1. Jagdish Dukre

2. OPTIC NERVE HYPOPLASIA
Optic nerve hypoplasia (ONH) is the most common
optic disc anomaly and is the third leading cause of
blindness in children in the western world after
cerebral damage and retinopathy of prematurity.
Risk factors for ONH include
 young maternal age,
 maternal smoking,
 preterm birth and its complications.

3. Clinical features
 An abnormally small optic
nerve head.
 Double-ring sign:
 The optic nerve is pale
surrounded by a yellowish
peripapillary ring of sclera and
an outer concentric ring of
hypopigmentation.
 outer ring of normal junction
between sclera and lamina
cribrosa
 inner ring denoting extension of
retina and RPE over lamina
cribrosa

5. A disc to centre of macula (DM): mean disc diameter
(DD) ratio
DM:DD ratio of
 3.00 should lead to serious consideration of the diagnosis
and a value of
 4.00 probably accords a definitive diagnosis.
 The visual acuity is associated with the DM: DD ratio.
 In one study of 19 children with ONH, all eyes with a DM:
DD ratio of more than 3 had reduced visual acuities but all
those with a ratio of less than 3 had normal acuities.

6. Histopathologically,
 optic nerve hypoplasia has subnormal number of
axons with normal mesodermal elements and glial
supporting tissue.
 A reduction in the diameter of the hypoplastic optic
nerve and chiasm is demonstrated reliably by MRI,
which establishes the presumptive diagnosis of optic
nerve hypoplasia.

7. Visual acuity:
 ranges from 20/20 to no light perception.
 Visual acuity usually remains stable throughout life unless
amblyopia develops in one eye or it is associated with
suprasellar tumour where it can lead to acquired visual loss.
 Optic nerve hypoplasia has recently been implicated in the
pathogenesis of amblyopia although it is still not clear whether
a small optic disc area is the cause for decreased vision or the
associated hyperopia and anisometropia.

8. Visual field defects: the affected eye shows localized visual
field defects.
Astigmatism: warrants attention to correction of refractive
error in children.
Associations: Magnetic resonance imaging has revealed
coexistent CNS abnormalities with ONH.
1) Isolated ONH: A reduction in the diameter of the
hypoplastic optic nerve and chiasm is demonstrated reliably by
MRI, which establishes the presumptive diagnosis of optic nerve
hypoplasia.
2) Septo-optic dysplasia (de Morsier syndrome)
constellation of optic nerve hypoplasia, absence of the septum
pellucidum, and partial or complete agenesis of the corpus
callosum.

9. sagittal MR shows absence of the
corpus callosum

10. 3) Forebrain malformations, schizencephaly and periventricular
leukomalacia, absence of the pituitary infundibulum with or
without posterior pituitary ectopia (can present in upto 74%)
 Cerebral hemispheric abnormalities indicate that
neurodevelopmental deficits are likely.
 Absence of the pituitary infundibulum with an ectopic
posterior pituitary gland indicates congenital hypopituitarism
and warrants endocrinologic evaluation in children.
 Growth hormone deficiency is most common which usually
presents by 3-4 yrs of age

11. MORNING GLORY DISC ANOMALY
 The morning glory disc anomaly is a
congenital excavation of posterior globe
that involves the optic disc.
 The term reflects the morphological
similarity to the flower of the morning
glory plant.
 Morning glory syndrome is ostensibly a
sporadic condition.
 It usually occurs as a unilateral condition,
though bilateral lesions have been
reported.
 Morning glory discs are more common in
females (2:1)

12. Pathogenesis
 The pathogenesis of the condition is unknown.
 One hypothesis argues that the condition results from
failure of closure of the foetal fissure and that it is a
variant of optic nerve coloboma.
 Alternatively, a primary mesenchymal abnormality has
been postulated on the basis of the glial tuft, the
scleral and vascular abnormalities.

13. Clinical features
Ophthalmosopic appearance:
It is characterized by
funnel-shaped and enlarged
dysplastic optic disc with
white tissue, and retinal
vessels arising from the
periphery of the disc (spoke
wheel pattern) and running
an abnormally straight
course over the peripapillary
retina .

15.  Visual acuity: visual acuity is often very low, being in the
range of counting fingers to 6/60, but it can be associated
with no perception of light.
 Amblyopia: variable depth based on the extent of the
alteration of the nerve fiber layer and difficult to predict
on the basis of disc appearance

16. Associations
With rare exceptions, the Morning glory disc anomaly is not
part of a multisystem genetic disorder.
Ocular anomalies
Retinal detachment, both serous and rhegmatogenous, occurs
in about one- third (26-38%) cases of MGDA.
Strabismus
Intracranial disorders
Basal encephalocele: Children who have this occult basal
encephalocele have characteristic facial features including
hypertelorism, depressed nasal bridge, midline upper lip notch
and sometimes midline cleft in soft palate.
Agenesis of corpus callosum
Absence of chiasm
Panhypopituitarism
Most affected children have no overt intellectual or neurologic
deficits.

17. (A) Morning glory optic disc anomaly; (B) hypertelorism and flat nasal
bridge – note bilateral iris colobomas;

18. OPTIC DISC COLOBOMA
 Optic disc coloboma can be present in one or both
eyes.
 They may arise sporadically or be inherited in
autosomal dominant fashion.
 It has recently been shown to be associated with PAX2
gene mutations as part of the renal-coloboma
syndrome.
 Pathogenesis: It is caused by an incomplete or
abnormal apposition of the proximal ends of the
embryonic fissure.

19. Clinical features
 Optic disc coloboma is
typically an enlarged disc
with sharply demarcated,
focal, glistening bowl
shaped excavation of the
optic disc.
 The coloboma occupies the
lower part of the optic nerve
head.
 The neuro-retinal rim is
absent inferiorly but is
usually identifiable
superiorly.

20. (A) Optic disc coloboma; (B) FA shows hypofluorescence of the cavity

21.  Visual acuity: may be minimally or severely affected
and difficult to predict based on the appearance.
 Careful analysis of the photographic appearances of
colobomata involving the optic nerve has shown that
the only feature that relates to visual outcome is the
degree of foveal involvement by the coloboma.
 Significant refractive error and anisometropia are
common and need to be dealt with optimal glass
prescription.

22. Associations
Optic nerve colobomas may be associated with the
following
 Microphthalmos
 Iris coloboma, lens coloboma and retinochoroidal
coloboma
 Serous macular detachment: can be rhegmatogenous or
non rhegmatogenous.
 Systemic associations like :
 CHARGE syndrome (coloboma, heart anomaly, choanal
atresia, retardation, genital and ear anomalies)
 Walker-Warburg syndrome
 Goldenhar’s syndrome

23. It needs to be distinguished from the other congenital disc lesions,
especially morning glory disc .

24. OPTIC PIT
 Optic nerve pits are rare congenital anomalies that are
part of a spectrum of congenital cavitary optic disc
anomalies that may be associated with juxtapapillary
retinal detachments.
 They occur in less than 1 in 10,000 patients seen in an
ophthalmic setting and are bilateral in 10% to 15% of
cases.

25. Pathogenesis
 These are formed through the herniation of dysplastic
retina into a collagen-lined pocket extending posteriorly
through a defect in the lamina cribrosa.
 They occur in locations unrelated to the embryonic
fissure, commonly located at temporal aspect of disc

26. Clinical features
 An optic disc pit is a round or
oval, gray, white or yellowish
depression in the optic nerve
head.
 Visual acuity is usually
normal unless associated
with serous macular
detachment.
 Visual field defects:
paracentral arcuate scotoma
is the most common.

27. (A) Optic disc pit; (B) optic disc pit and macular detachment

28. Associations
 Approximately one third to two thirds of patients with
optic pits develop serous macular detachments.
 These may occur during childhood or late in life but
are most common between the ages of 20 and 40.
 The fluid from optic pit initially produces an inner
layer retinal separation (retinoschisis) that overlies
posterior pole which then develops outer macular hole
and leads to serous macular detachment

29.  Various theories have been postulated for the source of
the subretinal fluid such as
1) cerebrospinal fluid (CSF),
2) liquefied vitreous entering through the pit or through
a macular hole, and
3) leakage from either choroidal vessels or permeable
vessels in the pit.
 Optic pits are not associated with brain malformations
– so they do not warrant neuroimaging.

30. Treatment
The treatment of serous macular detachment associated with an
optic disc pit is still controversial.
 Observation: spontaneous resolution has been seen in 25%
cases.
 Laser photocoagulation: creating a barrier of chorioretinal
adhesions at the temporal optic disc border but repeated
treatments may be required.
 Gas tamponade with laser photocoagulation: this induces
pneumatic displacement of the outer layer detachment and
improves central vision.
 Pars plana vitrectomy (PPV) combined with laser
photocoagulation and gas tamponade: currently this
approach is considered to be more effective than laser
photocoagulation or gas tamponade alone, particularly in eyes
with severe visual loss

31. MEGALOPAPILLA
 Megalopapilla is a generic term that connotes an
abnormally large optic disc that lacks the inferior
excavation of optic disc coloboma or the numerous
anomalous features of the morning glory disc anomaly.
 This condition is usually bilateral and often associated with
a large cup-to-disc ratio.
 Patients who have megalopapilla are often suspected to
have glaucoma.
 Unlike the situation in glaucoma, however, the optic cup is
usually round or horizontally oval with no vertical notch or
encroachment .

33.  Visual acuity is generally normal in megalopapilla but may
be mildly decreased in some cases.
 Visual fields are usually normal except for an enlarged blind
spot, which enables the examiner to rule out low-tension
glaucoma or a compressive lesion.
 Megalopapilla is only rarely associated with brain anomalies,
and neuroimaging is not warranted unless midline facial
anomalies are present.

34. CONGENITAL TILTED DISC SYNDROME
 The tilted disc syndrome is a nonhereditary bilateral
condition.
 The superotemporal optic disc is elevated and the
inferonasal disc is displaced posteriorly, which results in
an optic disc of oval appearance with its long axis
obliquely orientated.
 This configuration is accompanied by situs inversus of
the retinal vessels, congenital inferonasal conus,
thinning of the inferonasal retinal pigment epithelium
and choroid, and myopic astigmatism.
 These features presumably result from a generalized
ectasia of the inferonasal fundus that involves the
corresponding sector of the optic disc.

36. (A) Tilted disc; (B) tilted disc and inferonasal chorioretinal thinning

37.  Familiarity with this condition is important because
affected patients may present with the suggestion of
bitemporal hemianopias, which involve primarily the
superotemporal quadrants.
 However, these field defects, when observed carefully, do
not respect the vertical meridian (as do chiasmal
lesions).
 Furthermore, large and small isopters are fairly normal,
but medium-sized isopters are constricted selectively
because of the ectasia of the midperipheral fundus.

38.  Repeated visual field tests after correcting for the myopic
refractive error often eliminate the field defect, which
confirms its refractive nature.
 In some cases, retinal sensitivity is decreased in the area
of the ectasia, which causes the defect to persist despite
refractive correction.
 Rare cases of the tilted disc syndrome have been
documented in patients who have congenital suprasellar
tumors; neuroimaging is therefore warranted when the
associated bitemporal hemianopia respects the vertical
meridian.

39. CONGENITAL OPTIC DISC PIGMENTATION
 Congenital optic disc pigmentation is a condition in which
melanin anterior to or within the lamina cribrosa imparts a gray
appearance to the disc.

40.  True congenital optic disc pigmentation is extremely rare.
 Congenital optic pigmentation is compatible with good
visual acuity but may be associated with coexistent optic
disc anomalies that decrease vision.
 Most cases of gray optic discs are not caused by congenital
optic disc pigmentation.
 For reasons that are understood poorly, optic discs of
infants who have delayed visual maturation or albinism and
those of some normal neonates have a diffuse gray tint
when viewed ophthalmoscopically.
 In these disorders, the gray tint disappears within the first
year of life without visible pigment migration.