OCT-based crystalline lens topography in accommodating eyes.

Area of Science:

• Ophthalmic optics
• Biomedical engineering
• Vision science

Background:

• The crystalline lens undergoes dynamic shape changes during accommodation to maintain focus.
• Understanding these changes is vital for comprehending visual aberrations and developing effective ophthalmic interventions.

Purpose of the Study:

• To quantify anterior and posterior crystalline lens surface elevation during accommodation using custom Spectral Domain Optical Coherence Tomography (SD-OCT).
• To investigate the relationships between anterior segment surfaces and their aberrations during accommodation.

Main Methods:

• Custom SD-OCT with automated quantification and distortion correction was employed.
• Nine young eyes were measured under varying accommodative demands.
• Three-dimensional surface elevations were calculated by subtracting best-fit spheres.

Main Results:

• Lens radii of curvature decreased, anterior chamber depth reduced, and lens thickness increased with accommodation.
• Astigmatism became the dominant irregularity on the anterior lens surface (90%) during accommodation.
• Higher-order irregularities were significantly more prevalent on the posterior lens surface compared to the anterior surface.

Conclusions:

• Accommodation significantly alters crystalline lens shape and surface topography, particularly increasing anterior astigmatism.
• Significant correlations exist between lens surface aberrations, suggesting complex interactions within the anterior segment.
• The study highlights the dynamic nature of lens aberrations and their implications for visual quality.