Progressive night blindness refers to conditions in which difficulty seeing in dim light worsens over time, usually due to degenerative disease of the rod photoreceptors. It is commonly associated with rod-cone dystrophies such as retinitis pigmentosa.
Symptoms and Causes
Individuals may first notice problems seeing in dark rooms or outdoors at night, followed by narrowing of peripheral vision as retinal degeneration progresses. Genetic defects affecting photoreceptor structure or function are the main causes.
- Symptoms often begin in childhood or early adulthood
- Visual field testing shows constriction, especially in the periphery
- Fundus changes can include bone-spicule pigmentation and vessel narrowing
- Family history is frequently present, though new mutations can occur
Management
Management focuses on preserving useful vision and supporting adaptation to increasing visual limitations. This includes low vision assessment, orientation and mobility training, and environmental modifications.
- Genetic testing may identify a specific dystrophy and inform prognosis
- Regular monitoring can detect treatable complications such as cataract or macular oedema
- Use of good lighting and high-contrast aids improves function in dim settings
- Support services can assist with educational and occupational planning
