23 months ago

david 4.2k

@david_fe

This is section 7 of AGIS.

Other sections include:

1. Study design and methods and baseline characteristics of study patients
2. Visual field test scoring and reliability
3. Baseline characteristics of black and white patients

Abstract

Purpose: To investigate the association between control of intraocular pressure 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 we examine the relationship between intraocular pressure and progression of visual field damage over 6 or more years of follow-up. In the first analysis, designated Predictive Analysis, we categorize 738 eyes into three groups based on intraocular pressure determinations over the first three 6-month follow-up visits. In the second analysis, designated Associative Analysis, we categorize 586 eyes into four groups based on the percent of 6-month visits over the first 6 follow-up years in which eyes presented with intraocular pressure less than 18 mm Hg. The outcome measure in both analyses is change from baseline in follow-up visual field defect score (range, 0 to 20 units).

Results: In the Predictive Analysis, eyes with early average intraocular pressure greater than 17.5 mm Hg had an estimated worsening during subsequent follow-up that was 1 unit of visual field defect score greater than eyes with average intraocular pressure less than 14 mm Hg (P =.002). This amount of worsening was greater at 7 years (1.89 units; P <.001) than at 2 years (0.64 units; P =.071). In the Associative Analysis, eyes with 100% of visits with intraocular pressure less than 18 mm Hg over 6 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 intraocular pressure less than 18 mm Hg had an estimated worsening over follow-up of 0.63 units of visual field defect score (P =.083). This amount of worsening was greater at 7 years (1.93 units; P <.001) than at 2 years (0.25 units; P =.572).

Conclusions: In both analyses low intraocular pressure is associated with reduced progression of visual field defect, supporting evidence from earlier studies of a protective role for low intraocular pressure in visual field deterioration.

Commentary:

The Advanced Glaucoma Intervention Study (AGIS) was a multicenter, randomized controlled clinical trial designed to evaluate two sequences of treatments in patients with advanced, medically uncontrolled open-angle glaucoma. A total of 591 patients (789 eyes) were enrolled.

AGIS patients were recruited approximately 30 years ago, from 1988 to 1992. At that time, medical therapy for glaucoma consisted of beta-blockers, miotics, and oral carbonic anhydrase inhibitors. Since then, the landscape of glaucoma treatment has evolved significantly to include new medications, surgical techniques, and technological advances. If AGIS were to be repeated today, the likely modifications would be to decrease the target IOP. Additionally, whereas AGIS relied on visual acuity and automated perimetry to assess visual function, OCT could be added to monitor structural parameters of the optic disc and retinal nerve fiber layer. Source: glaucomatoday.com.

The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration.The AGIS Investigators - PubMed