Response of tear cytokines following intense pulsed light combined with meibomian gland expression for treating meibomian gland dysfunction-related dry eye

Abstract

PurposeThis study compared the changes in tear inflammatory cytokine levels after intense pulsed light (IPL) combined with meibomian gland expression (MGX) (IPL group) and instant warm compresses combined with MGX (physiotherapy group) as treatments for meibomian gland dysfunction (MGD)-related dry eye disease (DED) to explore their similarities and differences in therapeutic mechanisms.MethodsThis study was a post-hoc analysis of a randomized controlled trial. Thirteen patients with MGD-related DED were enrolled in each group and received three treatments correspondingly with 3-week intervals. The levels of 20 tear cytokines, namely, TNF-α, IL-6, MMP-9, CXCL8/IL-8, CXCL10/IP-10, IL-10, EGF, IL-6R, IL-1β, IFN-γ, lactoferrin, Fas ligand, IL-17A, LT-α, S100A9, LCN2/NGAL, IL-13, IL-12/IL-23p40, Fas, and CCL11/Eotaxin, were measured at baseline, before the second and third treatments, and 3 weeks after the third treatment. The primary outcome was the difference in cytokine levels between baseline and the last measurement, and the trends were analyzed at each measurement point.ResultsAt the last measurement, a significant decrease was observed in all tear cytokines for both IPL and physiotherapy groups compared with baseline. The IPL group showed greater reductions in IL-6, IL-6R, IL-1β, IL-13, and CCL11/Eotaxin than the physiotherapy group. TNF-α, CXCL8/IL-8, CXCL10/IP-10, IL-10, EGF, IL-1β, IFN-γ, and Lipocalin-2/NGAL levels continued to decrease with treatment time. Important interactions were found in the changes of IL-6 and IL-13 levels, where the levels first decreased and then slightly increased in the physiotherapy group after treatment, while they continued to decrease in the IPL group.ConclusionsThe mechanisms of IPL and physiotherapy in treating MGD-related DED were both associated with reducing inflammation, and the superiority of IPL could be attributed to its better inhibitory effect on inflammatory cytokines like IL-6. In addition, several cytokines were on a downward trend during treatment, suggesting that the vicious cycle of DED was suppressed.

Efficacy of recombinant human epidermal growth factor plus sodium hyaluronate eye drops in diabetic dry eye post-cataract surgery

“…Inflammatory cell infiltration and the release of inflammatory markers in DES activate cell signal transduction pathways, regulate the expression of related genes or proteins, and affect the growth cycle of conjunctival cells, resulting in morphological and functional changes[ 18 ]. TNF-α and IL-6 are inflammatory makers and cytokines that regulate inflammatory responses by downregulating neurotransmitter release and controlling tear secretion, leading to DES[ 19 ]. Our study revealed that rhEGF + SH eye drops were effective in lowering the content of TNF-α and IL-6 in tears, indicating that the administration of this treatment combination following cataract surgery effectively relieves inflammation and delays disease progression.…”

Efficacy and safety of intense pulsed light of upper and lower eyelids in Meibomian gland dysfunction: A prospective multicentric study

“…Also, IPL can have an antibacterial effect and reduce the bacterial load on the eyelid margin. 12,[20][21][22] Adverse effects of IPL have been reported in some studies, most resolving spontaneously within one week. Adverse events in Toyos et al's series of 91 patients included blistering, cheek swelling, conjunctival cyst, floaters, hair loss at brow and forehead, light sensitivity, and redness of the face.…”

“…Also, IPL can have an antibacterial effect and reduce the bacterial load on the eyelid margin. 12,20–22…”

Dry eye disease management

“…Intense pulsed light (IPL) therapy is a non-invasive treatment for dry eye disease secondary to meibomian gland dysfunction, rosacea, or blepharitis caused by Demodex infection 51525354. High intensity light pulses to the skin surface induce obliteration of abnormal blood vessels and alter meibomian gland architecture and composition, reducing inflammation and eradicating Demodex mites 53555657. Several small case series have reported meibomian gland anatomical and functional changes following IPL treatment, the mechanism of which is currently unknown 5556…”