Abstract
Purpose :
The presence of Demodex species can be associated with DED, but the precise relationship remains unclear. The purpose of this prospective, observational, cross-sectional study was to asses the objective ocular surface abnormalities in patients with DED coexisting with Demodex infestation
Methods :
This study was performed in accordance to the Declaration of Helsinki after approval by the Bioethics Committee. 180 eyes of 90 patients with DED diagnosed according to TFOS guidelines were recruited for the study. The study group (SG) consisted of 76 eyes of 38 patients with DED and coexisting Demodex infestation confirmed on sampled eyelashes. The control group (CG) consisted of 106 eyes of 53 DED patients. The groups were gender and age matched. Analysed ocular surface parameters included NITBUT, TMH, Meibomian gland drop-out, Bulbar redness were assessed by Keratograph 5M (Oculus). Measurements were performed twice in the morning and in the afternoon.
Results :
Distribution of OSDI scores were comparable between groups, as well the results of NITBUT and TMH. Mild DED was the most prevalent among groups (SG: 85,18%; CG: 77,35%). The groups differed significantly in the MG drop out (SG: 0,51±0,23; CG: 0,29±0,12 p<0.001) and conjunctival and limbal redness in the morning (SG: 1,2±0,43; 1,1±0,53 vs CG: 0,8±0,26, 0,7±0,2 p<0,0001; p<0,01 respectively). Parameters which were characterized by significant daily variability were NITBUT (p<0,001), TMH (p<0,0001) in both groups and conjunctival and limbal hypraemia in the study group.
Conclusions :
The infestation of the eyelids with Demodex species is associated with changes of the bulbar redness and anatomic changes of Meibomian gland in patients with DED, which confirm the role of the MGD and infalmmation in the disease pathogenesis. Daily variability in NIBUT, TMH and ocular redness should be taken into consideration in DED studies.
This is a 2021 ARVO Annual Meeting abstract.