New findings for an old disease: morphological studies on pseudoexfoliation syndrome-related keratopathy and binocular asymmetry.

PURPOSE: To review our previous studies regarding the morphology of the cornea in pseudoexfoliation syndrome (PEX) and anatomical discrepancies between PEX and contralateral eyes in unilateral PEX.

METHODS

We used in vivo confocal microscopy to observe the corneas of PEX, contralateral, and normal control eyes. Morphological alterations correlated with the corneal sensitivity of the eyes with PEX. Anterior segment optical coherence tomography was used to study patients diagnosed with unilateral PEX. Dynamic dark-light changes of the anterior chamber angle and iris were captured by anterior segment optical coherence tomography real-time video recording. Anterior chamber angle parameters and iridolenticular contact distance were analyzed. The result of a national survey on the etiology of bullous keratopathy is presented.

RESULTS

Corneal cell density was decreased in PEX eyes compared with that of normal control eyes. The density of the subbasal nerve plexus was significantly decreased but with increased tortuosity. Morphological changes correlated with decreased corneal sensitivity. Contralateral PEX eyes shared similar morphological changes with PEX eyes. Eyes with PEX had a significantly shallower anterior chamber and decreased angle openness during light-induced pupil constriction. The iridolenticular contact distance was significantly greater in PEX eyes than in contralateral eyes. A Japanese national survey demonstrated the increased incidence of PEX endotheliopathy as the cause of unknown bullous keratopathy.

CONCLUSIONS

PEX keratopathy involves all layers of the cornea. Morphological changes of the anterior chamber may contribute to PEX progression. Contralateral eyes were at preclinical stages of the PEX process. PEX endotheliopathy accounts for an increased incidence of bullous keratopathy, especially in a country with a large aged population, such as Japan.