Abstract: Acute primary angle closure (APAC) is an ocular emergency and requires immediate management to avoid blindness. The pathological mechanisms inducing APAC have not been entirely understood. Recent studies summarized the anatomical parameters associated with APAC, including crowded anterior chamber and angle, thicken and anterior moving lens, thinner ciliary body and expansive anterior rotating ciliary process, dynamic changing iris and choroid. Changes in single or multiple anatomical parameters of one or both eyes in such risk groups lead to the onset of APAC, under some predisposing factors (emotions, extreme weather and drugs, etc). (Int Rev Ophthalmol, 2023, 47: 18-24)

Key words: acute primary angle closure, risk factor