Effect of supine body position on central corneal thickness.
BACKGROUND
To evaluate the effect of supine body position on central corneal thickness (CCT) in open-angle glaucoma patients and in healthy subjects.


DESIGN
A cross-sectional study at a university eye clinic.


PARTICIPANTS
Twenty-three subjects were recruited in each group, for a total of 46 patients.


METHODS
CCT was measured using an ultrasound pachymeter in each subject. Three consecutive measurements in each eye were first taken in the sitting position, and repeated after 10 min and 30 min in a supine position. Results were analyzed using mixed model repeated measures, which adjusted for age, gender and laterality of eyes.


MAIN OUTCOME MEASURES
CCT RESULTS: In healthy subjects, CCT decreased with supine positioning at 10 min (mean = -5.2 µm, P = 0.0043) and at 30 min (mean = -6.5 µm, P < 0.0001). In the glaucoma group, CCT decreased with supine positioning at 10 min (mean = -6.7 µm, P = 0.0043) and at 30 min (mean = -10.2 µm, P < 0.0001). There was no statistically significant difference between the CCT at 10 min supine and at 30 min supine in the healthy subjects (P = 0.37) and glaucoma patients (P = 0.14). CCT was shown to decrease linearly over time (P < 0.0001), and the slopes were not statistically different between groups (P = 0.40).


CONCLUSIONS
CCT is a dynamic measurement that can be influenced by body position. It decreases linearly in the first 30 min of supine positioning at a similar rate in both open angle glaucoma patients and in healthy subjects.
['Maslin|Jessica S|JS|http://orcid.org/0000-0002-3406-0082', 'Teng|Christopher C|CC|', 'Chadha|Nisha|N|', 'Liu|Ji|J|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D003315:Cornea D063171:Corneal Pachymetry D003430:Cross-Sectional Studies D005260:Female D005902:Glaucoma, Open-Angle D064368:Healthy Volunteers D006801:Humans D007429:Intraocular Pressure D008297:Male D008875:Middle Aged D016683:Supine Position
open-angle glaucoma glaucoma pachymetry