[Target intraocular pressure and risk factors for progression of visual field loss in primary open-angle glaucoma]

Evaluation of intraocular pressure(IOP) control below the target level stated by Iwata and study of risk factors for progression of visual field loss in primary open-angle glaucoma (POAG) despite successful reduction of IOP.

Statistical difference of visual field deterioration between 27 eyes of POAG with IOPs above target levels and 48 eyes of POAG with IOP below target levels was examined for 28.1 +/- 10.2(mean +/- standard deviation) months. The relationship between the progression of visual field loss and factors of initial visual field loss, mean IOP, variance of IOP, peripapillary atrophy (zone beta), records of glaucoma surgery, age, and sex were studied in 48 patients(48 eyes) with IOPs below target levels.

Eight of the 48 eyes(16.7%) showed progression of visual field loss with IOPs below their target levels whereas 15 of the 27 eyes(55.6%) had IOPs above their target levels(p = 0.002). The risk factors for the progression of visual field loss in POAG despite good control of IOP were severity of initial visual field loss(p = 0.003), peripapillary atrophy(p = 0.002), and male sex(p = 0.03).

The control of IOP below target level is beneficial for patients with POAG. However, the risk factors which represent circulatory damage, such as peripapillary atrophy, may have a bad influence on the continuing deterioration of visual fields in patients with severe visual field damage, independently of good control of IOP.