Correct Answer - B
Placido disc examination is used to diagnose keratoconus. In a case of keratoconus
placido disc examination shows irregularities of the circles.


Placido's keratoscopic disc: It is a disc painted with alternating black and white circles. It
may be used to assess the smoothness and curvature of corneal surface. Normally, on
looking through the hole in the center of disc a uniform sharp image of the circle is seen on
the cornea. Distortion of the circles occur when irregularities are present on the corneal
surface.


Ref: Comprehensive Ophthalmology By AK Khurana, 4th edn, page 119

Correct Answer - A
Anterior uveitis , also known as iridocyclitis and iritis, is the inflammation of the iris and
anterior chamber. Anywhere from two-thirds to 90% of uveitis cases are anterior in location.
Injection, photophobia, pain, and blurred vision usually accompany iritis (anterior uveitis or
iridocyclitis).


Ref: Braverman R.S. (2012). Chapter 16. Eye. In W.W. Hay, Jr., M.J. Levin, R.R.
Deterding, J.J. Ross, J.M. Sondheimer (Eds), CURRENT Diagnosis & Treatment:
Pediatrics, 21e.

Correct Answer - A
A i.e. Fungal corneal ulcer

Correct Answer - B
B i.e. Central Retinal Artery Occlusion
Central retinal artery occlusion characteristically presents with
sudden painless loss of vision, cherry red spot & cattle-truck
appearanceQ (of retinal veins usually).
Source of emboli from carotid artery & heart disease, and thrombus
from arteriosclerosis along with hypertension & arteritis are
predisposing factors

A newborn is usually hypermetropic by +2D to
+3D because the diameter of the eyeball of the
newborn is relatively short.


◦ The antero-posterior (AP) diameter of
the eyeball at birth is about 16.5 mm.
• This is 70% of the adult size, and hence, light
rays tend to converge behind the retina,
causing hypermetropia


Eye at birth:


• The anteroposterior diameter of the eyeball
is about 16.5 mm (70% of the adult size).
• The corneal diameter is about 10 mm. Adult
size (11.7 mm) is attained by 2 years of age.
◦ The anterior chamber is shallow, and
the angle is narrow.
• The pupil is small and does not dilate fully.
◦ The lens is spherical at birth, and
embryonic/fetal nucleus is present.
◦ Retina: Apart from the macular area, the
retina is fully differentiated. Macula
differentiates 4-6 months after birth.
• Myelination of the optic nerve fibers has
reached the lamina cribrosa.
◦ Refractive status: The newborn is usual
hyper-metropic by +2 to +3 D.
◦ The orbit is more divergent (50) as
compared to the adult (45°).
• The lacrimal gland is still
underdeveloped, and tears are not secreted

The surface ectoderm gives rise to the lacrimal
glands.


Derivatives of surface ectoderm are as follows:


◦ Lacrimal glands
• Crystalline lens
• Corneal epithelium
◦ Conjunctival epithelium


The ectoderm is of 2 types:


◦ Neural ectoderm from the neural tube
◦ Surface ectoderm on the side of the head

INICET 25 RECALL IN group @doctorusmle

Embryonic development of ciliary muscles is
from the neural crest.


Neural crest cells give rise to the following
structures:


◦ Corneal stroma
• Corneal endothelium
• Trabecular meshwork
• Iris stroma
• Ciliary muscles
• Choroidal stroma
◦ Uveal and conjunctival melanocytes
• Orbital bones
• Orbital connective tissue

The optic groove appears by 3 weeks. By
approximately day 22, 2 small grooves appear
on either side of the developing forebrain in the
neural folds, these are called optic grooves. As
the neural tube closes, these grooves develop
outpouchings called optic vesicles. These optic
vesicles extend from the forebrain to the surface
ectoderm.