A ring scotoma is an annular (ring-shaped) visual field defect that is centered on the point of fixation, meaning the central point you focus on.
Understanding Ring Scotomas
A ring scotoma creates a blind area in a ring shape around your central vision. This means you might be able to see clearly in the very center and the outer edges of your vision, but have a blurry or blind spot in the area between.
Key Characteristics
- Annular Shape: The defect is ring-shaped.
- Centered on Fixation: The ring is located around the point where your gaze is fixed.
- Visual Field Defect: It represents a loss or reduction of vision in the affected area.
Causes of Ring Scotomas
According to available information, common causes of ring scotomas include:
- Age-Related Macular Degeneration (AMD): Particularly in elderly individuals.
- Hydroxychloroquine Toxicity: This medication, used for conditions like lupus and rheumatoid arthritis, can sometimes cause retinal damage leading to ring scotomas, particularly in younger patients.
Example of Ring Scotoma
Imagine looking at a clock. With a ring scotoma, you might see the numbers at the very center of the clock face (like the hour and minute hands) and the numbers around the edge (1, 2, 11, 12) clearly, but the numbers in between (3, 4, 5, 6, 7, 8, 9, 10) appear blurry or are missing altogether.
