Change in optical axial length after cataract surgery: segmental method vs composite method.

Purpose: To compare the changes in axial length (AL) obtained after cataract surgery by partial coherence interferometry (PCI), swept-source optical coherence tomography with the composite method (SS-OCT/CM), and SS-OCT with the segmental method (SS-OCT/SM).

Setting: National Hospital Organization, Tokyo Medical Center, Japan.

Design: Retrospective case series.

Methods: AL was measured preoperatively and 1 month postoperatively by PCI, SS-OCT/CM, and SS-OCT/SM.

Results: Two hundred sixty-eight eyes in 139 patients who underwent cataract surgery were included. The mean ALs measured by PCI and SS-OCT/CM decreased significantly from 24.14 ± 1.58 to 24.05 ± 1.58 mm (P < .0001) and from 24.15 ± 1.58 to 24.05 ± 1.59 mm (P < .0001), respectively. The mean differences between the preoperative and postoperative AL were 0.083 ± 0.044 mm (PCI) and 0.096 ± 0.045 mm (SS-OCT/CM), respectively; Bland-Altman analysis revealed fixed bias between the preoperative and postoperative values. The mean preoperative and postoperative ALs measured by SS-OCT/SM were 24.12 ± 1.54 and 24.12 ± 1.54 mm, respectively (P = 0.97). The mean difference between the preoperative and postoperative ALs was 0.00 ± 0.03 mm on SS-OCT/SM; Bland-Altman analysis indicated good agreement between these values.

Conclusions: The difference between preoperative and postoperative ALs is less with SS-OCT/SM than with PCI or SS-OCT/CM. Assuming that AL is not altered by cataract surgery, AL measurement is more accurate by SS-OCT/SM than by PCI or SS-OCT/CM.