Purpose:
To quantify posterior capsule opacification (PCO) in pseudophakic eyes using slit-lamp retroillumination photographs and rotating scheimpflug pentacam tomograms and to determine the correlation between the two methods.
Methods:
16 pseudophakic eyes were included in the study. The subjects were imaged using the Topcon digital slitlamp illumination system after full mydriasis and retroillumination photographs were captured at 6 megapixel resolution. The retroillumination photographs were analyzed using POCOman software (available as a free download from http://83.146.11.19/). The PCO value was obtained as a percentage. Pentacam Rotating Scheimpflug Imaging was performed on the same eyes, again after full mydriasis. The 50 scan image acquisition protocol was used and reconstructed high resolution tomograms were obtained for each eye. These tomograms were analyzed using ImageJ freeware (available as a free download from http://rsb.info.nih.gov/ij/) The central 3mm area was selected and the edge detection tool applied to it. The measure function was used to obtain the pixel intensity value of PCO. The values of PCO obtained using POCOman and ImageJ were correlated with each other.
Results:
Mean age of the patients was 52 ± 3.4 years. Male to Female ratio was 9:7. The mean PCO percentage value obtained using POCOman software was 23.34 ± 6.25 and the mean pixel intensity value using ImageJ was 29.84 ± 6.71 units. Pearson’s correlation coefficient was 0.934 demonstrating a significant positive correlation between the PCO value obtained using the slitlamp retroillumination images and the pentacam tomograms.
Conclusions:
Retroillumination photographs are currently the standard for quantifying PCO. Pentacam Tomograms have the advantage of being easier to obtain, more objective and being free of flash reflections. The correlation between the two methods demonstrates that ImageJ analysis of pentacam tomograms is a viable tool to quantify PCO objectively.
Keywords: posterior capsular opacification (PCO) • intraocular lens • cataract