low-tension glaucoma
This is glaucoma that occurs despite the eye pressure being “normal.” Glaucoma is normally defined as high intraocular pressure that causes damage to the optic nerve over many years. The underlying mechanism behind glaucoma is poorly understood but high pressure seems to be the main instigator. Some people seem to be exquisitely sensitive to mild pressure and develop nerve damage despite their eye pressure being in the “normal” range (10 to 21). These people require treatment to keep pressures very low. This is done with eye drops, lasers, and rarely glaucoma surgery.