Congenital Anomalies

Question 1

When is the most vulnerable period for eye malformation

Answer 1

24-40 days

Question 2

What is anophthalmia

Answer 2

COmplete abscence of ocular tissue

SOX2 gene mutation - lethal

Question 3

What is cyclopia

Answer 3

Formation of single globe in midline with absent optic nerve
Lethal

Question 4

What is synophthalmia?

Answer 4

Two incomplete globes join in midline
Lethal

Question 5

What is microphathlmia? Causes? Gene?

Answer 5

Small disorganised globes

Patau’s trisomy 13
Foetal alcohol sydnrome
Rubella
Toxoplasma
CMV

CHX10 mutations

Question 6

What is nanophtahlmia

Answer 6

Small eyes with normal lens - hypermtropia

Question 7

What is cryptophthalmia

Answer 7

Abnormal eyelid development andn fission - abnormal eye developement
Cornea and AC absent
REtina and ON normal

Question 8

What is megalocornea?

Answer 8

Corneas larger than 12mm at birth

Congential glaucoma
Marfan’s Alports
Downs
Albinism

Question 9

Whta is microcornea

Answer 9

corneal dimater < 10mm

Question 10

What is axenfeld rieger syndrome?

Answer 10

Autosomal dominant

Congenital malformation of the anterior segment

Thinning of cornea, polycoria

Displaement of schwalbe’s line anteirorly

Mutation of PITX2
FOXC1

Question 11

What is aniridia

Answer 11

Absence of neuroectoderm derived iris pigement peihtleium, sphincter, dilator muscles - absence of pupil

Associated with Wilm’s tumour

Question 12

What is ocular albinism

Answer 12

Defective melanin production

IRis pigment dficiency
Poor stable vision

Question 13

Where does iris coloboma occur

Answer 13

Inferonasal

Failrue of optic fissure to fuse on day 33

Question 14

What is CHARGE syndrome?

Answer 14

Coloboma
Heart defects
Atresia of nasal choanae
Retardation of growth
Genitourinary defects
Ear abnormalities

Question 15

What is Peter’s abnormality? Causes?

Answer 15

Abnormal cleavage of the developing cornea form the lens vesicle at day 33
Abnormal development of central, paracentral or entire corneal endothelium and Descement’s

Part 1 cornea does not adhere to lens

Type 2
Bialteral cataracts with keratolenticular stalk bridge connecting lens and cornea

PAX6 gene mutation
Exposure to ethanol and isotretinoin in utero

Question 16

What can cause cataract in utero?

Answer 16

Malnutrition
Infection
Rubella (pre 6 weeks gestation)
Genetic predisposition

Question 17

What is perisitent hyperplastic primary vitreous?

Answer 17

Fibrovascualr stalk links posterior lens nad optic nerve

Question 18

What is the cloquet’s canal?

Answer 18

Persistant hyaloid artery

Associated with premature low weight

Question 19

What is the mittendorf dot?

Answer 19

Failure of anteiror segment of hyaloid artery connection to lens to degenerate seen as plaque on the posterior surface of lens capsule nasally

Question 20

What is tunica vacsulosa lentis

Answer 20

Developing lens supplied by hyaloid artery and capillary meshwork on posterolateral surface of lens seen at birth if not completely regressed

Question 21

What is Bergmeister’s papilla

Answer 21

Failure of posterior section of hyaloid artery to degenerate leaves fibrous tuft and membrane attached ot optic disc

Question 22

What is the optic pit?

Answer 22

Locallised defect in optic fissure on ONH allows dysplastic retina to herniate into subdural space through defect in lamina cribrosa

Allows CSF to cause serous RD

USually loacted temporally or inferiorly