Axial Length in Idiopathic Macular Hole: Comparison of A-scan Ultrasound and IOL Master

Purpose: To compare A-scan ultrasound (Ocuscan RXP？？, Alcon, Fort Worth, TX, USA) and IOL Master (Carl Zeiss, Jena, Germany) with respect to the measurement of axial length (AL) in idiopathic macular hole (MH). Methods: In 24 eyes of 24 patients diagnosed with idiopathic MH. The AL was measured by both A-scan ultrasound and the IOL Master. It was expected that the AL would measure shorter than its actual length by ultrasound because the boundary around the fovea of the MH rises. To correct this, the difference in the central fovea thickness between the affected eye and normal fellow eye was added to the AL in the affected eye as measured by ultrasound, which was compared with the fellow eye. Results: There was no significant difference between AL measured by two measurements in the affected eye. There was also no significant differences in the AL of the affected and fellow eyes as measured by two measurements. In the case of ultrasound measurement, there was no difference between the fellow eye and affected eye after the difference in the central fovea thickness between both eyes was added to that of the affected eye. Conclusions: There was no significant difference in the AL of eyes with idiopathic MH. Likewise, no difference was identified in comparison with the fellow eye. Therefore, the postoperative myopic shift after MH combination surgery is not thought to be attributable to the measurement of a short AL.