Dear Editor,We read with interest the report by Vedantham et al.1 We
would like to make certain observations regarding inclusion
of primary inferior oblique overaction [PIOOA] as part of this
new syndrome.The authors do not offer evidence whether overelevation
in adduction in this case is due to inferior oblique overaction
and that too primary and not secondary. Secondary inferior
oblique overaction can arise due to superior rectus/oblique
underaction and overelevation in adduction has diverse
etiologies and presentations. As levator palpebre superioraris
[LPS], superior rectus [SR]/superior oblique [SO] and upper
halves of horizontal recti all develop from the same superior
mesodermal complex,2 they may get implicated together in
disorders like this and plausibly to a variable extent. It seems
more appropriate to ascribe overelevation in adduction in this
case to the underaction of SR or to both of superior muscles [SR,
SO], along with LPS, as both can produce overaction of inferior
muscles [IO and IR] leading to overelevation in adduction,
a V pattern and extorsion. A positive head tilt test on tilt to
either side will offer insight regarding primary or secondary
inferior oblique overaction provided both superior muscles
are not knocked out. Presence or absence of objective extorsion
may offer a clue regarding inferior oblique overaction. Results
of such tests are not known in the present case.To attribute overelevation in adduction in this case to PIOOA
is like clubbing all meningitides as meningococcal.