Diabetic cataract. The typical diabetic cataract is rare in young diabetic patients. Transient metabolic decompensation promotes the occurrence of a typical radial snowflake pattern of cortical opacities (snowflake cataract). Transient hyperopia and myopia can occur.
H Diabetic cataract progresses rapidly. Senile cataracts are observed about five times as often in older diabetics as in patients the same age with normal metabolism. These cataracts usually also occur two to three years earlier.
Galactosemic cataract. This deep posterior cortical opacity begins after birth. Galactosemia is a rare cause of early cataract in children lacking an enzyme required to metabolize galactose. The newborn receives ample amounts of galactose in the mother's milk. Due a lack of uridyl transferase, or less frequently galactokinase, galactose cannot be metabolized to glucose, and the body becomes inundated with galactose or with galactose and galactose-1-phosphate. If the disorder is diagnosed promptly and the child is maintained on a galactose-free diet, the opacities of the first few weeks of life will be reversible.
Galactosemic cataract is the only form of cataract that responds to conservative therapy.
Dialysis cataract. Hemodialysis to eliminate metabolic acidosis in renal insufficiency can disturb the osmotic equilibrium of lens metabolism and cause swelling of the cortex of the lens.
Other rare metabolic diseases that can cause cataract include mannosido-sis, Fabry's disease, Lowe's syndrome (oculocerebrorenal syndrome), and Wilson's disease (hepatolenticular degeneration).
Cataract with myotonic dystrophy. Opacities first occur between the ages of 30 and 50, initially in a thin layer of the anterior cortex and later also in the subcapsular posterior cortex in the form of rosettes. Detecting these opacities is important for differential diagnosis as cataracts do not occur in Thomsen's disease (myotonia congenita) or Erb's progressive muscular dystrophy.
Symptoms that confirm the diagnosis include cataract, active signs of myotonia (delayed opening of the fist), and passive signs of myotonia (decreased relaxation of muscles in the extremities following direct percussion of the muscle and absence of reflexes).
Tetany cataract. The opacity lies within a broad zone inferior to the anterior lens capsule and consists of a series of gray punctate lesions. Symptoms that confirm the diagnosis include low blood calcium levels, a positive hyperventilation test, and signs of tetany: positive Chvostek, Trousseau, and Erb signs.
Dermatogenous cataract. This may occur with chronic neurodermatitis, less frequently with other skin disorders such as scleroderma, poikiloderma, and chromic eczema. Characteristic signs include an anterior crest-shaped thickening of the protruding center of the capsule (Fig. 7.11).
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...