Intraocular pressure: modulation as treatment for glaucoma.

PURPOSE

To review the role of intervisit intraocular pressure (IOP) fluctuation as an independent risk factor for glaucoma.

DESIGN

Perspective after literature review.

METHODS

Analysis of pertinent publications in the peer-reviewed literature.

RESULTS

Disparate findings regarding the role of intervisit IOP variation have been published. IOP variation was a significant risk factor in the Advanced Glaucoma Intervention Study (AGIS), the Collaborative Initial Glaucoma Treatment Study, and other smaller studies. These studies have in common low IOPs (often after surgery) and moderately advanced disease. In the AGIS, when patients were stratified by mean IOP, only those patients with low IOPs showed the detrimental effects of IOP variation. IOP variation was not a significant risk factor in the Early Manifest Glaucoma Treatment Trial, and in 2 separate studies of ocular hypertensives. These studies have in common generally higher IOPs and an earlier stage of glaucoma (or no glaucoma at all). We believe these results are complementary rather than contradictory: existing data suggest that the effects of IOP variation depend on the characteristics of the patient, the baseline IOP, their stage of damage, the type of glaucoma, and other as-yet unknown factors.

CONCLUSIONS

Practitioners should consider whether patients who are progressing at low mean IOP may benefit from having IOP variation reduced. Single elevated measures of IOP may not be an anomaly or may not be related to compliance, but may identify patients who are at high risk for progressive glaucomatous damage, and thus should be monitored more carefully and potentially treated more aggressively.