Swept-Source Wide-Field OCT and OCTA (24 × 20 mm and 26 × 21 mm) in Inherited Retinal Dystrophies: First Clinical Experience with Two Novel Devices.

Background

Optical coherence tomography (OCT) and OCT angiography (OCTA) retinal imaging in inherited retinal dystrophies (IRD) has been limited to the posterior pole and central midperiphery (up to about 16.5 × 16.5 mm). Two novel commercially available swept-source (SS) OCT/-OCTA devices provide the possibility of wide-field (WF) evaluation of retinal and choroidal structures, including the vasculature, in a single examination.

Methods

A limited consecutive series of 16 IRD patients were examined with a BMizar (400 kHz, 24 × 20 mm scan width) and a Dream OCT (200 kHz, 26 × 21 mm scan width) in addition to the normal clinical examination protocol. This series included patients with retinitis pigmentosa, cone-rod dystrophy, macular dystrophy and autosomal recessive bestrophinopathy. In addition, 12 healthy probands were examined.

Results

WF-SS-OCT/-OCTA enabled the detection of retinal, choroidal and choriocapillaris alterations in the macular and midperiphery in a short, single examination session of up to 15 s. Even small foveal lesions and a small silent macular neovascularization were detected on WF screening. Regional alterations of choroidal and choriocapillaris flow patterns were identified. These were mostly in correspondence with areas that appeared clinically affected, but unexpected lesions were identified as well. Occlusion of peripheral retinal vessels was seen in retinitis pigmentosa, though flow was detected in retinal vessels, which were difficult to distinguish on fundus images. In one patient with nystagmus, WF-SS-OCT/-OCTA was performed, whereas standard OCT volume scan could not be obtained. The most frequent artifact were horizontal lines of misalignment, which did not interfere with the detection of pathologies.

Conclusions

Both WF-SS-OCT/-OCTA devices provide detailed insights in structural and vascular retinal and choroidal alterations in a single, short examination. Larger series of IRD patients examined with WF-SS-OCT/-OCTA promise to provide novel insights into the pathology of IRDs.