THE CAUSE OF Primary Open Angle Glaucoma
by Somkiat Athikhomkulchai , M.D.
An Ophthalmologist

1. The Trabecular Meshwork
          The anterior part of the eyeball, there is a circulating, water-like fluid called the aqueous humor. It is produced by the eye's ciliary body and initially excreted into the posterior chamber and then flow through the pupil into the anterior chamber , it leaves the eye mainly via the trabecular meshwork into the canal of Schlemm which is connected to veins that course through the scleral surface.
          Aqueous humor is actively produced by the eye which the outflow has to overcome a certain amount of resistance. This is the source of intraocular pressure, the IOP results from the balance between the production and outflow of the aqueous humor.
          In glaucoma patients, the trabecular meshwork becomes increasingly laden with substances that impair aqueous humor drainage. The increase in outflow resistance at trabecular meshwork cause elevated IOP. The higher IOP induce the higher retinal venous pressure and thus reduce retinal arterial perfusion that lead to ischemia and retinal ganglion cell death. That is, High IOP is a factor that impede Ocular Perfusion.
2. The Lamina Cribrosa
          The posterior part of the eyeball, there is a thin mesh-like elastic network rich in collagen, called the Lamina cribosa. It is the continuation of the scleral layer of the eyeball and has many tiny holes that traversed by optic nerve fibers and blood vessels.

The physiological function of the Lamina cribosa
          2.1 To seal around optic nerve fibers, retinal artery and retinal vein, preventing fluid leakage out of the eyeball, for the purpose to maintain the ocular tension.
          2.2 To absorb pulsatile force of the retinal arterial blood, when reach the optic nerve head before entering into the eyeball, by the elastic property of Lamina cribosa around the artery. The pulsation of retinal artery, if existed, may interfere the visual impulse sending to the brain.
          2.3 To increase retinal venous pressure by the tightening force around the vein. The pressure inside the retinal veins have to be at least as high as the IOP-or these vessels would collapse. If the wrapping is too tight or getting tough, it cause hemivein pulsation in someone.
          Collagen changes in Lamina cribosa whether from senile degeneration or genetic factor may impede axoplasmic and vascular flow . This is another factor that impede Ocular Perfusion.

In conclusion there are 2 factors that cooperate to be the cause of POAG
          1. the lamina cribosa and the impediment of blood supply
          2. The trabecular meshwork and the impediment of aqueous outflow with increased ocular tension that impede blood supply

The role of these 2 factors bring to the 3 types of POAG
          1.The high tension glaucoma
                    The degenerative change of Lamina cribrosa and Trabecular meshwork are the cause of this type of glaucoma. Inadequate ocular perfusion leading to ganglion cells ischemia and progressively die
                    1.1 Stretch out the Lamina cribrosa plate to widen the pore that traversed by the Retinal artery, enhancing ocular perfusion
                    1.2 Lowering the IOP to decrease the resistance of ocular perfusion.
            Nowadays , all Glaucoma patients get only IOP lowering methods ( Medication, Laser or Surgery ) without any treatment upon the Lamina cribrosa. This is the reason to explain why some of these patients still go blind with all modalities of IOP lowering method.
            Eye Massage can solve this problem because the procedure can stretch out and widen the Lamina cribrosa pores together with decreasing the IOP.
          2.The normal tension glaucoma
                    The degenerative change of Lamina cribrosa is the only and definite cause of this type of Glaucoma. The IOP may be normal or low that is why most patients of this group do not respond to all modalities of IOP lowering treament. Eye Massage is the only and the definite method to help these patients from going blind.
          3.The ocular hypertension
                    There is degenerative change of Trabecular meshwork and lead to elevated IOP but the ocular perfusion through the Lamina cribrosa is good enough to supply adequate amount of blood for all Ganglion cells. There is no Glaucomatous damage and no need for any treatment, follow-up examination should be done regularly to detect the Glaucomatous damage and when the treament is reasonable.

          This method can start as Complementary treament without any effect to the traditional method. After a month of treatment the patients can realize whether to do Eye Massage as the only treament or still couple with the traditional method.

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