Abstract
Purpose :
To explore predictive factors for going blind in the low and high maximum intraocular pressure (IOP) subgroups in normal tension glaucoma (NTG).
Methods :
We retrospectively investigated 375 patients diagnosed as bilateral NTG, and followed for at least 5 years. We reviewed the patients’ data of best-corrected visual acuity (BCVA) and visual field from our records. A cut-off value of maximum IOP was tentatively set as 18 mmHg. The blindness was defined according to the World Health Organization (WHO) criteria. The probabilities of blindness were calculated using Kaplan Meier life-table analyses. To identify risk factors for the development of blindness, we used a stepwise selection method for Cox proportional hazards regression.
Results :
The mean age at diagnosis was 56.1 ± 11.7 years. Men were 146, and women were 229. The mean follow-up period was 14.3 ± 5.8 years. The low IOP group included 127 patients (33.9%). The probability of blindness in at least one eye at 20 years was estimated to be 14.9 ± 2.7% in the high IOP group, and 9.5 ± 4.6% in the low IOP group (P=0.042; log-rank test). The Cox proportional hazard model analysis showed that a worse initial BCVA (both groups; P < 0.05), a smaller spherical equivalent refraction (high IOP Group; P = 0.035) and worse Advanced Glaucoma Intervention Study (AGIS) score at diagnosis (both groups; P < 0.05) were significantly associated with the development of blindness in at least one eye.
Conclusions :
An early detection of NTG might be most essential for preventing a future blindness.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.