Abstract
Purpose :
To determine the prevalence of demodex mites in a population of patients with dry eye disease. Ophthalmological findings, which are associated with demodex infestation were analysed. The importance of demodex folliculorum and its significance regarding the diagnostic and therapeutic procedures for patients suffering from dry eye were discussed.
Methods :
73 patients with mild to severe dry eye were included in the study. We compared the ophthalmological examination results of the group with demodex infestation (n=32; demodex group) with the group without any signs of demodex (n=41, control group). The results, the Ocular Surface Disease Index (OSDI)-Scores and the meibography findings were analyzed in two separate age groups. Demodex folliculorum was diagnosed after eyelash epilation by optical microscope evaluation. Anamnesis and examination parameters were tested for a statistical correlation with demodex infestation.
Results :
Demodex was found in 43.8% of all patients.The average number of demodex was 0.52 mites per eyelash. Demodex became more frequent with increasing age (p=0.035). Altogether, the lower lid was more often infected. The nineteen male patients were more often infected (52.6%) than the fifty-four female patients (40.7%). The average number of demodex was 0.52 mites per eyelash. The OSDI Score in patients with demodex infestation was 52.7± 23.9 compared to 42.8 ± 25.1 in the control group. 97.3% of sicca patients suffered from a blepharitis posterior, 41.1 % of these had demodex mites. A significant correlation between a demodex infestation and the occurence of a blepharitis posterior (p=0.035) was found. The Schirmer test with anaesthesia for patients with demodex infestation (9.42mm) was significantly lower in comparison to the sicca patients without demodex infestation (12.95mm; p=0.038). 62 Sicca patients had a meibomian gland dysfunction (MGD). 41.9% of those patients were ‘demodex positive’. There was a significant correlation between demodex evidence and both eyelash loss (p=0.048) and occurence of asymmetrical cylinders (p=0.003).
Conclusions :
Demodex folliculorum showed a high prevalence in patients with dry eye disease. Especially patients with meibomian gland dysfunction, posterior blepharitis, increased loss of eyelashes or the occurrence of asymetrical cylinders should be investigated for demodex infestation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.