At the end of the 10-year follow-up , ( 1 ) approximately one-third of the whole PDS patient population showed an IOP increase of 5 mm Hg or higher in at least 1 eye ; ( 2 ) phenylephrine testing identified eyes at high risk for developing IOP elevation ; and ( 3 ) LPI , when performed on high-risk eyes , reduced the rate of IOP elevation to the same level as the low-risk eyes .