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Updated: Apr 12, 2026

In Vivo Confocal Microscopy: A Standard Operating Procedure for the Detection of Demodex Mites at the Eyelid Margin
Published on: July 3, 2025
[Bacterial flora in blepharitis]
I Bezza Benkaouha1, C Le Brun2, P-J Pisella1
1Service d'ophtalmologie, hôpital Bretonneau, 2, boulevard Tonnellé, 37044 Tours cedex 9, France.
Introduction:
Blepharitis has multiple, poorly defined origins. The goal of this study was to investigate the bacterial flora present in patients affected with blepharitis in comparison with healthy subjects, so as to understand the role of bacterial etiologies in blepharitis.
Materials And Methods:
Fifty-four patients with blepharitis and 50 healthy controls participated in this study. Swabs were obtained and analyzed qualitatively and quantitatively for bacteria. A subgroup of 16 people (9 with blepharitis and 7 controls) also were investigated for Demodex.
Results:
The percentages of the positive cultures and the number of colonies/case were clearly higher for patients with blepharitis in comparison with healthy controls. Bacteria were isolated for 81% of cases versus 38% for controls, with a mean of 39 colonies versus 4.4 colonies for controls. Corynebacterium sp. were the most common microorganisms isolated from patients with blepharitis (53.7% for cases versus 18% for controls, P<0.01), and the bacterial load was 15 times higher (37.4 col/case versus 2.6 col/case). C. macginleyi was the most common Corynebacteria (33% versus 6%, P<0.01). S. epidermidis: 35.1% versus 16% (P=0.02) with 11.3 col/case versus 1.6 col/case. S. aureus: 13% versus 0% (P=0.01) with 24.7 col/case versus 0. We did not find a significant difference for Propionibacterium acnes: 14.8% versus 14% with 4.7 col/case versus 5.1 col/case, or for Demodex, with 22.2% versus 28.6%.
Conclusion:
Corynebacterium sp. and especially C. macginleyi seem to participate actively in the physiopathology of blepharitis. S. epidermidis and S. aureus also remain associated with this pathology.
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