title: Analysis of spatial lamellar distribution from adaptive-optics second harmonic generation corneal images.
abstract: The spatial organization of stromal collagen of ex-vivo corneas has been quantified in adaptive-optics second harmonic generation (SHG) images by means of an optimized Fourier transform (FT) based analysis. At a particular depth location, adjacent lamellae often present similar orientations and run parallel to the corneal surface. However this pattern might be combined with interweaved collagen bundles leading to crosshatched structures with different orientations. The procedure here reported provides us with both principal and crosshatched angles. This is also able to automatically distinguish a random distribution from a cross-shaped one, since it uses the ratio of the axes lengths of the best-fitted ellipse of the FT data as an auxiliary parameter. The technique has successfully been applied to SHG images of healthy corneas (both stroma and Bowman's layer) of different species and to corneas undergoing cross-linking treatment.
authors.affiliation: Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100 Murcia, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Bueno
authors.forename: Raquel
authors.initials: R
authors.lastname: Palacios
authors.forename: Mary K
authors.initials: MK
authors.lastname: Chessey
authors.forename: Harilaos
authors.initials: H
authors.lastname: Ginis
keywords: (110.2960) Image analysis; (170.3880) Medical and biological imaging; (170.4470) Ophthalmology; (180.4315) Nonlinear microscopy