In vivo OCT assessment of anterior segment central axial lengths with accommodation

To assess changes in anatomic structures in the anterior eye segment in terms of axial lengths with accommodation via optical coherence tomography.

In this observational study, 25 eyes of 25 healthy adults were examined using the Visante® omni optical coherence tomography system. Central corneal thickness, anterior chamber depth, central lens thickness, and anterior segment length were assessed. The evaluated parameters were obtained with accommodation using different stimulus vergences, namely 0.0, -1.0, -2.0, and -3.0 D. Variation of these parameters was compared among different levels of accommodation.

Central corneal thickness was not altered at any stimulus vergence during accommodation (p>0.05). Conversely, anterior chamber depth was significantly reduced (p<0.05), whereas central lens thickness was significantly increased (p<0.05). Anterior segment length also increased with accommodation (p<0.05), indicating backward movement of the posterior pole.

There are significant variations in anterior segment lengths that occur with accommodation. Studying these changes will provide useful information regarding the accommodation mechanism that can improve our understanding of this process and facilitate clinical decision-making by practitioners.