Abstract
Purpose :
Cataracts is caused by progressive clouding of the crystalline lens, and the only treatment is surgical replacement of the cataractous lens with an artificial intraocular lens (IOL). There are many specialized equipment (e.g. retinoscopy, aberrometers, optical coherence tomography, biometers) for the diagnosis of cataract; however, the performance of preoperative vision simulators is not sufficient for predicting postoperative visual acuity and existing devices are incapable of correcting aberrations and they are limited to static pinhole exit pupils. Holography is viewed as the ultimate display technology that can offer natural 3D with all required focus and depth cues. In this study, we propose a holographic vision simulator that provides best-corrected visual acuity of the eye with cataracts before the patient goes through cataract surgery.
Methods :
The wave-front computation algorithms in computer generated holography (CGH) enables essential features such as the ability to control the phase, size and shape of the light beam entering through the eye-pupil for an effective cataract vision simulator. Our instrument detects the small, non-cataractous regions on the crystalline lens, and directs the light beam with exit pupil shaping and pupil tracking. Holographic display shows a virtual Snellen Chart at the desired depth through these regions onto the retina, while correcting the existing refractive errors including myopia, hyperopia, and astigmatism.
Results :
Ten patients with various degrees of cataracts went through eye examinations before testing the simulator instrument. All the patients demonstrated better visual acuity when tested in our holographic simulator compared to the conventional eye examination. Patients without retina diseases performed 20/40 vision, whereas the patients with AMD or glaucoma performed 20/70 vision.
Conclusions :
Our holographic vision simulator was able to predict the postoperative visual acuity level of the patients before going to cataract surgery. Our augmented reality display device overperforms the existing vision simulators. This device can also be used for matching the right patient to the right choice of intraocular lenses (trifocal, monofocal, EDoF). Further studies are needed to optimize the outcomes of this selection process.
This is a 2021 ARVO Annual Meeting abstract.