Evaluation of lower tear meniscus shape with OCT

• Published in: Acta ophthalmologica (Oxford, England) England), 2012-09, Vol.90 (s249), p.0-0
• Main Authors: BANDLITZ, S, PURSLOW, C, MURPHY, PJ, PULT, H
• Format: Article
• Language: English
• Subjects: Ophthalmology
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2012.4641.x

Purpose When measuring the tear meniscus radius and calculating tear volume, the anterior radius of the meniscus is assumed to be spherical. This study aimed to define the shape of the meniscus more precisely using high‐resolution optical coherence tomography (OCT). Methods Images of the lower tear meniscus of 30 normal subjects (8M, 22F; mean age 27.5±9.6yrs), recruited from the patient pool of Höhere Fachschule für Augenoptik, Cologne, Germany, were taken using the Zeiss Cirrus HD OCT. Applying ImageJ software, the tear meniscus height (TMH) was measured and the xy‐coordinates of 12 marked points on the anterior tear meniscus curve were determined. With these coordinates a graph was plotted and the best fitting trend‐line (defining TM curvature) was calculated. Furthermore, the distance between the edge of the lower eyelid and the vertex of the curve (TMH‐V) was calculated and compared to the half TMH (TMH‐H). Results Mean TMH was 0.24 SD±0.06mm. The mean fitting trend‐line appeared to be a quadratic equation (R‐squared range from 0.908 to 0.996). TMH‐V (0.12±0.04mm) and TMH‐H (0.12±0.03mm) were significantly correlated (r=0.62; p