opthamology

Question 1

vision loss

what can go wrong?

Answer 1

1. focused light doesnt reach the retina
2. the retina doesnt turn it into nerve impulses
3. the optic nerve doesnt tranmit the impulses to the brain
4. Brain doesnt precess them correctly

Question 2

Cornea function

Answer 2

• transmission of light into the eye
• refraction of light

Question 3

optics of eye

Answer 3

emmetropia

• normal eye

hyperopia

• flat cornea, light not focused til behind eye
• farsighted

Myopia

• steep cornea
• near sighted

Question 4

cornea

major abnormalities

Answer 4

1. epitheliopathies (disruption, edema)
2. stromal opacities
   - scarring
   - edema (endothelial cell dysfunction)
3. irregular shape

Question 5

cornea

clinical disorders

Answer 5

1. keratitis sicca
2. infectious keratitis
3. peripheral ulcerative keratitis (RA)
4. Pseudophakic corneal edema
5. keratoconus

Question 6

cornea

symotoms

Answer 6

1. everything is white(opacities)
2. colored haloes (edema)
3. distortion (irregularities)
4. ghost images (refractive errors, epitheliopathies)

Question 7

ocular surface

definition:

important functions:

Answer 7

def:

• outer surface of globe
• inner surface of eyelid

imp functions:

• protects eye from exogenous factors
• maintains moist surface

Question 8

ocular surface

clinical disorders:

Answer 8

1. primary corneal disease
2. dry eyes
   - aqeous tear dificiency
   - tear dysfunction
3. conjunctival disease

Question 9

Eyelids

function:

major abnormalities:

Answer 9

function:

1. protect ocular surface
2. meaintain normal tear film

major abnormalities:

1. structural defects (tumors)
2. entrpion (trichiasis)
3. Ectropion/ eyelid laxity
4. dysfunction (lagophthalmos, ptosis)
5. weakness

Question 10

anterior segment

diseases:

Answer 10

1. diseases reduce vision by affecting function of other tissues
   - glaucoma
   - inflammation (uveitis)
2. most anatomic changes dont affect vision directly
   except:
   - opacified media (blood, fibrin)
   - membranes
   - cataracts

Question 11

lens

functions:

major abnormalitie

Answer 11

function:

1. transmission of light
2. additional focus of light
3. accomodation- (change focus for near vision)

major abnormalities:

1. dislocation
2. opacification (cataract)
3. swelling (change in refractive state)
4. hardening (failure to change shape; lack of accomodation)

Question 12

lens

symptoms:

Answer 12

1. poor quality of vision (poor color vision, altered contrast sensitivity)
2. poor focus
3. glare, ghost images
4. “foggy vision”, “haze”

Question 13

Retina

major abnormalities:

Answer 13

1. loss of tissue (infection, degeneration)
2. edema
3. disturbances of normal position
   - traction
   - retinal detachment

Question 14

retina

symptoms:

Answer 14

1. scotomata (blind spots), curtains
2. poor quality
3. blurring
4. patchy loss
5. metamophopsia (distortion)

Question 15

international ocular infections

Answer 15

1. trachoma
2. onchocerciasis
3. leprosy

Question 16

conjencitivitis

basic concepts

Answer 16

• red eye with no pain or decreased vision
• cornea is clear with good light reflex
• if pain or decreased vision, think:
• corneal ulcer
• anterior uveitis
• acute (narrow angle) glaucoma

Question 17

conjunctivitis- etiologies

Answer 17

1. allergic
   - itching
   - hx od atopy
   - mucus
2. bacterial
   - mucopurulent
   - +/- adenopathy
   - patential souce
3. viral
   - acute onset
   - hx of exposure/ contact
   - mucus
   - preauricular adenopathy

Question 18

epidemic conjunctivits

Answer 18

• caused mainly by adenovirus type 8,19,37
• others- coxsackie, enterovirus, strep pneumoniae
• 10-14 days
• can be infectious for 3 weeks (pre and after)
• highly contagious

Question 19

hemorrhagic conjunctivitis

Answer 19

• unilateral or bilateral
• may be associated with prodromal symtoms
• confluent subconjenctival hemorrhage
• caused by enterovirus or coxsackievirus
• highly contagious

Question 20

herpetic viral conjunctivitis

Answer 20

• primary infection at any age
• unilateral
• vesicular skin lesions on primary presentation
• corneal inveolvement with classic dendrite
• keratitis may worsen with topical steroids
• uveitis
• recurrence common

Question 21

organisms that cause ocular infections

Answer 21

viral: adeno, coxsackie, herpes simplex, herpes zoster, varicella, CMV, RSV

Bacterial: strep, staph, pseudomonas, neisseria, syphilis, borrelia (lyme disease)

chlamydial: trachoma
mycoplasma: TB, leprosy, atypial forms
fungal: mucomycosis, candida

protasoan and nematodes: acanthamoeba, filariasis, toxoplasmosis, toxocara

Question 22

method of ocular infection and spread

Answer 22

1. direct contact with or without disruption of normal protective bariers

2. direct spread (sinus infection)

3.opthalmia neonatorum

• chemical (24hrs), N. gonorrhea (4 days), chlamydia (3 wks), herpes simplex

4. hematogenous

• retinal and choroidal infections

embolic- endocarditis, meningitis, fungemia

5. iatrogenic- surgical and intravitreal
6. trauma

7. aerosol

Question 23

bacterial conjunctivitis

Answer 23

• preschool age
• bilateral or unilateral
• mucopurulent discharge
• otitis media association

Question 24

most common pediatric causes of acute conjenctivitis

Answer 24

• haemophilus influenzae
• strep pneumoniae
• moraxella catarrhalis

Question 25

delivery of ocular therapy

Answer 25

1. topical (drops or ointment)
2. intravitreal injections
3. systemic