Technical note: measurement of retinal contour and supine axial length using the Zeiss IOLMaster.

Accurate and repeatable assessments of ocular biometric factors are of vital importance to research laboratories conducting studies of ametropia. This is of particular importance to studies assessing the efficacy of myopia control strategies, and when investigating the effect of accommodation and posture on ocular biometry. In this technical note, two novel adaptations of the Zeiss IOLMaster are described: an adaptation to enable measurement of the axial length of the eye of a subject in a supine position, and an attachment to enable measurement of peripheral ocular dimensions and plotting of the central 80 degrees of the retina relative to the anterior corneal surface. Pilot data obtained using these modifications to the instrument are presented.