IMPORTANCE: Knowledge about the variability of measurements using the TearLab Osmolarity System is necessary when evaluating the clinical utility of readings. OBJECTIVE: To examine the variability of tear osmolarity measured by the TearLab Osmolarity System in patients with Sjögren syndrome (SS), patients with blepharitis, and control participants. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study at a tertiary care academic center from June 13, 2012, to March 21, 2013. Participants included 74 eyes of 37 patients from a volunteer sample (18 patients with SS, 11 patients with blepharitis, and 8 control participants) who were evaluated using the TearLab Osmolarity System, with 3 consecutive osmolarity measurements taken at 1-minute intervals in a session; 15 of these patients had the same measurements taken by the same examiner in 2 additional sessions on the same day (9 AM-10 AM, 12 PM-1 PM, or 3 PM-4 PM). Most patients with SS and patients with blepharitis were taking systemic or topical dry eye medications at the time of enrollment. MAIN OUTCOMES AND MEASURES: Mean osmolarity and its variability calculated from a linear mixed model for each disease group that accounts for the variations attributable to different patients, eyes, and sessions and measurement error specific to each disease group. RESULTS: Mean tear osmolarity was 307 mOsm/L, 304 mOsm/L, and 301 mOsm/L in the SS, blepharitis, and control groups, respectively (P = .46). The error associated with repeated measurements within a session in the patients without dry eye (10.5 mOsm/L [95% CI, 9.0-12.4]) was significantly lower than in the patients with blepharitis (14.6 mOsm/L [95% CI, 12.5-17.5]; P = .006) and patients with SS (15.8 mOsm/L [95% CI, 14.2-17.8]; P < .001) but a difference in the error of repeated measurements between patients with blepharitis and patients with SS was not identified (P = .46). CONCLUSIONS AND RELEVANCE: There was increased variability attributable to error in repeated measurements in patients with SS and patients with blepharitis compared with control participants. The high variability of TearLab osmolarity readings in all groups makes the clinical interpretation of measurements unclear.
IMPORTANCE: Knowledge about the variability of measurements using the TearLab Osmolarity System is necessary when evaluating the clinical utility of readings. OBJECTIVE: To examine the variability of tear osmolarity measured by the TearLab Osmolarity System in patients with Sjögren syndrome (SS), patients with blepharitis, and control participants. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study at a tertiary care academic center from June 13, 2012, to March 21, 2013. Participants included 74 eyes of 37 patients from a volunteer sample (18 patients with SS, 11 patients with blepharitis, and 8 control participants) who were evaluated using the TearLab Osmolarity System, with 3 consecutive osmolarity measurements taken at 1-minute intervals in a session; 15 of these patients had the same measurements taken by the same examiner in 2 additional sessions on the same day (9 AM-10 AM, 12 PM-1 PM, or 3 PM-4 PM). Most patients with SS and patients with blepharitis were taking systemic or topical dry eye medications at the time of enrollment. MAIN OUTCOMES AND MEASURES: Mean osmolarity and its variability calculated from a linear mixed model for each disease group that accounts for the variations attributable to different patients, eyes, and sessions and measurement error specific to each disease group. RESULTS: Mean tear osmolarity was 307 mOsm/L, 304 mOsm/L, and 301 mOsm/L in the SS, blepharitis, and control groups, respectively (P = .46). The error associated with repeated measurements within a session in the patients without dry eye (10.5 mOsm/L [95% CI, 9.0-12.4]) was significantly lower than in the patients with blepharitis (14.6 mOsm/L [95% CI, 12.5-17.5]; P = .006) and patients with SS (15.8 mOsm/L [95% CI, 14.2-17.8]; P < .001) but a difference in the error of repeated measurements between patients with blepharitis and patients with SS was not identified (P = .46). CONCLUSIONS AND RELEVANCE: There was increased variability attributable to error in repeated measurements in patients with SS and patients with blepharitis compared with control participants. The high variability of TearLab osmolarity readings in all groups makes the clinical interpretation of measurements unclear.
Authors: S C Shiboski; C H Shiboski; L A Criswell; A N Baer; S Challacombe; H Lanfranchi; M Schiødt; H Umehara; F Vivino; Y Zhao; Y Dong; D Greenspan; A M Heidenreich; P Helin; B Kirkham; K Kitagawa; G Larkin; M Li; T Lietman; J Lindegaard; N McNamara; K Sack; P Shirlaw; S Sugai; C Vollenweider; J Whitcher; A Wu; S Zhang; W Zhang; J S Greenspan; T E Daniels Journal: Arthritis Care Res (Hoboken) Date: 2012-04 Impact factor: 4.794
Authors: Benjamin D Sullivan; Leslie A Crews; Barış Sönmez; Maria F de la Paz; Ebru Comert; Victor Charoenrook; Aline L de Araujo; Jay S Pepose; Michael S Berg; Valerie P Kosheleff; Michael A Lemp Journal: Cornea Date: 2012-09 Impact factor: 2.651
Authors: Michael A Lemp; Anthony J Bron; Christophe Baudouin; José M Benítez Del Castillo; David Geffen; Joe Tauber; Gary N Foulks; Jay S Pepose; Benjamin D Sullivan Journal: Am J Ophthalmol Date: 2011-02-18 Impact factor: 5.258
Authors: Benjamin D Sullivan; Diane Whitmer; Kelly K Nichols; Alan Tomlinson; Gary N Foulks; Gerd Geerling; Jay S Pepose; Valerie Kosheleff; Allison Porreco; Michael A Lemp Journal: Invest Ophthalmol Vis Sci Date: 2010-07-14 Impact factor: 4.799
Authors: Mark D P Willcox; Pablo Argüeso; Georgi A Georgiev; Juha M Holopainen; Gordon W Laurie; Tom J Millar; Eric B Papas; Jannick P Rolland; Tannin A Schmidt; Ulrike Stahl; Tatiana Suarez; Lakshman N Subbaraman; Omür Ö Uçakhan; Lyndon Jones Journal: Ocul Surf Date: 2017-07-20 Impact factor: 5.033
Authors: Ali K Yetisen; Nan Jiang; Ali Tamayol; Guillermo U Ruiz-Esparza; Yu Shrike Zhang; Sofía Medina-Pando; Aditi Gupta; James S Wolffsohn; Haider Butt; Ali Khademhosseini; Seok-Hyun Yun Journal: Lab Chip Date: 2017-03-14 Impact factor: 6.799