Acute irreversible cataracts in diabetes mellitus

To report an unusual cause of blindness in a patient newly diagnosed with insulin-dependent diabetes mellitis (IDDM).

A 19-year-old man presented with classical symptoms of hyperglycaemia. On presentation his visual acuity and ophthalmic examination were normal. He was prescribed twice-daily insulin therapy and six weeks later presented with visual loss. He had only light and dark perception and was noted to have bilateral, dense, mature cataracts.

Right cataract extraction and intraocular lens implant was performed with restoration of vision. Despite good diabetic control the left cataract did not resolve. Seven months later the patient had left cataract extraction and intraocular lens implant, again with good result.

Mature dense cataracts rarely occur and appear not to resolve with control of hyperglycaemia, as in this case, and require surgical treatment.