Myocilin screening was performed from blood or saliva specimens taken from the village. The promoter region and exons 1-3 of myocilin were sequenced at the Portland Veterans Administration Medical center. Microsatellite marker analysis in the GLC1A region, including D1S452, D1S1619, D1S2790 and D1S242 was performed at deCODE (Reykjavik, Iceland).