title: [Measurement of the index of infection by Demodex spp in patients with chronic blepharitis and in patients without other ocular diseases].
abstract: BACKGROUND
  Infestation by Demodex spp. in the palpebral edge follicles in humans is common. However, these mites are not routinely diagnosed in patients with or without ocular pathologies in Chile and their relevance is unclear. One of the eye diseases most related to infestation by Demodex spp. is blepharitis, a chronic inflammation of the eyelid margin with intermittent exacerbations, which is very common in ophthalmic practice. Its management is prolonged treatment, which is often ineffective, leading to relapses and frustration of patient and treating physician. Blepharitis can be typed by its etiology into various types, one of them is caused by Demodex folliculorum and another species, D. brevis.
  
  
  OBJECTIVE
  The overall objective was to detect the presence and estimate the rate of infestation of Demodex spp. in healthy subjects and in patients with ocular pathology such as blepharitis, bacterial conjunctivitis, chalazion, and stye.
  
  
  METHODS
  Samples of tabs from both lower eyelids of ophthalmologically healthy patients (23) and patients with ocular pathologies (9) were mounted in immersion oil as described in literature, then visualized with a 10x objective and confirmed with 40x objective.
  
  
  RESULTS
  Detection rates of eggs, nymphs or adults of Demodex spp. in patients with and without ophthalmological problems were above and below 0.5 mites per tab, respectively. D.folliculorum was the species most frequently found.
  
  
  CONCLUSIONS
  The results are consistent with the international literature on both the rate of infestation as the predominant species.
  
  
  CONCLUSIONS
  This paper is the first study in Chile on this subject and represents a significant contribution to ophthalmic clinical diagnosis and treatment of patients with this disease.
authors.affiliation: Universidad de Concepción, Concepción, Chile, nrivera@udec.cl.
authors.forename: Nancy
authors.initials: N
authors.lastname: Rivera
authors.forename: Priscila
authors.initials: P
authors.lastname: Molina
authors.forename: Andrea
authors.initials: A
authors.lastname: Torres
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D001762:Blepharitis / Q000150:complications / Q000469:parasitology*; D016022:Case-Control Studies; D017043:Chalazion / Q000150:complications / Q000469:parasitology*; D002648:Child; D002908:Chronic Disease; D003234:Conjunctivitis, Bacterial / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D006726:Hordeolum / Q000150:complications / Q000469:parasitology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008924:Mite Infestations / Q000150:complications / Q000469:parasitology*; D012720:Severity of Illness Index; D055815:Young Adult