FIAT: A Device for Objective, Optical Measures of Accommodation in Phakic and Pseudophakic Eyes.

PURPOSE

To present FIAT, a novel optical instrument and analysis package that is designed to elicit and optically record accommodation in human eyes.

METHODS

FIAT employs a Shack-Hartmann wavefront sensor and a retro-illumination pupil camera that records from a single eye at video rates. It is effective at eliciting accommodation by offering the subject a full-field binocular view of an alternating distant target and a near-eye display. FIAT analysis software computes wave aberrations for each video frame over full- or subpupil sizes and computes accommodative dynamics and accommodative range.

RESULTS

The system is validated by showing accurate refraction measurements in model eyes and human eyes with trial lenses. Robust accommodative responses are shown for young eyes, and a lack of accommodative response is shown for a known presbyopes. Accommodative stimulus-response curves from five phakic subjects over a range of ages show expected results. Results from two individuals with monofocal intraocular lenses are shown.

CONCLUSIONS

FIAT is an effective instrument for making accurate, objective measures of accommodation in phakic and pseudophakic eyes.

TRANSLATIONAL RELEVANCE

We present a device that can play an important role in the development and testing of accommodating intraocular lenses.