TY - JOUR
T1 - Tear flow and evaporation in patients with and without dry eye
AU - Mathers, W. D.
AU - Daley, T. E.
N1 - Funding Information:
Originally received: February 7, 1995. Revision accepted: January 3, 1996. I Department of Ophthalmology, University oflowa Hospitals and Clinics, Iowa City. 2 Department of Ophthalmology, University oflowa Hospitals and Clinics, Iowa City. Supported in part by an unrestricted grant from Research to Prevent Blindness, New York, New York, and NEI grant ROI-EYI0151 , Be thesda, Maryland. Each author states that he has no proprietary interest in the development or marketing of this or a competing piece of equipment. Reprint requests to William D. Mathers, MD, University of Iowa Hospitals and Clinics, Department of Ophthalmology, 200 Hawkins Dr, Iowa City, IA 52242-1091.
PY - 1996
Y1 - 1996
N2 - Purpose: To evaluate the steady-state tear flow and evaporation from the ocular surface of patients with end without dry eye. Methods: Two groups of patients, 21 with dry eye and 34 without dry eye, with similar age distributions were selected by criteria based on tear osmolarity, Schirmer test, meibomian gland loss, and dry eye symptoms and were compared for tear flow, tear volume, percent turnover, and surface evaporation. Results: Tear flow averaged 0.10 ± 0.08 μl/minute in patients with dry eye versus 0.15 ± 0.12 μl/minute in patients without dry eye (P = 0.002). Tear volume averaged 2.13 ± 1.3 μl in patients with dry eye versus 2.23 ± 2.5 μl in patients without dry eye (P = not significant) and tear turnover averaged 5.3 ± 2.9% in patients with dry eye versus 8.2 ± 4.3% in patients without dry eye (P = 0.019). Evaporation averaged 25 ± 35 x 10-7 g/cm2/second in patients with dry eye versus 13 ± 6 x 10-7 g/cm2/second in patients without dry eye (P = 0.003). Conclusions: Measured tear flow was significantly lower than previously determined in patients with and without dry eye. Evaporation was increased in patients with dry eye and accounted for the majority of the tear loss in patients with dry eye. Normal tear osmolarity can be maintained, even with low tear flow, if evaporation is kept within the normal range.
AB - Purpose: To evaluate the steady-state tear flow and evaporation from the ocular surface of patients with end without dry eye. Methods: Two groups of patients, 21 with dry eye and 34 without dry eye, with similar age distributions were selected by criteria based on tear osmolarity, Schirmer test, meibomian gland loss, and dry eye symptoms and were compared for tear flow, tear volume, percent turnover, and surface evaporation. Results: Tear flow averaged 0.10 ± 0.08 μl/minute in patients with dry eye versus 0.15 ± 0.12 μl/minute in patients without dry eye (P = 0.002). Tear volume averaged 2.13 ± 1.3 μl in patients with dry eye versus 2.23 ± 2.5 μl in patients without dry eye (P = not significant) and tear turnover averaged 5.3 ± 2.9% in patients with dry eye versus 8.2 ± 4.3% in patients without dry eye (P = 0.019). Evaporation averaged 25 ± 35 x 10-7 g/cm2/second in patients with dry eye versus 13 ± 6 x 10-7 g/cm2/second in patients without dry eye (P = 0.003). Conclusions: Measured tear flow was significantly lower than previously determined in patients with and without dry eye. Evaporation was increased in patients with dry eye and accounted for the majority of the tear loss in patients with dry eye. Normal tear osmolarity can be maintained, even with low tear flow, if evaporation is kept within the normal range.
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U2 - 10.1016/S0161-6420(96)30637-4
DO - 10.1016/S0161-6420(96)30637-4
M3 - Article
C2 - 8618768
AN - SCOPUS:0029862988
SN - 0161-6420
VL - 103
SP - 664
EP - 669
JO - Ophthalmology
JF - Ophthalmology
IS - 4
ER -