Development of an image analysis device to measure transparency, folding and gerontoxon of organ cultured corneas

Abstract

Abstract Purpose: To develop an image analysis device devoted to the measurement of donor corneal transparency (T), folding (F) and clear corneal diameter excluding gerontoxon (G) during organ culture Methods: High res digital images of a retroilluminated test chart comprising parallel lines viewed through the cornea were analysed using a dedicated software. T (%) was a ratio of local contrast of the test chart and F (%) was a ratio of mean of line profiles, each measured with and without the cornea. Area of clear cornea outside gerontoxon was calculated from a circle delineated by the observer. On each image, 3 independent experts classified T, F and G according to 3‐level score (++/+/0) which served as reference. 179 human corneas (fresh, stored and deswelled) were consecutively analysed to include a broad spectrum of T and F Results: The device was able to discriminate between the 3 classes of T, F and G established by the experts. T was 20±4, 36±8 and 51±10% respectively for transparency deemed poor, average and excellent (P<0.01). F was 29±10, 22±6, and 17±6% respectively for folding deemed high, average and minimal (P<0.01). Diameter of clear central cornea was 7.7±1.1, 8.9±0.8, 10.4±0.6 mm respectively for gerontoxon deemed severe, moderate and absent (P<0.01) Conclusions: This simple and original device provides reliable quantitative objective measures of T, F and G. It will help standardizing quality assessment of corneas among eye banks.A trial designed to assess the ability of the device to select corneas before delivery in the setting of the routine practice of our cornea bank is ongoing.Grants :Etab Français des Greffes 2004 and PHRC/AOL 2007