Study on the Progression of Visual Field Defect and Clinical Factors in Normal-Tension Glaucoma

Purpose: We investigated the relationship between the progression of visual field defect and clinical factors in patients with normal-tension glaucoma (NTG).Subjects and Methods: Forty-eight eyes of 48 NTG patients undergoing more than 5-year follow-up were enrolled in this study. Their visual field defects ranged between Aulhorn's classification stage 2 and 4, and mean deviation (MD) more than -10 dB measured by Humphrey Field Analyzer (HFA). End points of this follow-up study were defined as follows: in HFA STATPAC 2 glaucoma change probability analysis, more than 5 points which significantly deteriorated at P <.05 were found at 2 consecutive examinations (Criterion 1) or a significant decrease in MD value at P <.025 was encountered at one examination or in MD value at P <.05 at consecutive examinations (Criterion 2).Results: During the follow-up period, 18 eyes of 48 patients satisfied Criterion 1 and 21 eyes Criterion 2. There were no significant differences in clinical factors between patients with progression and without progression. By multiple logistic regression analysis, minimum flow velocity of central retinal artery (CRA) showed significant relation (odds ratio for a 1 cm/sec rise = 0.2215; 95% confidence interval: 0.0530-0.9253) to progression of visual field defect in Criterion 1, and minimum flow velocity of CRA (odds ratio for a 1 cm/sec rise = 0.2099; 95% confidence interval: 0.0506-0.8712) and cholesterol (odds ratio for a 1 cm/dl rise = 1.0332; 95% confidence interval: 0.4096-2.6064) showed significant relation in Criterion 2.Conclusion: These results suggests that vascular risk factors of ocular blood flow may play a role in the progression of visual field defects in NTG patients.