Lens And Cataract

Question 1

What is the lens of eye

Answer 1

Is a transparent biconcave structure just immediately behind the iris

Question 2

What are the characteristics of lens

Answer 2

Focus the light on retina especially ( macula , fovea)

Derived from ectoderm
Avascular
Highly elastic but it hardness with age

Question 3

What are the layers of lens ?

Answer 3

Lens capsule
Lens epithelium
Lens differantiated fibers
Lens mature fibers

Question 4

Lens capsule composed of ?

Answer 4

Collgen type 4 and proteoglycans ( imp in protection and attachment of zonules )

Question 5

What is the type of lens epithelium ?

Answer 5

Single layer of cuboid cells present only in anterior surface of capsule ( the cells divide to provide new cells that differntiate as lens fibers )

Question 6

What are the differntiating lens fibers ?

Answer 6

Fibers still have their nuclei elongated and inside their cytoplasm proteins called crystallines

Question 7

What are the mature lens fibers ?

Answer 7

They lost their nuclei and became densly pached to produced hard structure

Question 8

What is cataract ?

Answer 8

Opacification of lens of the eye ( become cloudy and opaque )

Question 9

Cataract is the most common cause of ……… in the world

Answer 9

Treatable blindness

Question 10

How patients with cataract see the image ?

Answer 10

The image appears blurry , colors are distored and Glare present
Glare( the colors appear shiny and not same as real one )

Question 11

What are the types of cataract ?

Answer 11

Nuclear cataract
Cortical cataract
Posterior subcapsular cataract

Question 12

What is nuclear cataract ?

Answer 12

Most common type
Nucleus becomes hard scelortic due to 1) condensation of nucleus
2) deposition of brown pigment

Question 13

Nuclear cataract present with

Answer 13

Nearsightedness means that the patient has problems with distance vision while reading is less affected

Question 14

What is the cortical cataract?

Answer 14

Opacification of lens
Result from changes in water content of periphery of lens causes fissuring

Question 15

The cortical cataract associated with

Answer 15

Glare
Scattering at night

Question 16

What is the most common cause of cataract ?

Answer 16

Age ( senile cataract )

Question 17

Age related cause of cataract result from acculations of

Answer 17

Smoking
Alcohol
UV light exposure
Blood suger level ( uncontrolled diabetes )

Question 18

What are the ocular causes of cataract?

Answer 18

Trauma
Ocular tumors
Uveitis
Steriod
Myopia ( nearsightedness)

Question 19

What is fabry disease?

Answer 19

X linked lysosomal storage disease

Question 20

What is Lowe syndrome?

Answer 20

X linked recessive disease characterized by
Congenital cataract
Myotonia areflexia
Mental retraction
Aminoaciduria
Phosphaturia
Proteinurea
Glucoma ( 50% )

Question 21

What are the systematic disesae associated with cataract?

Answer 21

DM
Metabolic diseases( hypocalcemia , fabry disease, galactosemia)
Medications( steroid , chlorpromazine)
Infections
Myotonic dystrophy
Atopic dermatatis
Congenital
Infections
External radiation
Down syndrome
Lowe’s syndrome

Question 22

What are the symptoms of cataract?

Answer 22

Glare
Loss of vision
Amblyopia

Question 23

What are the signs of cataract?

Answer 23

Decreased visual acuity
Lens opacity with SLE
Black spot against red reflex of fundus
Leukocoria

Question 24

The main stay treatment of cataract?

Answer 24

Surgical removal of lens

Question 25

Indication for cataract surgery?

Answer 25

Cataract that reducing quality of life

Question 26

Post operative care ?

Answer 26

Short course of antiboitics and steroids