Abstract
Abstract: :
Purpose: To prospectively determine the prevalence and pattern of visual field loss in the first week after successful treatment of an acute angle closure (AAC) attack, and to identify risk factors for the development of these field defects. Method: Automated static threshold perimetry was performed on AAC patients in the first week following resolution with medication and laser peripheral iridotomy. The fields were obtained upon regaining corneal clarity, Snellen acuity of 6/18 or better and intraocular pressure of less than 22mmHg. Three tests were performed per patient; the first test was not used in the analysis. Subjects with corneal or retinal pathology or who failed to fulfil standard reliability criteria were excluded. The fields were considered abnormal if: a) the Glaucoma Hemifield Test was outside normal limits, and b) three or more contiguous points on the pattern deviation plot were depressed at P<5% level, and/or c) there was an abnormal corrected pattern standard deviation with P<5%. Further analysis was performed based on factors related to demography, past medical history and those related directly to the AAC attack. Results: The Humphrey Visual Field reports of 59 patients were reviewed. 8 were rejected due to unacceptable reliability indices. Of the remaining 51 patients, 42 (82%) were female. 16 (31%) subjects demonstrated significant visual field abnormalities. The majority of the field defects were arcuate hemifield defects, consistent with nerve fiber bundle pattern loss. Age, sex, ethnicity, duration of symptoms and presenting intra-ocular pressure, amongst other parameters, were not found to be significant risk factors for the presence of field defects. Conclusion: 69% of eyes with AAC have no detectable functional damage to the optic nerve in the first week after resolution of the acute episode. The majority of those with abnormal visual fields had defects consistent with nerve fiber bundle pattern loss, and such eyes may have underlying chronic angle closure glaucoma. The presence of field defects did not correlate significantly with factors related to demography, past medical history or the AAC attack itself.
Keywords: 624 visual fields • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials