HOT TOPICS IN AMBLYOPIA SRC 2008 LIONEL KOWAL

When to worry [and when not to worry] about strabismus and amblyopia

NOT TO WORRY… When it all ‘fits’ Right age / anisohyperopia / glasses help vision and alignment…. 4 year oldET L D: 25∆, N: 35 ∆ R 6/8, L 6/24R +3, L +4 Glasses L 6/24  6/18  6/12 Patching  6/10  6/9 ET 25/35  phoria 12 / ET’ 25 Bifocals  orthotropia

WHEN TO WORRY…. Lateral incomitance ET or XT greater to L or R gaze ET greater on lateral gaze 6th XT …. Brainstem / INO

WHEN TO WORRY…. Resistant amblyopia Check the pupil for afferent defect Re-examine the disc and retina

WHEN TO WORRY…. ET Distance > Near Raised intra cranial pressure 6th nerve palsy

WHEN TO WORRY…. Abnormal morphology Is the disc / macula normal?..size …shape...pigmentation If you find it difficult to be sure it’s OK or not, others probably will too Best test for a suspicious disc: show to someone else

Abnormal morphology 2008: Hi- tech imaging helps BUT Sub - expert HRT OFTEN misleading

When to operate in strabismus and when not to operate in strabismus. …& ‘why wasn’t this done years ago?’

When to operate in strabismus… WHY DO I OPERATE? TO MAKE THIS PATIENT’S LIFE BETTER Better visual system Stabilise/ improve amblyopia Better peripheral field [ET] Better binocularity AND… Normal appearance and improved psychosocial development Better motor co-ordination

When to operate in strabismus… Better outcome if Constantly misaligned < 4 mo [child] or < 12 mo [adult] Angle ≤ 50 ∆ ET, ≤ 35 ∆ XT

When NOT to operate in strabismus… Very variable strabismus Patient expectations ≠ mine +4DS, ET 30∆. Straight forever sc not realistic

When NOT to operate … Despite adequate education, parents remain opposed. Anti - surgery websites - death rates & complications exaggerated DON GETZ “The best "cure" rate is 11%” USA >20 deaths per year for strabismus surgery

When NOT to operate … ?Under- trained surgeon. Clearly a factor in other surgical areas ~20 ophthalmologists are Fellowship trained in peds or strabismus >20% of private strabismus surgeries in Australia [billed through Medicare] are done by 2 ophthalmologists ?reason for declining numbers [fewer repeat surgeries because so many are done by experts]

‘Why wasn’t this done years ago?’ 20 yo with 30∆ ET or XT dating back to childhood more likely to have PERMANENT paradoxical diplopia after alignment surgery than the same surgery in a 5 yo Childhood visual system more flexible - ARC less likely to be profound / persistent in a child than an adult

Delaying surgery ‘till s/he’s old enough to decide for him/her- self’ can mean deferring it to a time when a good cosmetic and functional result is no longer possible

Is full time occlusion dead? Factors that influence outcome of amblyopia treatment fall into two categories: those that relate to the underlying conditions ( condition factors ) and those that relate to its treatment ( treatment factors ).

Treatment factors 1. Optimal refraction - regularly re-checked 2. Occlusion method & dose 3. Accuracy of alignment

Occlusion method / dose PEDIG: 75+% get better with 2h/d [<6/24] or 6h/d [<6/120] CAN MORE OCCLUSION GET EVEN BETTER RESULTS?

Is full time occlusion dead? MOTAS <50% of the amblyopic deficit corrected in 23% Lines of residual end of treatment %

IS MORE EVEN BETTER?

THE IOWA STUDIES

Amblyopia Treatment Outcomes. WE. Scott.. JAAPOS April 2005 WE. Scott Retrospective review of patients who had full- time occlusion [24 h/d or all waking hours]. 600 pts followed for av. 7 y after the cessation of full-time patching. 90% ≥ 1 year. Success : ≥ 20/30 or better or equal VA by fixation pattern - seen in 96% 60% attained equal visual acuity.

Amblyopia Treatment Outcomes. WE. Scott.. WE. Scott Younger patients required less occlusion time to endpoint and had a better visual outcome (P < ). Initial VA related to best VA attained (P < ). Incidence of occlusion amblyopia 25.8%.

Amblyopia Treatment Outcomes. WE. Scott.. WE. Scott Looks like more = better BUT > 2ce risk of occlusion amblyopia Assume equal fixation = equal acuity < 100% followup

PEDIG - RECRUITING…. Treatment of residual amblyopia 6/9 to 6/15. Compare intensive treatment [8 h/d of patching + daily atropine] with glasses alone

IS MORE EVEN BETTER? For most children with amblyopia - probably not For some - maybe …….stay tuned!