Toxic responses of the eye

Question 1

main areas of ocular drug metabolism

Answer 1

cornea and retina

rich in enzymes more susceptible

Question 2

cornea susceptibility

Answer 2

avascular so less

Question 3

lens susceptibility

Answer 3

avascular not very susceptible

Question 4

phenothiazines (chlorpromazine) toxicity

Answer 4

pigmentation ranging from white to yellow to tan

begins of the anterior surface of the lense . cornea becomes involved when lenticular pigmentation reaches grade 3

Question 5

dose of chlorpromazine toxic

Answer 5

total cumulative >2500g

Question 6

how often should ppl on chlorpromazine get thier eyes checked

Answer 6

on high doses or long term low doses should be annually

Question 7

mechanism of corticosteroid toxicity

Answer 7

altered lens epithelium electrolyte balance
binding to proteins of the lens (corticosteroid crystalling adducts )
all forms!

Question 8

corticosteroid toxicity unlikely in

Answer 8

<10mg prednisone or treated for less than a year

Question 9

how often should ppl on steroids get thier eyes check

Answer 9

long term oral steroids every 6 months

Question 10

is corticosteroid toxicity reversible

Answer 10

yes

Question 11

why is an eye exam recommended at baseline and every 6 months with quetiapine

Answer 11

cataract development has been observed

Question 12

normal intraocular pressure

Answer 12

10-22mmhg

Question 13

open angle glaucoma

Answer 13

absence of pain
slow loss of peripheral visual field
often unnoticed

Question 14

closed angle glaucoma

Answer 14

happens to indiiduals genetically susceptible
narrow anterior chamber angle
caused by anything that dilates the pupil
painful

Question 15

aqueous humor flow

Answer 15

flows between the posterior surface of the iris and the anterior lens surface

Question 16

corticosteroids effect on pressure

Answer 16

increased ressitance to aqueous humor outflow seen with topical opthalmic agents

Question 17

agents affecting IOP

Answer 17

prolonged continuouis use of beclomethasone or budesonide daily for >3month
phenothiazines
TCA

Question 18

how are tears secreted

Answer 18

from lachrymal gland stimulated by cholinergic and adrenergic nerves

Question 19

drugs increasing production of tears

Answer 19

cholinergic - pilocarpine

adrenergic agonist - ephedrine

Question 20

drugs causing orange colored tears

Answer 20

oral erythromycin and rifampin

Question 21

what is anterior uveitis

Answer 21

inflammation of uvea (iris, ciliary body, choroid)

Question 22

symptoms of anterior uveitis

Answer 22

eye pain
conjuctival redness
photophobia and blurred vision
pupil is small and respond sluggishly to light

Question 23

drugs associated with vueitis

Answer 23

rifabutin

bisphosphonates

Question 24

retina susceptibility

Answer 24

highly organized structure wiht porrly developed repair
vascularized
very sensitive
damage can lead to permanent damage

Question 25

drugs affecting retina

Answer 25

``` chloroquine and hydroxychloroquine digoxin indomethacin tamoxifen retinoids quinine ```

Question 26

is chloroquine/hydroxy retinopathy reversible

Answer 26

no

Question 27

safe dose of hydroxychloroquine

Answer 27

<400mg/day

Question 28

visual symptoms of digoxin toxicity

Answer 28

``` dychromatopsia (color blindness) flickering or flasing light colored spots surround by coronas snowy hazy or vblurred vision glare sensitivity can occur at therapeutic doses ```

Question 29

digoxin mechanism of toxicity

Answer 29

inhibit nakATPase | cone receptor function

Question 30

is digoxin toxicity reversible

Answer 30

within a few weeks after dose reduction or discontinuation

Question 31

indomethacin dose producing toxicity

Answer 31

chronic 50-200mg/day for 1-2yrs

Question 32

symptoms of indomethacin toxicity

Answer 32

``` corneal opacities paramacular depigmentation decreased visual acuity altered visual fields blue yellow color deficity increased threshold for ark adaptation ```

Question 33

is indomethacin toxicity reversible

Answer 33

color disturbances return to normal after discontinuation

Question 34

tamoxifen xicity odse

Answer 34

chornic high dose | 180mg/day for 3 year

Question 35

mechanism of tamoxifen toxicity

Answer 35

permanent decrease in visual acuity and abnormal visual fields crystallizes in the retina

Question 36

retinoids toxicity symptoms

Answer 36

poor night vision glare sensitivity problems with color detection

Question 37

retinoids mechanism of toxicity

Answer 37

inhibition of retinol dehydrogenas which impairs rod cell function

Question 38

quinine symptoms of toxicity

Answer 38

blurred vision central and peripheral scotomata (blind spot) complete blindness

Question 39

when does vision loss ccur with quinine

Answer 39

can occur as late as 14hr after OD

Question 40

mechanism of quinine toxicity

Answer 40

neurotoxic injury to retinal ganglion cells permamne t loss and optic nerve retinal vasoconstiction

Question 41

drugs affecting optical nerve

Answer 41

ethambutol

Question 42

ethambutol toxicity

Answer 42

decreased contrast sensitivity an color vision

Question 43

signs of optical neuropathy caused by ethambutol

Answer 43

central scotoma visual field loss decreased visual activity

Question 44

dose of ethambutol toxicity

Answer 44

25-50mg/kg/d may cause loss of vision in 1-7months

Question 45

is ethambutol vision loss reversable

Answer 45

yes

Question 46

how to eliminate visual toxicity with ethambutol

Answer 46

biweekly high doses

Question 47

what is alcohol tobacco amblyopia

Answer 47

lazy eye due to combo of alcohol tobacco and nutrional deficiency

Question 48

cholinergic action of eye

Answer 48

cholinergic innervation of the iris sphincter aka the constrictor by cranial nerve

Question 49

symphathetic action on eye

Answer 49

innervation of the radial muscle of the iris aka the dilator

Question 50

miosis =

Answer 50

constriction

Question 51

mydriasis =

Answer 51

dilation

Question 52

drugs causing miosis

Answer 52

cholinergic agent opiates phenothiazine sedative hypnotic

Question 53

drugs causing mydriasis

Answer 53

anticholinergic antidepressant sympathomimetics

Question 54

what is nystagmus

Answer 54

unvoluntary eye movement

Question 55

what causes jerk nystagmus

Answer 55

phenytoin

Question 56

what causes vertical nystagmus

Answer 56

rare usually structural lesion of cns pehncyclidine ketamine DM

Question 57

nystagmus and opthalmoplegia (paralysis) caused by

Answer 57

thiamine deficiency

Question 58

drug abuse ocular complications

Answer 58

quinine amblyopia (lazy eye) if found in heroin talc retinopathy infectious complications HIV related cocaine diffus vasospasm - retinal ischemia and blindness crack eye - corneal injury from the smoke numbing sensation