Ectopia Lentis
 
 

A subluxated lens in the superior nasal direction. The patient has Marfan's  syndrome. Arachnodactyly (long fingers) in a Marfan's patient High arch palate in a Marfan's patient.

The pupil of the affected eye(s) is usually dilated for the examination. Describe the direction in which the lens is  subluxated, this can help with the diagnosis. If the eye is not dilated, look for iridodonesis (abnormal tremor of the  iris), phacodonesis (abnormal movement of the lens), deep anterior chamber depth or vitreous herniation into the  anterior chamber.  In the examination: look for signs of Marfan's syndrome (superior nasal subluxation of the lens, arachnodactyly, high arch  palate and arm span longer than height) rarely the patient has homocystinuria (downward subluxation oft he lens, same features as Marfan's syndrome  but patient tends to be mentally subnormal and may have fair hair) or Weill-Marchesani's syndrome (mental  retardation, short stature, stubby fingers) look for pseudoexfoliation syndrome  look for signs of trauma (which is the most common cause of subluxated lens but does not feature as commonly  as Marfan's syndrome in the clinical examination)

Questions:

1. What are the other causes of lens subluxation?

Answer
Trauma
Hypermature cataract
Aniriida
High myopia
Congenital glaucoma
Ehler-Danlo's syndrome
Hyperlysinaemia

2. What are the complications of a subluxated lens?

Answer
Optical problems including astigmatism and monocular diplopia
Uveitis
Pupillary block glaucoma

3. What are the risks of performing general anaesthesia on patient with Marfan's syndrome?

Answer
There are at risk of cardiac arrhythmia and spontaneous pneumothorax

4. What is the main risk of performing general anaesthesia in patient with homocystinuria?

Answer
Homocystinuria patient is at risk of arterial thrombosis.
 
 

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