Correlation between pupil diameter and angle configuration in the dark room provocative test

Area of Science:

• Ophthalmology
• Anatomic studies

Background:

• Primary angle closure is a significant risk factor for glaucoma.
• The dark room provocative test is commonly used to assess primary angle closure risk.
• Assessing anterior chamber angle configuration is crucial for diagnosing angle closure.

Purpose of the Study:

• To investigate the relationship between pupil diameter changes and anterior chamber angle configuration during the dark room provocative test.
• To determine the optimal duration of dark adaptation for reliable assessment of primary angle closure suspects.

Main Methods:

• Anterior segment optical coherence tomography (AS-OCT) was used to measure anterior chamber angle configuration and pupil diameter.
• The study included 70 primary angle closure suspects and 40 normal controls.
• Measurements were taken at 3 minutes and 1.5 hours of dark adaptation.

Main Results:

• The number of closed angle segments was significantly higher at 3 minutes of dark adaptation compared to room light or 1.5 hours.
• Pupil diameter was significantly associated with closed angle segments at 3 minutes but not at 1.5 hours.
• The dark room test was positive in more eyes at 3 minutes (63%) than at 1.5 hours (44%).

Conclusions:

• Assessing anterior chamber angle configuration by AS-OCT after short-term dark adaptation (3 minutes) is more reliable for identifying primary angle closure suspects.
• A 3-minute dark adaptation period is recommended for the dark room provocative test.