Does Posterior Capsule Opacification Affect the Results of Diagnostic Technologies to Evaluate the Retina and the Optic Disc?

Abstract

The visual outcome obtained after cataract removal may progressively decline because of posterior capsular opacification (PCO). This condition can be treated by creating an opening in the posterior lens capsule by Nd:YAG laser capsulotomy. PCO optical imperfections cause several light reflection, refraction, and diffraction phenomena, which may interfere with the functional and structural tests performed in different ocular locations for the diagnosis and follow-up of ocular disease, like macular and optic nerve diseases. Some parameters measured by visual field examinations, scanning laser polarimetry, and optical coherence tomography (OCT) have changed after PCO removal. Imaging quality also changes following capsulotomy. Consequently, the results of ancillary tests in pseudophakic eyes for studying ocular diseases like glaucoma or maculopathies should be correlated with other clinical examinations, for example, slit-lamp biomicroscopy or funduscopy. If PCO is clinically significant, a new baseline should be set for future comparisons following capsulotomy when using automated perimetry and scanning laser polarimetry. To perform OCT in the presence of PCO, reliable examinations (considering signal strength) apparently guarantee that measurements are not influenced by PCO.

Figure 1

Simulation of vision in a PCO-affected eye before (a) and after Nd:YAG capsulotomy (b).

Figure 2

Perimetric defect that mimics inferior arcuate scotoma in a PCO-affected eye (a). The defect partially disappeared after capsulotomy (b).

Figure 3

Scanning laser polarimetry examination before (a) and after Nd:YAG capsulotomy (b). Note that the thickness measurements reduce after PCO removal.

Figure 4

OCT maps of RNFL thickness before (a) and after (b) capsulotomy. Note that thickness measurements increase in the top half of the map after PCO removal.

Figure 5

OCT maps of total macular thickness before (a) and after (b) the capsulotomy. Note that most of the thickness measurements increase and image quality improves after PCO removal.