(1) Assuming the presence of amblyopia and nystagmus when trying to fixate with the amblyopic eye, would you keep patching? (a) Yes (b) No
2) Assuming the child is 6-months-old, when is the optimal time for surgery? (a) At the time of diagnosis (b) Between 6 and 12 months (c) After 12 months?
Between 6 and 12 months
3) Considering large deviations in infants; Would you use botox injection before surgery? (a) Yes (b) No? If yes, how many units?
Yes; 2.5 Units. I would routinely use Botox to treat children who present to me with infantile esotropia before the age of 6 months. I do this for two reasons; firstly, because I believe surgery is highly unpredictable in this age group and secondly, as there is evidence that realigning the eyes at the earliest opportunity gives the child the best chance of establishing some form of binocular vision. I do not want to wait until they are 6-9 months old to operate on them. The aim of the Botox treatment to both medial recti, which I carry out under a short 10 minute GA with direct visualisation of the MR via a tiny fornix based incision, is to make the child exotropic. They are followed up closely in the weeks following treatment and their binocular responses, if present, are recorded as they drift into an orthophoric position. Children fall into three groups following Botox treatment; those that return to their previously large angle esotropia, those who end up with a smaller angle esotropia (10-30^) and those who remain within 6^ of orthophoria. In the first group, I offer the parents definitive surgery 2-3 months’ post Botox and if the child has shown some binocular responses following botox I am cautiously optimistic about being able to restore some form of binocular vision. In the moderate angle esotropia children, I will offer them repeat Botox treatment or surgery.
(4) How many muscles would you operate on? (a) Two (b) Three (c) Four?
Three; If the Esotropia is >50^ I will operate on 3 muscles, if >70^ I will perform a 4 muscle surgery. The maximal medial rectus recession I will perform for children with infantile esotropia is 11 mm from the limbus (this usually equates to 6mm from the insertion) and this is enough to correct esotropias of up to 50^. For angles between 55-70^ I will operate on 3 muscles and for angles greater than 70^ I will operate on 4 muscles. An alternative approach for 55-60^ esotropias is to augment the medial rectus recessions with 2.5 units of Botox to each muscle and this also works well in my hands.
(5) Do you consider general anesthesia as a risk when operating on a six-month old child?
If a child is otherwise fit and well and is not an ex-premature infant (when 6 months might only be 3 months post-gestational age) I am happy that general anaesthesia carries a low short and long term risk to the child. I do however work with a very experienced paediatric anaesthetist.
(6) Considering overaction of both IO at the time of diagnosis, would you perform IOAT OU in the first procedure?
Only if it was more than a +2 overaction; If a child has more than 2+ inferior oblique overreaction on presentation, which in my experience is unusual, I would perform bilateral inferior oblique anteriorisations at the same time as BMRRs. If three or four muscle surgery was needed for a large angle esotropia I would explain to the parents that inferior oblique surgery may well be needed as a planned second procedure.