Refractive outcomes after immediate primary phacoemulsification for acute primary angle closure

This study investigated the refractive outcomes of 64 eyes overall including 32 immediate primary phacoemulsification in acute primary angle closure (APAC) eyes and 32 of their fellow eyes. We investigated best-corrected visual acuity, intraocular pressure (IOP), average keratometric diopter (K), spherical equivalent, axial length (AL), central corneal thickness, and anterior chamber depth (ACD) at preoperative examination (Pre) and more than 1-month post-phacoemulsification (1 m), and changes in values. Using SRK/T, Barrett Universal II (Barrett), Hill-Radial Basis Function Version 3.0 (RBF 3.0), and Kane formulas, we calculated and compared refractive prediction error (PE), absolute value of PE (AE), and changes in K, AL, and ACD from Pre to 1 m between APAC and fellow eyes. From Pre to 1 m, K remained similar in APAC and fellow eyes (p = 0.069 and p = 0.082); AL significantly decreased in APAC and in fellow eyes (both p < 0.001); and ACD significantly increased in APAC and in fellow eyes (both p < 0.001). The change in AL differed significantly between the two groups (p = 0.007). Compared to the fellow eyes, PE with SRK/T and Barret formulas (p = 0.0496 and p = 0.039) and AE with Barrett and RBF 3.0 formula (p = 0.001 and p = 0.024) were significantly larger in the APAC eyes. Thus, attention should be paid to refractive prediction error in immediate primary phacoemulsification for APAC eyes caused by preoperative AL elongation due to high IOP.