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Purpose: To investigate the difference between the segmented axial length (AL) and the composite AL on a swept-source optical coherence tomography biometer and to evaluate the subsequent effects on artificial intelligence intraocular lens (IOL) power calculations: the Kane and Hill-RBF 3.0 formulas compared with established vergence formulas., Setting: National Hospital Organization, Tokyo Medical Center, Japan., Design: Retrospective case series., Methods: Consecutive patients undergoing cataract surgery with a single-piece IOL were reviewed. The prediction accuracy of the Barrett Universal II, Haigis, Hill-RBF 3.0, Hoffer Q, Holladay 1, Kane, and SRK/T formulas based on 2 ALs were compared for each formula. The heteroscedastic test was used with the SD of prediction errors as the endpoint for formula performance., Results: The study included 145 eyes of 145 patients. The segmented AL (24.83 ± 1.89) was significantly shorter than the composite AL (24.88 ± 1.96, P < .001). Bland-Altman analysis revealed a negative proportional bias for the differences between the segmented AL and the composite AL. The SD values obtained by Hoffer Q, Holladay 1, and SRK/T formulas based on the segmented AL (0.52 diopters [D], 0.54 D, and 0.50 D, respectively) were significantly lower than those based on the composite AL (0.57 D, 0.60 D, and 0.52 D, respectively, P < .01)., Conclusions: The segmented ALs were longer in short eyes and shorter in long eyes than the composite ALs. The refractive accuracy can be improved in the Hoffer Q, Holladay 1, and SRK/T formulas by changing the composite ALs to the segmented ALs., (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Purpose: To evaluate the performance of a new formula of intraocular lens (IOL) power calculation (the O formula) based on ray tracing without commonly used parameters, including ultrasound-compatible axial length, keratometry readings, and A-constant., Setting: Tokyo Medical Center, Tokyo, Japan., Design: Retrospective consecutive case series., Methods: 423 eyes (423 patients) implanted with a single-piece, L-loop, acrylic IOL were enrolled. All biometric data for the O formula were obtained by anterior segment swept-source optical coherence tomography (SS-OCT) and SS-OCT-based biometer. The performance of the O formula was compared with those of the Barrett Universal II (BUII) and Kane formulas at 1 month postoperatively. Statistical analysis was applied according to a heteroscedastic test with SD of prediction errors as the main parameter for formula performance., Results: The SD of the O formula (0.426) was statistically significantly lower than that of the BUII formula (0.464, P = .034) but not statistically significantly different from that of the Kane formula (0.433, P = .601). The percentages of patients with refractive prediction errors within ±0.50 diopter (D) and ±1.00 D of the O, BUII, and Kane formulas were 75.4% and 98.6%, 77.1% and 97.9%, and 76.6% and 98.1%, respectively., Conclusions: The O formula, based on ray tracing using SS-OCT-based devices, is one of the promising approaches for IOL power calculation, although additional larger scale studies are needed. It may be used as an alternative in IOL power calculation because of its independence from commonly used parameters., Competing Interests: Disclosures: N. Maeda has received lecture fees from Tomey Corp. for sponsored seminars unrelated to this article. The coauthors of this article report no additional potential conflicts of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS.)

Purpose: To compare the change in intraocular lens (IOL) axial movement, corneal power, and postoperative refraction of eyes implanted with two different single-piece, open loop, acrylic foldable IOLs with planar-haptic design: one IOL with hinges vs. one IOL without hinges. The role of IOL axial movement on short-term refractive shift after cataract surgery was also evaluated., Methods: This retrospective comparative study enrolled consecutive patients who had phacoemulsification with aspheric IOL implantation. The IOL depth (the distance from corneal endothelium to IOL surface) and corneal power were measured via anterior-segment optical coherence tomography at 4 days and 1 month postoperatively. The changes in axial movement of the IOL, corneal power, and manifest refractive spherical equivalent (MRSE) were compared among groups, and the correlations between each lens were evaluated., Results: IOL with hinges was implanted in 42 eyes of 42 patients and IOL without hinges was implanted in 42 eyes of 42 patients. The change in axial movement between 4 days and 1 month was significantly smaller in the IOL with hinges group than in the IOL without hinges group (p < 0.001). The axial movement of IOL with hinges did not correlate with the MRSE change; however, the forward shift of IOL without hinges correlated with the myopic refractive change (Pearson r = 0.62, p < 0.001)., Conclusion: The postoperative axial movement of IOL was more stable in the IOL with hinges group than the IOL without hinges group between 4 days and 1 month after cataract surgery. Even though the two study IOLs with planar-haptic design are made of similar acrylic materials, other characteristics such as hinge structure may affect IOL stability in the bag., Competing Interests: SG is supported by Grants Manpei Suzuki Diabetic Foundation and Japan Society for the Promotion of Science Overseas Research Fellowships that are not related to the submitted work. SG, NM, and TN received honoraria for speaking outside the submitted work from Alcon Japan Ltd. These do not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products to declare.

Purpose: To evaluate the accuracy of a new formula for predicting postoperative anterior chamber depth (ACD) with preoperative angle-to-angle (ATA) depth using anterior segment (AS) optical coherence tomography (OCT) and to compare it with established methods., Design: Retrospective consecutive case series., Participants: Three hundred four eyes (276 patients) implanted with acrylic intraocular lenses (IOLs) were divided randomly into a training set (152 eyes) and a validation set (152 eyes)., Methods: Based on the training set data, the postoperative ACD measured 1 month after surgery was analyzed via multiple linear regression analysis with 5 preoperatively measured variables: ATA depth, ATA width, preoperative ACD measured with AS OCT, axial length (AL), and corneal power. A new regression formula for predicting postoperative ACD was developed using the results of the stepwise analysis. In the validation set data, the coefficients of determination (R 2 ) between the measured postoperative ACD and the predicted postoperative ACD obtained using the new formula were compared with those obtained using the Sanders-Retzlaff-Kraff theoretic (SRK/T) and Haigis formulas. The absolute prediction errors were compared with each formula., Main Outcome Measures: Postoperative ACD, median absolute prediction error of postoperative ACD, and ocular biometric parameters., Results: In the training set, ATA depth yielded the highest standard partial regression coefficient value, indicating that ATA depth is the most effective parameter for predicting postoperative ACD. The new regression formula was developed with 3 variables; ATA depth, preoperative ACD, and AL. In the validation set, the postoperative ACDs of the new formula, the SRK/T formula, and Haigis formula were predicted with R 2 of 0.71, 0.36, and 0.55, respectively, and the medians of the absolute prediction errors were 0.10 mm, 0.65 mm, and 0.30 mm, respectively. The absolute prediction error with the new formula was significantly smaller than those obtained with the SRK/T and Haigis formulas (P < 0.0001)., Conclusions: The new formula with 3 preoperative parameters-ATA depth, preoperative ACD, and AL-predicted postoperative ACD more accurately than the SRK/T and Haigis formulas. It may be possible to improve the accuracy of IOL power calculation using an improved postoperative ACD prediction with the ATA depth measured by AS OCT., (Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the quality of an image of a grating target placed in a model eye and viewed through implanted toric intraocular lenses (IOLs)., Design: Laboratory investigation., Methods: Toric IOLs, SN6AT5 with a cylinder power of 3.0 diopters (3.0 D, Alcon), ST6AT9 (6.0 D, Alcon), 311T5 (3.0 D, HOYA), or 311T9 (6.0 D, HOYA), were placed in a fluid-filled model eye. A United States Air Force test target was placed internally on the posterior surface of the model eye. A flat contact lens or a wide-angle contact lens was placed on the cornea. The contrast and length of the grating targets perpendicular (vertical) or parallel (horizontal) to the flat meridian of the toric IOL were compared with those obtained through aspheric IOLs., Results: The contrast of the targets viewed through the flat contact lens and toric IOLs in the vertical direction was significantly lower than that viewed through the aspheric IOL at 16 cycle/mm (SN6AT9, P=.002; SN6AT5, P=.028; 311T9, P=.002; 311T5, P =.011) but not with the wide-angle viewing lens at 16, 32, and 64 cycle/mm. The vertical length of the target with a flat contact lens was longer and the horizontal length was shorter than that through the aspheric IOL by 1% to 3% with the SN6AT5 and 311T5 IOLs and by 3% to 5% with the SN6AT9 and 311T9 IOLs. However, the vertical and horizontal lengths were not significantly different through the wide-viewing lens., Conclusion: Toric IOLs affect the contrast of a grating target viewed through a flat contact lens but not through a wide-angle viewing lens. The wide-angle viewing system is not influenced by cylindrical aberrations., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To determine the quality of the image of a grating target placed in the vitreous of isolated pig eyes and photographed through implanted refractive and diffractive multifocal intraocular lenses (IOL)., Methods: Refractive multifocal (NXG1, PY60MV), diffractive multifocal (ZM900, SA60D3) and monofocal (SA60AT, ZA9003) IOL were implanted in the capsular bag of isolated pig eyes. A grating target was placed in the vitreous and photographed through a flat or a wide-field viewing contact lens. The contrast of the grating targets of different spatial frequencies was measured., Results: With the flat corneal contact lens, the gratings appeared clear and not distorted when viewed through the optics of the NXG1 and PY60MV for far vision but were distorted with reduced contrast when viewed through the optical zone for near vision. The images through the diffractive zone of the ZM900 and SA60D3 were more defocused than with the monofocal IOL (p < 0.005). Ghost images oriented centrifugally of the original image were seen with the ZM900 resulting in lower contrast at higher spatial frequencies than with the SA60D3 with less defocused images only in the central area. With the wide-field viewing contact lens, the images were less defocused and the contrast was comparable to both refractive and diffractive multifocal IOL., Conclusion: Both refractive and diffractive multifocal IOL reduced the contrast of the retinal image when viewed through a flat corneal contact lens but less defocused when viewed through a wide-field viewing contact lens., (© 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.)

Purpose: To evaluate the quality of the image of a grating target placed in a model eye viewed through multifocal intraocular lenses (IOLs)., Design: Laboratory investigation., Methods: Refractive (NXG1 or PY60MV) or diffractive (ZM900 or SA60D3) multifocal IOLs were placed in a fluid-filled model eye with human corneal aberrations. A United States Air Force resolution target was placed on the posterior surface of the model eye. A flat contact lens or a wide-field contact lens was placed on the cornea. The contrasts of the gratings were evaluated under endoillumination and compared to those obtained through a monofocal IOL., Results: The grating images were clear when viewed through the flat contact lens and through the central far-vision zone of the NXG1 and PY60MV, although those through the near-vision zone were blurred and doubled. The images observed through the central area of the ZM900 with flat contact lens were slightly defocused but the images in the periphery were very blurred. The contrast decreased significantly in low frequencies (P<.001). The images observed through the central diffractive zone of the SA60D3 were slightly blurred, although the images in the periphery were clearer than that of the ZM900. The images were less blurred in all of the refractive and diffractive IOLs with the wide-field contact lens., Conclusion: Refractive and diffractive multifocal IOLs blur the grating target but less with the wide-angle viewing system. The peripheral multifocal optical zone may be more influential on the quality of the images with contact lens system., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: To evaluate the predictability of total postoperative spherical aberration after aspheric intraocular lens (IOL) implantation using preoperative corneal spherical aberration., Setting: Keio University Hospital, Tokyo, Japan., Methods: Corneal and ocular higher-order aberrations (HOAs) were analyzed preoperatively and postoperatively in eyes having cataract extraction with aspheric IOL implantation. The predicted postoperative total spherical aberration Z(4,0) was calculated by adding the preoperative corneal spherical aberration and the labeled spherical aberration of the IOL. The prediction error of the postoperative total spherical aberration was calculated by subtracting the predicted postoperative total spherical aberration from the postoperative total spherical aberration. Surgically induced corneal spherical aberration was calculated by subtracting the postoperative from the preoperative corneal spherical aberration., Results: There were no statistically significant differences between preoperative and postoperative corneal spherical aberration, 3rd-order aberration, or HOAs. The prediction error of the postoperative total spherical aberration was within +/-0.05 microm in 9 (24.3%) of the 37 eyes evaluated and within +/-0.10 microm in 18 eyes (48.6%). Statistically significantly correlations were found between the surgically induced corneal spherical aberration and prediction error of postoperative total spherical aberration, the preoperative corneal spherical aberration and surgically induced corneal spherical aberration, and the preoperative corneal spherical aberration and prediction error of postoperative total spherical aberration., Conclusions: Predictability of postoperative ocular spherical aberration after cataract surgery with aspheric IOL implantation was insufficient because of the surgically induced corneal spherical aberration. Considering surgically induced corneal spherical aberration could improve the predictability of postoperative ocular spherical aberration., ((c) 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the feasibility of correcting spherical aberration with aspheric intraocular lenses (IOLs) in cataract surgery based on individual pupil diameter., Setting: Keio University Hospital, Tokyo, Japan., Methods: In this prospective study, eyes having cataract surgery were divided into 4 groups based on IOL type: aspheric SN (AcrySof SN60WF), aspheric ZA (Tecnis ZA9003), aspheric PY (Hoya PY-60 AD), and spherical (AcrySof Natural SN60AT). Postoperative higher-order aberrations (HOAs) of the cornea and whole eye and the pupil diameter under photopic and mesopic conditions were measured. The HOA was calculated using the individual pupil diameter. The correlation between corneal and ocular spherical aberrations and pupil diameter was evaluated., Results: Each group comprised 30 eyes. Ocular spherical aberrations were significantly lower than corneal spherical aberrations under mesopic conditions in the aspheric SN group, the aspheric ZA group, and the aspheric PY group (P<.05); there was no significant difference between the aberrations in the spherical group. Linear regression showed significant correlations between postoperative corneal and ocular spherical aberrations (beta = 0.39, aspheric SN; beta = 0.38, aspheric ZA; beta = 0.58, aspheric PY; beta = 0.79, spherical). The differences in corneal and ocular spherical aberrations were significantly correlated with pupil diameter in the aspheric IOL groups but not in the spherical IOL group., Conclusions: The amount of spherical aberration correction by aspheric IOLs varied depending on IOL type and individual pupil diameter. The linear regression equation in this study may make it possible to customize postoperative ocular spherical aberration after cataract surgery.

Purpose: To evaluate the effect of decentration of a monofocal intraocular lens (IOL) and a refractive multifocal IOL on retinal image quality using a new visual simulation system., Methods: Using a new visual simulation system, we performed visual simulation of a monofocal and a multifocal IOL at 5, 4, 3, 2, 1, and 0.4 m with several decentered IOL positions from 0 to 1.0 mm through a 3- or 4-mm aperture using Landolt visual acuity (VA) charts. The VA was estimated under each condition from the simulated retinal image., Results: With a monofocal IOL, the image was affected minimally by decentration at 4 and 5 m; at 2 and 3 m, the image contrast decreased slightly with increased decentration. With the multifocal IOL, some loss of image contrast developed at all distances compared with the monofocal IOL; however, the images of the Landolt's rings were still recognizable under all conditions., Conclusions: Our results suggest that up to 1.0 mm of decentration of a monofocal and multifocal IOL would not greatly affect the retinal image quality., ((c) Japanese Ophthalmological Society 2005.)

Objective: To evaluate the effect of chromatic aberrations in pseudophakic eyes with various types of intraocular lenses (IOLs)., Patients and Methods: The study included 51 eyes of 33 patients who underwent cataract surgery. The eyes were divided into 3 groups according to the material from which their IOL was made: group 1, polymethyl methacrylate; group 2, silicone; and group 3, an acrylate/methacrylate copolymer. Ten normal phakic control eyes (group 4) underwent the same examination. Best-corrected distance visual acuity and contrast sensitivity were measured under white light and monochromatic light with wavelengths of 470 nm, 549 nm, and 630 nm, with the best correction under white light., Results: There were no significant differences in best-corrected visual acuity and contrast sensitivity under the 549-nm monochromatic light in any group. However, under both white multichromatic light and 470- and 630-nm monochromatic light, the mean contrast sensitivity in group 3 tended to be lower, sometimes significantly, than in the other IOL groups., Conclusions: Our results showed that longitudinal chromatic aberrations of some IOLs may degrade the quality of the retinal image. Attention must be paid to the detailed optical performance of IOL materials to achieve good visual function.