Abstract
Purpose: :
Personalized eye modeling for normal and diseased conditions is achievable and has been demonstrated (ARVO 2011). Even more realistic modeling that includes retinal structure, tear properties, scattering properties is promising. The ability to perform virtual clinical trials for ocular instruments is of great interest.Our long-term goal is to be able to perform and demonstrate accurate virtual (computer) clinical trials for new ocular instruments using customized eye models of normal and diseased populations. This paper examines the feasibility of predicting fundus image measurements in 16 keratoconus and 17 normal ammetropic eyes.
Methods: :
We constructed 16 mild- to-moderate keratoconus and 17 ammetropic customized eye models that used age-dependent lens index and anterior/posterior corneal topographies, wavefront aberration (RMS error less than 0.01um) and ocular biometry identical to the patients’ clinical measurements. Point Spread Function of each eye model was examined over a wide range of field angles. Simulation of fundus image measurements was performed under various pupil sizes, best correction of spherical refraction, best spherical/cylindrical correction, color, red-free, and angiography conditions using ZEMAX optical program. The retinal condition was selected from normal, diabetes, and retinitis pigmentosa conditions.
Results: :
The simulation results show the expected influence on pupil size. The cylindrical correction for the fundus camera is very significant for the keratoconus group of patients, even if the condition is mild. Without the astigmatic correction, not only was there difficulty in bringing the images to a tight focus ,but also "double images" were observed in areas of some of the keratoconus eyes.
Conclusions: :
This demonstration is one step forward toward achieving the desired virtual clinical trial.
Keywords: computational modeling • aberrations • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)