Amblyopia pt.2 Flashcards
what 3 things must you make sure of before you start treating someone with amblyopia
- Always carry out fundus & media examination
e. g. poor vision in one eye may not just be due to amblyopia, but can be something more sinister - Always carry out cycloplegic refraction
- Don’t start occlusion if visual acuity is reduced in both eyes
e. g. if put patch over slightly better eye, then can make that eye even worse
list the steps of how you should treat a patient with amblyopia from beginning to end
- Correct any significant refractive errors with glasses
Period of 18-22 weeks constant glasses wear before starting patching for refractive adaptation - Allow vision to plateau before starting patching treatment
- Consider Contact Lenses
what improvement do many patients being treated for amblyopia with glasses alone gain and how many patients’ amblyopia gets resolved fully with glasses alone.
For how long will these patients need to wear these glasses
- 2-3 line improvement
- 27% resolved vision, so never need to patch
- to wear glasses full time for 18-22 weeks/5 months and if still improving then continue to wear
what will you wait for before starting patching treatment on a patient who is being treated with glasses for that time being
- to allow the vision to plateau before starting patching treatment
- even if after 4-5 months the vision is still improving in the amblyopic eye just with glasses, then continue just with glasses and wait until it plateaus off
for which types of patients will you consider using contact lenses to treat their amblyopia
- High refractive error
- High anisometropia
what treatment can you do after refractive adaptation
Occlusion (patching)
how is occlusion (patching) done
- Occlusion (patch) placed on good eye (to make bad eye work)
- Plasters best worn on face and not specs, as specs can slip off and therapy won’t work
what did the results of MOTAS find about the improvement which occurred during patching therapy
- 75% improvement occurred during first 6 weeks
Some further improvement up to 12 weeks - Younger patients improved with less hours patching - so the younger the px started their treatment, the better the prognosis
for which level of acuities does the RCO suggest 2 hours of patching for in the UK
acuities from 0.2 to 0.6 LogMAR (6/9 to 6/24 Snellen)
for which level of acuity does the RCO suggest 6 hours of patching for in the UK
acuities below 0.6 LogMAR (worse than 6/24 Snellen)
list 8 factors that can affect the prognosis of occlusion therapy to treat amblyopia
- Age of onset - earlier the onset of the problem, the worse the prognosis
- Duration of amblyopia - the longer they had, the worse the prognosis
- Type of amblyopia - worst is cataract in one eye congenitally
- Age you commence treatment - older, worse the prognosis
- Other pathology present
- Type of treatment
- Presence of eccentric fixation - further away from fovea, worse the prognosis
- Compliance (research has shown that this is the main predictor of visual outcome)
how does age of onset affect the prognosis of occlusion therapy to treat amblyopia
earlier the onset of the problem, the worse the prognosis
how does the duration of amblyopia affect the prognosis of occlusion therapy to treat amblyopia
the longer they had, the worse the prognosis
how does the type of amblyopia affect the prognosis of occlusion therapy to treat amblyopia
worst is cataract in one eye congenitally
how does the age you commence affect the prognosis of occlusion therapy to treat amblyopia
older, worse the prognosis
how does the presence of eccentric fixation affect the prognosis of occlusion therapy to treat amblyopia
further away from fovea, worse the prognosis
what is the biggest thing to affect the prognosis of occlusion therapy to treat amblyopia
compliance
list 5 things that can be explained to improve communication to a parent in order to improve compliance
Explain why its is important to treat by mentioning:
- DVLA requirements
- Stopped from certain jobs
- Pathology to good eye in later life
- Show parent what they can see
- Explain the SENSITIVE period - If don’t treat now then less able to treat when older
list 3 possible occlusion therapy methods used to exclude light and form
- patches such as plasters (advise on face to avoid peeking)
- hand made cloth to go over glasses or (may peek)
- opaque contact lenses
name an appliance that can be used in occlusion therapy to exclude form vision
blenderm = frosted glass
Better for older/adult patients
name an appliance that can be used in occlusion therapy for producing partial vision
Banger foils = occlusion covering part of the lens
Better for older/adult patients
name 2 advantages of occlusion/patching
- Cheap
- Can specify exact time (as soon as time is up, px can remove patch)
list 4 disadvantages of occlusion/patching
- Cosmetically disfiguring - bullying
- Children can remove easily
- Allergic to elastoplast
- More of a barrier to stereopsis (only improves vision)
name an alternative to occlusion/patching therapy
optical penalisation
what does optical penalisation do
Blurs the visual acuity in the better eye sufficiently to make the worse eye work
what are the 3 types of optical penalisation
- Distance penalisation
- Near penalisation
- Total penalisation
what is near penalisation used for and how is it done
- Encourages the use of the amblyopic eye for close work.
- Instil cycloplegia, Atropine to the better eye.
- Add convex lens to the amblyopic eye to help it see better.
what is distance penalisation used for and how is it done
- Encourages the more amblyopic eye in the distance.
- Adding +3.00 DS to the good eye to blur in the distance.
- Prescribe the optimum correction for the amblyopic eye.