Incomplete achromatopsia is a variant of congenital achromatopsia in which cone function is impaired but not completely absent. People typically have reduced colour discrimination and visual acuity, but symptoms may be milder than in complete forms.
Clinical Features
Affected individuals often experience photophobia, nystagmus, and blurred central vision, with some residual perception of certain colours. Vision may improve slightly in lower light levels, though detail still remains limited.
- Usually shares the same genetic causes as complete achromatopsia, with different functional impact
- Colour vision tests show severe but not absolute loss of chromatic discrimination
- Fundus appearance can be normal or show subtle macular changes
- Symptoms are typically stable over time
Management
Management principles mirror those for complete achromatopsia, aiming to reduce light sensitivity and enhance usable vision. Tailored low vision support and educational adjustments are important.
- Tinted or filter lenses can improve comfort and contrast
- Magnification devices assist with reading and near tasks
- Regular assessments track functional vision and adapt support as needs change
- Genetic counselling offers information on inheritance and potential future therapies
