Contrast Sensitivity in Early to Intermediate Age-Related Macular Degeneration (AMD)

Area of Science:

• Ophthalmology
• Vision Science

Background:

• Advanced age-related macular degeneration (AMD) is known to affect contrast sensitivity (CS).
• Previous research on CS in early/intermediate AMD patients yields contradictory findings.
• Normal visual acuity does not preclude CS deficits in early/intermediate AMD.

Purpose of the Study:

• To evaluate the efficacy of contrast sensitivity (CS) testing in distinguishing early/intermediate age-related macular degeneration (AMD) patients with normal visual acuity from healthy controls.
• To investigate potential differences in CS between early/intermediate AMD and control groups.

Main Methods:

• Forty-nine participants (25 controls, 24 AMD patients) were recruited.
• CS functions were measured under photopic and mesopic conditions using stationary and counter-phase stimuli.
• Stimuli were presented at the fovea and 4 degrees eccentric fixation on a VPixx monitor.

Main Results:

• No significant differences in CS were observed between early AMD patients and control subjects across all tested conditions.
• Intermediate AMD patients exhibited significantly reduced CS compared to controls, particularly under mesopic (low light) conditions.
• Post-hoc analysis confirmed significant CS deficits in intermediate AMD patients under both stationary photopic and mesopic conditions at 1.5 cycles per degree.

Conclusions:

• Contrast sensitivity testing is not effective in discriminating early AMD from normal controls.
• Intermediate AMD patients demonstrate impaired CS, especially in low light conditions.
• Further research should explore alternative tests, such as those under dark-adapted conditions, for early AMD detection.