Abstract
Purpose::
To evaluate visual function in eyes with a cataract using a point spread function (PSF) analyzer.
Methods::
Double-pass PSF images were analyzed using a PSF analyzer (Topcon, Tokyo) in 44 eyes with a cataract. Retinal images were simulated by convolution of the calculated single-pass PSFs using a variety of sizes of Landolt rings. The vision was estimated based on the contrast analysis of the simulated Landolt rings and compared with the subjective best-corrected visual acuity (BCVA) values. Modulation transfer functions of the optical systems were obtained through equal-sized apertures (the entrance and exit pupils), and the phase transfer functions were obtained through unequal-sized apertures. The simulated retinal images were reconstructed with and without a phase-retrieval algorithm.
Results::
No significant correlation between the subjective BCVAs and the estimated visual acuity by PSF analysis based on the unequal-pupil method with the phase-retrieval algorithm was seen; vision estimation correlated better with the equal-pupil method without the phase-retrieval algorithm in cataractous eyes.
Conclusions::
Evaluation of the visual function in eyes with a cataract is difficult using the double-pass method through unequal-sized apertures with the phase-retrieval algorithm. Better visual estimates were obtained without the phase-retrieval algorithm in cataractous eyes.
Keywords: cataract • visual acuity • imaging/image analysis: clinical