Abstract
Structure-function relations were studied in patients with a variety of retinal diseases. Functional measures included the cone-mediated, multifocal electroretinogram (mfERG), visual fields and contrast sensitivity using stimuli restricted to retinal areas imaged at high resolution. Three bench top instruments were used for imaging: (1) adaptive optics (AO) flood-illumination which results in approximately 2 µm lateral resolution retinal photographs, (2) Fourier-domain optical coherence tomography (Fd-OCT) providing high speed (9–36 frames/sec) B-scans with ∼5 µm axial resolution and 15 µm lateral resolution, and (3) AO and FdOCT to result in 3 µm isotropic resolution and 3D reconstruction of retina. Our results indicate that mfERG losses in AMD are not restricted to areas with drusen, but structure-function correlations are clearer in cases of retinal dystrophy. AO images clearly demonstrated losses of cones in cone-rod dystrophies that were correlated with localized functional changes including contrast sensitivity, multifocal ERG and visual field sensitivity. The high-resolution Fd-OCT images also showed changes in the photoreceptor layer at the corresponding locations. Furthermore, the AO-OCT images revealed irregularities in the arrangement of cone photoreceptors as well as in anterior retinal layers in cone-rod dystrophies.