SH Lee, et al. PSEUDO-DUANE’S RETRACTION SYNDROME A B Fig. 3. Preoperative orbital CT scan shows an old fracture of the right medial orbital wall with entrapment of the right medical rectus muscle. (A) Axial view. (B) Corneal view. as Duane’s retraction syndrome.1 Other authors preferred the names of ‘inverse Duane, reverse Duane, or mirror-image Duane retraction syndrome’ owing to the presentation of opposing clinical features compared with those of classic Duane’s retraction syndrome. The etiology is, also, comple- tely different from that of classic Duane’s retraction syndrome. The primary lesion in pseudo-Duane’s retraction syndrome is suspected to be the medial rectus muscle. Most cases have been reported to result from the entrapment of the medial rectus muscle within the medial orbital wall due to trauma.1,3 Congenital cases,4 recurrent pterygium,5 and myocysticercosis involving the medial rectus muscle6 have also been reported to be related with inverse Duane’s retraction syndrome. In Korea, Jo et al.7 reported on inverse Duane’s retraction syndrome with exotropia, and Lew et al.8 reported a case of congenital inverse Duane’s retraction syndrome with a tight medial rectus muscle. Recently, a case of innervational etio- logy, such as bilateral inverse Duane’s retraction syndrome, due to simultaneous co-contraction of both horizontal rectus muscles has been reported by Khan.9 To the best of our knowledge, there is no report presenting very similar clinical features as those of classic Duane’s retraction syndrome arising from the entrapment of the medial rectus muscle in a medial orbital wall fracture. This case would most appropriately be categorized as pseudo-Duane’s retraction syndrome instead of inverse or reverse Duane’s retraction syndrome. There might be some possibility that the patient acquired Duane’s retraction syndrome prenatally, and that the medial orbital wall then fractured after birth. However, several pictures of this patient around one year of age re- vealed that there was no conspicuous head turn, and his family recalled that the limited eye movement was not noted until 2-3 years of age. The limitation of his eye movements, there- fore, could be concluded as acquired due to unnoticed orbital trauma after one year of age. We report a case of pseudo-Duane’s retraction syndrome caused by entrapment of the medial rectus muscle in an old medial orbital wall fracture presenting very similar clinical features as those of classic Duane’s retraction syndrome. The importance of several tests such as the forced duction test and an imaging study should be emphasized in making the diagnosis for limited eye movement. References 1. Duane TD, Schatz NJ, Caputo AR. Pseudo-Duane’s retraction syndrome. Trans Am Ophthalmol Soc 1976;74:122-32. 2. DeRespinis PA, Caputo AR, Wagner RS, Guo S. Duane’s retraction syndrome. Surv Ophthalmol 1993;38:257-88. 3. Gittinger JW Jr, Hughes JP, Suran EL. Medial orbital wall blow- out fracture producing an acquired retraction syndrome. J Clin Neuroophthalmol 1986;6:153-6. 4. Chatterjee PK, Bhunia J, Bhattacharyya I. Bilateral inverse Duane’s retraction syndrome: a case report. Indian J Ophthalmol 1991;39: 183-5. 5. Khan AO. Inverse globe retraction syndrome complicating re- current pterygium. Br J Ophthalmol 2005;89:640-1. 6. Murthy R. Inverse Duane’s retraction syndrome following myo- cysticercosis. Indian J Ophthalmol 2008;56:89-90. 7. Jo KI, Jo YH, Rho YB, et al. A case of inverse Duane’s retraction syndrome. J Korean Ophthalmol Soc 1980;21:615-9. 8. Lew H, Lee JB, Kim HS, Han SH. A case of congenital inverse Duane’s retraction syndrome. Yonsei Med J 2000;41:155-8. 9. Khan AO. Bilateral inverse globe retraction (Duane’s) syndrome. Indian J Ophthalmol 2007;55:388-9. 331