Abstract: Plateau iris syndrome (PIS) presents a diagnostic challenge in ophthalmology, characterized by the anatomical predisposition to angle closure despite a patent iridocorneal angle. This article provides a comprehensive review of PIS, exploring its underlying mechanisms, clinical features, diagnostic criteria, treatment strategies, and recent advancements. By delving into the intricacies of PIS, ophthalmologists can refine their approach to patient care and optimize outcomes in this condition.

Introduction: Plateau iris syndrome represents a subtype of primary angle-closure glaucoma characterized by a flat iris configuration and anteriorly positioned ciliary processes, leading to angle closure despite apparent angle width on gonioscopy. Understanding the pathophysiology and clinical features of PIS is essential for accurate diagnosis and appropriate management.

Mechanisms: Plateau iris configuration predisposes individuals to angle closure by pushing the peripheral iris against the trabecular meshwork, obstructing aqueous outflow and elevating intraocular pressure (IOP). The mechanism involves a combination of anatomical factors, including shallow anterior chamber depth, steep iris curvature, and anteriorly positioned ciliary processes.

Clinical Features: Patients with PIS may present with symptoms of angle closure, including ocular pain, blurred vision, and halos around lights. However, clinical examination may reveal a patent iridocorneal angle on gonioscopy, leading to diagnostic confusion with other forms of glaucoma. Ancillary tests such as ultrasound biomicroscopy (UBM) or anterior segment optical coherence tomography (AS-OCT) may aid in confirming the diagnosis by visualizing the configuration of the iris and ciliary processes.

Diagnostic Criteria: Diagnosis of PIS requires a comprehensive ocular examination, including measurement of IOP, assessment of optic nerve morphology, visual field testing, and evaluation of angle structures. Ancillary tests such as UBM or AS-OCT play a crucial role in identifying the characteristic features of plateau iris configuration and guiding treatment decisions.

Management Strategies: Management of PIS aims to prevent angle closure episodes, lower IOP, and preserve visual function. Treatment modalities may include laser peripheral iridotomy (LPI) to relieve pupillary block, argon laser peripheral iridoplasty (ALPI) to flatten the peripheral iris, and topical medications to lower IOP. In cases of refractory angle closure or progressive optic nerve damage, surgical interventions such as trabeculectomy or glaucoma drainage devices may be considered.

Recent Advances: Recent innovations in PIS management focus on optimizing diagnostic techniques, refining treatment algorithms, and improving outcomes for affected individuals. Advancements such as swept-source AS-OCT and enhanced depth imaging (EDI) OCT offer high-resolution imaging of anterior segment structures, enabling precise assessment of iris configuration and ciliary body anatomy. Additionally, emerging pharmacological agents targeting iris dynamics and aqueous humor dynamics hold promise for improving IOP control and reducing the risk of angle closure in PIS.

Conclusion: Plateau iris syndrome poses diagnostic and therapeutic challenges in ophthalmology, necessitating a multidisciplinary approach to management. By staying informed about the latest research and innovations in PIS, ophthalmologists can optimize patient outcomes and improve quality of life for individuals affected by this condition.

For further reading and reference:

• American Academy of Ophthalmology – Plateau Iris Syndrome: https://www.aao.org/eye-health/diseases/plateau-iris-syndrome
• Glaucoma Research Foundation – Plateau Iris Syndrome: https://www.glaucoma.org/glaucoma/plateau-iris-syndrome.php
• National Eye Institute – Glaucoma: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma