2. TERMINOLOGIES
Optic disc - Intraocular portion of optic nerve. Termination of all retinal layers
except nerve fibres, which pass through lamina cribrosa into the optic nerve.
Optic nerve head - Optic disc along with underlying pre-laminar layer of optic
nerve and region of lamina cribrosa
Optic papilla - Slightly elevated periphery of optic disc.
Physiological cup - Depression seen in optic disc
3. GENERAL FEATURES
Shape
Circular or ovoid
Location
Centre of disc lies 4 mm nasally and 1 mm superiorly to fovea
Colour
โข Optic cup is white - due to lamina cribrosa and medullated nerve fibres behind it
and absence of vascular choroid
โข Neural rim is yellow-pink - rich capillary network
โข Fair-skinned, blond, myopic people with large optic discs have a light coloured
discs, and vice versa
4. Zones of the optic nerve head and peripapillary pigmentation
CUP
NRR
SCLERAL LIP
ZONE ฮฒ
ZONE ฮฑ
5. Margin
โข Nasal margin - not well defined
โข Margins at superior and inferior poles and in small optic discs - obscured due to
crowding of nerve fiber bundles
โข Choroidal crescent - gap in RPE revealing underlying choroid because of oblique
insertion of optic nerve and tilting of disc
โข Scleral crescent - when both RPE and choroid are deficient
โข Both crescents mostly arise on temporal aspect of disc
6. Dimensions
Vertical diameter = 1.8 mm
Horizontal diameter = 1.5 mm
Depth = 1 mm
Cup : Disc ratio - Ratio of vertical diameter of optic cup
to that of optic disc
May vary from 0.1 - 0.9
Correction factors for estimating optic disc diameter:
Volk +78 D = 1.1 x
Volk +90 D = 1.3 x
ISNT rule - Inferior NRR is broadest followed by superior, nasal and temporal
Small and moderate sized optic discs follow the rule, large discs may not
7. โข Physiologic cupping - horizontally oval and deeper in nasal quadrant
โข Only 2 % of normal population have C:D ratio > 0.7
โข Number of optic nerve fibres, and area of neural rim they comprise, is constant.
Thus, small optic discs have small cup because of concentration of nerve fibres
at their point of confluence
โข Small discs - 0.35
Large discs - 0.55
โข Early glaucomatous changes can be missed in small discs
Cupping over diagnosed in large discs
8. Retinal vessels on and near optic disc
โข CRA enters globe through physiological cup - divides dichotomously within cup
and on surface of disc - 4 branches (ST, SN, IT, IN)
โข May divide within optic nerve head - 2 or 4 branches emerging separately from
within the physiological cup
โข Veins lie temporal to arteries
โข Cilioretinal artery - in 40% people and emerge from temporal aspect of optic
disc
9. Spontaneous vascular pulsations
โข Venous pulsation - seen at sharp bend in the vein as it turns into lamina cribrosa
โข Absent in 20% healthy people
โข Can be elicited by elevating IOP by pressing gently on globe
โข Indication of normal ICP, if IOP is normal
โข Can be seen in presence of elevated ICP if IOP is high
โข Arterial pulsation - raised IOP or elevated pulse pressure
10. Other important observations
โข Copper-wire appearance - reflection of light at vessel centre
โข Relative sizes of arteries and veins (normally - 2:3)
โข Thickening of arterioles - ageing, arteriosclerosis, hypertension
โข Very narrow, thready arterioles - tapetoretinal degenerations
โข Changes at AV crossings
12. NON-PROGRESSIVE CONGENITAL OPTIC DISC ANOMALIES
COLOBOMA
โข Enlarged optic disc, partially or almost totally excavated
โข Deepest part of coloboma is usually situated inferiorly
โข Glistening white, tinged with grey on its surface
โข Increased number of blood vessels cross border of coloboma - represent
branches of central retinal vessels which have divided on optic disc surface
before reaching retina
โข Peripapillary pigmentary changes (hyper or hypo)
13. TILTED OPTIC DISC / NASAL FUNDUS ECTASIA SYNDROME /
FUCH'S COLOBOMA / DYSVERSION OF THE OPTIC DISC
โข Usually inferiorly or inferonasally
โข Choroidal or scleral crescent
โข Situs inversus - in 80% of eyes with tilted disc. Temporal retinal vessels first turn
nasally before curving temporally towards macula
14. OPTIC DISC PIT
โข Round or oval
โข Pigmented (usually)
โข 1 pit per optic disc, occasionally 2 or 3
โข Size = 1/4 - 1/2 DD
โข Larger optic disc with distinct physiological cup
โข Base of pit may pulsate - underlying blood vessels, or transmission from
subarachnoid space
โข Peripapillary chorioretinal atrophy
โข Retinal vessels cross the pit - running superficially or dipping below its surface
โข 60% cases - cilioretinal artery arises from periphery of pit
โข Serous RD develops in 30% cases - resolves spontaneously
15.
16. APLASIA AND HYPOPLASIA
โข Abnormally small optic disc with pathologically low number of nerve fibers
โข Grey or pale
โข Double ring sign - peripapillary halo bordered by ring of increased or
decreased pigmentation
โข Deficit visual function
17. ALTITUDINAL HEMIHYPOPLASIA
โข Hypoplasia restricted to upper half of disc
โข In children of severe diabetic mothers with poor control during pregnancy
โข Little or no visual field below horizontal meridian
MICROPAPILLA
โข Smaller optic disc
โข Blurred margins
โข Small or absent cup
โข Normal visual function
18. MEGALOPAPILLA / MACROPAPILLA
โข Extraordinarily large optic disc
โข Very large central cup and narrow but healthy neuroretinal rim
โข Bilateral
โข Peripapillary pigmentary changes may be present
โข Normal optic nerve function
19. MORNING GLORY OPTIC DISC
โข Enlarged, nearly circular optic disc containing a deep conical depression with
white to pink glial tissue at its base
โข Grey or black halo
โข Retinal vessels loop over the edge of optic disc in a radial fashion (origin and
early branching obscured by glial tissue)
โข Serous RD - may fluctuate and resolve spontaneously
20. MYELINATED NERVE FIBRES
โข 1% of normal population
โข Not present at birth; develop post-natally
โข White, highly reflective lesion with feathery margins. Dark slits within the
lesion represent normal, unmyelinated fibres
21. CONGENITAL VASCULAR ANOMALIES
PERSISTENT HYALOID ARTERY
โข Bloodless, transparent, thread-like remnant extending forwards from optic disc
โข Portion near the disc may contain blood
Anteriorly the artery may retain its attachment to posterior lens capsule - Mittendorf's dot
22. BERGMEISTER'S PAPILLA (PERSISTENT HYPERPLASTIC PRIMARY
VITREOUS)
โข Faint grey or yellow-white protuberance over the optic disc
โข Nasally in 90% cases
โข Physiological optic cup is reduced or absent
23. PREPAPILLARY VASCULAR LOOPS
โข Short and simple, or may be long with several spiral twists
โข Never reach the posterior surface of lens
โข Loop usually originates from, and returns to the vessels on the optic disc;
occasionally may arise from an artery on disc and return to a retinal branch
โข Arterial loops generally affect inferior central retinal vessels (may pulsate)
โข Venous loops usually affect superior retinal veins
24. ACQUIRED VASCULAR ANOMALIES
NEOVASCULARISATION AT DISC
โข Fine network of vessels lying flat on disc or protruding into vitreous
โข Do not branch dichotomously
Causes -
โข Proliferative diabetic retinopathy
โข Retinal vein occlusion
โข Old retinal artery occlusion
โข Ocular ischemic syndrome
โข Radiation retinopathy
โข Carotid-cavernous fistula
27. PAPILLITIS
โข Early phase - disc is moderately swollen and hyperemic
โข Indistinct margins
โข Splinter haemorrhages on the disc surface
โข Later - secondary optic atrophy
NEURORETINITIS
โข Early phase - disc may appear swollen; later - consecutive optic atrophy
28. OPTIC NEUROPATHY
RETROBULBAR OPTIC NEUROPATHY
Early phase - disc appears normal; later - primary optic atrophy
ISCHEMIC PAPILLOPATHY
Acute phase - swollen and pale optic disc (usually sectorial), superficial splinter
haemorrhages
Chronic phase - secondary optic atrophy
ARTERITIC PAPILLOPATHY
Features same as in ischemic papillopathy
30. LEBER'S HEREDITARY OPTIC NEUROPATHY
โข Swollen and hyperaemic optic disc
โข Dilated telangiectatic capillaries mainly on, and extending from, temporal side
of optic disc
โข Chronic stage - secondary optic atrophy, marked reduction in vascularity
31. OPTIC ATROPHY
PRIMARY OPTIC ATROPHY
โข Chalky white optic disc with clearly defined margins
โข Disc pallor, more on temporal side
โข Atrophied neural rim - loss of physiological cup and flattening of optic disc
โข No gliotic or vascular changes
32. SECONDARY OPTIC ATROPHY
โข Grayish white swollen optic disc
โข Poorly defined margin
โข Partially or completely filled physiological cup
โข Gliotic changes may or may not be present
33. CONSECUTIVE OPTIC ATROPHY
โข Pale yellow, waxy looking flat optic disc
โข Well defined margins
โข Minimal gliotic changes
โข e.g. Retinitis pigmentosa
CAVERNOUS OPTIC ATROPHY OF SCHNABEL
โข Seen in ischemic lesions of optic nerve head
โข Diffusely enlargement and bean pot like cupping
34. PERIPAPILLARY ATROPHY
Alpha Zone:
โข Hypo and hyper-pigmented areas
โข Present in glaucomatous as well as non-glaucomatous eyes
Beta Zone:
โข Large choroidal vessels become visible
โข Larger beta zone often has thin NRR in the same area
โข More common in glaucomatous eyes and progression of beta zone is
associated with glaucoma progression
35. MYOPIA
โข Optic disc is sometimes distorted
โข Tilting of optic disc, usually temporally
โข Retinal vessels appear dragged
โข Nasal vessels curve around the elevated nasal sector of disc, temporal vessels
pursue a straightened course
โข Myopic crescent
36. HYPERMETROPIA
โข Small, pink optic disc, appears elevated and congested, but capillaries are not
dilated
โข Central retinal vessels crowd the centre of small optic disc; spontaneous venous
pulsation not affected
โข Severe cases - horizontal choroidal folds in peripheral fundus
37. GLAUCOMA
Focal atrophy
โข Polar notching - small, discrete neural atrophy, usually in inferotemporal
quadrant
โข Selective loss of neural rim tissue in inferotemporal and superotemporal
sectors - vertical or oblique enlargement of cup
โข With progression temporal neural rim is involved followed by nasal quadrant
โข Bayoneting sign - Retinal vessel bending sharply at the edge of disc
Concentric atrophy
โข Less common
โข Begins temporally, progresses circumferentially - temporal unfolding
38. LARGE OPTIC DISC WITH LARGE
PHYSIOLOGIC CUPPING
GLAUCOMATOUS CUPPING
Preserved healthy NRR widest at inferior
pole and narrowest in temporal quadrant
(I>S>N>T)
Cup extends to the disc margin
39. Deepening of cup
โข Overpass cupping - vessels initially bridge the deepened cup, later collapse into it
โข Laminar dot sign - Exposure of underlying lamina cribrosa. Fenestration with
striate appearance has higher association with glaucomatous damage than dot-
like appearance
Pallor/cup discrepancy
โข In early stages of glaucomatous optic atrophy - size of cup > area of pallor
โข Other causes of optic atrophy - area of pallor > size of cup
โข Area of cupping recognized by observing kinking of vessels at cup margin
โข Saucerisation - diffuse, shallow cupping extending to disc margins
โข Focal saucerisation - localized shallow, sloping cup, usually in inferotemporal
quadrant
โข Tinted hollow - normal NRR colour in area of focal saucerisation
โข Shadow sign - grayish hue of NRR
40. Advanced glaucomatous cupping
โข Total cupping - white disc with loss of all neural rim tissue
โข Bending of vessels at disc margin
41. Optic disc haemorrhages
โข NTG > COAG
โข Most commonly in inferior quadrant
โข Resolve spontaneously and reappear at same or different location
โข Cross the disc margin - papillary portion often disappears first during
resorption, leaving the appearance of an extrapapillary haemorrhage
โข Decline in frequency with advanced damage
โข Associated with progressive changes of visual field
Peripapillary pigmentary disturbance
โข Scleral lip or peripapillary halo
โข Peripapillary atrophy (both zone beta and zone alpha)
42. PAPILLOEDEMA
Early phase
โข Swollen optic disc with indistinct margin
โข First seen in nasal quadrant and then in superior and inferior sectors (because
of variation in density of nerve fibres in NRR)
โข Physiological cup is maintained giving the disc a cylindrical appearance
โข Disc is hyperemic due to capillary dilatation
โข Retinal veins are congested and non-pulsatile
โข Circumpapillary accumulation of fluid - concentric retinal folds (Patonโs lines)
and choroidal folds (best seen with red-free filter)
43. Acute phase
โข Optic disc becomes increasingly swollen and elevated
โข Physiological cup may still be maintained
โข Retinal venous congestion more pronounced.
โข Some blood vessels partially obscured at the edge of disc
โข Flame-shaped haemorrhages on disc margin
โข Macular star - accumulation of fluid and exudates, most prominent on nasal
aspect of macula
44. Long standing phase
โข Disc markedly swollen and physiological cup obliterated โ Champagne cork
appearance
โข Circulatory adjustments lead to resolution of venous congestion and retinal
edema
45. Atrophic stage
โข Pale optic disc (Secondary optic atrophy)
โข Neuronal degenerative changes - punctate white opacities in superficial nerve
fibre layer
โข Attenuated retinal arteries
โข Circumpapillary choroidal pallor and RPE atrophy with areas of pigmentary
clumping
46. OPTIC DISC DRUSEN
Children
โข Small optic disc
โข Drusen hidden within substance of nerve head
โข Pseudopapilledema
โข Retinal veins not distended, spontaneous retinal pulsation not affected
โข Central retinal vessels may show anomalous branching (10% cases)
โข Cilioretinal arteries commonly occur
47. Adolescents and adults
โข Drusen - single or multiple, glistening, semi-translucent; may coalesce โ give
disc a yellow-pink appearance
โข Optic disc may become enlarged and its border indistinct or irregular
โข Physiological cup is obliterated
โข Splinter haemorrhages on disc surface, subretinal haemorrhages in
peripapillary area
48. TUMOURS AND TUMOUR-LIKE CONDITIONS
MELANOCYTOMA
โข Grey to jet-black
โข Eccentrically placed on optic disc, extending over disc margin
โข Optic disc adjacent to the tumour is normal, may be swollen
49. ASTROCYTIC HAMARTOMA
โข Early stage - Smooth semi-translucent mass
โข Mature stage - Mulberry-like white reflective mass, may become calcified
โข Very vascular; blood vessels can be seen coursing through their substance
50. CAPILLARY HAEMANGIOMA
โข Localised, round, orange-pink
โข Vascular
โข Situated eccentrically on disc overlapping the disc margin and extending
forwards into vitreous
51. CAVERNOUS HAEMANGIOMA
โข Grape-like saccular aneurysms lying flat on the retina
โข Circulation through haemangioma is sluggish and blood tends to stagnate in
each saccule, with red blood cells sedimenting in response to gravity, leaving
a pale layer of plasma above
52. GLIOMA
โข Smooth, elevated, white mass partially or completely obscuring the disc
โข Compression of disc may cause occlusion of central retinal vessels
โข Glioma situated posterior to lamina cribrosa may cause primary optic atrophy
53. MENINGIOMA
Direct involvement of optic nerve
โข Elevated, pale mass obscuring the optic disc and displacing the peripapillary
retina
โข Splinter haemorrhages may be seen over the surface of the mass
Optic nerve compression
โข Pale, swollen optic disc
โข Optociliary shunt vessels
54. OPTIC DISC GRANULOMA
Acute stage
โข Raised, irregular, hyperaemic lesion affecting the optic disc and extending into
the adjacent retina
โข Peripapillary sub-retinal fluid accumulation
Later stage
White mass of scar tissue overlying the disc causing traction retinal folds
