Risk factors for progression of visual field defect in young normal-tension glaucoma patients

Abstract

Prevalence of glaucoma is increasing with ageing. Young aged glaucoma patients are uncommon and age is not a modifiable factor. That is why there have been no studies about young aged open angle glaucoma (OAG). In case of young OAG patients, life expectancy is remained longer than older OAG patients. As there will be more chances of irreversible glaucomatous progression, more strict and steady examination and treatment are needed. The purpose of this study was to investigate the risk factors for the progression of visual field defect in young (18 to 40 years old) normal-tension glaucoma (NTG) patients. We retrospectively reviewed the records of all 1489 patients who had been diagnosed with NTG between 1998 and 2008 at two large medical centers, Severance hospital and Gangnam severance hospital of Yonsei university. Among the 1489 NTG patients, only 22 patients, 27 eyes were eligible for inclusion and exclusion criteria and were enrolled in this retrospective study. Criteria for glaucoma progression were similar to those of the Collaborative NTG Study. Univariate analysis were performed between patients with visual field progression and those with no progression. In addition, Cox proportional hazard regression and survival analysis were performed. Twenty two patients, 27 eyes, were enrolled in this study. With 15% lowering IOP, 58% young NTG patients (<40 years old) have shown visual field deterioration in 5 years follow up. Almost eyes have myopic refractive error, and 54% eyes were high myopia (under -6.00 diopter). beta-zone parapapillary atrophy (β-PPA) were prevalent in young aged NTG patients (85.7%). In Cox proportional hazards regression analysis, presence of β-PPA (HR=29.46; P=0.04) was associated with visual field progression. In conclusion, Patients with high myopia and β-PPA are frequent in young NTG patients. β-PPA was associated with visual field progression in young NTG patients. Further study would be needed to elucidate the pathogenetic mechanism of NTG in young patients.