A biochemical research team led by Professor Shih-Hsiung Wu, Distinguished Research Fellow and Deputy Director of Institute of Biological Chemistry, has successfully explained the biochemical mechanism behind a type of eye drops commonly used for cataract. It has been unknown why this eye drop solution was effective against cataract. The research was published in the online edition of Inorganic Chemistry, one of journals published by the American Chemical Society, on Dec. 7, 2010.
    Eye drops containing a compound named pirenoxine (PRX) have been commonly used by cataract sufferers for nearly 60 years, and have a reputation for being very effective. Up until now, however, the biochemistry behind their effectiveness was unknown, and the legitimacy of their use has been questioned by doctors.

In their study, first author of the article, Dr. Jiahn-Haur Liao, and his colleagues showed how PRX binds to calcium and selenite in the lens, effectively reducing the opacity seen in cataract. Abnormally high levels of calcium are known to result in the loss of transparency in the cortex of the lens. Selenite has also been connected to lens opacity in scientific studies.

In Taiwan eye drops containing pirenoxine can only be purchased by prescription, but in several Asian countries they are available over-the-counter. The study may pave the way for the further use of pirenoxine as a bona fide treatment for cataract.

The full article entitled "Ditopic Complexation of Selenite Anions or Calcium Cations by Pirenoxine: An Implication for Anti-Cataractogenesis" is available in the online version of Inorganic Chemistry at: http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/ic102151p

The full list of authors is: Jiahn-Haur Liao, Chien-Sheng Chen, Chao-Chien Hu, Wei-Ting Chen, Shao-Pin Wang, I-Lin Lin, Yi-Han Huang, Ming-Hsuan Tsai, Tzu-Hua Wu, Fu-Yung Huang and Shih-Hsiung Wu.