Plateau Iris and Severity of Primary Angle Closure Glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Anatomical Studies

Background:

• Primary angle closure glaucoma (PACG) is a significant cause of vision loss.
• Plateau iris is an anatomical variation that can predispose eyes to angle closure.
• Understanding the distribution of plateau iris across PACG severity is crucial for disease management.

Purpose of the Study:

• To investigate the prevalence and distribution of plateau iris in patients with varying degrees of primary angle closure glaucoma (PACG).
• To correlate plateau iris configuration with disease severity using standardized ultrasound biomicroscopy (UBM) criteria.

Main Methods:

• A cross-sectional study involving 187 patients with PACG who had undergone laser peripheral iridotomy.
• Ultrasound biomicroscopy (UBM) was used to assess plateau iris based on specific criteria (anteriorly directed ciliary body, absent ciliary sulcus, iris angulation, flat iris plane, iridotrabecular contact).
• Disease severity was classified based on visual field mean deviation (MD) into early-to-moderate, advanced, and severe categories.

Main Results:

• Plateau iris was identified in 36.9% of the study population.
• The prevalence of plateau iris was significantly higher in the severe PACG group (50%) compared to the early-to-moderate PACG group (32.0%).
• In the severe PACG group, eyes with plateau iris had smaller anterior chamber area and volume.

Conclusions:

• A higher proportion of plateau iris configuration is observed in severe PACG eyes.
• Plateau iris may be a contributing factor to the progression and severity of primary angle closure glaucoma.
• Further research into the role of plateau iris in PACG pathogenesis is warranted.