University of British Columbia and Vancouver Coastal Health scientistshave developed a potential cure for a rare eye disease, showing for the firsttime that a drug can repair a birth defect.

Aniridia is caused by the presence of a "nonsense mutation" – an extra "stop sign" on the gene that interrupts production of a protein crucial for eye development. Aniridia patients don't have an iris (the coloured ring around the pupil), and suffer many other eye abnormalities.
Ataluren is believed to have the power to override the extra stop sign, thus allowing the protein to be made. The UBC-VCH scientists initially thought the drug would work only in utero – giving it to a pregnant mother to prevent aniridia from ever arising in her fetus. But then they gave their specially formulated Ataluren eye drops, which they call START, to two-week-old mice with aniridia, and found that it actually reversed the damage they had been born with.
Source-Eurekalert