Diurnal variation of human tear meniscus volume measured with tear strip meniscometry self-examination

Abstract

Tear secretion is critical for maintenance of healthy ocular surface and vision. Most of normal subjects and dry eye patients feel worsening of ocular dryness in the afternoon, however, diurnal variation of tear meniscus volume has not been directly measured because there was no appropriate method. We used a simple, non-invasive technique, tear strip meniscometry (SM) by self-examination. Previous investigations indicated the values of SM correlated strongly with those of the Schirmer test, tests of tear break up time, and tear meniscus height measurement by anterior optical coherence tomography. The purpose of this study was to capture diurnal variation of aqueous availability at the tear meniscus by measuring wetted length using SM through self-examination. Methods Thirty-six medical personnel (mean age; 35.7 years) participated and SM self-examination was performed using a mirror seven times a day. The strip is applied for 5 seconds to the lateral side of the lower lid tear meniscus without touching the ocular surface. Results The measured SM value was the highest upon awakening (4.44 ± 3.14 mm) and gradually decreased in the evening; 3.81

Influence of Circadian Rhythm in the Eye: Significance of Melatonin in Glaucoma

“…Regarding tear volume, its diurnal variations have been confirmed, which would follow a circadian cycle [98][99][100]. In healthy subjects, there is a discrepancy between studies reporting higher tear volume during the morning [98,100] and others during the afternoon [99], but they all showed lower tear volume late in the day.…”

“…Regarding tear volume, its diurnal variations have been confirmed, which would follow a circadian cycle [98][99][100]. In healthy subjects, there is a discrepancy between studies reporting higher tear volume during the morning [98,100] and others during the afternoon [99], but they all showed lower tear volume late in the day. On the other hand, tear osmolarity also seems to follow a circadian pattern [99,101], despite a study of Oncel et al [102] showing a stable profile throughout the daytime.…”

Strip Meniscometry Correlates With Ocular Surface Tests and Symptoms

“…The small heterogeneous groups studied here may be partly responsible for the lack of correlation between SM and tested parameters. Second, SM measurements show diurnal variation 24 and may vary depending upon season, climate, environment, medications, and systemic comorbidities. Therefore, further investigations are warranted to confirm the clinical applicability of SM.…”

“…11 SM has been used for numerous clinical and experimental studies, [12][13][14][15][16][17][18][19][20][21] including in veterinary medicine 22,23 and in a study where medical personnel self-examined seven times per day, revealing a diurnal variation in human tear meniscus volume. 24 DED practitioners often encounter discrepancies between signs and symptoms of DED, 25,26 and SM could be a suitable alternative clinical indicator to ST if SM were associated with any signs and symptoms of DED. This study aimed to investigate the association of DED-related parameters with two tear function tests, ST and SM, to explore the clinical applicability of SM.…”

“… 11 SM has been used for numerous clinical and experimental studies, 12 – 21 including in veterinary medicine 22 , 23 and in a study where medical personnel self-examined seven times per day, revealing a diurnal variation in human tear meniscus volume. 24 …”