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The visual field following acute primary angle closure.

PURPOSE
To determine the frequency and type of visual field loss six months after an episode of acute primary angle closure (APAC), and to identify risk factors for the development of such field loss.


METHODS
This was a cross sectional observational study. All patients who suffered from an episode of APAC at two Singapore hospitals over a one-year period underwent static automated threshold perimetry six months after presentation.


RESULTS
38% of (29) patients with APAC have significant visual field defects six months after the acute episode. The majority of those with abnormal fields had hemifield defects, consistent with nerve fiber bundle pattern loss. Those with pre-existing chronic glaucoma or who develop a rise in intraocular pressure during follow-up are at risk of visual field loss. The risk of visual field loss is also significant if the duration of symptoms exceeds 7 days.


CONCLUSIONS
The frequency of visual field loss at 6 months after APAC was low at only 38%. As the majority of eyes have no evidence of detectable functional damage developing as a consequence of the acute episode, APAC may not be blinding if treated promptly and adequately.