Objective To determine the long-term changes in optic disc parameter and the thickness of circumpapillary retinal nerve fiber layer (CP-RNFL) and macular retina after acute primary angle closure.Methods Prospective clinical case-control study.A total of 26 patients (30 eyes) with acute primary angleclosure glaucoma (APACG) were in the APACG group,whose intraocular pressure were control after a single episode acute primary angle closure;30 age-and sex-matched healthy subjects (30 eyes) in the control group.All subjects underwent three dimensional optical coherence tomography (3D-OCT) examination with 3D optic disk scanning or circle optic disk scanning and 6 mm× 6 mm macular scanning.The parameters included average thickness of entire CP-RNFL,thickness of nasal,superior,temporal and inferior quadrant of CP-RNFL,disc area,disc cup area,rim area,cup/disc (C/D) area ratio,C/D horizontal diameter ratio and C/D vertical diameter ratio.The foveal retinal thickness,center retinal thickness (≤ 1 mm from the fovea),4 quadrants of macular inner-ring (＞ 1 mm but ≤3 mm from the fovea) retinal thickness,4 quadrants of macular outer-ring (＞3 mm but ≤6 mm from the fovea) retinal thickness,average thickness of macular retinal thickness and macular volume were measured and analyzed.Results The disc area,disc cup area,C/D area ratio,C/D horizontal diameter ratio and C/D vertical diameter ratio in APACG group were significantly bigger than the control group (t=3.22,4.12,3.90,3.00,3.23;P＜0.05),rim area was smaller than the control group (t=-2.63,P＜0.05).The average thickness (t=-6.68) and the thickness of superior (t =-5.90),temporal (t =-11.64) and inferior (t =-5.06) quadrants of CP-RNFL,center retinal thickness (t=-2.50),4 quadrants of macular inner-ring retinal thickness (t=-4.91,-4.88,-2.83,-3.59),nasal (t=-2.13) and superior (t=-2.49) quadrants of macular outerring retinal thickness as well as average thickness of macular retinal thickness (t=-2.65) were significantly thinner than the control group (P＜0.05),and the macular volume (t=-2.69) was significantly smaller than the control group (P＜0.05).There was no statistically difference at nasal CP-RNFL (t=-0.11),foveal retinal thickness (t=-0.59),temporal (t=-0.67) and inferior (t=-1.02) quadrants of macular outer-ring retinal thickness between two groups (P＞0.05).Conclusions In comparison with the healthy subjects,the disc area,disc cup area,C/D area ratio,C/D horizontal diameter ratio,C/D vertical diameter ratio in APACG eyes were bigger,while rim area was smaller;the CP-RNFL and macular retinal thickness were thinner except nasal CP-RNFL,fovea,temporal and inferior quadrants of macular outer-ring retinal.