Glaucoma tube shunt, or the valved implants, such as the Ahmed glaucoma valve implant or the ExPress Mini Shunt and the later generation pressure ridge Molteno implants. These are indicated for glaucoma patients not responding to maximal medical therapy, with previous failed guarded filtering surgery (trabeculectomy). The flow tube is inserted into the anterior chamber of the eye, and the plate is implanted underneath the conjunctiva to allow a flow of aqueous fluid out of the eye into a chamber called a bleb. The ongoing scarring over the conjunctival dissipation segment of the shunt may become too thick for the aqueous
Normal tension glaucoma nerve head, in the absence of elevated IOP. While the excavation of the optic nerve head and the thinning of its rim appear in all kinds of glaucoma (with high tension and with normal tension,in Primary open angle glaucoma (POAG) and in secondary glaucoma), small hemorrhages close to the optic disc have been identified as a characteristic clinical sign of normal tension glaucoma. Visual field is very important to detect NTG. It shows a defect that typically appear deeper, steeper and closer to fixation comparing to patients with POAG. Since NTG is closely linked to vascular irregularities, a medical check-up