title: Tear osmolarity in ocular graft-versus-host disease.
abstract: OBJECTIVE
  The aim of this study was to evaluate tear osmolarity in patients with chronic graft-versus-host disease (cGVHD) with ocular involvement.
  
  
  METHODS
  In this observational cross-sectional study of 56 patients with ocular cGVHD referred to the tertiary-care Ocular Immunology and Uveitis Service at the San Raffaele Scientific Institute, Milan, from May 2010 to November 2013, we evaluated the following clinical parameters: Ocular Surface Disease Index (OSDI) symptoms questionnaire, tear osmolarity, Schirmer test, tear film break-up time (TBUT), corneal and conjunctival staining.
  
  
  RESULTS
  All patients developed systemic GVHD after undergoing allogeneic hematologic stem cell transplantation. Mean osmolarity was 314.0 ± 22.1 mOsm/L, mean OSDI score was 26.4 ± 21.2, mean TBUT was 6.50 ± 4.75 seconds, and mean Schirmer test value was 3.8 ± 3.3 mm. Tear osmolarity significantly inversely correlated with TBUT (r = 0.681; P < 0.001). Statistically significant inverse correlation was present with the Schirmer test (r = 0.203; P < 0.001), and positive correlation with the OSDI score (r = 0.188; P < 0.001), but both with low correlation strength. Osmolarity was statistically different in the subgroups according to the Oxford corneal staining scale (P = 0.0006) and to the van Bijsterveld conjunctival staining score (P = 0.006).
  
  
  CONCLUSIONS
  Tear osmolarity increased in patients with ocular cGVHD, significantly correlated with TBUT and, to a lesser extent, with the Schirmer test value and OSDI. These results emphasize the role of aqueous-deficient and evaporative dry eye disease in patients with cGVHD after undergoing allogeneic hematologic stem cell transplantation. Tear osmolarity may be considered a useful test in diagnostic assessment of dry eye disease associated with cGVHD.
authors.affiliation: Department of Ophthalmology, San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Berchicci
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Iuliano
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Miserocchi
authors.forename: Francesco
authors.initials: F
authors.lastname: Bandello
authors.forename: Giulio
authors.initials: G
authors.lastname: Modorati
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006086:Graft vs Host Disease / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D033581:Stem Cell Transplantation / Q000009:adverse effects; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*; D014065:Tonometry, Ocular; D055815:Young Adult