Optical coherence tomography angiography of the macular microcirculation in acute primary angle closure treated with phacoemulsification

Purpose To measure the changes of macular microcirculation in cases with unilateral acute primary angle closure (APAC) who were managed by phacoemulsification. Methods Patients with unilateral APAC and managed by phacoemulsification were enrolled. The contralateral unaffected eyes were served as fellow group, and normal individuals were recruited as control group. Optical coherence tomography angiography (OCT-A) was performed to analyze the macular whole image vessel density (wiVD) and parafoveal vessel density (pfVD). The retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses were assessed using spectral-domain optical coherence tomography. Results A total of 36 APAC patients and 35 eyes from 35 normal individuals were recruited. In the APAC eyes, the mean wiVD (42.1% +/- 3.7%) and pfVD (45.2% +/- 3.8%) in the superficial layers (wiVD-SL and pfVD-SL) were both significantly reduced, compared to fellow eyes (45.7% +/- 3.1%, 48.7% +/- 3.1%) and control eyes (44.4% +/- 4.7%, 47.4% +/- 5.1%) (P < 0.05). They were all statistically correlated with RNFL, GCC, visual field pattern standard deviation (PSD), and mean deviation (MD). Conclusion The macular OCT-A parameters including wiVD-SL and pfVD-SL were significantly reduced in the eyes with APAC compared to the fellow unaffected eyes and normal control eyes. They were correlated well with RNFL, GCC, PSD and MD. The macular vessel density parameters may help monitor the progression of APAC.