Prevalence of Infestation of Eyelashes with Demodex spp. in Patients with Blepharitis and Control Subjects

Purpose: To determine the prevalence of Demodex spp. on the eyelashes of subject controls with normal eyelids and patients with Blepharitis Methods: : In this Cross-sectional Case-control study, 75 patients with Blepharitis and 100 healthy controls were enrolled. One eye of each patient was included in the study. One eyelash from each quadrant of the upper and lower eyelids was pulled out to investigate under light microscope for presence of Demodex spp. Ocular surface signs and symptoms were evaluated.Results: Demodex spp. was found in 29.3% Of cases and 25.7% of control (P=0.612). Demodex infestation was correlated with ocular surface symptoms including discomfort, burning, tearing and blurred vision (P< 0.05). In addition, corneal staining, corneal vascularization and eyelid margin telangiectasia was more frequent in patients with Demodex infestation (P< 0.005).Conclusion: In our study, the prevalence of Demodex infestation of eyelashes was lower than previous reports in other population. However, Demodex infestation was significantly associated with ocular surface signs and symptoms in patients with and without Blepharitis