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Scotopic sensitivity: relation to age, dietary patterns, and smoking status
B R Hammond1, A J Wenzel, M S Luther
1Visual Sciences Laboratory, Arizona State University, West Campus, Phoenix 85069-7100, USA.
Summary
Scotopic sensitivity loss in healthy individuals under 65 is minimal, even with factors like smoking. Age-related declines in rod-mediated vision are slow before 65, suggesting limited use for retinal health indicators in younger populations.
Area of Science:
- Ophthalmology
- Vision Science
- Gerontology
Background:
- Previous research suggests age-related rod-mediated sensitivity decline.
- This decline may be insignificant in healthy individuals under 65.
- Confounding factors like smoking and diet require consideration.
Purpose of the Study:
- To assess the relationship between age and scotopic sensitivity loss in individuals under 65.
- To determine if scotopic sensitivity losses are detectable when controlling for confounding factors.
- To investigate the impact of iris color, smoking status, and dietary patterns on scotopic sensitivity.
Main Methods:
- 121 subjects aged 20-63 were tested under dark-adapted (scotopic) conditions.
- Scotopic sensitivity measured as absolute thresholds to a 550-nm test light.
- Stimuli presented in Maxwellian view at 6 degrees in the temporal hemiretina.
Main Results:
- A slight, nonsignificant trend for scotopic sensitivity to decline with age was observed overall (p < 0.11).
- Significant declines were found in older past and never smokers (p < 0.024 and p < 0.05).
- Dietary vitamin E intake significantly explained variation in scotopic sensitivity (p < 0.03); no link with iris color.
Conclusions:
- Age-related scotopic sensitivity loss is slow before age 65.
- Individual variations in scotopic sensitivity are minimal in younger subjects, despite stressors like smoking.
- Scotopic sensitivity measurements may not be reliable indicators of retinal health in individuals under 65.