4. For females capable of becoming pregnant, agree to have urine pregnancy testing performed prior to randomization of the study eye and on the day of the fellow eye treatment (which occurs between the 3 to 6 month study eye visits); must not be lactating, and must agree to use a medically acceptable form of birth control for at least one week prior to the randomization visit and continue to use the method until one month after the last dose of test article. Acceptable forms for birth control are spermicide with barrier, oral contraceptive, injectable or implantable method of contraception, transdermal contraceptive, intrauterine device, or surgical sterilization of partner. For non-sexually active females, abstinence will be considered an acceptable form of birth control. Women considered capable of becoming pregnant include all females who have experienced menarche and have not experienced menopause (as defined by amenorrhea for greater than 12 consecutive months) or have not undergone successful surgical sterilization (e.g. hysterectomy, bilateral tubal ligation, or bilateral oophorectomy);