PURPOSE: Following exposure to a bright light that bleaches a significant portion of photopigment, the eyes take several minutes to regain sensitivity. This slow process, known as dark adaptation, is impaired in patients with age-related macular degeneration and is an important candidate biomarker for this disease. The aim of this study was to evaluate the effect of age on cone dark adaptation. METHODS: Data were obtained from 41 healthy adults aged between 20 and 83 years. Pupils were dilated and 96% of cone photopigment was "bleached," before threshold was monitored continuously for 5 min in the dark, using a 4° diameter achromatic spot centered on the fovea. Threshold recovery data were modeled, and the time constant of cone recovery (τ), initial cone thresholds, and final cone thresholds were determined. Regression analysis was used to determine the relationship between age and cone dark adaptation parameters. RESULTS: Cone τ increased by 16.4 s/decade of life, indicating a progressive slowing of dark adaptation with increasing age. This change in cone τ throughout adulthood was significant (p < 0.0005). There was no significant relationship between increasing age and initial cone threshold (p = 0.84) or final cone threshold (p = 0.82). CONCLUSIONS: 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.
PURPOSE: Following exposure to a bright light that bleaches a significant portion of photopigment, the eyes take several minutes to regain sensitivity. This slow process, known as dark adaptation, is impaired in patients with age-related macular degeneration and is an important candidate biomarker for this disease. The aim of this study was to evaluate the effect of age on cone dark adaptation. METHODS: Data were obtained from 41 healthy adults aged between 20 and 83 years. Pupils were dilated and 96% of cone photopigment was "bleached," before threshold was monitored continuously for 5 min in the dark, using a 4° diameter achromatic spot centered on the fovea. Threshold recovery data were modeled, and the time constant of cone recovery (τ), initial cone thresholds, and final cone thresholds were determined. Regression analysis was used to determine the relationship between age and cone dark adaptation parameters. RESULTS: Cone τ increased by 16.4 s/decade of life, indicating a progressive slowing of dark adaptation with increasing age. This change in cone τ throughout adulthood was significant (p < 0.0005). There was no significant relationship between increasing age and initial cone threshold (p = 0.84) or final cone threshold (p = 0.82). CONCLUSIONS: 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.
Authors: Frans Vinberg; Grazyna Palczewska; Jianye Zhang; Katarzyna Komar; Maciej Wojtkowski; Vladimir J Kefalov; Krzysztof Palczewski Journal: Neuroscience Date: 2019-08-07 Impact factor: 3.590
Authors: Daniel Ruminski; Grazyna Palczewska; Maciej Nowakowski; Agnieszka Zielińska; Vladimir J Kefalov; Katarzyna Komar; Krzysztof Palczewski; Maciej Wojtkowski Journal: Biomed Opt Express Date: 2019-08-09 Impact factor: 3.732
Authors: Ji-Young Kim; Hui Zhao; Jennifer Martinez; Teresa Ann Doggett; Alexander V Kolesnikov; Peter H Tang; Zsolt Ablonczy; Chi-Chao Chan; Zhenqing Zhou; Douglas R Green; Thomas A Ferguson Journal: Cell Date: 2013-07-18 Impact factor: 41.582