diagnostic drugs Flashcards
What is mydriatics?
used to dilate the pupil ( open up)
what is the importance of mydriatic drugs?
expansion of co management schemes ( primary open angle glaucoma
-increase in professional negligence cases
what conditions do you dialate?
Diabetes uveitis pigmented fundus lesion hypertension suspected glaucoma FH of retinal detachment peripheral retinal degeneration cataract AMD history of metastic cancer
which symptoms do you dilate?
- -Flashes or floates
- –new distortion
- -unexplained vision loss
- recent blunt force trauma
which px do you dilate?
nystagmus squint stereoscopic view of retina systemic mediactions with potential side effects get good fundus photograph
what are the benefits for dilation?
ability of ophthalmoscopy to grade correctly diabetic retinopathy more 50% through dilated pupil than through undilated pupil
What Myrdiatics are use?
Tropicamide 0.5%
Tropicamide 0.1%
Phenlepharine
when using drugs what do you have to remember under collage of optometrist guidelines?
batch number
dosage
date of expiry
what precautions do you take with mydriasis ?
prev experience of mydriatic and allergy medical history current medication iop measurment assessment of risk of angle closure glaucoma
what is most risk of px getting with mydriatics?
acute attack of ACG
what do you need to tell patient?
what mydriatics are for duration stings risks glare problems temp vision reduced drivingh difficulties
what is the risk of provoking acute ACG?
more risk with phenlyepharine
no risk with tropicamide
what other points do you need to note for acute ACG?
if someone has very narrow angle should refer anyway as at high risk of attack of ACG at any time.
if px has suspect of retinal detachment wet AMD etc what do you do?
if px has retinal detachment and wet AMD you cannot obtain sufficient view must either dilate or refer on worst case scenario
how do you assess angle closure?
Van herick or hospital - gonioscopy flashlight test smith's slit- lenth method methods using pachmymeters]
During dilation what is the most common problem?
glare
what do drivers need to be told when dilated?
it is recommended that driving should be avoided whilst your vision is affected
what is tropicamide?
tropicamide is an anti muscarinic drug which causes mydriasis by relaxing the sphincter muscle of the iris and cycloplegia by relaxing the ciliary muscle
what is the onset of action of tropicamide?
10-30 mins
what is the max effect of tropicamide?
20-40 mins
what is recovery to normal of tropicamide?
4-9 hours
how do drugs duration in patient vary?
individual responses to drugs are very variable
what are risk associated with tropicamide?
- few allergic reaction
- CNS affected can occur with cyclopentalate
- risk of ACG in predisposed eye
- be careful with possible interaction with other anti mscarinic drugs
What is Phenylepharine?
A sympathomimetic drug which causes mydriasis by stimulating the dilator muscle of the iris
