Table 1.

Preoperative comparability of primary trabeculectomy (PT) and multiple treatment (MT) groups^*

Variable	PT group	MT group
Presenting visual field defects	Early	Advanced
Duration of disease	Days/weeks	1–17 years
History of failed medical treatment	20% of group destined to fail treatment	100% of group
History of prior laser surgery	No	Yes (25% of group)

^*PT group has less than 8 weeks of medical treatment. MT group has 1 to 17 years of medical treatment.