We examined a group of normal subjects to evaluate the tear film function by measuring reflex tear capacity using the Schirmer test without anesthetic, steady state tear flow using fluorophotometry, meibomian gland function based on gland drop-out, expressible lipid volume and viscosity, tear loss from evaporation, and tear osmolarity. We found the average tear flow to be 0.19 +/- 0.19 microliters/min, lower than previously measured. The average tear volume was also correspondingly less, 2.74 +/- 2.0 microliters. We found there was a decline associated with advancing age for all parameters except the decay constant and lipid volume. The highest correlations with aging were tear volume (-0.64), Schirmer test (-0.63), and tear osmolarity (0.59). Our results indicate that there is a decline in tear film function throughout life and that tear flow is considerably less than previously estimated.
This research output has an Altmetric Attention Score of 12. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 12 May 2026.
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#3,778,495
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Outputs from Cornea : The Journal of Cornea and External Disease
#170
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Outputs of similar age
#2,426
of 39,457 outputs
Outputs of similar age from Cornea : The Journal of Cornea and External Disease
#2
of 5 outputs
Altmetric has tracked 34,360,257 research outputs across all sources so far. Compared to these this one has done well and is in the 88th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 4,160 research outputs from this source. They receive a mean Attention Score of 4.0. This one has done particularly well, scoring higher than 95% of its peers.
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