Three-dimensional imaging of pigment epithelial detachment in age-related macular degeneration using optical coherence tomography, retinal thickness analysis and topographic angiography

Introduction: New diagnostic tools such as the retinal thickness analyzer (RTA), optical coherence tomography (OCT), and topographic angiography (TAG) were introduced into clinical ophthalmology during the last years giving the examiner new insights into anatomical and functional aspects of macular disease. In this study, advantages and disadvantages of the new imaging methods have been evaluated in patients with serous (sPED) and fibrovascular pigment epithelial detachments (fPED) secondary to age-related macular degeneration (AMD). Methods: TAG, using fluorescein angiography (FA), provides a three-dimensional profile of the fluorescein pattern based on the analysis of a set of 32 confocal images over a depth of 4 mm. RTA and OCT provide cross-sectional images of the neurosensory retina and the retinal pigment epithelium-choriocapillary complex as well as retinal thickness data encoded in a false color map. We compared and evaluated these modalities in 15 patients with fPED and 15 patients with sPED secondary to AMD. Results: In patients with classic fPED, TAG detected neovascular structures and delineated their configuration. In sPEDs, pooling of extravascular fluid was detected in a dome-shaped configuration. OCT provided detailed information on the neurosensory retina's structures but failed to detect the neovascular membrane in fPED. Mapping the retinal thickness, RTA and OCT both failed to detect the PED and showed typical algorithm error-based patterns. Conclusions: TAG OCT and RTA are useful imaging modalities in the evaluation of AMD cases. TAG visualizes the vascular configuration, dynamic perfusion, and leakage changes. OCT and RTA are able to complementarily document intra-, subretinal, and sub-RPE fluid accumulation secondary to CNV. However, OCT seems to be more efficient in imaging AMD-related pathologies than RTA, as this modality is often compromised by intra- or subretinal structural abnormalities. Nevertheless, all modalities may provide further valuable insight into AMD pathogenesis, enhance diagnostic quality, and improve the assessment of therapeutic effects.