Supplier

Input

Process

Output

Customer

Ophthalmic surgeon

Patient

General and preoperative evaluation

IOP under control

Patient

Assistant surgeon

Microscope

Preoperative regulation of sistemic body health

Long-term survival of the optic nerve

Nurse

Surgical equipment

Preparation of conjunctival and scleral flap

Preservation of visual acuity

Anaesthesia doctor

Light

Trabeculectomy

Preservation of visual field

Suture material

Suturation of scleral flap and conjunctiva

Discharge