New research out of China—and published in Photobiomodulation, Photomedicine, and Laser Surgery—assessed the efficacy of intense pulsed light (IPL) therapy combined with a heated eye mask (HEM) for treating the signs and symptoms of evaporative dry eye disease (DED).
Let’s start with some background.
Prior study findings have identified the independent use of IPL and HEM for improving both the tear film lipid layer (TFLL)—which has antimicrobial characteristics that keep the lipid margin and ocular surface healthy—and DED symptoms.A key component of evaporative DED is meibomian gland dysfunction (MGD). In fact, it’s been noted as being, by far, the most prevalent cause of the disease, according to research.
And how are these connected to this new study?
Previous studies have noted the advantages of using local heating on the eyelid margin to treat MGD (and, as a result, evaporative DED).
Similarly, IPL is known for its benefits as a treatment for “a broad severity spectrum of DED,” including evaporation.However, the combined use of these two therapies has yet to be explored.
Now this study.
Conducted at the Dry Eye Clinic, Department of Ophthalmology, He Eye Specialist Hospital in Shenyang, China, the randomized study enrolled 150 patients (ages 18+; mean age of 33) diagnosed with DED based on the following criteria:
- Dry eye symptoms
- Either qualitative or quantitative tear film disturbance
- Determined via Schirmer’s test [5 mm] or tear break-up time (TBUT) [5 sec]
- Conjunctivocorneal epithelial damage
- Based on:
- Fluorescein staining score (> 3 points)
- Rose bengal staining score (>3 points)
- Lissamine green staining score (>3 points)
- Based on:
How were they divided?
Patients were randomized 1:1:1 into three groups:
- Group 1: combined IPL and HEM
- Group 2: IPL only
- Group 3: Untreated evaporative DED (control)
What was evaluated?
Evaluations were conducted at baseline, Day 21, Day 42, and Day 84, for the following:
- Noninvasive TBUT
- TFLL
- Corneal conjunctival staining (CCS)
- Meibomian gland quality (MGQ)
- Meibomian gland expressibility (MGE)
- Ocular Surface Disease Index (OSDI) Score
Talk about the treatment.
Group 1 participants underwent IPL treatment on both eyes (12 pulses each) at baseline and on Days 21 and 42; HEM was used for 20 minutes for the study duration (84 days).
Group 2 participants underwent IPL treatment only on both eyes (12 pulses each) at baseline, on Day 21, and Day 42.
Group 3 participants did not receive either IPL or a combination of both for the duration of the study; however, data was still collected at baseline, Day 21, Day 42, and Day 84.
What else?
All participants were asked to not use other dry eye medications / eye drops (including preservative-free artificial tears) during the study period.
Any limitations?
Per the authors: yes. They listed the following:
- No inclusion of inflammatory indicators or parameters
- No generalization due to age range (only 22 to 40 years old)
Now the results.
Overall, IPL with or without HEM was found to improve the signs and symptoms of evaporative DED. However, according to the study authors, “IPL combined with HEM had greater therapeutic efficacy in improving the TFLL in patients with [evaporative DED].”
Talk numbers.
A significant improvement for noninvasive TBUT in Group 1 (IPL+HEM) was noted— the greatest out of all groups—from 4.22 + 0.71 sec at baseline to 9.00 + 0.93 sec at Day 84 (p < 0.001).
Groups 2 and 3 experienced a gradual improvement and significant deterioration, respectively.
What about the TFLL score?
At baseline, the TFLL score was:
- Group 1 → 3.16 + 0.68 (p = 0.488)
- Group 2 → 3.24 + 0.43 (p = 0.488)
- Group 3 → 3.10 + 0.61 (p = 0.488)
By Day 84, no significant changes were noted for Group 3 (control; p = 0.456), while both Group 1 and 2 (IPL alone) significantly improved:
Group 1 → 1.14 + 0.35 (p < 0.001)
Group 2 → 2.22 + 0.42 (p < 0.001)
Changes in TFLL (baseline - Day 84) included:
- Group 1 → 2.02
- Group 2 → 1.02
- Group 3 → –0.58
Meaning…
By Day 84 for Groups 1 and 2, significant changes with a significant correlation were noted for all study parameters; comparatively, Group 3 did not experience any significant improvements.
According to the study authors, these findings are supported, “by the fact that the TFLL not only supports the tear film homeostasis, but reports suggest that meibum possesses antibacterial properties,” which maintain lid margin health.
Expert input?
While the authors recommend further research with a larger sample size and a randomized study, they concluded that the findings indicated the use of IPL with and without HEM improved evaporative DED signs and symptoms. However, they further stated that, “IPL combined with HEM had greater therapeutic efficacy in improving the TFLL.”