title: Time Spent in Lateral Sleep Position and Asymmetry in Glaucoma.
abstract: OBJECTIVE
  To explore sleep position in asymmetric primary open-angle glaucoma (POAG) with a focus on low pressure glaucoma (LPG).
  
  
  METHODS
  Sleep laboratory videos of 54 POAG patients were examined for lateral sleep. Then, 29 LPG patients (intraocular pressure [IOP] < 22 mm Hg) with an intereye visual field index (VFI) asymmetry of more than 5% continuously recorded their sleep position at home for 2 nights by using a portable device. Correlations were sought between sleep position, visual field (VF), and retinal nerve fiber layer (RNFL) symmetry as well as ocular biometric data and positional IOP changes. Finally, an expanded data set of 178 POAG patients (63 LPG and 115 high pressure glaucoma [HPG; IOP ≥ 22 mm Hg]) was used to correlate VF and the RNFL symmetry to the self-assessed sleep position collected in a survey.
  
  
  RESULTS
  In the video analysis, patients spent 19% ± 2% (mean ± SEM) more time sleeping on one side than on the other. Right-sided sleep was preferred. Right-sided sleep was 1.6 times more common in continuously recorded home data and correlated to an asymmetric VF that was worse in the left eye (b = -0.422, P = 0.002). Pulse amplitude of left eyes was lower in the right decubitus position (P = 0.02). In the expanded survey, 73% of LPG and 58% of HPG patients slept asymmetrically. Right-sided sleepers had a worse RNFL symmetry score.
  
  
  CONCLUSIONS
  Asymmetric sleep behavior is common. Right-sided sleep was preferred and correlated with a lower VFI on the left.
authors.affiliation: Department of Ophthalmology Stony Brook University, East Setauket, New York, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kaplowitz
authors.affiliation: Department of Ophthalmology, Johns Hopkins University, Baltimore, Maryland, United States.
authors.forename: Sonya
authors.initials: S
authors.lastname: Blizzard
authors.affiliation: Department of Orthopedic Surgery, Duke University, Durham, North Carolina, United States.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Blizzard
authors.affiliation: Department of Internal Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
authors.forename: Eberechi
authors.initials: E
authors.lastname: Nwogu
authors.affiliation: Department of Ophthalmology, Harvard University, Boston, Massachusetts, United States.
authors.forename: Cecily E
authors.initials: CE
authors.lastname: Hamill
authors.affiliation: Hamilton Glaucoma Center and Shiley Eye Center, Department of Ophthalmology, University of California San Diego, La Jolla, California, United States.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Section of Pulmonary, Critical Care and Sleep Medicine, Yale University, New Haven, Connecticut, United States.
authors.forename: Vahid
authors.initials: V
authors.lastname: Mohsenin
authors.affiliation: Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Nils A
authors.initials: NA
authors.lastname: Loewen
mesh_terms: D000368:Aged; D005260:Female; D005902:Glaucoma, Open-Angle / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D011446:Prospective Studies; D012890:Sleep; D013997:Time Factors