Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT.
Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) provided with automatic quantification and distortion correction algorithms was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo in four subjects, for accommodative demands between 0 to 6 D in 1 D steps. Anterior and posterior lens radii of curvature decreased with accommodative demand at rates of 0.73 and 0.20 mm/D, resulting in an increase of the estimated optical power of the eye of 0.62 D per diopter of accommodative demand. Dynamic fluctuations in crystalline lens radii of curvature, anterior chamber depth and lens thickness were also estimated from dynamic 2-D OCT images (14 Hz), acquired during 5-s of steady fixation, for different accommodative demands. Estimates of the eye power from dynamical geometrical measurements revealed an increase of the fluctuations of the accommodative response from 0.07 D to 0.47 D between 0 and 6 D (0.044 D per D of accommodative demand). A sensitivity analysis showed that the fluctuations of accommodation were driven by dynamic changes in the lens surfaces, particularly in the posterior lens surface.
Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas, C/Serrano 121, 28006 Madrid, Spain.
Enrique
E
Gambra
Sergio
S
Ortiz
Pablo
P
Perez-Merino
Michalina
M
Gora
Maciej
M
Wojtkowski
Susana
S
Marcos
(110.4500) Optical coherence tomography; (110.6880) Three-dimensional image acquisition; (120.4640) Optical instruments; (120.6650) Surface measurements, figure; (330.7322) Visual optics, accommodation; (330.7327) Visual optics, ophthalmic instrumentation