title: Prevalence and severity of dry eye in candidates for laser in situ keratomileusis for myopia in Russia.
abstract: OBJECTIVE
  To assess the prevalence and severity of dry-eye disease in patients with myopia being evaluated for laser in situ keratomileusis.
  
  
  METHODS
  Nine ophthalmology centers in Russia.
  
  
  METHODS
  Prospective noninterventional cross-sectional study.
  
  
  METHODS
  The assessments included the Schirmer I test, tear breakup time (TBUT), lissamine green and fluorescein staining (Oxford grading scheme), Ocular Surface Disease Index (OSDI) questionnaire, and Dry Eye Workshop (DEWS) dry-eye severity grading.
  
  
  RESULTS
  The study comprised 400 patients with myopia (mean age 29.7 years); 145 (36.2%) wore contact lenses, and 81 (20.2%) used topical dry-eye medication. The mean Schirmer test score was 15.2 mm; 36.5% of patients had evidence of tear-volume deficiency (Schirmer score ≤10 mm). The mean TBUT was 11.7 seconds; 10.1% of patients had tear-film instability (TBUT <5 seconds). Conjunctival (lissamine green) staining intensity was categorized as minimal or greater (grade ≥1) in 62.3% of patients and mild or greater (grade ≥2) in 22.8% of patients. The mean OSDI score was 20.4, indicating mild ocular disability. Dry-eye severity (DEWS grading) was mild/episodic in 66.2%, moderate in 29.5%, and severe in 4.3% of patients. No clear correlation was evident between the Schirmer/TBUT scores and the lissamine green/OSDI scores.
  
  
  CONCLUSIONS
  The prevalence of dry eye in this population was estimated at approximately 10% to 40% (based on clinical signs) and 40% to 55% (based on symptoms); dry-eye severity was predominantly mild/episodic. The proportion of patients requiring dry-eye therapy (based on OSDI and DEWS severity findings) was almost 2 times higher than the proportion receiving treatment.
authors.affiliation: From the Department of Therapeutic Ophthalmology, Svyatoslav N. Fyodorov State Institution Eye Microsurgery Complex, Moscow, Russian Federation. Electronic address: maychuk@mail.ru.
authors.forename: Dmitry Yurevich
authors.initials: DY
authors.lastname: Maychuk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D015995:Prevalence; D011446:Prospective Studies; D012426:Russia / Q000453:epidemiology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires