Effect of ocular demodicosis on the stability of the tear film and the tear break up time

Aleksandra Sędzikowska,Daniel Młocicki,Joanna Moneta-Wielgoś,Grzegorz Tarkowski,Krzysztof Grzyliński,Witold Tarkowski

doi:10.1038/s41598-021-03801-y

Abstract

The aim of the study was to analyze the correlation between the presence of Demodex mites in the hair follicles of patients' eyelashes and the stability and break up time of the tear film assessed with the Non-Invasive Tear Break Up Times (NIBUT) method. 319 patients were included in the study (195 women, 124 men). The patients were divided into two groups: those with Demodex infestation and without visible symptoms of eyelid or eye surface diseases, and asymptomatic non-infested patients. The NIBUT analysis was performed with a 5 M keratograph (oculus). Non-invasive tests were performed to identify the first and mean values of the tear break up time. The first and mean tear break up time in the Demodex-infested group was lower than in the non-infested subjects. The difference was a highly statistically significant. There was a significant correlation with the age of the patients for the first break up time. The first break up time in both eyes decreased with the age of the Demodex-infested and non-infested patients. The NIBUT analyses indicate the impact of Demodex mites on the tear film stability. This may suggest possible association of demodicosis with dry eye syndrome.

Highlights

The aim of the study was to analyze the correlation between the presence of Demodex mites in the hair follicles of patients’ eyelashes and the stability and break up time of the tear film assessed with the Non-Invasive Tear Break Up Times (NIBUT) method. 319 patients were included in the study (195 women, 124 men)
According to TFOS-DEWS II (Dry Eye Workshop)[17], dry-eye syndrome is a multifactorial pathology of tears and the ocular surface with such manifestations as discomfort, visual disturbances, and instability of the tear film increasing the risk of damage to the ocular surface, which is accompanied by hyperosmolarity of the tear film and inflammation on the ocular surface
The present study demonstrated a difference in the tear break up time between the patients with diagnosed demodicosis without visible eye lid or eye surface disorders, and the non-infested subjects

Summary

Introduction

The aim of the study was to analyze the correlation between the presence of Demodex mites in the hair follicles of patients’ eyelashes and the stability and break up time of the tear film assessed with the Non-Invasive Tear Break Up Times (NIBUT) method. 319 patients were included in the study (195 women, 124 men). The NIBUT analyses indicate the impact of Demodex mites on the tear film stability This may suggest possible association of demodicosis with dry eye syndrome. The lipid layer is produced by Meibomian glands located in the tarsal plate of upper and lower eyelids It inhibits evaporation of the underlying aqueous layer, ensures a smooth and regular optical surface of the cornea, produces surface tension of the tear film, preventing tears from flowing along the eyelid margin, and lubricates the eyelids reducing friction during their movement over the ocular s urface[9]. Sidique and B raun[18] examined how well the floating lipid layer can be approximated by a insoluble surfactant monolayer in the context of lubrication theory Their model includes the effects of surface tension, insoluble surfactant monolayer transport, solutal Marangoni effects, evaporation, osmolarity transport, osmosis and wettability of corneal surface. This model predicts that the Marangoni effect coupled with evaporation can determine the location of first breakup; it agrees with other models of breakup that predicts elevated osmolarity when breakup occurs[18]

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