Diurnal variation of anterior scleral and conjunctival thickness
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Accepted Manuscript (AM)
Author(s)
Read, Scott A
Alonso-Caneiro, David
Free, Kelly A
Labuc-Spoors, Elspeth
Leigh, Jaron K
Quirk, Charlotte J
Yang, Zoe Y-L
Vincent, Stephen J
Griffith University Author(s)
Year published
2016
Metadata
Show full item recordAbstract
Purpose: To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period. Methods: Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) ...
View more >Purpose: To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period. Methods: Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) for each subject at each measurement session. Results: Both the anterior sclera and conjunctiva were found to undergo significant diurnal variations in thickness over a 24-h period (both p < 0.01). The sclera and conjunctiva exhibited a similar pattern of diurnal change, with a small magnitude thinning observed close to midday, and a larger magnitude thickening observed in the early morning immediately after waking. The amplitude of diurnal thickness change was larger in the conjunctiva (mean amplitude 69 ± 29 μm) compared to the sclera (21 ± 8 μm). The conjunctiva exhibited its smallest magnitude of change at the SS location (mean amplitude 56 ± 17 μm) whereas the sclera exhibited its largest magnitude of change at this location (52 ± 21 μm). Conclusions: This study provides the first evidence of diurnal variations occurring in the thickness of the anterior sclera and conjunctiva. Studies requiring precise measures of these anatomical layers should therefore take time of day into consideration. The majority of the observed changes occurred in the early morning immediately after waking and were of larger magnitude in the conjunctiva compared to the sclera. Thickness changes at other times of the day were of smaller magnitude and generally not statistically significant.
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View more >Purpose: To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period. Methods: Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) for each subject at each measurement session. Results: Both the anterior sclera and conjunctiva were found to undergo significant diurnal variations in thickness over a 24-h period (both p < 0.01). The sclera and conjunctiva exhibited a similar pattern of diurnal change, with a small magnitude thinning observed close to midday, and a larger magnitude thickening observed in the early morning immediately after waking. The amplitude of diurnal thickness change was larger in the conjunctiva (mean amplitude 69 ± 29 μm) compared to the sclera (21 ± 8 μm). The conjunctiva exhibited its smallest magnitude of change at the SS location (mean amplitude 56 ± 17 μm) whereas the sclera exhibited its largest magnitude of change at this location (52 ± 21 μm). Conclusions: This study provides the first evidence of diurnal variations occurring in the thickness of the anterior sclera and conjunctiva. Studies requiring precise measures of these anatomical layers should therefore take time of day into consideration. The majority of the observed changes occurred in the early morning immediately after waking and were of larger magnitude in the conjunctiva compared to the sclera. Thickness changes at other times of the day were of smaller magnitude and generally not statistically significant.
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Journal Title
Ophthalmic and Physiological Optics
Volume
36
Issue
3
Copyright Statement
© 2016 The College of Optometrists. This is the peer reviewed version of the following article: Diurnal variation of anterior scleral and conjunctival thickness, Ophthalmic and Physiological Optics, 2016, 36 (3), pp. 279-289 which has been published in final form at https://doi.org/10.1111/opo.12288. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/WileyCDA/Section/id-828039.html)
Subject
Clinical sciences
Ophthalmology and optometry
Other health sciences
Science & Technology
Life Sciences & Biomedicine
anterior segment
conjunctiva