Birdshot Chorioretinopathy with Double-Layer Sign and Choroidal Neovascularization: A Single-Centre Analysis.

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Diseases

Background:

• Birdshot chorioretinopathy (BSCR) is a chronic posterior uveitis.
• The double-layer sign on optical coherence tomography (OCT) involves hyperreflective material between the retinal pigment epithelium (RPE) and Bruch's membrane.
• The clinical significance of this sign in BSCR requires further elucidation.

Purpose of the Study:

• To describe the clinical features associated with the double-layer sign on OCT in patients with BSCR.
• To investigate the prevalence and characteristics of the double-layer sign in BSCR.
• To correlate the double-layer sign with choroidal neovascularization (CNV) and treatment outcomes.

Main Methods:

• Retrospective observational study of patients diagnosed with HLA-A29+ BSCR.
• Review of patient charts and OCT images to identify the presence of the double-layer sign.
• Analysis of clinical features, including CNV, exudation, and treatment, in eyes with the double-layer sign.

Main Results:

• The double-layer sign was observed in 15% of eyes from 9 patients (18%) with BSCR.
• Choroidal neovascularization (CNV) was confirmed in 73% of eyes with the double-layer sign.
• Intra- or subretinal exudation occurred in 33% of affected eyes, with 20% receiving intravitreal bevacizumab treatment.

Conclusions:

• The double-layer sign on OCT in BSCR can indicate the presence of non-exudative or minimally active choroidal neovascularization.
• This OCT finding may be a marker for chronic inflammation affecting the posterior pole in birdshot chorioretinopathy.
• Further research is warranted to understand the long-term implications of the double-layer sign in BSCR management.