What is the value of incorporating tear osmolarity measurement in assessing patient response to therapy in dry eye disease?
OBJECTIVE
To evaluate the correlation between changes in tear osmolarity, symptoms, and corneal fluorescein staining in patients with dry eye disease (DED).


METHODS
Retrospective, clinic-based cohort study.


METHODS
In this single-institution study, we reviewed the charts of 186 patients with DED from whom we had data on tear osmolarity, symptoms, and corneal fluorescein staining from 2 separate visits. Main outcomes included the correlation of the changes between the 2 visits for tear osmolarity (TearLab system), symptoms (Ocular Surface Disease Index), and corneal fluorescein staining (modified Oxford scheme). For tear osmolarity and corneal fluorescein staining the scores from the eye with highest readings were analyzed. The correlations were repeated on subgroups based on proposed cutoffs for DED severity and on patients' treatment.


RESULTS
We found a modest, though statistically significant, correlation between changes in corneal fluorescein staining and symptoms of DED (R = 0.31; P < .001). However, there was no correlation between the recorded change in tear osmolarity and symptoms (R = -0.091; P = .38) or between changes in tear osmolarity and corneal fluorescein staining (R = -0.02; P = .80). This lack of correlation was consistent in all the subgroups studied. A multivariate analysis revealed that changes in corneal fluorescein staining had predictive value on symptom changes, whereas tear osmolarity changes did not.


CONCLUSIONS
Changes in tear osmolarity do not correlate significantly with changes in patient symptoms or corneal fluorescein staining in dry eye disease.
Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
Francisco
F
Amparo
Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
Yiping
Y
Jin
Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
Pedram
P
Hamrah
Brigham and Women's Hospital, Division of Preventive Medicine, Harvard Medical School, Boston, Massachusetts; Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts.
Debra A
DA
Schaumberg
Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts. Electronic address: reza_dana@meei.harvard.edu.
Reza
R
Dana
D018501:Antirheumatic Agents / Q000627:therapeutic use; D001769:Blood; D003315:Cornea / Q000473:pathology*; D016572:Cyclosporine / Q000627:therapeutic use; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D015590:Fluorophotometry; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D053590:Interleukin 1 Receptor Antagonist Protein / Q000627:therapeutic use; D054327:Lubricants; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000627:therapeutic use; D009994:Osmolar Concentration; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*
D018501:Antirheumatic Agents; D005456:Fluorescent Dyes; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D053590:Interleukin 1 Receptor Antagonist Protein; D054327:Lubricants; D009883:Ophthalmic Solutions; D016572:Cyclosporine; D019793:Fluorescein