[Measuring visual field loss by automated perimetry in chronic glaucoma stabilized by trabeculectomy]

The progression of field loss was determined by Humphrey Automated threshold perimetry in the short and intermediate term after surgical trabeculectomy for chronic glaucoma: mean indices (MD, PSD et FOV) were studied before and after normalisation of the intraocular pressure. Risk factors such as secondary glaucoma, previous visual field defects and cardiovascular risk factors were significantly correlated to poor or bad progression of field loss: the mean variation of MD = +1.23 dB +/- 2.84 (p < 1.5%), the mean variation of PSD = 0.50 dB +/- 1.37 (p < 6%), but the mean variation of FOV was not significant; so 36% of field defects were improved, 42% were stabilized and 22% were aggravated. When the risk factors were absent, 86% of field losses were stabilised but when cardiovascular factors were present, only 64% were stabilised. These risk factors can also be used to ascertain the prognosis of post-surgical progression of visual field, as already shown in previous reports. Automated threshold perimetry was useful to study the visual field progression with standardized and reliable numerical parameters, allowing statistical computerised management of the patients with glaucoma.