The aim of the study was to analyze the prevalence of ocular demodicosis and ocular surface conditions in patients selected for cataract surgery. Eyelashes from 73 patients selected for cataract surgery were evaluated at × 40 and × 100 magnification using light microscopy. The anterior segment was assessed with the slit lamp. Additionally, Schirmer I and break up time (BUT) tests were carried out before surgery and 1 and 3 months postoperatively. A specially designed questionnaire containing e.g. information about chronic skin and eye diseases, previous ophthalmic surgeries, and patient's hygiene habits was used to assess the demographic variables. A majority of patients were at the age of 70-79 years, and there were more females (83%) in the study group. Demodex folliculorum was found in 48% of the patients. There was a correlation between the number of parasites and the presence of blepharitis, discharge at eyelid margins, and conjunctival hyperemia. Schirmer I and BUT test results were lower in patients with Demodex infestation before and after cataract surgery. The higher number of mites was correlated with lower Schirmer I test results postoperatively. The presence of Demodex mites influences the conjunctiva and lid margins leading to inflammation. The higher number of Demodex mites disturbs the tear film over time after cataract surgery.
Keywords: Demodex folliculorum; Schirmer I test; blepharitis; break up time test; cataract surgery; ocular demodicosis; tear film.