This study has shown cone-mediated dark adaptation to be significantly impaired in ARM. Our results provide compelling evidence in support of the diagnostic potential of cone dark adaptation and the use of annular stimuli at 12°. The observation that cone τ is highly diagnostic at this eccentricity is significant clinically because this parameter may be quantified within a few minutes.

Purpose: The global prevalence of age-related macular degeneration and associated central vision loss is rising. Central vision loss hinders the performance of many activities of daily living. Adaptive strategies such as eccentric viewing and steady eye strategy may be used to compensate for central vision loss. In order to establish the potential of these rehabilitation strategies, this systematic review evaluates current literature regarding the effectiveness of eccentric viewing and steady eye strategy training in people with central vision loss. Results: The search strategies identified 2605 publications, 36 of which met the inclusion criteria for the review, but only three of which were randomised controlled trials. This literature shows that eccentric viewing and steady eye strategy training can improve near visual acuity, reading speed, and performance of activities of daily living in people with central vision loss. However, there was insufficient literature to establish a relationship between training and distance visual acuity or quality of life. There is no conclusive evidence to show that a particular model of eccentric viewing training is superior to another, little clear evidence of a relationship between participant characteristics and training outcomes and no data regarding the cost effectiveness of training. Conclusion: This report highlights the need for further robust research to establish the true potential and cost effectiveness of eccentric viewing and steady eye strategy training as a rehabilitation strategy for individuals with central vision loss.

Our results provide evidence for age-related slowing of cone dark adaptation after a full bleach in healthy adults, which is likely to contribute to visual difficulties when moving from bright to dim photopic light levels. We propose that the sensitivity and specificity of cone τ as a biomarker for early age-related macular disease could be improved by taking into account the significant age-related decline in this parameter.

This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent AbstractBackground: This study aimed to identify the pre-adapting light intensity that generated the

We describe a new technique, high fidelity Imaging Retinal Densitometry (IRD), which probes the functional integrity of the outer retinal complex. We demonstrate the ability of the technique to map visual pigment optical density and synthesis rates in eyes with and without macular disease. A multispectral retinal imaging device obtained precise measurements of retinal reflectance over space and time. Data obtained from healthy controls and 5 patients with intermediate AMD, before and after photopigment bleaching, were used to quantify visual pigment metrics. Heat maps were plotted to summarise the topography of rod and cone pigment kinetics and descriptive statistics conducted to highlight differences between those with and without AMD. Rod and cone visual pigment synthesis rates in those with AMD (v = 0.043 SD 0.019 min −1 and v = 0.119 SD 0.046 min −1 , respectively) were approximately half those observed in healthy controls (v = 0.079 SD 0.024 min −1 for rods and v = 0.206 SD 0.069 min −1 for cones). By mapping visual pigment kinetics across the central retina, high fidelity IRD provides a unique insight into outer retinal complex function. This new technique will improve the phenotypic characterisation, diagnosis and treatment monitoring of various ocular pathologies, including AMD. Continuous photoreceptor function is dependent on the constant renewal of visual pigment molecules by a physiological process known as the visual cycle 1. Remarkably, the key enzymatic steps in the canonical visual cycle reside not in the photoreceptors but in the cells that nourish them, the retinal pigment epithelium (RPE). More specifically, the RPE converts the retinoid all-trans retinol back to 11-cis retinal via a series of relatively slow enzymatic reactions which, in the healthy eye, determine the rate at which visual pigment molecules can regenerate 2. Hence by measuring rod photoreceptor visual pigment synthesis rates we can probe a key aspect of RPE physiology. The RPE also supports the regeneration of visual pigments in cone photoreceptors but an additional visual cycle pathway that involves the neural retina's Müller Cells is also involved 2,3. The RPE, Bruch's membrane and the choriocapillaris, are associated with many ocular pathologies, most notably age-related macular degeneration (AMD) the developed world's leading cause of sight loss 4,5. In AMD, an increase in the thickness of basal laminar deposits, the presence of soft drusen and choriocapillaris drop out all work to impair normal RPE function 5. Hence, by measuring visual pigment synthesis rates we not only obtain information about the status of a vital physiological process, the visual cycle, but also information about the functional integrity of the outer retinal complex i.e. the photoreceptors, RPE, Müller Cells, Bruch's membrane and the choriocapillaris. Fortunately, visual pigment synthesis rates can be measured by recording the subtle changes in retinal reflectance associated with the visual cycle using a technique called densitometry 6,7. Although the...