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Purpose: To investigate whether standard keratometry (K) or total corneal power (TCP) leads to more accurate refractive outcomes for intraocular lens (IOL) power calculation., Setting: Public hospital., Design: Retrospective evaluation of a diagnostic test instrument., Methods: Preoperatively, all patients underwent optical biometry with Anterion, a swept-source optical coherence tomography device providing both K and TCP. The same IOL model was implanted in all cases. The whole sample was divided into a training dataset, used to optimize the formula constants, and a testing dataset, used to investigate the spherical equivalent prediction error (SEQ-PE) of 8 IOL power formulas. Trueness, precision, and accuracy were evaluated by means of the robust 2-sample t test. Cochran Q test was performed to assess whether the percentage of eyes with an SEQ-PE within each threshold was significantly different; in such an event, the McNemar test was then applied., Results: Both the training and testing datasets included 317 eyes. No significant differences were detected for trueness because of constant optimization. Precision and accuracy were better when K was entered, although a statistically significant difference was observed only with the EVO (precision: P = .02 and accuracy: P = .03) and Haigis ( P < .01 for both precision and accuracy) formulas. No significant differences were observed for the percentage of eyes with an absolute SEQ-PE within any threshold., Conclusions: With most formulas, IOL power calculation is not more accurate when TCP is used instead of K., (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Purpose: To compare the accuracy of intraocular lens (IOL) power calculation formulas for myopic eyes requiring negative diopter powered IOLs., Design: Retrospective case series., Setting: K… hospital and Y… Hospital, …, …., Methods: Sixty-one eyes that underwent phacoemulsification with implantation of a negative power IOL were investigated. The trueness, precision and accuracy of IOL power calculation were assessed for the Barrett Universal II (BUII), EVO 2.0, Haigis, Hoffer QST, Holladay 1 and SRK/T formulas using the Eyetemis online tool. The analysis was performed using 1) the ULIB IOL constants and 2) after constant optimization., Results: With ULIB constants, the Haigis, Holladay 1 and SRK/T resulted in a hyperopic mean prediction error (PE) >1.00 diopter (D), which was significantly different from zero (adjusted p <0.05). The mean PE of the remaining formulas was closer to zero. The absolute PE was significantly higher with the Holladay 1 and SRK/T (adjusted p <0.05) with respect to the remaining formulas. After constant optimization, the outcomes of traditional formulas improved and no statistically significant differences were found among any of the formulas in terms of trueness, precision and accuracy. The percentage of eyes with an absolute PE within 0.50 D was low (<50%) even after constant optimization., Conclusions: With ULIB constants, the BUII, EVO 2.0 and Hoffer QST were more accurate than traditional formulas in eyes with negative-diopter IOLs. The results of IOL power calculation in these eyes remain poor even after constant optimization., (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

This study aimed to compare the postimplantation clinical outcomes of 2 types of posterior chamber phakic intraocular lenses (IOLs): Visian™ implantable collamer lenses (ICL; EVO+ V5; Staar Surgical, Monrovia, CA) and an implantable phakic contact lens (IPCL) (IPCL V2.0, Care Group Sight Solution, India) to correct high myopia and myopic astigmatism. This retrospective study included patients who had undergone phakic IOL implantation performed by a single surgeon between March 2021 and March 2022. Preoperative assessments included slit-lamp examination, fundus examination, spherical equivalent, uncorrected distant visual acuity (UDVA), corrected distant visual acuity (CDVA), specular microscope parameters, and optical quality analysis system parameters. Postoperative assessments after 1 year included slit-lamp examination to detect adverse effects and spherical equivalent, UDVA, CDVA, specular microscope, optical quality analysis system, and anterior-segment optical coherence tomography. Eighty eyes from 42 patients (47 eyes from 24 patients in the ICL group and 33 eyes from 18 patients in the IPCL group) were included. No statistically significant differences were observed between the 2 groups regarding preoperative parameters. At 1-year postoperatively, the mean UDVA in the ICL and IPCL groups was 0.019 ± 0.040 logMAR and 0.019 ± 0.041 logMAR, respectively. The mean CDVA was 0.001 ± 0.008 logMAR and 0.001 ± 0.007 logMAR in the ICL and IPCL groups, respectively, showing no statistically significant differences. The postoperative parameters did not differ significantly between the 2 groups. The visual acuity and refractive results of both groups were excellent, and both groups exhibited similar efficacy and safety profiles., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)