"Stepwise Extension Treatment (SET) Protocol" Versus "Pro Re Nata Regimen" of Intense Pulsed Light for Meibomian Gland Dysfunction.

Purpose: To compare the efficacy of a Stepwise Extension Treatment (SET) protocol and a Pro Re Nata (PRN) regimen of intense pulsed light (IPL) therapy with warm compresses for meibomian gland dysfunction (MGD).

Design: A prospective, comparative study PARTICIPANTS: Participants with meibomian gland expressibility (MGE) or meibum quality (MQ) grade 2 or higher.

Methods: All participants initially received four IPL sessions at 4-week intervals. In the SET group, intervals were extended or shortened by 2 weeks based on clinical response. In the PRN group, retreatment was performed only when predefined criteria were met. Retreatment was indicated if the Ocular Surface Disease Index (OSDI) was ≥ 23 or increased from the prior visit, along with MGE or MQ ≥ 2. A linear mixed model was used for analysis.

Main outcome measures: The primary outcome measures were the longitudinal changes in the Ocular Surface Disease Index (OSDI), meibomian gland expressibility (MGE), and meibum quality (MQ). The total number of IPL sessions administered from baseline to 24 months was assessed as a secondary outcome.

Results: Among 412 participants, 308 (74.8 %) completed the study. Mean changes in OSDI, MGE, and MQ from baseline to 24 months were -16.0, -0.8, and -0.9 in the SET group and -15.3, -0.7, and -0.8 in the PRN group, respectively (all P > 0.05). In patients with baseline MGE or MQ grade ≤ 2, both protocols effectively reduced scores to below 1.5. In patients with MGE grade 3, the SET group demonstrated greater improvement (P < 0.01), and episodic exacerbations were observed in the PRN group. The mean number of IPL sessions over 24 months was 14.8 ± 4.2 [median 13.0] in the SET group and 10.0 ± 6.4 [median 8.0] in the PRN group (P < 0.01).

Conclusions: Both SET and PRN regimens led to symptomatic and functional improvement in MGD. Patients with mild-to-moderate MGD responded well to either regimen. In severe MGD, the SET protocol may provide more stable long-term control, suggesting the importance of individualized treatment approaches.