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Abstract #15872 Published in IGR 2-3
The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration
The AGIS InvestigatorsAmerican Journal of Ophthalmology 2000; 130: 429-440
PURPOSE: To investigate the association between control of intraocular pressure (IOP) after surgical intervention for glaucoma and visual field deterioration. METHODS: In the Advanced Glaucoma Intervention Study, eyes were randomly assigned to one of two sequences of glaucoma surgery, one beginning with argon laser trabeculoplasty and the other trabeculectomy. In the present article, the authors examine the relationship between IOP and progression of visual field damage over six or more years of follow-up. In the first analysis, designated predictive analysis, they categorize 738 eyes into three groups, based on IOP determinations over the first three six-month follow-up visits. In the second analysis, designated associative analysis, the authors categorize 586 eyes into four groups, based on the percentage of six-month visits over the first six follow-up years in which eyes presented with an IOP of less than 18 mmHg. The outcome measure in both analyses is change from baseline in follow-up visual field defect score (range, 0-20 units). RESULTS: In the predictive analysis, eyes with an early average IOP greater than 17.5 mmHg had an estimated worsening during subsequent follow-up that was one unit of visual field defect score greater than eyes with an average IOP of less than 14 mmHg (p = 0.002). This amount of worsening was greater at seven years (1.89 units; p < 0.001) than at two years (0.64 units; p = 0.071). In the associative analysis, eyes with 100% of visits with an IOP of less than 18 mmHg over six years had mean changes from baseline in visual field defect score close to zero during follow-up, whereas eyes with less than 50% of visits with an IOP of less than 18 mmHg had an estimated worsening over follow-up of 0.63 units of visual field defect score (p = 0.083). This amount of worsening was greater at seven years (1.93 units; p < 0.001) than at two years (0.25 units; p = 0.572). CONCLUSIONS: In both analyses, low IOP is associated with reduced progression of visual field defect, thus supporting evidence from earlier studies of a protective role for low IOP in visual field deterioration.
Dr. P.C. VanVeldhuisen, AGIS Coordinating Center, 11325 Seven Locks Road, Suite 214, Potomac, MD 20854, USA. pvanveldhuisen@emmes.com
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
6.6.2 Automated (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
