Peripapillary and macular choroidal area in patients with normal-tension glaucoma

Purpose To evaluate normal and normal-tension glaucoma (NTG) eyes for differences in peripapillary and macular choroidal area measurements. Methods This cross-sectional comparative study enrolled 52 normal subjects and 35 NTG patients. Peripapillary and macular choroidal images were recorded by enhanced depth imaging optical coherence tomography (EDI-OCT), with conversion of the luminal and interstitial areas to binary images performed using the Niblack method. Results While there was a significant difference between normal subjects and NTG patients for the peripapillary choroidal area (1,853,672 +/- 626,501 mu m(2) vs. 1,606,448 +/- 418,214 mu m(2), P = 0.047), there were no significant differences between the normal subjects and NTG patients observed for the macular choroidal area (345,365 +/- 119,248 mu m(2) vs. 316,442 +/- 85,732 mu m(2), P = 0.23). In the NTG patients, multivariate regression analysis demonstrated a correlation between the macular choroidal area and the axial length (beta = -0.345, P = 0.04). Furthermore, there was also a significant correlation between the peripapillary choroidal area and the age of the NTG patients (beta = -0.469, P = 0.004). In addition, there was no relationship between the glaucoma severity and the peripapillary and macular choroidal areas in the NTG patients. Conclusions There was no correlation between the peripapillary choroidal area and glaucoma severity in NTG patients, even though the area was smaller in these patients.