gms | German Medical Science

Background: Optical coherence tomography (OCT) is indispensable for studying the progression of age-related macular degeneration (AMD), since it can show quantitatively morphological changes of the retina. However, current OCT devices can only be used in clinical settings and do not provide functional information. We developed a full-field (FF) technology for OCT which acquires all A-scans in parallel. This technology allows for very compact (shoe box size) low cost (5000 €) devices which can be used in point of care and home care settings. FF-OCT also allows invasive marker-free functional imaging of retinal function.

Methods: Two FF-OCT devices were evaluated. The low-cost version used the time domain (TD) principle and was tested with 39 patients with neovascular AMD for detection of relevant biomarkers. The device measured a field of 2 mm x 4 mm at 15 µm resolution within 10 seconds.

The second device used swept-source OCT for ultra-fast imaging of the retina with more than 100 volumes/s. Nanometer dynamic changes of the thickness of the photoreceptor and the ganglion cell layer were evaluated after optical stimulation in healthy subjects.

Results: With the low-cost version, patients were able to do unassisted OCT imaging of their retina with high success rate after only 5 to 10 min training. The most relevant biomarkers for AMD (i.e. intraretinal fluid, subretinal fluid and pigment epithelium detachment) were visible in the OCT volumes.

With the ultra-fast OCT, responses of photoreceptor and neuronal cells could be measured quantitatively.

Conclusions: FF-OCT opens new perspectives in imaging AMD progression by enabling daily self-surveillance by the patient at home. Continuous evaluation of the disease may become possible using automatic evaluation by artificial intelligence.

Functional imaging may enable an even earlier detection of disease progression.