Gradual Vision Loss

Question 0

List the different types of refractive error

Answer 0

1. Hyper-metropia ( long sight): can’t see near–> focus behind retina–> want less diverge–> CONVEX
2. Myopia ( near sight) : can’t see far–> focus in front->diverge more- CONCAVE
3. Presbyopia ( age associated loss of accommodation) : diverge less- CONVEX* age related myopia
4. Astigmatism : 2 diff curvatures of cornea

Question 1

List 7 causes of gradual vision loss

Answer 1

1. Refractive error
2. Cataract
3. Corneal blindness
4. Optic atrophy
5. ARMD
6. Diabetic macular edema
7. Chronic ocular inflammation/ infection

Question 2

How does one prove refractive error?

Answer 2

Vision improves with 1mm pin hole

Parallel rays pass through - needing no refraction to get a clear image

Question 3

What is a cataract?

Answer 3

Cloudy / less clarity of lens

Question 4

List 4 causes of cataract

Answer 4

1. congenital

2. Acquired: senile, diabetes, trauma, steroid, chronic uveitis

Question 5

Sx and Sn of cataracts

Answer 5

1. Blindness gradual
2. Glare
3. Mono-ocular diplopia
4. Refractive error
5. Loss of red reflex
6. Leukocoria

Question 6

Other cause se of leukocoria

Answer 6

1. Toxo
2. Toxocariasis
3. Retinoblastoma
4. Long standing retinal detachment

Question 7

Mx of cataracts

Answer 7

1. Microsurgery
   ( safe, cost effective, quick)

Cataract extraction->
1. Intra capsular: remove with lens and capsule- eye is aphakic( no lens) replace with powerful glass lense +10

2. Extra capsular : lens only removed- leave capsule so replace lens

Question 8

Methods of Extra capsular excision

Answer 8

1. Traditional: large limbal cut- needle make hole in capsule - remove by applying pressure
2. Small incision : tunnel via sclera–> hydrostatic removal –>no suture
3. Phaco-emulsification: ultrasound probe emulsify and aspirated –> no suture - short recovery time

Question 9

What is corneal blindness?

Answer 9

Anything that causes an Opacified cornea - low Va

Question 10

What is the difference between a cataract and cornaeal blindness (sign)

Answer 10

Visible iris in cataract

Non-visible iris behind a opaque cornea

Question 11

Causes of corneal blindness?

Answer 11

1. Infection :
   A. Trachoma : chlamydia, spread by housefly–> recurrent infections. Cause conj scaring-entropion-trichaisis- cornaeal scar

B. Intersistinal keratitis: congenital syphillis, TB, measels

2.UV
A. Climatic droplet keatopathy: prolonged uv light ( outdoor workers or desert land)–> looks like “bubbling cornea” - Mx patch or ointment work temp ( may have ass cataract)

Question 12

What is optic atrophy?

Answer 12

PALE optic disc
Damage to nerve fibers at any point from the retina to LGB
1. Glaucomatous atrophy ( large optic disc cup)” cupping “
2. Non Glaucomatous atrophy/diffuse

Question 13

Sn and Sx of optic atrophy

Answer 13

1. Gradual vision loss
2. Low colour vision
3. Loss VF
4. AFFERENT PUPIL DEFECT
5. Pale disc

Question 14

Causes of optic atrophy

Answer 14

Any interruption on the retina or the optic nerve including chasm
1 . Nerve compression : tumor
2. Damage nerve head : glaucoma ( pressure response) or chronic
3. Nerve ischemia : central rental artery occlusion:
4. Damage to retina : metabolic ( retinitis pigmantosa) infective ( syphillis) genetic , toxic (ethambutol. Tabbaco-ethoh amblyopia ).

Question 15

What is Glaucoma?

Answer 15

Optic neuropathy with

1. Optic docs cupping
2. Chart artistic visual field loss (. Central vision maintained)

Associated with
1. Increased IOP (N 10-21 mmHg)

*can have normal cup and VA AND IOP

Question 16

What is the normal CSF opening pressure?

Answer 16

70-180 mmHg–> 7-18 cm Hg

Question 17

Classify glaucoma?

Answer 17

1. Acute vs chronic
2. Open vs closed angle: anterior chamber angle( gonioscopy)
3. Primary vs secondary : other related ds?-uveitis, cataract

*primary chronic open Angle -most common

Question 18

Risk factors for glaucoma ( poag)?

Answer 18

1. Age>45
2. Black
3. Myopia
4. Dm, hpt uncontrolled
   5 genetic: TIGR MYOCILLIN gene

Question 19

Sx sn glaucoma

Answer 19

1. ASX, no pain, normal va/low
2. Peripheral VF lost-> follows path of recital nerve damage (out in)
   -tunnel vison
   -nasal step
   -ring scotoma
   -eventual blin
3. Optic disc
   -pale
   ->o.6= Glaucomatous cupping = loss of nerve fibre cause bigger cup
   +disc hge
   +cup pallor> disc
   +laminar dot sign
   +vessel change : nasalization, baring, bayonetting
   +disc notching

Question 20

Mx glaucoma

Answer 20

• lifelong: progression
  1. Medically Drop IOP: drops Bb, PG analogue
  2. Surgically drop IOP; drain - trabeculectomy ( SE:Can cause bleb on eye ; looks like cyst on conjunctiva)

Question 21

What is retinitis pigmantosa (RP)?

Answer 21

-inherited retinal atrophy–> dystrophy of photoreceptors

Question 22

Sn and Sx of RP

Answer 22

• gradual vision loss
• night blind
• tunnel vison

Sn
-waxy pale disc
-bone speckle pigmentary retinopathy
-annuated bv
-

Question 23

What else should you screen for in a patient with RP?

Answer 23

1. Deafness
2. Heart block
3. Cerebellar disease

Question 24

What is Papilloedema?

Answer 24

Bilateral discs swelling due to INCREASED ICP - cause intermittent visual disturbances that re-occurs during the day - chronic: vidialy acuity loss so pallor = optic atrophy

Question 25

What are the signs and Sx of ICP

Answer 25

Sx: early morning headache, nausea, intemittend visual disturbance , LOC/ personality change Sn : 1 papilloodema 2 cushings triad : high bp, wide pp, Brady cardia (+ deep respiration ) 3 cranial nerve 6 palsy : can't ad-duct eye--> have convergent squint on distant fixation ( FALSE LOCALIZING SIGN) * cn 6 out of the bottom of brain first affected at inc ICP / long intracranial path

Question 26

Dx? If a pt disc is 1. Swollen 2, sudden COMPLETE vision loss

Answer 26

Papillitis causes optic neuritis

Question 27

Age related macular degeneration is diease of elderly > 65 And in light skinned. But how does it present?

Answer 27

1. Central vision loss( scaring , leaking or bleeding sub retinal neo-vascular membrane 2. Distorted image/ metamorphopsia Types: 1Loss slow/dry 2 fast/wet(due to bleeding). Sn: 1. Drusen : pale deposit in MACULAR (early sign) 2. Dry-->Retinal pigment epithelial atrophy (dry) 3. Wet --> hge and exudate from sub retinal neovascular membrane

Question 28

Mx of ARMD

Answer 28

1. Laser 2. Antivascular GF - intraviteral injection 3. Visual aid of mild

Question 29

Diabetetes?

Answer 29

Macular odema

Question 30

Chronic ocular inflammation

Answer 30

H