Anterior segment biometry during accommodation imaged with ultralong scan depth optical coherence tomography

Area of Science:

• Ophthalmology
• Biomedical Optics
• Anatomical Imaging

Background:

• Accurate measurement of ocular structures is crucial for understanding visual function.
• Accommodation involves dynamic changes in the anterior segment of the eye.
• Ultralong scan depth optical coherence tomography (UL-OCT) offers potential for detailed anterior segment imaging.

Purpose of the Study:

• To assess dimensional changes in the anterior segment of human eyes during accommodation using UL-OCT.
• To evaluate the repeatability and reliability of UL-OCT measurements in vivo.

Main Methods:

• Healthy subjects (n=41) underwent repeated UL-OCT imaging at minimal and maximal accommodation.
• Custom software corrected optical distortions for biometric measurements.
• Repeatability and reliability were assessed using coefficients of repeatability and intraclass correlation coefficients.

Main Results:

• UL-OCT demonstrated excellent repeatability and reliability for most anterior segment parameters.
• During maximal accommodation, pupil diameter, anterior chamber depth, and lens curvature changed significantly.
• Lens thickness and anterior segment length increased, while the lens moved forward and its posterior surface steepened.

Conclusions:

• UL-OCT is a reliable tool for measuring dynamic anterior segment changes during accommodation.
• Accommodation involves significant anterior segment remodeling, including lens repositioning and shape alteration.
• Findings contribute to a better understanding of the biomechanics of the human eye.