DIS - Uveitis Management II - Week 5 Flashcards
List four night time options for a q1h dosage of steroid to treat acute anterior uveitis. Note which of these is generally for the worst uveitis cases and which is not very helpful.
One drop every hour, including at night -for the worst cases Loading dose before bed -i.e. a drop every minute for 5 minutes A few drops at bed time and two more mid-sleep (i.e. during a night time loo visit) Steroid ointment noce -not very helpful
Give the relative anti-inflammatory effects of the following steroids:
Dexmethasone
Prednisolone
Fluoromethalone
Dexmethasone - 100%
Prednisolone - 90%
Fluoromethalone - 75%
Describe the penetrance (not strength) of the following formularies of steroids (highest to lowest) and note which are good to use in anterior uveitis treatment and which should not be used. Explain what ocular structure affects penetrance. Fluoromethalone acetate (flarex) Fluoromethalone (FML) Prednisolone phosphate Hydrocortisone ointment Dexmethasone phosphate Dexmethasone (maxidex) Prednisolone acetate (pred forte)
Good penetrance
Prednisolone acetate (pred forte) - 100%
Fluoromethalone acetate (flarex) - 90%
Dexmethasone (maxidex) - 75%
Poor penetrance Dexmethasone phosphate Fluoromethalone (FML) Prednisolone phosphate Hydrocortisone ointment -do not use these primarily to treat AAU -they may have use only at the end of tapering
Corneal epithelium affects penetrance
Can high dose steroids be maintained long term?
No
What is a requirement to begin tapering the dosage of steroids and for how long after should the dose be maintained? What should patients be warned of?
Reduce the dose gradually but only with improvement to signs/symptoms
Maintain the dosage for 3-5 days afterr imrovement
Warn patients about rebound
List four possibilities for tapering steroids.
Reduce dosing frequency (binary) Reduce steroid concentration -not viable in australia Adjust steroid potency by changing medications -flarex for pred forte Other NSAIDs for longterm management -cyclosporin
Are NSAIDs useful for primary treatment of acute anterior uveitis?
Not
-they have insufficient potency or clinical efficacy
Note 5 significant side effects of topical steroids.
Increased IOP -steroid responder Secondary infection/reactivation of infection Masking of clinical signs Delayed wound healing Posterior sub-capsular cataract
Note 2 minor side effects of topical steroids.
Transient discomfort/burning/stinging
Worsening of dry eye
What is the likelihood of cataracts with short-term topical steroid use? How does this risk compare to oral steroids - which is more likely to cause cataracts?
Very unlikely to get cataract from short-term topical steroids
Greatest risk of steroid is from oral steroid
-more than 15mg/day for >6 months
What is the initial IOP response in acute anterior uveitis? Explain why this is so.
Decrease in IOP
-reduced aqueous production by inflamed ciliary body
What happens to IOP after the initial response? Give 5 possible reasons to why this may happen. Note which of these indicates the steroid given was not aggressive enough. What technique can rule out some of these possibilities?
IOP subsequently rises after the initial drop and may be due to:
-associated trabeculitis - steroid not agressive enough
-steroid responder
-debris/blood in the TM
-bombe following pupil block (posterior synechiae)
-PAS - steroid not agressive enough
Gonioscopy will rule out the last three options
When treating acute anterior uveitis with steroids, in what three cases is medical treatment necessary?
IOP >30mmHg
IOP >8mmHg above baseline for >2 weeks
If you begin to see glaucomatous signs
-disc responses etc
Describe how the general population responds to topical steroid (steroid responder) and give percentages.
3% - high IOP response
30% - moderate response
66% little/no response
For the following steroids, order them by the IOP response they elicit
Pred forte
Maxidex
Flarex
Maxidex > pred forte»_space; flarex
What type of secondary infection is particularly more likely with steroid use?
Viral
What should you do if you begin to see glaucomatous changes to the eye or the IOP is too high (>30) when using steroids to treat acute anterior uveitis? What should you not do (2)? What drug should be avoided and why?
You should not cease steroid therapy Begin glaucoma therapy -can be medical -can be surgical -do not use pilocarpine -avoid using PGAs as they may exacerbate inflammation
List 3 reasons why cycloplegics/mydriatics are used in the management of acute anterior uveitis.
Relieves pain/photophobia
Reduces ciliary/sphincter spasm
Breaks synechiae
What does the breakage of posterior synechiae reduce the risk of (3)?
Iris bombe
Glaucoma
Cataract
True or false
Posterior synechiae can form even in the dilated iris position.
True
When should the use of cycloplegics/mydriatics be discontinued when treating acute anterior uveitis and why?
When inflammation is well-controlled
-synechiae is unlikely to form
What innervation does the iris sphincter muscle receive and via what neurotransmitter? What types of drugs inhibit the action of this muscle? List 3.
Parasympathetic innervation -muscarinics/ACh Block with anti-cholinergics -atropine -homatropine -tropicamide
What innervation does the iris dilator muscle receive and via what neurotransmitter? What types of drugs stimulate this muscle? List 3.
Sympathetic innervation -adrenergics Stimulate alpha receptors with sympatho-mimetics -alpha1 - phenylephrine -alpha2 - apraclonidine, brimonidine
What drug class is the first choice for cycloplegia/mydriasis when treating acute anterior uveitis? What are two options if synechiae are already present?
Anti-cholinergics
- stronger agent
- second agent (activate dilator
What drug induces the most powerful dilation? What is the dosage and what concentration?
Atropine
1% tid usually
What is released with iris inflammation/injury/surgery and what does it do? What effect does atropine have on it?
Substance P is released
-causes iris sphincter contraction
Atropine counteracts the effects of substance P
How long can mydriasis last for after inflammation subsides in acute anterior uveitis?
1-2 weeks longer