Diurnal macular choroidal area fluctuation in normal and primary open angle glaucoma groups

AIM:To assess and compare the diurnal macular choroidal area fluctuation in normal and primary open angle glaucoma(POAG) groups using enhanced depth imaging optical coherence tomography(EDI-OCT).METHODS: Twenty-eight normal and 27 POAG eyes were enrolled in this study. EDI-OCT was used to measure the macular choroidal area every 3h from 9:00 a.m. to 21:00 p.m. RESULTS: Significant diurnal fluctuations of macular choroidal area were observed in both normal(P=0.003) and POAG groups(P<0.001). But no significant macular choroidal area difference has been found between the two groups at all the five measurement time-points(512778±166242 vs 455079±207278 μm2,P=0.195 at 9:00 a.m.; 501526±168953 vs 447846±211147 μm2,P=0.245 at 12:00a.m.; 501982±173158 vs 448024±206653 μm2,P=0.239 at 15:00 p.m.; 508912±174589 vs 457783±207081 μm2,P=0.252 at 18:00p.m.;503787±171241 vs 453230±205955 μm2,P=0.274 at 21:00 p.m.;respectively). Furthermore,neither the fluctuation manners nor the change in macular choroidal area between the two adjacent measurement time points showed significant difference between normal and POAG groups(all P>0.05). In the meantime,significant diurnal intraocular pressure fluctuations were also observed in normal and POAG groups(both P<0.001).CONCLUSION: In diurnal time,the macular choroidal area in both normal and POAG groups fluctuated significantly; moreover,neither the value of macular choroidal area,nor the fluctuation of macular choroidal area in POAG group is significantly different from that in normal group.