionnaire scores, tear meniscus height, non-invasive keratometric tear break-up times (NIKBUT) and ocular redness using the Oculus Keratograph 5M device and meibum expressibility and quality via slit lamp examination (video-recorded). Results : 13 subjects (2 male and 11 female) were enrolled. ). After 1 treatment 3 subjects defaulted follow-up or refused further treatment. Baseline average NIKBUT were 6.12 (± 2.70) secs for right eye and 7.80 (±2.60) secs for left eye. Baseline average OSDI score was 23.3 (±15.1). At 1 month after treatment, average NIKBUT was 8.75 (± 2.67) secs in the right eye and 8.41 (± 2.79) secs in the left eye. Correspondingly, the average OSDI score was 6.7 (± 4.31) at 1 month after treatment. The difference between pre- and post-treatment measurements were statistically significant. Compared to baseline, 90% of subjects had improvement in OSDI score, while 80% of subjects had demonstrated improvement in tear film metrics. This was associated with 100% of patients demonstrating improved meibum quality and expressibility after two courses of treatments. At the end of the study 60% of patients no longer required regular lubricating eyedrops. Adverse events reported during the study included mild pain, blepharospasm, skin erythema and skin dryness. Conclusions : Intense pulsed light therapy is potentially a safe and effective treatment for meibomian gland dysfunction-related dry eye disease. Similar to other eyelid warming methods, the underlying mechanism is through modulation of meibum quality and expressibility