Congenital cataracts are a major cause of blindness with early detection the most important factor in reducing impact on future vision.
Incidence is ~3 per 100,000 in the United Kingdom 1. Although the incidence tends to be higher in areas with increased rates of congenital infection 5.
- low birth weight prematurity
Congenital cataracts may be unilateral or bilateral 2.
There are over 50 causes of congenital cataracts. Some common causes include:
- idiopathic (~50%) 2,4
- hereditary e.g. trisomy 21 (Down syndrome), trisomy 13, Lowe syndrome
- infection, e.g. rubella, VZV, cytomegalovirus, HSV, toxoplasmosis
- metabolic, e.g. galactokinase deficiency
- assessment of the lens is recommended on second-trimester anomaly scans 3
- lens will appear echogenic
The MRI features of congenital cataract include 6:
- increase thickness of the lens(es) > 4 mm
- low signal on T1
- high signal on T2
Treatment and prognosis
Congenital cataracts that cause significant visual disturbance are treated early with surgery 1,2.
- 1. Russell HC, McDougall V, Dutton GN. Congenital cataract. BMJ. 2011;342 (may27 1): d3075. doi:10.1136/bmj.d3075 - Pubmed citation
- 2. Lloyd IC, Goss-Sampson M, Jeffrey BG et-al. Neonatal cataract: aetiology, pathogenesis and management. Eye (Lond). 1992;6 ( Pt 2) (2): 184-96. doi:10.1038/eye.1992.37 - Pubmed citation
- 3. Bethune, M., Alibrahim, E., Davies, B., & Yong, E. A pictorial guide for the second trimester ultrasound. AJUM August 2013; 16 (3):98-113. Free article.
- 4. Ophthalmology review. Thieme Publishing Group. ISBN:3131278412. Read it at Google Books - Find it at Amazon
- 5. Evidence-based ophthalmology. BMJ Books. ISBN:072791443X. Read it at Google Books - Find it at Amazon
- 6. Barakat E, Ginat DT. Magnetic resonance imaging (MRI) features of cataracts in pediatric and young adult patients. (2020) Quantitative imaging in medicine and surgery. 10 (2): 428-431. doi:10.21037/qims.2020.01.03 - Pubmed