Phantom-based model eyes for adaptive optics performance assessment

Ophthalmic adaptive optics (AO) senses and corrects for ocular aberrations providing cellular-level resolution of the retina. Because AO instruments adapt to each subject’s eyes in a personalized manner, AO as an enabling technology creates a unique challenge for medical device regulation in terms of standardized performance assessment. One way to assess device performance is with biomimetic phantoms that match retinal anatomy. To that end, we developed an AO model eye with a retinal phantom that mimics the human photoreceptor mosaic. Cylindrical cone photoreceptors that match the size, spacing, and arrangement in human eyes were created using two-photon polymerization (TPP) – a type of 3D printing. The AO model eye was also engineered to allow imaging in both scanning laser ophthalmoscopy and optical coherence tomography modes, and reflections were managed to allow wavefront sensing and AO correction. TPP should allow a wide variety of phantoms to be fabricated easily and quickly. Results from testing on two different AO imagers revealed interesting information on interference phenomena (speckle and waveguiding). More recent progress toward complex instrument stress tests, using a dynamic AO model eye with a multi-element deformable lens to assess aberration correction, will be discussed. The AO model eye is a regulatory science tool that can significantly enhance the ability of regulators and developers to evaluate and quantify AO device performance.