Vertical fusional amplitudes in patients wearing vertical anisometropic correction

Objective: To examine the relationship between vertical anisometropic spect acle correction and vertical fusional amplitudes in patients. Design: Comparative observational case series. Participants: Twenty-one patients exposed to greater than 0.5 diopters of v ertical anisometropic spectacle correction were compared with 46 patients n ot exposed to anisometropic correction. Methods: Vertical fusional amplitudes were recorded in all patients using a prism bar. Main Outcome Measures: Vertical fusional amplitudes and vertical anisometro pia. Results: In patients exposed to greater than 0.5 diopters of vertical aniso metropic spectacle correction, vertical fusional amplitudes measured 5.2 +/ - 1.4 prism diopters. Patients not exposed to anisometropic correction had vertical fusional amplitudes of 2.7 +/- 1.2 prism diopters (P < 0.0001). Conclusion: Patients with vertical anisometropic correction have increased vertical fusional amplitudes. This finding is relevant when evaluating pati ents with ocular motility disorders, especially with regard to distinguishi ng acquired versus longstanding deviations.