The trial includes 2 period:
1. Screening period: 4 weeks. For subjects entering the screening period, 0.005% latanoprost will be administered for 4 consecutive weeks, one drop for each eye, once per day.
2. Evaluation period: 8 weeks. Subjects who are eligible are randomly assigned to the OPC-1085EL group or 0.005% latanoprost group at a ratio of 1:1, one drop for each eye, once per day.