Thirty-nine ( 75 % ) of 52 patients with pterygia that recurred were aged < 50 years ( young ) vs. 72 ( 52 % ) of 138 young patients with no recurrence ; odds ratio ( OR ) = 1.54 ; 95 % confidence interval ( 95 % CI ) = 0.70-3 .36 ; p = 0.28 .