Differentiating vertical misalignment using different head positions: a reappraisal (S26.003)

OBJECTIVE:To evaluate whether testing ocular vertical alignment and torsion in the seated position vs. supine position aids in diagnosis of vertical diplopia. BACKGROUND:Prior reports document a substantial decrease or complete resolution of vertical misalignment and ocular torsion in approximately 80[percnt] of patients with skew deviation when measured in the supine position. DESIGN/METHODS:Prospective patients with new onset binocular vertical diplopia over the age of 18 were recruited from our institutions. Subjects with childhood strabismus, extraocular muscle surgery, or visual acuity worse than 20/70 were excluded. Vertical ocular alignment in the seated position was measured using alternate cover and/or Maddox rod both with the head upright and tilted sideways; subjective ocular torsion in primary position was recorded using double Maddox rod with the head upright. These measurements were then repeated in the supine position. RESULTS: In this ongoing study, 20 patients were recruited: 12 had skew deviation (skew) while 8 had other causes (non-skew) including 4th nerve palsy (3), decompensated phoria (3), ocular myasthenia (1), and Brown syndrome (1). Vertical misalignment in the upright position was 6.6 prism diopters (PD) (SD 2.1) for skew, and 7.5 PD (SD 2.9) for the non-skew group. Both groups showed vertical misalignment decrease in the supine position: 1.4 PD (SD 0.9) for skew and 0.3 PD (SD 0.8) for non-skew group (p=0.45). Only skew patients evidenced decrease >50[percnt] (3/12; sensitivity 25[percnt]). Ocular torsion in the upright position was -1.1 degree (SD 2.1) hypertropic/-1.1 degree (SD 1.8) hypotropic in the skew group. In the supine position, skew patients substantially intorted the hypertropic eye -5.7 degrees (SD 4.3) and extorted the hypotropic eye 7.4 degrees (SD 3.9). CONCLUSIONS:In contrast to prior studies, the upright supine test in our skew population showed a 25[percnt] sensitivity, and ocular torsion increased in the supine position. Disclosure: Dr. Lemos has nothing to disclose. Dr. Subei has nothing to disclose. Dr. Sousa has nothing to disclose. Dr. Coelho has nothing to disclose. Dr. Cunha has nothing to disclose. Dr. Glisson has received personal compensation for activities with Biogen Idec and Lundbeck. Dr. Eggenberger has received personal compensation for activities with Biogen Idec, Genzyme, Questcor, Novartis, Acorda, Prime Pharma, Allergan, Inc. and Teva. Dr. Eggenberger has received research support from Teva, Allergan, Inc., Serono, and Berlex.