Clinical characteristics and topographic findings of corneal ectasia in patients with symptomatic Demodex blepharitis

PURPOSE: The purpose of this study is to present characteristics and topographic findings of patients with corneal ectasia and symptomatic ocular demodicosis. MATERIALS AND METHODS: A retrospective, noncomparative study. Twenty-one patients with symptomatic ocular demodicosis and corneal ectasia since 2017 to 2019 were enrolled. Patients with dry eye syndrome and meibomian gland dysfunction were identified and treated. Demographic data, topography, and clinical data were collected. All patients underwent lash sampling to confirm Demodex mite infestation by direct visualization under the microscope. RESULTS: Twenty-one ectasia patients (36 eyes) were enrolled with male preponderance (M:F =18:3). Mean age (years) was 28.6 ± 8.12. Of the 21 cases reviewed, the average number of topography taken was 6.8 within 43.8 months of follow-up. Corneal ectasia was characterized by focal thinning area beside central cornea, with corresponding mean thickness of 487.1 μm and 518 μm, respectively. All ectasia patients were combined with Demodex blepharitis and associated symptoms, proven by direct microscopic examination. After treatment with eyelid cleanser (OCuSOFT® Lid Scrub® PLUS), warm compress, and improved daily hygiene, ocular demodicosis and topographic changes were controlled and even reversed. CONCLUSION: Our results indicated that ocular demodicosis may be potentially associated with corneal ectasia. Demodex blepharitis still remains an overlooked differential diagnosis in clinic; however, it may be one of the risk factors triggering eye rubbing. Comorbidity of lid infestation with eye rubbing may lead to corneal ectasia, even in elder patients with thick cornea. Therefore, meticulous examination and intensive treatment were highly recommended in this group of patients.