title: Effect of Sleep Position on the Ocular Surface.
abstract: OBJECTIVE
  Dry eye disease is a multifactorial disease with numerous well-documented risk factors. However, to date, sleep position has not been associated with this condition. After observing patients in our practice, we believe that the sleep position in some cases may significantly affect dry eye and meibomian gland dysfunction (MGD).
  
  
  METHODS
  This is a single-centered, cross-sectional, noninterventional, institutional review board-approved, single-masked, nonrandomized study of 100 patients whose complaints were related to dry eye disease and a control group of 25 age-matched asymptomatic patients. Two questionnaires were used: one to analyze patients' sleep habits and the other to assess patients' Ocular Surface Disease Index. Dry eye severity was graded based on the MGD stage, fluorescein corneal staining and lissamine green staining, Schirmer 1 testing, tear osmolarity levels, and clinical examination.
  
  
  RESULTS
  A statistically significant difference was shown with back sleeping compared with left side sleeping using lissamine green staining (analysis of variance, P = 0.005). The Ocular Surface Disease Index score was also found to be elevated in patients who slept on their right or left side (36.4 and 34.1, respectively) as opposed to back sleepers (26.7) with P < 0.05. There was no statistically significant correlation found between the sleep position and degree of MGD.
  
  
  CONCLUSIONS
  In addition to current treatment, patients who sleep on their side or face down might see a reduction in dry eye and MGD if they change their sleep pattern to the supine position.
authors.affiliation: *Ophthalmic Consultants of Long Island, Rockville Centre, NY; and †Department of Ophthalmology, Nassau University Medical Center, East Meadow, NY.
authors.forename: David
authors.initials: D
authors.lastname: Alevi
authors.forename: Henry D
authors.initials: HD
authors.lastname: Perry
authors.forename: Alexander
authors.initials: A
authors.lastname: Wedel
authors.forename: Eric
authors.initials: E
authors.lastname: Rosenberg
authors.forename: Limor
authors.initials: L
authors.lastname: Alevi
authors.forename: Eric D
authors.initials: ED
authors.lastname: Donnenfeld
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000503:physiopathology*; D005141:Eyelid Diseases / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008537:Meibomian Glands / Q000503:physiopathology*; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D013666:Tears / Q000737:chemistry; D055815:Young Adult