Mims et al, Anti elevation syndrome after anterior transposition of the ...

336 Mims and Woodincreased the incidence of AES (P = .011). A similar analysisusing only our patients indicated only a trend in thisdirection, not statistical significance (P = .19). There werenot enough patients who were anteriorly transposed 0 to 1mm with concurrent displacement 3 to 5 mm laterally todetermine whether lateral displacement was also a hazardwith less anterior displacement.For now, it appears that if the new insertion of the IOmuscle is anteriorized more than 1 mm (Y >1 mm), the newinsertion of the IO muscle should not be spread out morethan 2 mm, unless the severity of the DVD warrants risk oflater development of AES. The mm of anteriorization ofthe IO muscle’s posterior fibers beyond the lateral edge ofthe IR muscle insertion required to effectively treat variousdegrees of DVD severity is not yet well characterized. 12-14Also, whether spreading out the muscle less will decreasethe effectiveness of ATIO in the treatment or prevention ofDVD has not yet been studied adequately.Once AES has developed, properly performed bilateralnasal myectomy is preferable to denervation-extirpationbecause denervation-extirpation can unleash significantDVD. Prevention should be possible because the AESappears to be the result of an excessive downward forcevector after ATIO. AES may be prevented by attaching theposterior fibers of the anteriorized IO muscle no morethan 2 mm lateral to the IR muscle insertion.Bunching the IO muscle insertion at the lateral edge ofthe IR muscle insertion as described by Kushner 2 shouldbe associated with a very low incidence of AES; the incidenceand cure of DVD were not reported. 2 This studydid not include enough patients with lateral displacementat the exact level of the IR muscle insertion as described byKratz et al 12 to predict the incidence of AES in this technique.Placing the new IO muscle insertion 4 to 5 mm justlateral to and parallel with the anterior end of the IR muscle,as recently described by Guemes and Wright, 15 shouldJournal of AAPOSVolume 3 Number 6 December 1999reduce the incidence of AES, but may reduce the controlof DVD. The technique of ATIO as described by Mims 3should probably be limited to severe cases of DVD.References1.Stein LA, Ellis FJ.Apparent contralateral inferior oblique muscleoveraction after unilateral inferior oblique weakening procedures. JAAPOS l997;1:2-7.2.Kushner BJ.Restriction of elevation in abduction after inferioroblique anteriorization. J AAPOS 1997;1:55-62.3.Mims JL, Wood RC.Bilateral anterior transposition of the inferiorobliques. Arch Ophthalmol 1989;107:41-4.4.Scott AB.Planning inferior oblique surgery.In: Reinecke RD, editor.Strabismus. New York: Grune and Stratton; 1978. p. 347-54.5.Elliott RL, Nankin SJ.Anterior transposition of the inferior oblique.J Pediatr Ophthalmol Strabismus 1981;18:35-8.6.Elliott RL, Parks MM.A comparison of inferior oblique muscleweakening by anterior transposition or denervation-extirpation.Binocular Vision Eye Muscle Surg Q 1992;7:205-10.7.Weakley DR, Stager DR.Inferior oblique weakening procedures.Ophthalmology Clin N Am 1992;5:57-65.8.Mims JL.Benefits of bilateral anterior transposition of the inferiorobliques. Arch Ophthalmol l986;104:800-1.9.Stager DR, Weakley DR Jr, Stager D.Anterior transposition of theinferior oblique: anatomic assessment of the neurovascular bundle.Arch Ophthalmol 1992;110:360-2.10.Stager DR.The neurovascular bundle of the inferior oblique muscleas its ancillary origin. Trans Am Ophthalmol Soc 1996;94:1073-94.11.Stager DR.The neurovascular bundle of the inferior oblique muscleas the ancillary origin of that muscle. J AAPOS l997;1:216-25.12.Kratz RE, Rogers GL, Bremer DL, Lequire LE.Anterior tendondisplacement of the inferior oblique for DVD. J Pediatr OphthalmolStrabismus l989;26:212-7.13.Bacal DA, Nelson LB.Anterior transposition of the inferior obliquemuscle for both dissociated vertical deviation and/or inferior obliqueoveraction: results of 94 procedures in 55 patients. Binocular VisionEye Muscle Surg Q 1992;17:219-25.14.Ziffer AJ, Isenberg SJ, Elliott RJ, Apt L.The effect of anterior transpositionof the inferior oblique muscle. Am J Ophthalmol 1993;116:224-7.15.Guemes A, Wright KW.Effect of graded anterior transposition ofthe inferior oblique muscle on versions and vertical deviation in theprimary position. J AAPOS 1998;2:201-6.