3 - optic disc abnormalities

What is the most common congenital optic nerve anomaly?

optic nerve hypoplasia (CONH)

Who gets optic nerve hypoplasia?

babies who mother had/is:

-maternal diabetes

-young maternal age

-maternal alcohol/drug use

What causes optic nerve hypoplasia?

1. exaggeration of ONH axon reduction in development

2. compressive lesion inhibiting normal ON development

Is optic nerve hypoplasia uni or bilateral?

bilateral > unilateral

What are the visual signs of optic nerve hypoplasia?

1. VA normal to no light perception

2. VF loss possible

3. absent or decreased direct pupillary response

What is the appearance of ONH (ON hypoplasia)?

1. disc smaller → 1/3 to 1/2 of normal size

2. disc is paler (may be segmental)

3. double ring sign

4. increased DM/DD ratio (>3)

What is the double ring sign in ONH?

ONH is surrounded by outer ring of scleral (yellow) with variable pigmentation (RPE)

What are the systemic association of ONH?

septo-optic dysplasia (De Morsier's syndrome)

"rare congenital disorder characterized by a combination of optic nerve hypoplasia, midline brain abnormalities (like absence of the septum pellucidum), and hypopituitarism"

What are the signs/appearance of septa-optic dysplasia?

1. ONH hypoplasia

2. pituitary hypoplasia → endocrine abnormalities (esp growth hormone)

3. agenesis of septum pellucidum and corpus callosum (lobes of the brain)

What is the management for ONH in a child?

refer for MRI, endocrine workups and consult for systemic abnormalities

What is the treatment for ONH?

1. treat any visual problems → RE, strabismus, amblyopia, low vision, routine eye exams

2. pt ed

3. protective eyewear if unilaterally decreased vision

What is a coloboma?

failure of complete closure of the embryonic tissue of optic cup

What are the visual signs of a coloboma?

1. depression of disc, retina, or coloboma

2. corresponding VF defect

3. variable VA deficit

What is the ocular complication of coloboma?

non-rhegamatogenous retinal detachment → monitor area of chorioretinal coloboma

What are the systemic associations of a coloboma?

1. midline facial or skull abnormalities

2. transsphenoidal encephalocele - displacement of brain through holes in skull

3. cardiovascular abnormalities

4. CHARGE syndrome

What is CHARGE syndrome?

coloboma

heart defects

choanal atresia - nasal passage blockage

growth retardation

genital abnormality

ear abnormality

What is the management of coloboma ?

1. treat vision

2. may need workup if suspect CHARGE syndrome

What is an optic pit?

congenital greyish or yellowish pit of optic disc

what are the potential causes of an optic pit?

1. incomplete closure of fetal fissure

2. anomalous differentiation of primitive epithelial papilla

Is optic pit unilateral or bilateral?

unilateral (85%) > bilateral

What is the appearance of optic pit?

1. usually only one → commonly I or T

2. round, oval, or a slit

3. may have pigmentation

4. glial retinal remnants at base of pit → membranes over pit

What are the visual signs of optic pit?

1. normal acuity unless detached macula

2. may have corresponding visual field defect

What are the complications of an optic pit?

1. serous RD

2. may increased risk for low tension glaucoma

what is the management for an optic pit?

monitor and pt ed with regular examination in cases with no maculopathy

What is a morning glory disc?

congenital excavated disc

Who gets morning glory disc?

1. females

2. caucasians

is morning glory disc unilateral or bilateral?

unilateral > bilateral

What are the visual signs of morning glory disc?

1. variable VAs → slight decrease to hand motion only, profound vision loss more common

2. corresponding VF defect or enlarged blind spot

What does a morning glory disc look like?

1. large excavated optic nerve

2. central glial tuft

3. radial vessel pattern

4. disruption of surrounding choroidal pigment

What are the ocular complications of morning glory disc?

1. non-rhegamatogenous RD

2. retinoschisis

What are the systemic associations with morning glory disc?

1. midline facial abnormalities

2. transsphenoidal basal encephalocele - meninges bulge in to nasal cavity

What is the management for morning glory disc?

refer for MRI

Whta is megalopapilla?

large optic disc (>2.1 mm diameter)

is megalopapilla uni or bilateral?

either

What are the visual signs of megalopapilla?

1. VA normal to slightly decreased

2. enlarge blind spot → VF otherwise normal

What is the appearance of megalopapilla?

1. disc >2.1mm diameter

2. decreased DM/DD ratio (<2:1)

3. associated large cup → simulate asymmetrical C/D ratios of glaucoma

4. anomalous vessel pattern

5. circumpapillary RPE disturbances

What is optic disc drusen?

globular deposits anterior to lamina cribrosa

Who gets optic disc drusen?

1. Caucasians

2. women=men

What are the visual signs of optic disc drusen?

1. normal VA

2. may have RAPD if unilateral or asymmetric

3. arcuate VF defect

what is the apperance of optic disc drusen?

variable → can be buried or at surface

Is optic disc drusen uni or bilateral?

bilateral (70%) > unilateral

What are the complications of optic disc drusen?

shearing of BVs → circumpapillary hemes, choroidal neovasc

disruption of axoplasmic flow and shearing of nerve fibers → slow progressive VF loss

how do you properly diagnose optic disc drusen?

1. clinical findings

2. ultrasonography

3. CT

4. OCT

5. FANG

6. AF

must differentiate from papilledema if bilateral or buried

What is the management of optic disc drusen after proper diagnosis?

1. baseline VF

2. annual exams

3. pt ed

What is a tilted optic disc?

oblique insertion of ON into globe

Who gets tilted optic discs?

1. myopes

2. astigmats

What are the visual signs of tilted optic disc?

1. may have decreased VAs

2. may have bitemporal defect that does not respect the vertical midline

What is the appearance of a tilted optic disc?

1. oval d/t vertical tilt

2. tilted inferior or inferior nasally → superior elevation

3. inferior nasal staphyloma and crescent

what is the management for a tilted optic disc?

routine exam

What is a malinserted disc?

oblique insertion of the ON into the scleral canal

What are the visual signs of a malinserted disc?

may have altered VF → otherwise normal

What is the appearance of a malinserted disc?

1. disc tilted temporally → elevated nasally

2. usually will have (scleral) crescent

3. R + L are mirror images

what is the management for a malinserted disc?

routine eye exams

what is the management of congenital disc anomalies general guidelines?

1. regular examinations

2. ed risk of RD

3. tx of associated ocular anomalies

4. baseline VF testing

5. refer for associated systemic associations