The binocular intraocular lens power difference in eyes with different axial lengths

To investigate the binocular intraocular lens (IOL) power difference in eyes with short, normal, and long axial lengths (AL) using Lenstar LS 900 optical biometry.

A total of 716 (1432 eyes) participants were included. The groups were categorized into short (group A: AL<22 mm), normal (group B: 22 mm≤AL≤25 mm), and long AL groups (group C: AL>25 mm). The central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), AL, anterior corneal keratometry, white-to-white (WTW), pupil diameter (PD), as well as IOL power calculated using embedded Barrett formula were assessed. Bland-Altman plots were used to test the agreement of the binocular parameters.

In group A, the CCT of the right eye was significantly thinner than that of the left eye (P=0.044) with a difference of -2±8 µm [95% limits of agreement (LoA), -17.8 to 13.2 µm]. For group B, the PD and IOL power in the right eye were significantly lower than those of the left eye (P=0.001, <0.001) with a difference of -0.05±0.32 mm (95%LoA, -0.68 to 0.58 mm) and -0.18±1.01 D (95%LoA, -2.2 to 1.8 D). The AL of right eye was longer than that of the left eye (P=0.002) with a difference of 0.04±0.25 mm (95%LoA, -0.45 to 0.52 mm). No significant difference was observed for all the binocular parameters in group C. The percentage of participants with binocular IOL power difference within ±0.5 D were 62% (31/50), 68.3% (339/496), and 38.8% (66/170) in groups A, B, and C, respectively.

The binocular parameters related to IOL power are in good agreement, but the binocular IOL power difference of more than half of participants with long AL is more than 0.50 D.