#43. Congenital cataracts. Changes of lens location - traumatic, congenital.

Question 1

What are Cataracts?

Answer 1

• OPACITY of the Lens of the Eye
• Where Fluid GATHERS BETWEEN the Lens Fibres
• REFRACTIVE INDEX Alters, causing LIGHT SCATTER
• Leading to BLURRED VISION

Question 2

What is the CAUSE of CONGENITAL CATARACTS?

Answer 2

1) UNILATERAL (1 eye)
- Unknown Cause

• ## Linked with other conditions such as - eye trauma, baby affected by infection whilst developing in wound2) BILATERAL (both eyes)
• Runs in the family; inheritance, by 23%
• Linked with other Conditions / Infections (Rubella)
• ## Conditions affecting Baby’s Metabolism is another cause0 Cataract Clouding is associated with Aging, but can occur in new-borns due to:
• Inheritance
• Infection (Measles, Rubella, Chicken Pox, Herpes Simplex, EBV, Syphilis)
• Metabolic Problems
• Diabetes
• Trauma = Blow to the eye; 40% of cases in older children
• Inflammation
• Drug Reactions = TETRACYCLINE Antibiotics (Pregnant Women)

Question 3

What are the 4 TYPES of Congenital Cataracts?

Describe each of them.

Answer 3

1) ANTERIOR POLAR Cataracts
- Well-defined
- Located in FRONT PART of Eye Lens
- Associated with INHERITANCE
- TOO SMALL for Surgical Intervention

2) POSTERIOR POLAR Cataracts
- Well-Defined
- Located in BACK PORTION of Eye Lens

3) NUCLEAR Cataracts
- Located in CENTRAL PART of Eye Lens
- VERY COMMON Form

4) CERULEAN Cataracts
- Found in BOTH EYES!
- DISTINGUISED Via Small, BLUISH Spots in Lens
- NO Vision Problems !!!
- Associated with INHERITANCE

Question 4

How does CONGENITAL Cataract AFFECT Visual System Development?

Answer 4

1) Visual System develops until child is 7/8 y/o

2) Visual System is Stimulated + Developed by our vision

3) IF born with Cataract, it’ll LOWER amount of Visual STIMULATION the eye + brain RECEIVE

4) IF 1 of the child’s eye is sending poor, unclear images to the brain, it’ll IGNORE it in order to FAVOUR the images provided by the STRONGER eye = AMBLYOPIA / LAZY EYE

5) IF BOTH of child’s eyes (Bilateral Cataract), the visual system will still develop, but it’ll be LIMITED, resulting in PERMANENT Vision Loss = AMBLYOPIA in BOTH eyes!

** Lead to OTHER Eye problems - STRABISMUS + INABILITY to fix a GAZE UPON objects, IMPACTING learning, personality + appearance!!!

Question 5

What is the Lens?

Answer 5

• Transparent
• Disk-Shaped Structure
• Focuses light ONTO Retina, ALLOWING us to see clearly

Question 6

What is a DISSOCIATED Lens?

Answer 6

• Lens that’s MALPOSITIONED
• DUE to Some / All Supporting Ligaments are BROKEN
• ECTOPIA LENTIS = Displacement / Malposition of CRYSTALLINE LENS of eye

Question 7

What are the 2 TYPES of Lens DISSOCIATIONS?

Answer 7

1) DISLOCATED / LUXED

• Lens lies:
  a. COMPLETELY OUTSIDE the LENS PATELLAR FOSSA
  b. IN the ANTERIOR CHAMBER
  c. FREE-FLOATING in the VITREOUS
  d. DIRECTLY ON the RETINA - COMPLETELY Detached from CILIARY BODY

2) SUBLUXED
- Lens is PARTIALLY Displaced
- STILL CONTAINED within the Lens Space
- REMAINS ATTACHED to CILLIARY BODY

Question 8

How does TRAUMA cause DISLOCATION of LENS?

Answer 8

• BLUNT TRAUMA = With a HIGH-ENERGY PROJECTILE e.g. Baseball / Golf ball

a. Head
b. Orbit
c. Eyes

• There’s DISRUPTION / DYSFUNCTION of ZONULAR FIBRES of the LENS = Underlying pathophysiology of ECTOPIA LENTIS

0 DEGREE of Zonular IMPAIRMENT determines, DEGREE of Lens DISPLACEMENT

Question 9

How does CONGENITAL cause DISLOCATION of LENS?

Answer 9

Some people are born with conditions, causing WEAK LIGAMENTS, that are PRONE to having DISLOCATED Lens

• Marfan’s syndrome
• Homocystinuria
• Marchesani’s syndrome
• Weill Marchesani syndrome
• Hyperlysinemia
• sulphite oxidase deficiency

Question 10

What are the SYMPTOMS of DISLOCATED LENS?

Answer 10

• Blurred Vision

0 AMOUNT of Blurring DEPENDS ON EXTENT of DETACHMENT

** PARTIALLY Detached DOES NOT cause such symptoms!

Question 11

What is the DIAGNOSIS for DISLOCATED LENS?

Answer 11

• Upon Eye Examination, Physician looks for Lens that’s OFF-CENTRE - can be seen by naked eye!
• Physician can ALSO USE SPECIAL DROPS to DILATE the Pupil, in order to see the LENS BEHIND IT more clearly

Question 12

What is the PREVENTION for DISLOCATED LENS?

Answer 12

PROTECT the Eyes AT ALL TIMES!

• Goggles
• Protective Eye Wear

Question 13

What is the TREATMENT for DISLOCATED LENS?

Answer 13

• NO TREATMENT

0 MONITORED by a Physician PERIODICALLY to make sure the CONDITION REMAINS STABLE

0 IF Dislocation is ACCOMPANIED BY OTHER Eye problems (Cataract / Retinal Detachment), SURGERY IS REQUIRED to remove the lens + REPLACE it with PLASTIC LENS

0 BLURRY Vision due to LENS DISLOCATION can be CORRECTED VIA GLASSES