Intense Pulsed Light (Eswin) for Meibomian Gland Dysfunction and Evaporative Dry Eye
Intense pulsed light (IPL) began as a dermatological treatment for rosacea and vascular skin lesions, and its migration into dry eye care is one of the better-evidenced stories in device-based ocular surface therapy. At the New Zealand Eye Research Centre (NZERC) IPL is delivered on the Eswin platform as part of the management of meibomian gland dysfunction (MGD) and evaporative dry eye.
How IPL works
IPL delivers pulses of broad-spectrum, non-coherent light (roughly 500–1200 nm) to the periocular skin over the cheeks and lids. Several mechanisms are thought to act together: the light is absorbed by haemoglobin and closes the abnormal telangiectatic blood vessels along the lid margin that carry pro-inflammatory mediators; the absorbed energy warms and liquefies meibum to relieve gland obstruction; it reduces the load of Demodex mites and surface bacteria implicated in lid-margin disease; and there is a proposed photobiomodulation effect on the glands themselves. In practice IPL is delivered as a course — commonly three to four sessions two to four weeks apart — and is frequently paired with meibomian gland expression, which the evidence suggests amplifies the benefit.
What the evidence shows
IPL for MGD is supported by multiple randomised controlled trials and several meta-analyses. A 2025 Bayesian network meta-analysis (Chen et al.) pooling six IPL randomised trials found significant improvements over control, and earlier meta-analyses (Liu et al. 2020; Demolin et al. 2023, pooling a larger body of RCTs) reached consistent conclusions, particularly for tear stability and symptoms when IPL is combined with gland expression.
| Outcome (IPL vs control) | Effect | Significance |
|---|---|---|
| Tear break-up time (TBUT) | +2.08 s (95% CI 0.39–3.71) | p = 0.02 |
| SPEED symptom score | −2.9 (95% CI −5.18 to −0.64) | p = 0.01 |
| OSDI symptom score | Reduced | Not significant in this pooled model |
TFOS DEWS III (2025) includes IPL among the device-based therapies for MGD-related evaporative dry eye. Across the literature, the strongest and most consistent signal is improved tear-film break-up time and symptom scores, with the largest gains generally reported when IPL is combined with meibomian gland expression rather than used alone.
An honest read of the evidence
IPL has more randomised evidence behind it than most dry eye devices, but the trials are heterogeneous — different devices, energy settings, session numbers and, importantly, very different control arms (from no treatment to warm compresses to gland expression), which inflates uncertainty in pooled estimates. The 2025 network meta-analysis is explicit that no head-to-head trial yet compares IPL directly with LipiFlow. IPL is also contraindicated in very dark or very light skin types and around tattoos, so patient selection matters.
Device-based dry eye research at NZERC
IPL's relatively deep randomised evidence base, combined with real between-study heterogeneity, is exactly the situation where a well-run trial site can contribute — standardised protocols, defined controls and careful measurement. The New Zealand Eye Research Centre (NZERC) delivers IPL (Eswin) within a structured, measurement-driven ocular surface service built for clinical research. Research organisations, device manufacturers and sponsors evaluating a New Zealand site for IPL, MGD or evaporative dry eye studies are invited to partner with NZERC. Clinicians and practices are welcome to contact Rose Optometry for support with complex meibomian gland and ocular surface cases.
References
- Chen KY, Chan HC, Chan CM. Which treatment works better for Meibomian Gland Dysfunction: LipiFlow or intense pulsed light? A systematic review and network meta-analysis. Photodiagnosis and Photodynamic Therapy. 2025. PMID 40360035.
- Liu R, Tang H, Dong Y, et al. Intense pulsed light for the treatment of Meibomian gland dysfunction: A systematic review and meta-analysis. Experimental and Therapeutic Medicine. 2020.
- Liu C, Zhou X, Gao M, et al. Efficacy of intense pulsed light and meibomian gland expression treatments in meibomian gland dysfunction: A meta-analysis of randomized controlled trials. Medicine. 2022.
- Demolin L, Es-Safi M, Soyfoo MS, et al. Intense Pulsed Light Therapy in the Treatment of Dry Eye Diseases: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2023.
- Gupta PK, Massaro-Giordano M, Bunya VY. Intense pulsed light treatment for the management of meibomian gland dysfunction. Current Opinion in Ophthalmology. 2024.
- Jones L, Craig JP, Markoulli M, et al. TFOS DEWS III: Management and Therapy. American Journal of Ophthalmology. 2025;279:289-386.
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