title: Intraocular pressure elevation and choroidal thinning.
abstract: OBJECTIVE
  To evaluate changes in subfoveal choroidal thickness (SFCT) and peripapillary choroidal thickness (PPCT) after acute intraocular pressure (IOP) elevation provoked by a dark room prone provocative test (DRPPT).
  
  
  METHODS
  The prospective cohort study included 114 eyes from 65 individuals who had an IOP elevation ≥2 mm Hg during the DRPPT. The participants stayed in a dark room for 2 h with the forehead placed on a desk. At baseline and within 5 min after the end of the DRPPT, tonometry and enhanced depth imaging by spectral-domain optical coherence tomography were carried out.
  
  
  RESULTS
  During the DRPPT, IOP increased by 10.1±10.9 mm Hg, SFCT decreased significantly (p<0.001) from 280±80 µm to 267±76 µm and PPCT decreased significantly (p<0.001) from 177±74 to 169±70 µm. In multivariate analysis, a more marked SFCT thinning was associated with higher IOP increase (p<0.001) and shallower anterior chamber depth at baseline (p=0.01). In a similar manner, a higher PPCT change was correlated with a higher IOP increase (p<0.001), and a thicker choroidal thickness at baseline (p<0.001).
  
  
  CONCLUSIONS
  Choroidal thickness in the subfoveal region and in the peripapillary region decreased parallel to an acute increase in IOP in individuals 2 h after a dark room test. Choroidal thickness depends on the actual IOP, which may be noted when choroidal thickness is measured.
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Ya Xing
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Jiang
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Xiao Lei
authors.initials: XL
authors.lastname: Ren
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Jian Dong
authors.initials: JD
authors.lastname: Chen
authors.affiliation: College of Biomedical Engineering, Capital Medical University, Beijing, China.
authors.forename: Hong Li
authors.initials: HL
authors.lastname: Shi
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.affiliation: Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Wen Bin
authors.initials: WB
authors.lastname: Wei
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.|Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg, Seegartenklinik Heidelberg, Germany.
authors.forename: Jost B
authors.identifier: http://orcid.org/0000-0003-2972-5227
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000473:pathology*; D003623:Dark Adaptation; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011187:Posture; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*; D014065:Tonometry, Ocular
keywords: Choroid; Glaucoma; Imaging; Intraocular pressure