A Fourier Method for Assessing Wrinkling and Fribrotic bands on the Posterior Capsule Following Cataract Surgery.

Abstract

Abstract: : Purpose: To develop a Fourier method to assess wrinkling and other regular structure on the posterior capsule following cataract surgery Methods: Digital images were recorded of eyes with posterior capsule opacification following cataract surgery using a Kodak DCS–100 digital camera system mounted on a Nikon FS–2 photo slit–lamp. Slit–lamp settings were a slit angle of 45^o, beam width of 3mm, 25x magnification and a flash intensity of 2. Images were transfered to image processing software (Image Pro + v4.5.1, Media Cybernetics, Silver Spring, MD) and a 3 x 3mm area centred on the pupil selected. The Fourier Transform was taken and meridional data extracted from the amplitude spectrum image. The Fourier Transform of a sine wave grating was used as a test function and fitted to data from all meridians. Data extracted from the fits were used to quantify the periodicity and orientation of any regular features in the original images. Results: Amplitude spectra clearly indicated the presence and orientation of structure within images of the posterior capsule. Quantification proved possible for the small number of images tested (N = 5). However larger data sets should be examined to further confirm the initial findings and the possible utility of the method. Conclusions: Initial results demonstrate that Fourier methods permit ready recognition of periodic structure on the posterior capsule. This may have application to studies of posterior capsule opacification where wrinkling is known to guide migration of lens epithelial cells or be due to the contractile nature of newly formed fibrocytes.

Keywords: posterior capsular opacification (PCO) • image processing • imaging/image analysis: clinical