A Glimpse into the mysteries of glaucoma: From theories to clinics

Theories of glaucoma include mechanical, vascular, biochemical, genetic, glymphatic, translaminar pressure gradient, insulin signaling, excitotoxic, intracranial pressure, lamina fragility, glymphatic, bioenergetics etc, but the disease management still remains synonymous to the tradition of ocular hypertension. Such a scenario is inevitable because intraocular pressure (IOP) is the only proven modifiable factor till now. IOP management is important but insufficient and misleading as glaucoma is not merely “ocular hypertension.” This is because (1) many cases with elevated IOP, but no glaucoma are seen, (2) many individuals with normal IOP develop glaucoma, and (3) several cases still progress to glaucoma even after controlled IOP. The fallacy is that lowering IOP in normotensive cases slows down the progression of the disease pointing toward individual differences in the sensitivity of retinal ganglion cells (RGCs) to IOP and arguably additional factors – an individual specific sensitivity coefficient for RGC loss