Session: Poster session C

Secondary glaucoma after nasal transposition of the split lateral rectus muscle.

Introduction: Nasal transposition of the split lateral rectus muscle (NTSLR) has been recognized as an effective procedure to improve primary position alignment in patients with third nerve palsy. Although NTSLR has been generally recognized as a satisfactory procedure, there have also been reports on vision-threatening complications including choroidal effusion, elevated intraocular pressure, anterior segment ischemia and one case of optic nerve edema.

Method: We present a case involving a 64-year-old male who underwent a NTSLR on his left eye for complete bilateral third nerve palsy. The patient had undergone a recession of both lateral muscles five months earlier. He presented with a large exotropia of more than 90PD and a left hypertropia of 20 PD. He was amblyopic on his right eye and had adapted a head turn to the right to make optimal use of his left eye.

Results: The patient complained of pain and nausea only hours after the procedure. Upon examination, a shallowed anterior chamber and an intraocular pressure of 50 mm Hg were noted; efforts to reduce the pressure, including release of the transposed muscles, administration of intraocular pressure-lowering medications and performing a peripheral laser iridectomy, proved unsuccessful. Normalization of intraocular pressure was achieved only after a vitrectomy was performed.

We argue that taut muscles or an incomplete split of the lateral muscle may have compressed the vortex veins, leading to choroidal effusion and causing a mechanical anterior shift of the iris-lens diaphragm resulting in an aqueous misdirection syndrome.

In the end, the left eye achieved nearly a primary position, while the right eye persisted with an exotropia of 35PD and a right hypertropia of 18 PD.

Conclusion: Nasal transposition of the split lateral rectus muscle (NTSLR) is an effective procedure to improve alignment in patients with third nerve palsy. Caution should be exercised due to the potential of vision-threatening complications.