Age and Sex-Related Changes in Retinal Function in the Vervet Monkey

Area of Science:

• Neuroscience
• Ophthalmology
• Gerontology

Background:

• Retinal function declines with age, with early changes occurring in the retina.
• Sex-related differences in retinal function are increasingly recognized.
• Understanding retinal aging trajectories is crucial for visual health.

Purpose of the Study:

• To investigate age- and sex-related changes in retinal function using the flicker electroretinogram (ERG).
• To assess the cone-bipolar pathway's response to light stimulation across different age groups and sexes.

Main Methods:

• Utilized light-adapted flicker electroretinogram (ERG) in age- and sex-matched vervet monkeys (N=35, aged 9-28 years).
• Stimulated the retina with light flashes at frequencies from 5 to 40 Hz to isolate the cone-bipolar axis.
• Compared electroretinogram (ERG) waveform characteristics between younger (9-20 years) and older (21-28 years) monkeys.

Main Results:

• Older monkeys exhibited significantly prolonged implicit times in flicker ERG responses across all tested frequencies (p < 0.05).
• A significant reduction in response amplitude was observed specifically in older male monkeys (p < 0.05).
• Sex-specific differences in voltage and temporal characteristics of retinal responses were noted in older individuals.

Conclusions:

• Aging negatively impacts photopic retinal responses, consistent with findings in humans and other species.
• Degenerative processes may target retinal circuitry, particularly the cone subsystem, with aging.
• Hormonal environment differences might contribute to sex-specific retinal aging patterns.