What Causes Sudden Vision Loss?

Discussion
Vision loss, whether chronic or acute, is distressing at any time for patients and families. Prompt evaluation and treatment are important as maintenance of any acuity and light or movement is considered paramount. Most vision loss is due to chronic problems and aging issues but the differential diagnosis is broad. For any age, but especially children, uncorrected refractive errors can cause problems in not only in childhood but throughout someone’s lifetime.
Visual impairment for distance vision is considered mild if worse than 6/12 in meters = 20/40 in feet or 0.3 LogMAR and for moderate impairment is 6/18 meters = ~20/60 = ~0.6 LogMAR. LogMAR stands for the Logarithm of the Minimum Angle of Resolution and is considered more accurate than other charts. Near vision is considered impaired if acuity is worse than N6 or N8 at 40 cm with existing correction. N numbers are the size of the letters on the handheld card.
Examples of some visual acuity scale equivalents

Foot
20/16
20/20
20/32
20/40
20/63
20/80
20/100

Meter
6/4.8
6/6
6/9.5
6/12
6/19
6/24
5/30

LogMAR
-0.1
0.0
0.2
0.3
0.5
0.6
0.7

Learning Point
Sudden vision loss is most commonly due to an acute event that has an obvious cause such as trauma, stroke, or seizure. Others can be less obvious such as a migraine or slow-growing tumor. Psychiatric causes can be more difficult to evaluate and tease out from other causes. Common presentations of factitious disorder can be found here.
The differential ...

Source: PediatricEducation.org - September 5, 2022 Category: Pediatrics Authors: Pediatric Education Tags: Uncategorized Source Type: news