An Observational, Multicenter, Parallel-Cohort Study Evaluating the Association of Clinical Manifestations and Patient-Reported Outcomes in Patients with Demodex Blepharitis

Purpose: This study aimed to evaluate the clinical manifestations and patient-reported outcomes related to Demodex blepharitis. Patients and Methods: In this observational, multicenter, cross-sectional, parallel-cohort study conducted at 7 sites in the United States, adult participants were assigned to study cohorts based on collarette grade: Control Cohort (no collarettes), Cohort 1 (1– 10 collarettes), or Cohort 2 (> 10 collarettes). Key outcome measures included collarette grading, lid margin erythema, ocular symptoms (itching, fluctuating vision, irritation, redness, and burning) measured on a visual analog scale (VAS), and the location of ocular itching when present. Results: A total of 147 participants were enrolled and completed the study: 47 in the Control Cohort, 46 in Cohort 1, and 54 in Cohort 2 (a total of 100 participants with ≥ 1 collarette, identified as having Demodex blepharitis). Eighty-five percent of patients with Demodex blepharitis were symptomatic, reporting at least 1 ocular symptom. Mean VAS scores were statistically significantly worse (higher) in participants with Demodex blepharitis for itching (24.5 vs 15.1, p = 0.025), fluctuating vision (24.2 vs 9.8, p = 0.0005), irritation (27.6 vs 17.3, p = 0.021), and redness (19.8 vs 9.9, p = 0.0128) compared to those without Demodex blepharitis. Mean VAS scores for burning were similar between cohorts. The lid margin was the most common location for ocular itching in patients with Demodex blepharitis compared to the corner(s) of the eye in patients without collarettes. Conclusion: This study demonstrated the vast majority (85%) of patients with Demodex blepharitis were symptomatic, reporting at least 1 ocular symptom, and an association between increasing collarette severity in participants with Demodex blepharitis and ocular symptoms (itching, fluctuating vision, irritation, and redness), as well as increased lid margin erythema. Keywords: blepharitis, Demodex , collarettes, patient-reported outcomes, visual analog scale, ocular symptoms, fluctuating vision