How does elevated intraocular pressure contribute to retinal ganglion cell death in glaucoma?

How does elevated intraocular pressure contribute to retinal ganglion cell death in glaucoma?

• A. Increased blood flow to retina causing edema
• B. Mechanical and ischemic stress at lamina cribrosa, disrupting axonal transport and leading to retinal ganglion cell death and optic neuropathy
• C. Degeneration of photoreceptors
• D. Demyelination of optic nerve

Answer: (B)

Elevated intraocular pressure damages retinal ganglion cells by creating mechanical and ischemic stress at the lamina cribrosa, the region where their axons pass as they exit the eye. The pressure deforms this doorway and compresses the axons, interrupting axoplasmic transport. When the flow of nutrients, neurotrophic signals, and waste removal along the axon is disrupted, retinal ganglion cells lose essential support and energy, making them prone to apoptosis. At the same time, higher pressure can reduce blood flow to the optic nerve head, worsening ischemia and accelerating ganglion cell loss, producing glaucomatous optic neuropathy. This mechanism is different from photoreceptor degeneration in outer retinal diseases or optic nerve demyelination seen in other conditions, and it’s not simply edema from increased blood flow.

Elevated intraocular pressure damages retinal ganglion cells by creating mechanical and ischemic stress at the lamina cribrosa, the region where their axons pass as they exit the eye. The pressure deforms this doorway and compresses the axons, interrupting axoplasmic transport. When the flow of nutrients, neurotrophic signals, and waste removal along the axon is disrupted, retinal ganglion cells lose essential support and energy, making them prone to apoptosis. At the same time, higher pressure can reduce blood flow to the optic nerve head, worsening ischemia and accelerating ganglion cell loss, producing glaucomatous optic neuropathy. This mechanism is different from photoreceptor degeneration in outer retinal diseases or optic nerve demyelination seen in other conditions, and it’s not simply edema from increased blood flow.