Disorders of the Lens

Ageing is the most common cause of cataracts (Figure 1), but a number of systemic conditions are also associated with development of cataracts, e.g. myotonic dystrophy (Christmas tree cataract, Figure 2), medications (such as anti-psychotics causing stellate cataract) and Wilson’s disease (sunflower cataract).

Figure 1. Nuclear sclerosis cataract – this is the most common form of cataracts which is associated with ageing. The nucleus of the lens has become yellow in colour.

Figure 2. Christmas tree cataract – this type of cataract is associated with myotonic dystrophy.

Subluxation of the lens (Figure 3) is a feature of Marfan’s syndrome. Other causes of lens subluxation include trauma, pseudo-exfoliation syndrome, high myopia, very mature cataract etc.

Figure 3. Lens subluxation – commonly seen in Marfan’s syndrome. In this patient, the zonules can still be seen.