Cataracts Research Today is a free monthly online journal that collates and summarizes the latest research about Cataracts, including details on surgical procedures, outcomes, causes, treatment.

Presbyopia: the first stage of nuclear cataract?

McGinty SJ, Truscott RJ

Save Sight Institute, Sydney, and Institute for Biomolecular Science, University of Wollongong, Wollongong, Australia.

Presbyopia, the inability to accommodate, affects almost everyone at middle age. Recently, it has been shown that there is a massive increase in the stiffness(1) of the lens with age and, since the shape of the lens must change during accommodation, this could provide an explanation for presbyopia. In this review, we propose that presbyopia may be the earliest observable symptom of age-related nuclear (ARN) cataract. ARN cataract is a major cause of world blindness. The genesis of ARN cataract can be traced to the onset of a barrier within the lens at middle age. This barrier restricts the ability of small molecules, such as antioxidants, to penetrate into the centre of the lens leaving the proteins in this region susceptible to oxidation and post-translational modification. Major protein oxidation and colouration are the hallmarks of ARN cataract. We postulate that the onset of the barrier, and the hardening of the nucleus, are intimately linked. Specifically, we propose that progressive age-dependent hardening of the lens nucleus may be responsible for both presbyopia and ARN cataract.

Published 22 May 2006 in Ophthalmic Res, 38(3): 137-48.
Full-text of this article is available online (may require subscription).

© 2005-2008 Cataracts Research Today. All Rights Reserved.