Mean preoperative intraocular pressure ( IOP ) levels ( OLO : 28.0 9.4 ; MMC : 23.9 5.0 mm Hg ; p = 0.21 ) and medication score ( OLO : 3.4 1.6 ; MMC : 3.6 1.5 ; p = 0.56 ) were comparable in both groups .