Quantification of the ciliary muscle and crystalline lens interaction during accommodation with synchronous OCT imaging

Abstract

Two SD-OCT systems and a dual channel accommodation target were combined and precisely synchronized to simultaneously image the anterior segment and the ciliary muscle during dynamic accommodation. The imaging system simultaneously generates two synchronized OCT image sequences of the anterior segment and ciliary muscle with an imaging speed of 13 frames per second. The system was used to acquire OCT image sequences of a non-presbyopic and a pre-presbyopic subject accommodating in response to step changes in vergence. The image sequences were processed to extract dynamic morphological data from the crystalline lens and the ciliary muscle. The synchronization between the OCT systems allowed the precise correlation of anatomical changes occurring in the crystalline lens and ciliary muscle at identical time points during accommodation. To describe the dynamic interaction between the crystalline lens and ciliary muscle, we introduce accommodation state diagrams that display the relation between anatomical changes occurring in the accommodating crystalline lens and ciliary muscle.

Ciliary muscle dimensions by swept‐source optical coherence tomography and correlation study in a large population

“…OCT imaging at long wavelengths enables deeper visualization of the posterior CM boundary and the inner apex, which is key to obtaining accurate CM thickness measurements (Ruggeri et al. ).…”

Non-invasive measurements of the dynamic changes in the ciliary muscle, crystalline lens morphology, and anterior chamber during accommodation with a high-resolution OCT

“…Imaging the ciliary muscle during the accommodation could help to understand the ageing of the accommodative system [5]. Despite all of this, the biggest challenge in imaging these structures is the light attenuation caused by the sclera and ciliary body, which reduce the image contrast, and makes it more difficult to recognize [26].…”

“…Despite all of this, the biggest challenge in imaging these structures is the light attenuation caused by the sclera and ciliary body, which reduce the image contrast, and makes it more difficult to recognize [26]. Nevertheless, OCT with a wavelength of 1300 nm allows deeper visualization of the posterior ciliary muscle boundary and the inner apex [26,27], which is important to obtain accurate ciliary muscle thickness measurements [5]. After all this, the OCT used in the present study seems to be an appropriate system to measure the CMA, because it works with a wavelength of 1310 nm.…”

“…In an attempt to measure the ciliary muscle with high resolution, a previous study synchronized two spectral domain OCTs working at 840 and 1325 nm, and a dual channel accommodation target to image the accommodative system during dynamic accommodation [5]. Concretely, that system enables synchronous recording of temporal images of the anterior segment and the ciliary muscle at 13 frames per second during accommodation, which is sufficient to characterize the dynamics of the response.…”

“…Concretely, during this process the lens' radii of the anterior and posterior surfaces experiences a decrease [1], and its thickness increase. At the same time, the anterior chamber depth (ACD), anterior chamber angle, and pupil diameter are reduced [2][3][4], meanwhile, the ciliary muscle area (CMA) increases [4,5]. Nonetheless, contradictory results regarding corneal changes with accommodation have been reported in the literature.…”