Cataract is an opacification or thickening of the lens and is the leading cause of blindness in the world 2.
Visual deterioration occurs with increasing degrees of severity. The diagnosis is made clinically.
Common causes include:
- old age (most common)
- congenital (see: congenital cataract)
- diabetes (osmotic)
- e.g. the 'radiation-induced cataract' in the interventional radiologist 1
Ocular ultrasound is performed when there is suspicion of posterior globe pathology but visualisation of the back of the eye is obscured by the opaque lens.
Especially useful in acute cataract formation with increased fluid within the lens as in traumatic and osmotic cataract (hyperglycaemia) as well as unsuspected lens injury. The affected lens is hypodense compared to the contralateral lens with a mean density difference of about 30 HU 3.
Treatment and prognosis
Treatment is surgical removal of the lens which is usually replaced by an intraocular lens implant.
- 1. Ainsbury EA, Bouffler SD, Dörr W et-al. Radiation cataractogenesis: a review of recent studies. Radiat. Res. 2009;172 (1): 1-9. doi:10.1667/RR1688.1 - Pubmed citation
- 2. Congdon N, Vingerling JR, Klein BE et-al. Prevalence of cataract and pseudophakia/aphakia among adults in the United States. Arch. Ophthalmol. 01;122 (4): 487-94. doi:10.1001/archopht.122.4.487 - Pubmed citation