👁 Glaucoma: From Pressure to Vision Loss
StageDescription
| Cause | Elevated intraocular pressure (IOP ↑) |
| Process | Glaucomatous optic disc cupping |
| Outcome | Visual field loss |
🔬 Structure + Function = Glaucoma Diagnosis
- Structural changes: optic disc cupping, RNFL thinning
- Functional loss: characteristic visual field defects (VFDs)
✅ Diagnosis requires both structure & function
🧠 Anatomical Basis of Visual Field Loss
- The optic nerve head (ONH) is where RNFL fibers converge
- Most vulnerable site to pressure: Inferotemporal (IT) region
- Damage here → field loss in the Bjerrum (arcuate) area
🔍 Key Visual Field Defects
Defect TypeDescription
| Paracentral scotoma | Near central vision, early glaucoma sign |
| Seidel scotoma | Arc-shaped defect from blind spot toward nasal field |
| Arcuate scotoma | Classic pattern in Bjerrum area, most reliable VFD |
→ All typically arise from IT RNFL damage
✅ Summary
- Glaucoma progresses as IOP ↑ → structural loss → visual field defect
- Site of optic nerve damage = location of field defect
- Most common site: Inferotemporal ONH → Bjerrum area loss
- Both structural & functional evaluations are critical for diagnosis
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