RT Journal Article T1 Diurnal variations of tear film osmolarity on the ocular surface A1 Pena Verdeal, Hugo A1 García Resúa, Carlos A1 García Queiruga, Jacobo A1 Sabucedo Villamarín, Belén A1 Yebra-Pimentel Vilar, Eva A1 Giráldez Fernández, María Jesús K1 Tear film K1 Osmolarity K1 Diurnal variation K1 Dry eye disease K1 Tear osmometer AB The measurement of tear film osmolarity has been suggested as a gold standard in the diagnosis of dry eye. Many tear film physiological variables oscillate during the day, therefore previous reports have studied how this variable changes throughout the day. The present brief review article will summarize the current clinical knowledge and the main conclusion of the diurnal osmolarity variation in the tear film. For this purpose, the review performs a critical analysis of sample size and characteristics, the differences in the diurnal osmolarity variation on healthy versus altered tear film conditions or environment eyes, and time of day and number of measurements done. A total of twenty-one studies where one of the main objectives was to analyse the variance of the tear film osmolar value along different time points in a day on a human cohort were compared. Osmolar tear film value does appear to be somewhat influenced by the time of day in healthy subjects and patients with ocular surface disease or altered by environmental conditions. Both, healthy and no-physiological tear film stable cohorts, showed variations in results depending on the study: no variations during the day or statistically different values at some point in the day (these differences could be in the middle of the day or between the beginning and the end of the day, with higher values in the morning than in the afternoon, or even the opposite situation). The possibility of diurnal variations in tear film osmolarity should be considered by the clinician since the time of day when the tear film measurements are made can be critical in making the right diagnosis. Future studies in the diurnal variation field may have to use a well-established range of measurement time-points and a larger group of healthy and tear film altered by pathological or environmental conditions subjects. PB Taylor and Francis SN 0816-4622 YR 2022 FD 2022-04-11 LK http://hdl.handle.net/10347/32764 UL http://hdl.handle.net/10347/32764 LA eng NO Hugo Pena-Verdeal, Carlos Garcia-Resua, Jacobo Garcia-Queiruga, Belen Sabucedo-Villamarin, Eva Yebra-Pimentel & Maria Jesus Giraldez (2023) Diurnal variations of tear film osmolarity on the ocular surface, Clinical and Experimental Optometry, 106:4, 351-361, DOI: 10.1080/08164622.2022.2051697 DS Minerva RD 28 abr 2026