Glaucoma is a progressive ocular neuropathy which is one of the leading causes of blindness in the world. In glaucoma, there is a gradual rise in the intraocular pressure which causes damage to the retina. Damage to retina causes gradual progressive loss of vision which is primarily peripheral vision loss which with the course of disease slowly involves the central vision.
The normal intraocular pressure is around 10 mm of Hg -21 mm of Hg.
How Long Does It Take To Go Blind From Glaucoma?
It is not true that a sustained high intraocular pressure always causes loss of vision. Almost in 10 to 20% of the glaucomatous patient around the world, with an intraocular pressure ranging between 21 to 24 mm of Hg tends to develop peripheral loss of vision over a period of 10 years. Studies show that in a patient with an intraocular pressure of 25 mm of Hg to 28 mm of Hg, almost 50% of the patient under the study lost their vision and in people having intraocular pressure more than 30 mm of Hg almost 90% of the patient lost their vision.
It is now well documented from the studies patient having an intraocular pressure of 21 to 24 mm of Hg, will gradually progress to blindness from early glaucomatous changes within of period of average 13-15 years.
Similarly, a patient with the intraocular tension of the range 25 to 28 mm of Hg will take an average of 7-8 years. And patient with the intraocular pressure of more than 30 mm of Hg progressive to blindness in a period of average 3 years.
In some recent studies estimated that out of 10, 4 patients with open-angle glaucoma develop vision loss unilaterally within a year and out of 6, 1 develops bilaterally.
It is found that in a time span of average 10 years that one in every four patient lost their vision unilaterally and 1 in every 20 patient, bilaterally.
For newly diagnosed glaucoma patient it is the risk of developing Visual impairment is the most important. Glaucoma is second most important cause for the blindness all over the world and among various types of glaucoma open-angle glaucoma contributes the most.
The progression of the glaucoma is estimated by looking at the changes in the optic disc where there is a cupping of the disc which increases with the loss of retinal cells and with the advancement of the technology and introduction of the optical coherence tomography, now we can measure ganglion cell loss and retinal nerve fiber layer thinning.
It is the threshold point beyond which there is a sudden and rapid progression of the structural changes and functional impairment and the visual field effect are clinically quite observable. The tipping point is found to be around 17% of the total Retinal nerve fiber layer loss.
Chronic glaucoma is a major risk for vision loss. There is no presenting pain and there is no apparent field loss but the vision is damaged.
Currently, with the availability of standard treatment for glaucoma only some of the patients still progress to vision loss. Unluckily the vision loss in glaucoma is permanent. There is no standard preventive medical treatment for glaucoma is available. The best way to prevent blindness by glaucoma is to have a regular ocular examination.
Data from various studies show that the medical and surgical treatment currently available can slow down the speed of vision loss and ultimately its progression to the blindness.
Various regenerative strategies are being tried to regenerate the vision loss. The promoter of growth factors such as oncomodulin has shown some promising results in optic nerve regeneration. Stem cell approach also shows a positive result in Glaucoma.
Vision loss associated with glaucoma is permanent. Changes to the optic disc and field of vision are permanent and are progressive in nature.