Posterior Capsular Opacification Formation Research Articles

Intraocular lens-capsular bag imaging with ultrahigh-resolution optical coherence tomography: pseudophakic human autopsy eyes

Linnola et al.1 evaluated the capsule–intraocular lens (IOL) interface and posterior capsular opacification formation in 7 human pseudophakic autopsy eyes with a prototype high-resolution optical coherence tomography (OCT). Nevertheless, in light of the knowledge of applied optics, the design of this in vitro study hardly simulates the in vivo situation, and the reproduction of a similar-quality scan in real life is doubtful. Optical coherence tomography is a noninvasive imaging technology capable of producing high-resolution images, but it is not a technique without limitations in clinical application. From the law of physical optics, Podoleanu et al.2 show that variations in lamellar orientation, hydration, and thickness of the cornea can alter the geometry of refraction and have a significant bearing over polarization of OCT images. In scanning the IOL and posterior capsule of a pseudophakic patient, the cornea is the first layer separating air from tissue; if this layer is represented undistorted on OCT, the shape of the deeper layers, including the IOL, is bound to be increasingly blurred as a result of the cumulative effect of different and even unknown indices of refraction up to the depth of interest.2 These image distortions render the morphometric inference (orientation and shape) of the tissue involved impossible.2 Linnola et al. noted that the cornea of all the specimen eyes had been removed so that the authors were practically scanning the IOL/posterior capsule complex directly without the mentioned interference from the usual intervening corneal layers. In face of the high-resolution pictures provided, we wonder whether any image correction algorithm was implemented in the study and whether such an imaging technique can be successfully extrapolated in vivo.