This document discusses optic disc changes in glaucoma. It defines key terms like optic nerve head and lamina cribrosa. It describes physiological cupping and normal cup-to-disc ratios. Pathogenesis of optic nerve head changes in glaucoma involves mechanical effects of increased intraocular pressure and vascular effects of ischemia. Signs suggestive of glaucoma include increased cup size, asymmetry between eyes, thinning of the neuroretinal rim, notches, splinter hemorrhages, and retinal nerve fiber layer defects preceding other changes. Advanced glaucoma shows total cupping and bending of retinal vessels at the disc margin.

1. GLAUCOMA OPTIC DISC CHANGES
PRESENTED BY-
PRAGATI JAIN

2. • Chronic progressive optic neuropathy caused by group of ocular
conditions which lead to damage of optic nerve with loss of visual
function.

3. Definitions
• ONH-distal portion of optic nerve,extends from retinal surface to
myelinated portion of optic nerve.
• Composed of the nerve fibres which originates in the Ganglionic cell
layer of retina & converge upon the nerve head from all points in the
fundus.
• Relation between ONH and glaucoma was first described by von
Graefe in 1857

4. • Physiological cup-represents partial or complete absence of
axons
Pallor of cup results from exposure of lamina cribrosa and lack of
glial tissue in the centre
• NRR-tissue b/w cup and disc margin
I>S>N>T
• Normal CDR is 0.3 :1
2% have CDR 0.7:1

5. Lamina cribrosa-
porous region of sclera and also a specialized extracellular matrix
that consists of fenestrated sheets of connective tissue and
occasional elastic fibres lined by astrocytes

6. • Peripapillary area-RNFL seen as striations in light reflex from
bundles of nerve fibres.
Distribution of retinal nerve fibre-
Arrangement of nerve fibres within ONH-
From peripheral part of retina lie deep in retina & occupy most
superficial part of OD
Fibres closer to ONH lie superficial in retina.

7. Pathogenesis of ONH changes in glaucoma
• Mechanical effect-raised IOP forces lamina cribrosa backwards
and squeezes nerve fibres within ,disturb axoplasmic flow
• Vascular effect-ischaemic atrophy of nerve fibre

8. ONH Signs Suggestive Of Glaucoma
• Size of cup in relation to size of ONH-
Small disc with deep cup
Medium disc with deep cup
Meduim disc with large cup
Large disc with large cup

9. • Asymmetry of cups-
0.2 in both eyes suspicion.

10. • Vertical enlargement of cup-
Vertical CDR > horizontal CDR
Loss of axons occur more in superior and inferior regions so NRR
thinning at vertical poles

11. • Focal atrophy and polar notching
Inferotemporal region,sometimes superotemporally
Small discrete defect due to loss of neural rim tissue

12. • Sharpened nasal margins-
As focal defect enlarges and deepens it may develop sharp nasal
margins adjacent to major blood vessels.

13. • Sharpened rim-
NRR is lost adjacent to edge of the disc
No visible neural rim is seen

14. • `
• Bayonetting sign-
double angulation of blood vessel
When retinal vessels cross the sharpened rim,it will bend sharply at
the edge of the disc

15. • Laminar dot sign/shadow sign
 As loss of axon progresses the normal colour is replaced by greyish hue.
 Deepening of cup
 s/o Advanced damage

16. • Overpass cupping-
Vessels initially bridge the deepened cup and later collapse into it

17. • Pallor areas on the disc-
 Kinking of vessels at cup margin
 Colour cup-
extent of central pallor
 Contour cup-
site at which vessel change their contour
 Enlargement of cup may progress ahead of pallor
 Pathognomic of glaucomatous optic atrophy

18. • Saucerization-
Diffuse shallow cupping extends disc margin with retention of central pale
cup
Focal saucerization –more localized shallow sloping cup
Early s/o glaucoma
• Tinted hollow-
Retention of normal NRR colour in area of focal saucerization

19. • Splinter haemorrhage or Drance heamorrhage-
At disk margin,extends from NRR onto retina
m/c inferotemporally
Significant early finding,risk factor for development and
progression
Precedes RNFL changes and field defects

20. • Barring of circumlinear vessels-
Space b/w NRR and superficial blood vessels
Vessels appear to be barred from margin of the cup

21. • Tortousity of retinal vessels-
As response to chronic ischaemia
• Collaterals b/w 2 veins at the disc may also be seen

22. • Advanced glaucomatous cupping-
Loss of all neuroretinal tissue
Total cupping seen as white disc
Bending of vessels at margin of disc
Bean pot cupping

23. • RNFL defect precedes detectable OD and visual field changes
• It can be a. localized wedge shaped defect
b. diffuse defect that are larger and have indistinct borders
• More evident following disc haemorrhage
• Red free light are used to see the defects

24. • Peripappillary pigmentary disturbances
• Scleral lip/peripappillary halo-even white rim that marks disc
margin,anterior extension of sclera b/w choroid and optic nerve
• Zone beta
• Zone alpha

25. • Alpha zone-irregular hypo or hyper pigmented zone associated
with chorioretinal thinning.
• Beta zone-represents loss of RPE and choriocapilaries leaving
intact choroidal vasculature.

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