Trans 022 Ophthalmic Patho part 2

Question 1

• Most commonly due to aging.
• May occur due to trauma or radiation, congenital, following
eye surgery for other problems
• Risk factors include diabetes, smoking tobacco, prolonged
exposure to sunlight, and alcohol.

Answer 1

Cataract

Question 2

Age-related cataract typically results from opacification

of the lens nucleus

Answer 2

nuclear sclerosis

Question 3

2 types of lens opacity in cataracts?

Answer 3

hydration vs Coagulative opacity

Question 4

Hydration vs coagulative opacity?

Answer 4

o Hydration opacity
- Biochemical, electrolytic and permeability factors
produce abnormal osmotic gradient leading to an
influx of water and sodium ions and an egress of
potassium ions.
o Coagulative opacity
- An irreversible chemical change. Denaturation of
the lens proteins may initiate or potentiate the
process of water influx and cellular fragmentation.

Question 5

Most delicate bone of the face =

Answer 5

Lacrimal bone

Question 6

• Most common form of retinal degeneration; not inflammatory.
• Group of rare inherited disorders; progressive peripheral
vision loss and night vision difficulties (nyctalopia) that can
lead to central vision loss.

Answer 6

Retinitis Pigmentosa

Question 7

• Rod-cone dystrophy in which the genetic defects cause cell
death (apoptosis).

• Predominantly in the rod photoreceptors; less commonly, the retinal pigment epithelium and cone photoreceptors
• Associated with melanin migrating from the choroid to be sequestered by macrophages located around retinal vessels.

Answer 7

Retinitis Pigmentosa

Question 8

• Thickening of the capillary basement membrane and hyaline arteriolosclerosis.
• Dilatation of these vessels, abnormal fragility and increased permeability.
• Consequently, exudates, hemorrhage, and retinal ischemia; retinal ischemia causes the production of angiogenetic factor.
• Formation of new blood vessels called proliferative retinopathy.

Answer 8

Diabetic Retinopathy

Question 9

o composed of accumulations of neuronal debris within the nerve fibre layer.
o Small fluffy whitish superficial lesions that obscure underlying blood vessels.

Answer 9

Cotton wool spots

Question 10

• Separation of the neural retinal layer from the pigment epithelium thereby losing metabolic support
• May lead to degeneration of photoreceptors if detachment is prolonged

Answer 10

Retinal detachment

Question 11

Causes of retinal detachment

Answer 11

Tractional retinal detachment

Exudative detachment

Shearing of the retina

Question 12

scar tissue on the retina’s surface contracts and causes your retina to pull away from the back of your eye; common in diabetic retinopathy

Answer 12

Tracntional retinal detac

Question 13

no tears or breaks in retina; due to retinal diseases:
▪ Inflammatory disorder causing fluid accumulation behind retina
▪ Tumor behind retina

Answer 13

Exudative detachment

Question 14

may cause small retinal tears
▪ Vitreous humor leaks through a retinal hole or tear and collects underneath the retina e.g., injury
▪ Thinning of the retina due to aging or retinal disorders
▪ Tear in the retina develops when the vitreous collapses and pulls on the retina with enough force to create a tear.

Answer 14

Shearing of the retina

Question 15

is associated with a full thickness retinal defect. Retinal tears may develop after the vitreous collapses structurally, and the posterior hyaloid exerts traction on points of abnormally strong adhesion to the retinal internal limiting membrane.

Answer 15

Rhegmatogenous retinal detachment

Question 16

may complicate retinal vascular disorders associated with significant exudation and any condition that damages the RPE and permits fluid to leak from the choroidal circulation under the retina. Retinal detachments associated with choroidal tumors and malignant hypertension are examples of non-rhegmatogenous retinal detachment.

Answer 16

Non-rhegmatogenous retinal detachment

Question 17

• Rare: usually < 5 years of age
• Arises from a multipotential precursor cell that could develop into almost any type of inner or outer retinal cell
• Associated with a loss of a specific tumor suppressor gene RB (40% of cases)
• Mutation in the long arm of chromosome 13 band 13q14
• Metastasize to the brain and marrow

Answer 17

Retinoblastoma

Question 18

is the most common primary intraocular malignancy of children.

occurs in individuals who inherit a germline mutation of one RB allele.

Answer 18

Retinoblastoma

Question 19

A halo of cells surrounds a central hub that contains a meshwork of fibers. The delicate fibrillary material found within the central hub is composed of neuropil, which contains primitive neuronal processes or neurites. Encountered in neuroblastomas.

Answer 19

Homer-Wright Rosette

Question 20

most important risk factor for death

• Invasion of optic nerve (Most common method)
• Directly through sclera

Answer 20

Extraocular extension of tumor

Question 21

in retinoblastoma, Secondary tumor development: most commonly

Answer 21

osteosarcoma

Question 22

• Small or atrophic and internally disorganized eye
• Causes:
o Trauma
o Intraocular inflammation
o Chronic retinal detachment
 Trauma, intraocular inflammation, chronic retinal detachment, and many other conditions can give rise to an eye that is both small (atrophic) and internally disorganized:

Answer 22

PHTHISIS BULBI: END-STAGE EYE

Question 23

 The presence of exudate or blood between the ciliary body and sclera and the choroid and sclera (ciliochoroidal effusion).
 The presence of a membrane extending across the eye from one aspect of the ciliary body to the other (cyclitic membrane);
 Chronic retinal detachment;
 Optic nerve atrophy;
 The presence of intraocular bone, which is thought by many to originate from osseous metaplasia of the RPE;
 And a thickened sclera, especially posteriorly

Answer 23

Phthisical eyes typically show the following changes: