Single-shot ultrawide-field polarization diversity optical coherence tomography imaging of retinitis pigmentosa and choroidal lesions

Abstract

Purpose : To investigate the potential clinical utility of ultrawide-field polarization diversity optical coherence tomography (UWF-PD-OCT) in the diagnosis and management of retinal and choroidal conditions, and to compare its performance with that of other imaging modalities such as fundus photography and autofluorescence.

Methods : Two prototype UWF-PD-OCT systems were implemented and compared for this study. Both systems employed a 400kHz vertical-cavity surface-emitting laser (VCSEL) centered at 1060 nm, enabling a long imaging range and high-volume scan speed. The first-generation system was based on a 55-degree field-of-view (FOV) retinal scanner. The second-generation UWF-PD-OCT system further extended the imaging area to 120-degree FOV, allowing visualization of the peripheral retina. Melanin distribution in the retina can be visualized with the adaptive kernel-based Degree-of-polarization-uniformity (DOPU) calculation. Patients with choroidal lesions and retinal conditions were recruited from clinics in Vancouver General Hospital; including choroidal nevi (N=22), choroidal melanomas (N=15), and retinitis pigmentosa (RP; N=16) patients. The diagnostic accuracy of UW-PD-OCT was compared with other imaging modalities. The reproducibility and repeatability of UW-PD-OCT measurements were also assessed.

Results : The results of this study showed that UWF-PD-OCT was able to provide detailed and high-resolution images of the retina and choroid in all patients. In patients with choroidal nevi and melanomas, UWF-PD-OCT was able to highlight the margins of the lesions more clearly compared to standard imaging modalities such as fundus photography (Figure 1). In addition, UWF-PD-OCT was able to track changes in the lesions over time more accurately. In RP patients, UWF-PD-OCT was able to visualize not only the photoreceptors and retinal pigment epithelium changes in the central retina, but also show abnormalities in the peripheral retina (Figure 2). This is particularly important as RP often progresses from the peripheral retina inward.

Conclusions : This study demonstrated the clinical utility of UWF-PD-OCT in the diagnosis and management of retinal and choroidal diseases. The ability to visualize the peripheral retina with melanin-specific contrast is a significant advantage over other imaging modalities.

This abstract was presented at the 2023 ARVO Imaging in the Eye Conference, held in New Orleans, LA, April 21-22, 2023.