Table 1. Year of development of different Implants and their postoperative complications.

Name of glaucoma drainage devices.	Year of development	Types of opening	Postoperative complications.
Molteno	1979	Non-valvular	More chances of hypotony.
Baerveldt	1990	Non-valvular	More chances of hypotony. Greatest amount of chances of diplopia are found with this implant.
Krupin	1990	Valvular	Comparatively fewer chances of hypotony
Ahmed	1993	Valvular	Comparatively fewer chances of hypotony. Choroidal effusion.