Elsevier

Ophthalmology

Volume 112, Issue 6, June 2005, Pages 980-984
Ophthalmology

Original article
Visualization of Anterior Chamber Angle Dynamics Using Optical Coherence Tomography

https://doi.org/10.1016/j.ophtha.2005.01.022Get rights and content

Purpose

To describe the technology of optical coherence tomography (OCT) in imaging the anterior chamber angles and its impact on understanding the pathophysiology of angle-closure glaucoma (ACG).

Design

Observational case series.

Participants

Three subjects with, respectively, impending angle-closure attack, plateau iris syndrome, and phacomorphic glaucoma were recruited.

Methods

The anterior chamber angle in each patient was imaged with a commercially available OCT unit. The angle configurations were assessed and compared before and after laser peripheral iridotomy (LPI) and argon laser peripheral iridoplasty (ALPI).

Main Outcome Measures

Visualization of the changes in the anterior chamber angle configurations and normalization of the intraocular pressure (IOP).

Results

A patient with impending angle-closure attack precipitated by a topical mydriatic agent was treated with LPI. Optical coherence tomography imaging of the anterior chamber angles was performed before and after the laser procedure. Conversion of anterior iris bowing and angle crowding to iris straightening and angle opening after LPI was demonstrated. Intraocular pressure became normalized with the change in angle configuration. The second patient presented with symptoms of intermittent angle-closure attacks and was initially diagnosed with primary ACG. Despite successful LPI, the angles remained occludable, and the IOP continued to be elevated. Optical coherence tomography was used to review the anterior chamber angle configuration and demonstrated a typical pattern compatible with the diagnosis of plateau iris syndrome. Subsequent ALPI converted the plateau configuration to open angle, with normalization of IOP and disappearance of symptoms. The third patient presented with an acute angle-closure attack and was diagnosed with phacomorphic glaucoma. Argon laser peripheral iridoplasty was performed successfully to open the angle, as evident by the OCT images, and the IOP was brought under control, together with relief of symptoms.

Conclusions

The commercially available OCT unit can be practically employed for anterior chamber angle imaging. The different patterns of angle configurations are correlated with the underlying pathophysiology in different forms of ACG.

Section snippets

Materials and Methods

The study was conducted in accordance with the ethical standards stated in the 1964 Declaration of Helsinki and approved by the Hong Kong Hospital Authority Kowloon West Cluster Clinical Research Ethics Committee. Informed consent was obtained from 3 Chinese patients, followed up in the Department of Ophthalmology, Caritas Medical Centre Hong Kong after explanation of the purpose and nature of the investigation. We imaged the anterior chamber angle using the OCT 3 unit Stratus OCT. The scanning

Case 1

A 74-year-old Chinese man had been followed up for the management of ocular hypertension. During a recent visit, dilated fundus examination was arranged. However, middilated pupils with intraocular pressures (IOPs) of 27 mmHg and 35 mmHg in the right and left eyes, respectively, were detected an hour after the application of a topical mydriatic agent. A presumptive diagnosis of impending angle-closure attack secondary to mydriasis was made. Optical coherence tomography was performed over both

Discussion

Although it is uncommon in Caucasians, PACG is a major form of glaucoma and a leading cause of glaucoma blindness in the East Asian population.5 An occludable angle, commonly defined as having <90° of the posterior trabecular meshwork seen under gonioscopy, is known to be associated with the development of angle-closure glaucoma (ACG) and acute angle-closure attack.6 Gonioscopy, particularly compression gonioscopy, is the gold standard for angle assessment, yet it may be limited in assessing

References (12)

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Manuscript no. 2004-22.

The authors have no proprietary interest in the development or marketing of any product mentioned in the article, and the study receives no financial support.

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