The advanced glaucoma intervention tudy (AGI): 7. the relationhip between control of intraocular preure and viual field deterioration

PURPOE: To invetigate the aociation between control of intraocular preure after urgical intervention for glaucoma and viual field deterioration. METHOD: In the Advanced Glaucoma Intervention tudy, eye were randomly aigned to one of two equence of glaucoma urgery, one beginning with argon laer trabeculoplaty and the other trabeculectomy. In the preent article we examine the relationhip between intraocular preure and progreion of viual field damage over 6 or more year of follow-up. In the firt analyi, deignated Predictive Analyi, we categorize 738 eye into three group baed on intraocular preure determination over the firt three 6-month follow-up viit. In the econd analyi, deignated Aociative Analyi, we categorize 586 eye into four group baed on the percent of 6-month viit over the firt 6 follow-up year in which eye preented with intraocular preure le than 18 mm Hg. The outcome meaure in both analye i change from baeline in follow-up viual field defect core (range, 0 to 20 unit). REULT: In the Predictive Analyi, eye with early average intraocular preure greater than 17.5 mm Hg had an etimated worening during ubequent follow-up that wa 1 unit of viual field defect core greater than eye with average intraocular preure le than 14 mm Hg (P = .002). Thi amount of worening wa greater at 7 year (1.89 unit; P < .001) than at 2 year (0.64 unit; P = .071). In the Aociative Analyi, eye with 100% of viit with intraocular preure le than 18 mm Hg over 6 year had mean change from baeline in viual field defect core cloe to zero during follow-up, wherea eye with le than 50% of viit with intraocular preure le than 18 mm Hg had an etimated worening over follow-up of 0.63 unit of viual field defect core (P = .083). Thi amount of worening wa greater at 7 year (1.93 unit; P < .001) than at 2 year (0.25 unit; P = .572). CONCLUION: In both analye low intraocular preure i aociated with reduced progreion of viual field defect, upporting evidence from earlier tudie of a protective role for low intraocular preure in viual field deterioration