For estimating functional consequences of VE-821 morphological alterations and assess treatment benefits in a more objective way. In previous attempts to correlate retinal function and structure, visual acuity was correlated with central retinal thickness derived from OCT measurements, e.g. in diabetic macular edema. However, the relationship was found to be poor and it was concluded that retinal thickness is a poor surrogate for visual acuity. Using SD-OCT and an automated segmentation technique, it was recently shown that the correlation between visual acuity and specifically the outer retinal thickness is considerably stronger than for full macular thickness suggesting that detailed image analysis is essential to find a correlation. Since visual acuity testing exclusively reveals foveal function but does not provide a functional map of the retina, kinetic or automated static perimetry has been used to reveal and quantify functional defects of the visual field. Using these techniques, there was a consistent relationship between the thickness of the photoreceptor layers as determined by SD-OCT and retinal sensitivity in retinitis pigmentosa, which is genetically heterogeneous group of photoreceptor degeneration. However, these techniques do not provide an accurate correlation between retinal structural pathology and functional defects. Co-registration of microperimetry, cSLO- and SD-OCT datasets now provides an exact overlay of functional and structural exams and reveals the functional impact of microstructural alterations in vivo. The cross sectional data show that there can be remarkable functional preservation if the pathology spares the outer neurosensory retina that accommodates the process of phototransduction, highlighting the eminent importance of photoreceptor layer integrity for maintaining visual function. Notably, anti-VEGF-A therapy appeared to be ineffective to prevent such functional loss in the longitudinal interventional clinical trial. Actually, recent studies showed that VEGF-inhibition can cause dysfunction and damage of the murine retina. There has long been the fundamental question about whether morphological changes in the neurosensory system precede functional alterations or vice versa. Our data may suggest that high-resolution imaging can detect very early retinal pathology before its progression causes functional loss as detected by functional mapping. It cannot unequivocally be decided whether there are compensatory functional mechanisms when there are sufficiently small morphological defects or whether microperimetry is methodologically limited to detect the earliest functional deficits, or both. In either case, high-resolution OCT appears superior to functional mapping to detect relevant damage of the central retina early in the disease process. cSLO topographic imaging of the retina provides approximately 15 mm transversal resolution. However, if aberrations are compensated using adaptive optics, the transversal resolution of a cSLO could be improved to less than 3 mm.