Comparison of IOLMaster(R) and A-Scan Ultrasound: Change in Axial Length After Vitrectomy in Macular Disease

ABSTRACT

PURPOSE: To evaluate the differences between IOLMaster(R) and A-scans in changes in axial length after vitrectomy in patients with macular disease. METHODS: Using IOLMaster(R) and A-scans, we measured preoperative and postoperative axial length in 12 eyes with epiretinal membranes (ERM) and in 8 eyes with macular holes (MH). The relationship between the absolute error in axial length after vitrectomy and both methods was assessed using Mann-Whitney U test. The correlation to central macular thickness was evaluated by Spearman's correlation coefficient. RESULTS: In eyes with ERM and MH, preoperative and postoperative axial lengths obtained with both methods had no significant difference (p>0.05). The absolute error in axial length after vitrectomy was not significant using IOLMaster(R) (ERM 0.07+/-0.05 mm, MH 0.04+/-0.02 mm, p>0.05) but was significant using A-scan (ERM 0.20+/-0.11 mm, MH 0.30+/-0.07 mm, p0.05, MH; correlation coefficient = -0.054, p>0.05, A-scan ERM; correlation coefficient = -0.210, p>0.05, MH; correlation coefficient = -0.156, p>0.05). CONCLUSIONS: The IOLMaster(R) is more useful than the A-scan when measuring axial length without refractive errors after vitrectomy in eyes with macular disease.