Characteristics of Patients with Refractory Meibomian Gland Dysfunction Unresponsive to Intense Pulsed Light Treatment Using a Vascular Filter.

Objectives: To investigate the clinical characteristics of patients with meibomian gland dysfunction (MGD) who are refractory to additional intense pulsed light (IPL) treatment. Materials and Methods: This retrospective study included 66 eyes of 66 patients with moderate-to-severe MGD who had previously undergone four sessions of IPL treatment with a 590 nm filter at another clinic and, received an additional four sessions of IPL treatment with a vascular filter. Patients' subjective assessments before and after the additional IPL treatments were scored on a scale from 0 to 4, where 0 = moderate improvement, 1 = mild improvement, 2 = no change, and 3 = aggravated MGD. Patients who scored 0 or 1 were classified as Group 1 (Responsive group), while those who scored 2 or 3 were classified as Group 2 (Refractory group). Results: Among the 66 eyes from 66 patients, Group 1 comprised 32 eyes and Group 2 comprised 34 eyes. Patients in the refractory group, who did not respond to additional IPL treatment, exhibited poor ocular staining scores before additional IPL treatment. The responsive group showed better treatment responses with regard to the Oxford and Sjögren's International Clinical Collaborative Alliance (SICCA) staining scores (all p < 0.001), upper and lower lid meibum quality and meibum consistency, and meibomian gland grade (all p < 0.001). Changes in the Oxford staining score (p = 0.032), SICCA staining score (p = 0.003), meibum quality (p < 0.001), meibum consistency (p < 0.001), and meibomian gland grade (p < 0.001), before and after the additional treatment, were significantly greater in Group 1 than in Group 2. Conclusions: Additional IPL treatment with a vascular filter may provide further clinical benefits in selected patients with moderate-to-severe MGD who have previously undergone IPL therapy. Poor baseline ocular surface staining was associated with a lower likelihood of treatment response and may help identify patients who are less likely to benefit from additional IPL treatment.