Author: Safa Mohanna
Co-authors: Leila S. Eppenberger, Oliver Pfäffli, Lucas M. Bachmann, Michael A. Thiel, Martin K. Schmid
Abstract
PurposeTransscleral optical imaging (TOI) is a novel microscopy technique which allows for in-vivo assessment of retinal structures in humans with the potential of clinical application in a multimodal retinal imaging approach. Here we share first clinical experiences using TOI with age-related macular degeneration (AMD) patients to qualitatively assess differences in retinal layers by an explorative description of acquired images.
Setting/Venue
Single center prospective observational study conducted at the Eye Clinic of the Cantonal Hospital Lucerne, Switzerland. The protocol is registered on ClinicalTrials.gov (Identifier: NCT04912622).
Methods
Currently patients with age-related macular degeneration receiving treatment at the medical retinal clinic of the Cantonal Hospital Lucerne are being recruited as part of the main study. Here, a selection of patients with wet or dry AMD and the absence of exclusion criteria, namely history of epilepsy or inability to follow the procedures of the study (i.e., dementia, psychological disorders, language problems etc.) are being descriptively analyzed. Participants undergo clinical ophthalmological examination, followed by optical coherence tomography (OCT), autofluorescence (AF) and optical biometry examinations, ahead of TOI imaging. TOI image acquisition is conducted using the novel retinal camera Cellularis® (prototype version 2.0). Both RPE and PR layer images are acquired across five macular zones of 6.7° x 6.7°.
The explorative description of each acquired TOI image consists of labelling and classification according to observed patterns.
Results
120 eyes of 70 participants (59% women; mean age 78±8 years) were analyzed. Regarding AMD diagnosis, 52% (n=62) of the eyes were early to dry AMD versus 48% (n=58) wet AMD. Across AMD diagnosis, we observed the emergence of five recurring patterns. The patterns were observed consistently, sometimes different patterns were observed in the same eye. The first pattern by order of prevalence, “Blob”, was characterized by a clearly delineated zone of circular shape composed of extracellular mass between RPE-cells (n=63). The second pattern observed, “Spots”, was a homogeneous motif of small hyperreflective clusters, the motif was typically formed of numerous (20 to 50) small clusters (n=39). The third pattern, “Clumps” was a salient pattern below RPE-cells, associated with early stages of AMD, characterized by a homogenous mosaic of similarly sized circular clusters (about 230 µm) of hyperreflective material surrounded by hyporeflective lines, each adjacent to one another (n=31). The fourth pattern, “Drops”, was composed of few (4 to 7) homogeneously sized distanced hyporeflective clusters surrounded by hyperreflective lines below and sometimes between RPE cells (n=14). Finally, the fifth pattern, “Dark Spot”, was composed of unique isolated hypo-reflective cluster of circular shape composed of RPE-cells (n= 9).
Conclusions
We report first clinical experiences using TOI with AMD; and share an explorative analysis and description of recurring patterns observed. This initial qualitative classification represents a first basis for future comparison to clinical and morphological features. These very first results with AMD patients highlight the promising potential of TOI in the clinical setup, particularly by adding further value to existing multimodal imaging in disease evolution and monitoring.
Financial Disclosure
None.
