Invest Ophthalmol Vis Sci. 2011 Jul 29;52(8):5587-97. Print 2011 Jul.
van Bree MC, van der Meulen IJ, Franssen L, Coppens JE, Reus NJ, Zijlmans BL, van den Berg TJ.
PURPOSE: Posterior capsule opacification (PCO) degrades visual function by reducing visual acuity, but also by increasing intraocular light-scatter. An in vitro model was used to elucidate the effect of PCO-morphology on light-scatter and its functional aspect, as can be assessed with straylight measurement.
METHODS: Forward PCO-scatter by opacified capsular bags was recorded with a goniometer and camera. The camera position mimicked the anatomic position of retinal photoreceptors; the camera recorded the scattered light that the photoreceptors would sense in an in vivo situation. Scattered light was recorded at different wavelengths and scatter angles, which were divided into a near (1° < θ ≤ 7°) and far (θ > 7°) large-angle domain. Using scattered light, the camera produced grayscale PCO images. The nature of the angular dependence of PCO-scatter was compared with that of scatter in the normal eye, by rescaling PCO images relative to the normal eye's point-spread function.
RESULTS: The scattered light images closely followed PCO severity. The angular dependence of PCO-scatter resembled that of scatter in the normal eye, irrespective of severity and PCO type. PCO shows the type of wavelength dependence that is normal for small particles: monotonically decreasing with increasing wavelength. At the near large-angle domain, the angular dependence of PCO scatter resembled the angular dependence of scatter in the normal eye less closely.
CONCLUSIONS: Surprisingly, PCO scatter and scatter in the normal eye have similar underlying scattering processes. However, data obtained at the near large-angle domain demonstrates that, apart from scatter, PCO may also have a refractile component, which is most pronounced in pearl-type PCO.
PMID: 21622703 [PubMed - in process]