Meibum Expressibility Improvement as a Therapeutic Target of Intense Pulsed Light Treatment in Meibomian Gland Dysfunction and Its Association with Tear Inflammatory Cytokines

Abstract

Many recent studies have demonstrated the efficacy of intense pulsed light (IPL) for the treatment of meibomian gland dysfunction (MGD); however, its effective treatment targets have not yet been elucidated. This study aimed to investigate the baseline characteristics associated with an improvement in symptoms after IPL treatment; to examine the course of change in inflammatory tear cytokines, meibomian gland function, and tear stability; and to investigate the correlation between cytokines and ocular surface parameters. Thirty participants underwent three sessions of IPL treatment. During each examination, tear film lipid layer interferometry, meibography, tear meniscus height measurement, tear sampling, and slit-lamp examination were performed, and the Ocular Surface Disease Index (OSDI) questionnaire was administered. Meibum quality, meibum expressibility, lid margin abnormality, tear film break-up time (TBUT), ocular surface staining, and the OSDI significantly improved after treatment. Poor meibum expressibility and short TBUT were associated with greater recovery in the OSDI after IPL. Tear levels of IL-4, IL-6, IL-10, IL-17A, and TNF-α decreased after IPL, and IL-6, and TNF-α were correlated with the improvement in meibum expressibility. Therefore, IPL treatment improved meibomian gland function, stabilized the tear film, and decreased ocular surface inflammation. Patients with obstructive MGD and tear instability were more likely to experience an improvement in ocular discomfort after IPL treatment.

Ocular Surface Workup in Patients with Meibomian Gland Dysfunction Treated with Intense Regulated Pulsed Light

“…This combination of treatments allowed for the successful management of refractory cases of MGD, as demonstrated in a recent multicenter prospective study [35]. It was recently demonstrated that the treatment reduces consistently also tear inflammatory cytokines [33,34]. Although different speculative pathophysiological theories have been proposed to explain the positive effects of intense pulsed light upon dry eye signs and symptoms, the mechanisms of actions are still not fully elucidated.…”

“…Treatments currently available are mainly palliative solutions, often insufficient to improve clinical signs and overcome patient's discomfort symptoms. Intense pulsed light was recently introduced in the field of ophthalmology and recent clinical studies showed that it is able to provide an improvement of both signs and symptoms in MGD patients (Table 2) [12][13][14][15][16][23][24][25][26][27][28][29][30][31][32][33][34][35]. IPL can be performed in combination with other therapies, like meibomian gland expression, and thus also represents a promising complementary treatment for MGD.…”

The use of intense pulsed light therapy in the treatment of refractory meibomian gland dysfunction

“…The clinical safety and tolerability of IPL therapy have been confirmed by numerous clinical studies which report no major adverse events following IPL therapy [14,16,[19][20][21][22][23][24][25][26][27][28]. However, minor or transient side effects, including mild pain, light sensitivity, eyelash loss, eyelid erythema, crusting, hyperpigmentation, and blistering have been described [12,[29][30][31].…”

“…In addition, a recent randomized trial showed that a three-month course of IPL therapy inhibited periocular Corneybacterium macginleyi load [14]. Furthermore, the anti-inflammatory action of IPL therapy has also been demonstrated with the reduction of inflammatory markers in tear samples, including IL-4, IL-6, IL-10, IL-17A, TNF-α, and PGE2 [15,16].…”

“…The efficacy of IPL therapy has been reported by a large number of clinical studies. Retrospective and prospective nonrandomized studies have demonstrated that IPL therapy is associated with improvements in dry eye symptomology scores, tear film stability, tear osmolarity, lipid layer thickness, meibomian gland expressibility, meibum quality, eyelid margin vascularity and edema, conjunctival injection, corneal staining, and Schimer test values [12,16,[19][20][21][22][23][24][25][26][27]29,30,[34][35][36][37]. In addition, a recent prospective non-controlled study showed a reduction in tear inflammatory cytokines following IPL therapy [16], while another prospective controlled study reported significant improvement in tear protein and lipid content and composition [21].…”