DISEASES OF THE ORBIT

Question 1

IDIOPATHIC STENOSIS

Answer 1

the most common cause of NLDO

Question 2

Wegener disease

Answer 2

granulomatosis with polyangiitis

Question 3

sump syndrome

Answer 3

surgical opening in the lacrimal bone is too small and too high

Question 4

the lower end of the nasolacrimal duct in the region of the valve of Hasner

Answer 4

this is the last portion of the lacrimal drainage system to canalize which is soon after birth

Question 5

Leukocoria or cats eye reflex

Answer 5

this is seen in retinoblastoma and is the most common presentation
also known as white pupillary reflex

Question 6

Probing

Answer 6

the definitive management for NLDO

Question 7

dacryocystitis

Answer 7

infection of the lacrimal sac

Question 8

epiphora

Answer 8

excessive tearing/watering of the eye

Question 9

Flucloxacillin or co-amoxiclav

Answer 9

the treatment for acute dacryocystitis

Question 10

mucocele

Answer 10

this is usually evident as a painless swelling at the inner canthus of the eye in patients with chronic dacryocystitis

Question 11

Dacryocystorhinostomy

Answer 11

the treatment for chronic dacryocystitis

Question 12

Retinoblastoma

Answer 12

the most common primary intraocular malignancy of childhood

Question 13

Flexner Wintersteiner Rosettes

Answer 13

formation of these help in the differentiation of retinoblastoma

Question 14

RB1

Answer 14

the tumor suppressor gene in which mutations predisposing to retinoblastoma occurs

Question 15

germline mutations

Answer 15

these mutations are autosomal dominant

Question 16

group A

Answer 16

small intraretinal tumors whose sizes are less than 3 mm and they are away from foveola and disc

Question 17

group b

Answer 17

tumors are larger than 3 mm and they are macular to juxtapapillary location or with subretinal fluid

Question 18

group c

Answer 18

tumor with focal subretinal or vitreous seeding within 3mm of the tumor

Question 19

group D

Answer 19

tumor with diffuse subretinal or vitreous seeding more than 3 mm from the tumor

Question 20

group e

Answer 20

extensive retinoblastoma occupying more than 50% of the globe with or without neovascular glaucoma, hemorrhage, an extension of the tumor to the optic nerve or anterior chamber

Question 21

intraretinal tumor

Answer 21

a homogenous dome-shaped white lesion that can become irregular with white flecks of calcification

Question 22

endophytic

Answer 22

into the vitreous space

Question 23

exophytic

Answer 23

into the subretinal space

Question 24

red reflex testing

Answer 24

simple screening test for leukocoria

Question 25

chronic Toxocara endophthalmitis

Answer 25

may cause a cyclitic membrane and a white pupil

Question 26

vitreoretinal dysplasia

Answer 26

caused by faulty differentiation of the retina and vitreous that results in a detached dysplastic retina forming a retrolental mass with leukocoria

Question 27

Norrie disease

Answer 27

x linked where males are blind at birth or early infancy and there are mutations in the NDP gene that causes this

Question 28

Incontinentia pigmenti

Answer 28

x linked that is lethal in utero for boys and there are mutations found in the NEMO gene for this

Question 29

Walker warburg syndrome

Answer 29

autosomal recessive where there is an absence of cortical gyri

Question 30

Retinoma or Retinocytoma

Answer 30

this is manifesting as a whitish dome-shaped lesion and can later become or transform into retinoblastoma

Question 31

preseptal cellulitis

Answer 31

infection of the subcutaneous tissues anterior to the orbital septum

Question 32

S aureus and S pyogenes

Answer 32

organisms usually responsible for preseptal cellulitis

Question 33

bacterial orbital cellulitis

Answer 33

serious infection of the soft tissues behind the orbital septum which can be sight and life threatening

Question 34

ethmoid sinus

Answer 34

this is typically the main originating cause of bacterial cellulitis

Question 35

optic nerve compression

Answer 35

if there is a RAOD and color vision impairment and VA is reduced

Question 36

SUBCUTANEOUS EMPHYSEMA

Answer 36

there is a crackling sensation on palpation due to air in the subcutaneous tissues

Question 37

differential intraocular pressure test

Answer 37

increased IOP as a restricted muscle presses on the globe