[Central physiologic relative scotoma after dark adaptation].

Area of Science:

• Ophthalmology
• Visual Neuroscience
• Physiology

Context:

• Understanding dark adaptation is crucial for assessing visual function in low light.
• Physiologic central retinal scotoma is a normal finding during scotopic vision.
• Previous research has not fully elucidated the precise conditions for its appearance.

Purpose:

• To determine the conditions and characteristics of the physiologic central retinal scotoma during dark adaptation.
• To establish the optimal duration for dark adaptation to reveal this scotoma.
• To provide data for the accurate examination of the visual analyzer under scotopic illumination.

Summary:

• Examinations of 80 healthy eyes revealed that a physiologic central retinal scotoma emerges 20-25 minutes into dark adaptation under scotopic illumination.
• The optimal duration for dark adaptation to consistently reveal this scotoma was found to be 40-45 minutes.
• The scotoma is often observed superior to the fixation point, with horizontal dimensions of 4-10 degrees and vertical dimensions of 3-8 degrees.

Impact:

• The findings are essential for interpreting visual field tests conducted in scotopic conditions.
• Recognizing this physiologic scotoma aids in the differential diagnosis of ophthalmological conditions.
• This research contributes to a better understanding of normal visual function in low light environments.