Purpose: To evaluate the accuracy of a new intraocular lens power calculation formula using segmental refractive index-based axial length (AL). Setting: Chukyo Eye Clinic, Nagoya, Japan. Design: Retrospective observational study. Methods: This study included patients undergoing preoperative examination for cataract surgery with the new Barrett True AL (BTAL) and Emmetropia Verifying Optical (EVO) formulas using segmental refractive index, and conventional Barrett Universal II (BU II) formula using equivalent refractive index. The predicted refractive error of each formula was compared with the postoperative subjective spherical equivalent. Results: The mean prediction error (MPE) in the short AL group (≤22 mm; 44 eyes) was 0.32 ± 0.40 diopter (D) for BU II, 0.22 ± 0.37 D for BTAL, and 0.10 ± 0.37 D for EVO (P < .0001). MPE in the long AL group (≥26 mm; 92 eyes) was 0.01 ± 0.32 D for BU II, 0.04 ± 0.32 D for BTAL, and 0.09 ± 0.32 D for EVO (P < .0001). In patients with an AL ≥ 28 mm, BU II showed a myopic trend in 57.1% of cases, while BTAL and EVO showed a hyperopic trend in 71.4%. The MPE for patients with an AL ≥ 28 mm was −0.16 ± 0.34 D for BU II, 0.18 ± 0.33 D for BTAL, and 0.16 ± 0.32 D for EVO (P < .0001). Conclusions: The new EVO and BTAL formulas showed higher accuracy than BU II in short eyes, whereas there was no difference in long eyes.

Purpose: To compare three biometers equipped with swept-source optical coherence tomography (OCT), including ARGOS (OCTB1), IOLMaster 700 (OCTB2), and Anterion (AS-OCTB). The primary aim was to assess the axial length (AL) acquisition success rates, and secondary aims included comparing parameters obtained from the three devices and evaluating postoperative refractive prediction errors. Setting: Chukyo Eye Clinic, Nagoya, Japan. Design: Retrospective observational study. Methods: The study included patients undergoing preoperative assessments for cataract surgery using the three biometers. The AL acquisition success rates and parameters obtained from the three devices were compared and the postoperative refractive prediction errors (defined as the difference between subjective refractive error and predicted refractive error) were assessed at one month after surgery. Results: The study included 361 eyes from 361 patients. The AL acquisition success rates for all patients were 100.0% (n=361) (OCTB1), 98.6% (n=356) (OCTB2), and 96.7% (AS-OCTB) (P < .0001), and those for nuclear sclerosis of grade 4 or higher were 100.0%, 87.8%, and 87.8%, respectively (P = .007). The AL of mature cataract was measurable only with OCTB1 using the enhanced retina visualization mode. Although there were significant differences in parameters obtained on the three devices, there were no significant differences in postoperative refractive prediction errors. Conclusions: OCTB1 demonstrated the highest AL acquisition success rate and was able to measure AL even in eyes with dense or mature cataract. AS-OCTB using a wavelength of 1300 nm showed lower AL acquisition success rates compared to the other two devices probably due to reduced light transmission through the vitreous body.

Background/Objectives: Cataract surgery often reveals preexisting corneal astigmatism, which can be corrected using a toric intraocular lens (T-IOL). However, postoperative T-IOL rotation may compromise correction. We investigated T-IOL rotation, focusing on deployment time and proximity to the posterior capsule (PC), using intraoperative optical coherence tomography (iOCT). Methods: Six different T-IOL models were inserted into acrylic simulated lens capsule models under different tacking durations (5 s, 30 s, and 60 s) and temperature conditions (23 °C, 28 °C, and 32 °C). The selection criteria for porcine lenses for examination required that they match human lens dimensions, typical of those used to train cataract surgeons. T-IOL misalignment due to vibration was assessed. Additionally, the impact of temporary intraocular pressure (IOP) reduction on T-IOL proximity to the PC was measured using iOCT in porcine eyes. Results: Tacking time and temperature independently affected T-IOL deployment, with shorter tacking durations and higher temperatures leading to faster deployment. Among lenses tested under identical tacking time and temperature conditions, iSert Micro Toric Aspheric 1-Piece IOL (355T3) had the slowest expansion time, while Avansee™ Preload 1-Piece Toric (YP-T3) had the fastest. Porcine eyes with a corneal white-to-white major axis < 16.0 mm fell within the 95% confidence interval for matching human lens size. Temporarily reducing IOP during surgery improved T-IOL adhesion to the PC, reducing both the occurrence and degree (from 14.0° to nearly 0°) of postoperative rotation. Conclusions: Optimal T-IOL deployment, temporary IOP reduction during surgery, and enhanced adhesion to the PC can reduce the risk and degree of T-IOL rotation. Intraoperative iOCT aids in monitoring T-IOL positioning, which is essential to prevent rotation. Accumulated fluid between the T-IOL and PC may contribute to rotation, which requires further investigation. These findings provide practical strategies for enhancing T-IOL stability and improving the effectiveness of astigmatism correction in cataract surgery.

A light-adjustable lens™ (LAL) (RxSight, Inc.) is an intraocular lens inserted during cataract surgery. The lens shape can be changed after surgery by ultraviolet light using a Light Delivery Device™ (LDD) to adjust the subjective refractive power. This study evaluated shape changes in the LAL using anterior segment optical coherence tomography (OCT). In Case 1, the right eye of a 70-year-old male was examined. Spherical power changed from +0.75 D to −0.25 D after LDD adjustment with a target of S−0.5 D. Shape analysis using anterior segment OCT showed that the radius of curvature of the front surface of the LAL decreased from 11.59mm to 9.03mm, while that of the back surface increased from 10.98mm to 13.41mm after LDD adjustment. In Case 2, we examined the right eye of an 80-year-old female. Refractive power changed from Cyl-1.50 D (axis 105°) to S+0.25 D after LDD adjustment with the target of emmetropia. The radius of curvature of the front of the LAL decreased from 10.26mm to 7.99mm, while that of the back surface increased from 11.10mm to 21.78mm after the LDD adjustment, and that of the back showed a variation in the radius of curvature depending on the refraction angle. The findings in Case 1 highlighted a change in shape while maintaining a spherical lens shape, while in Case 2, the change in asymmetric shape may have occurred to correct astigmatism on the back of the LAL. Taken together, these findings indicate that anterior segment OCT captures the shape changes in the LAL. The LAL was postoperatively adjusted to the target refraction through shape change.