IOP Stress Testing Identifies Glaucoma Eyes at Risk of Fast Progression Despite Controlled Office Pressure

Area of Science:

• Ophthalmology
• Glaucoma Research
• Intraocular Pressure Management

Background:

• Glaucoma management relies on controlling intraocular pressure (IOP) to prevent functional and structural damage.
• Standard office IOP measurements may not fully capture an individual's risk for glaucoma progression.
• Identifying patients at risk despite seemingly controlled IOP is crucial for timely intervention.

Purpose of the Study:

• To determine if an intraocular pressure (IOP) stress test, specifically the water-drinking test (WDT), can identify glaucoma eyes at risk for faster progression.
• To evaluate the WDT's ability to detect progression risk in patients with apparently controlled office IOP.

Main Methods:

• A prospective cohort study involving 67 eyes of 36 glaucoma participants.
• Participants underwent a standardized water-drinking test (WDT) as an IOP stress test.
• Visual field (VF) and spectral-domain optical coherence tomography (SD-OCT) were used to assess functional and structural changes over time, with analyses adjusted for office IOP.

Main Results:

• Eyes with a WDT peak IOP greater than 21 mmHg showed significantly faster rates of mean deviation (MD) loss and retinal nerve fiber layer (RNFL) thinning.
• 37% of eyes with office IOP within target had a WDT peak IOP >21 mmHg, indicating a higher risk.
• The WDT identified 77% of fast-progressing eyes, whereas only 23% were above target based on office tonometry alone.

Conclusions:

• IOP stress testing, such as the WDT, is associated with faster functional and structural glaucoma progression.
• The WDT identified higher-risk eyes among those with apparently controlled office IOP.
• IOP stress testing provides complementary prognostic information to routine office tonometry for glaucoma management.