Consecutive Exotropia Lionel Kowal Elaine Wong CONSECUTIVE XT

Consecutive Exotropia Lionel Kowal Elaine Wong

CONSECUTIVE XT l Any XT happening after previous ET [usually after ET surgery] l Rare: spontaneous consecutive XT

CONSECUTIVE XT - WHY? l 1. The ET correction doesn’t ‘grow’ with the pt l Ciancia: perfect early alignment after Cong ET surgery 30% consec XT after 25 y l Recession MR : mechanical disadvantage

CONSECUTIVE XT - WHY? l 2. Early consec XT: l Wrong surgical dose l Poor surgical technique l Poor early healing

CONSECUTIVE XT - WHY? l 3. Later consec XT: l ‘Stretched scar’ - look for stretchmarks, healing of other surgical scars, …. l Irene Ludwig : Scar remodelling & Scar migration l Scar remodeling after strabismus surgery - very under recognised l Ludwig IH, Chow AY. , J AAPOS. 2000 l Ludwig IH Trans Am Ophthalmol Soc. 1999 l Need to use non- absorbable sutures if recognised

Consecutive XT l l l Results of consecutive XT in LK’s practice over last 2 years 91 cases of consecutive XT Average time to XT ~ 8 years 58 had XT surgery by LK 32 with follow up >1 yr Number of surgeries: 1 -4 l Median: 1 l Avg. no. of surgeries: 1. 3 l No. of Botox for ET : 4 (10%) l No. of Adjustables: 19 (45%) l

Pre-op: Range 6 – 66 XT; Avg 31 XT Post-op: Range 18 ET – 45 XT; Avg 0

Spontaneous consec XT l 2 l cases of spontaneous consec XT accounts for 2% of all consecutive XT l Case l 10 1 yo girl with infantile ET l Noted XT at ~ 2 yo l Now XT 10Δ with V pattern l Hypermetropia R +8. 75 L +7. 00 l R amblyopia 6/12 l No surgical Rx

Spontaneous XT l Case l 30 2 yo female l Infantile ET ? When noted XT l RXT of 35Δ l No obliques OA l Hypermetropia R +7. 50, L +4. 50 l R Amblyopia 6/45 l RMMRs 5. 5 mm, RLMRc 7. 5 mm l Post op – RET 7Δ

Conclusions l Spontaneous consecutive XT – rare! l Consecutive XT a difficult surgical problem l 69% with good surgical results