Glaucomatous Optic Disc Cupping, damage of Retinal ganglion cells (RGCs) & Optic nerve fibers (axons)

👁 What is Glaucoma?

Glaucoma is a progressive optic neuropathy
with structural and functional damage involving:

1. Retinal ganglion cells (RGCs)
2. Optic nerve fibers (axons)

✅ Diagnosis requires BOTH:

• Structural change (e.g. optic disc cupping)
• Functional loss (e.g. visual field defects)

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💡 Analogy to Systemic Hypertension

Systemic HypertensionOcular Hypertension (Glaucoma)

Narrowed vessels → high BP	Blocked outflow → increased IOP
Heart under strain	Optic nerve under pressure

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💧 Aqueous Humor & IOP Dynamics

• Produced in the ciliary body
• Flows: Posterior chamber → pupil → Anterior chamber
• Exits via trabecular meshwork (TM) and Schlemm’s canal

✅ Normal flow = stable IOP (10–21 mmHg)
❌ Blocked outflow = pressure buildup = IOP elevation

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⚠ Pressure Targets the Optic Disc

• Optic disc = most vulnerable spot in the posterior eye
• High IOP causes focal inward depression (cupping)
• Normal cupping: small & symmetrical
• Glaucomatous cupping: larger, deeper, often asymmetric

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📸 Features of Glaucomatous Optic Disc Cupping

FeatureNormal DiscGlaucomatous Disc

Cupping size	Small	Enlarged
Rim appearance	Even	Notched/thinned
Blood vessels	Cross center	Shifted peripherally
Symmetry	Bilateral equal	Often asymmetric

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✅ Summary

• Glaucoma = IOP-induced optic nerve damage
• Optic disc cupping is the hallmark of structural change
• Functional loss confirmed via visual field testing
• Must monitor both structure & function for proper diagnosis