Purpose:
To demonstrate the detection of high-order ocular aberrationsusing photorefraction (PR).Background: Photorefraction (PR)is a viable large-scale screening technique that has been usedprimarily to measure refractive errors and ocular alignmentin small children. However, the PR reflex carries optical informationthrough all ocular elements including aberrations from diffractionand scattering that have not been carefully explored.
Methods:
The near-infrared, multi-meridian PR technique is employed toimage eyes with normal and abnormal degrees of high-order (HO)aberrations. PR images were obtained of patients with abnormalHO aberrations, including 20 eyes with keratoconus (KC) andectacia, 10 with optical opacities, and 5 eyes with tear-filmbreakup, and were compared to the control group of 20 normaland pre-LASIK patient eyes.
Results:
Images show distinguishable characteristic patterns in eachgroup of patients. Fig.1 shows the PR images of 2 normal eyeswith 20/20 BCVA (left) and 2 KC eyes with 20/25 and 20/30+1(right). The normal and ametropic eyes have symmetric PR refleximages as the false-color images show. The images in Fig. 2are reflexes with cortex cataract (left), and tear-film breakup(right).
Conclusions:
Infrared PR provides a simple, low-cost, objective, and versatilemethod in screening high-order ocular aberrations.
Keywords: clinical laboratory testing • keratoconus • visual acuity