Correction of axial length measurement error by IOLMaster 700 could improve refractive prediction accuracy in silicone oil-filled eyes.

PURPOSE: To determine whether correcting the axial length (AL) measurement error of the IOLMaster 700 could improve the refractive prediction accuracy in silicone oil-filled eyes. METHODS: This study included 265 cataract patients (265 eyes) with silicone oil tamponade who were scheduled for phacoemulsification with intraocular lens (IOL) implantation. The performances of various formulas, including Barrett Universal II, Emmetropia Verifying Optical, Hoffer-QST, Kane, Ladas Super Formula, Pearl-DGS, Radial Basis Function and traditional formulas (Haigis, Hoffer Q, Holladay 1 and SRK/T), were evaluated. The refractive prediction errors (PE) calculated with measured AL (ALmeas ) and corrected AL with silicone oil adjustment (SOAL ) were compared. Subgroup analysis was performed based on the ALmeas (<23 mm; 23-26 mm; ≥26 mm). RESULTS: Using SOAL significantly reduced the hyperopic PE of formulas when compared to ALmeas (-0.05 to 0.17 D vs 0.15 to 0.38 D, p < 0.001). After applying AL correction, all formulas showed a lower mean absolute PE (0.47-0.57 D vs 0.50-0.69 D). The percentage of eyes within ±1.0 D of PE increased from 84.91%-88.68% to 89.81%-91.32% for new formulas and from 78.11%-83.40% to 85.66%-88.68% for traditional formulas, with the use of SOAL . Subgroup analysis showed that the majority of formulas with SOAL in prediction accuracy for eyes with an AL ≥26 mm (p < 0.05). CONCLUSIONS: The refractive prediction accuracy in silicone oil-filled eyes was improved by correcting the AL measurement error of the IOLMaster 700, especially for long eyes.

Comparison of intraocular lens power calculation formulas in patients with a history of acute primary angle-closure attack.

BACKGROUND: To compare the accuracy of nine intraocular lens (IOL) power calculation formulas, including three traditional formulas (SRK/T, Haigis, and Hoffer Q) and six new-generation formulas (Barrett Universal II [BUII], Hill-Radial Basis Function [RBF] 3.0, Kane, Emmetropia verifying optical [EVO], Ladas Super, and Pearl-DGS) in patients who underwent cataract surgery after acute primary angle closure (APAC). METHODS: In this retrospective cross-sectional study, 44 eyes of 44 patients (APAC) and 60 eyes of 60 patients (control) were included. We compared the mean absolute error, median absolute error (MedAE), and prediction error after surgery. Subgroup analyses were performed on whether axial length (AL) or preoperative laser peripheral iridotomy affected the postoperative refractive outcomes. RESULTS: In the APAC group, all formulas showed higher MedAE and more myopic shift than the control group (all P < 0.05). In APAC eyes with AL ≥ 22 mm, there were no differences in MedAEs according to the IOL formulas; however, in APAC eyes with AL < 22 mm, Haigis (0.49 D) showed lower MedAE than SRK/T (0.82 D) (P = 0.036) and Hill-RBF 3.0 (0.54 D) showed lower MedAE than SRK/T (0.82 D), Hoffer Q (0.75 D) or Kane (0.83 D) (P = 0.045, 0.036 and 0.027, respectively). Pearl-DGS (0.63 D) showed lower MedAE than Hoffer Q (0.75 D) and Kane (0.83 D) (P = 0.045 and 0.036, respectively). Haigis and Hill-RBF 3.0 showed the highest percentage (46.7%) of eyes with PE within ± 0.5 D in APAC eyes with AL < 22 mm. Iridectomized eyes did not show superior precision than the non-iridotomized eyes in the APAC group. CONCLUSIONS: Refractive errors in the APAC group were more myopic than those in the control group. Haigis and Hill-RBF 3.0 showed high precision in the eyes with AL < 22 mm in the APAC group.

Technical failure rates for biometry between swept-source and older-generation optical coherence methods: a review and meta-analysis.

PURPOSE: Precise ocular measurements are fundamental for achieving excellent target refraction following both cataract surgery and refractive lens exchange. Biometry devices with swept-source optical coherence tomography (SS-OCT) employ longer wavelengths (1055-1300 nm) in order to have better penetration through opaque lenses than those with partial coherence interferometry (PCI) or low-coherence optical reflectometry (LCOR) methods. However, to date a pooled analysis showing the technical failure rate (TFR) between the methods has not been published. The aim of this study was to compare the TFR in SS-OCT and in PCI/LCOR biometry. METHODS: PubMed and Scopus were used to search the medical literature as of Feb 1, 2022. The following keywords were used in various combinations: optical biometry, partial coherence interferometry, low-coherence optical reflectometry, swept-source optical coherence tomography. Only clinical studies referring to patients undergoing routine cataract surgery, and employing at least two (PCI or LCOR vs. SS-OCT) optical methods for optical biometry in the same cohort of patients were included. RESULTS: Fourteen studies were included in the final analysis, which presented results of 2,459 eyes of at least 1,853 patients. The overall TFR of all included studies was 5.47% (95% confidence interval [CI]: 3.66-8.08%; overall I2 = 91.49%). The TFR was significantly different among the three methods (p < 0.001): 15.72% for PCI (95% CI: 10.73-22.46%; I2 = 99.62%), 6.88% for LCOR (95% CI: 3.26-13.92%; I2 = 86.44%), and 1.51% for SS-OCT (95% CI: 0.94-2.41%; I2 = 24.64%). The pooled TFR for infrared methods (PCI and LCOR) was 11.12% (95% CI: 8.45-14.52%; I2 = 78.28%), and was also significantly different to that of SS-OCT: 1.51% (95% CI: 0.94-2.41%; I2 = 24.64%; p < 0.001). CONCLUSIONS: A meta-analysis of the TFR of different biometry methods highlighted that SS-OCT biometry resulted in significantly decreased TFR compared to PCI/LCOR devices.

Accuracy of new-generation intraocular lens calculation formulas in eyes with variations in predicted refraction.

PURPOSE: To investigate the characteristics of eyes with large variations in predicted refraction using four traditional intraocular lens (IOL) formulas and evaluate the accuracy of new-generation intraocular lens power calculation formulas. METHODS: Eyes that had variation in predicted refraction (≥ 0.75 D) using four traditional formulas (SRK/T, Holladay 1, Hoffer Q, and Haigis formulas) were included. Axial length (AL), anterior chamber depth (ACD), average keratometry (AK), and the ratio of axial length to corneal radius (AL/CR) were measured. New-generation formulas (Barrett Universal II, Emmetropia Verifying Optical 2.0, Kane, and Pearl-DGS formulas) and traditional formulas were compared. The median absolute error (MedAE) was the main parameter to evaluate the accuracy of formulas. RESULTS: A total of 79 participants (79 eyes) who had variation in predicted refraction of (≥ 0.75 D) using four traditional formulas out of 510 eyes (510 patients) underwent uncomplicated cataract surgeries. The Barrett Universal II (0.29 D), EVO 2.0 (0.31 D), Kane (0.30 D), and Pearl-DGS (0.33 D) formulas produced significantly lower median absolute errors (MedAEs) than the Hoffer Q (0.61 D) and Holladay 1 (0.59 D) formulas (P < 0.01). The Wang-Koch (WK) adjustment significantly improved the accuracy of the Holladay 1 formula in long eyes (P < 0.001). CONCLUSIONS: Abnormal AL, ACD, and AK are more likely to lead to prediction errors using traditional formulas. New-generation formulas and traditional formulas with WK adjustment showed satisfactory prediction accuracy.

Selection of intraocular lens calculation formula for cataract surgery in glaucoma patients / 国际眼科杂志(Guoji Yanke Zazhi)

Glaucoma and cataracts are the leading causes of blindness, and surgery is an important treatment option. Patients with glaucoma have clinical characteristics such as high intraocular pressure, shallow anterior chamber and short axial length, and the ocular structure is often altered after anti-glaucoma surgery like trabeculectomy. These changes also lead to differences in the accuracy of intraocular lens(IOL)refractive calculation between cataract surgery after anti-glaucoma surgery or combined glaucoma and cataract surgery and alone cataract surgery. Meanwhile glaucoma patients' individual clinical characteristics and structural changes caused by anti-glaucoma surgery have shown differences in the impact on the predictive accuracy of IOL diopters and the type of refractive drift. This article reviews the latest research advances in the causes of refractive error(RE), the characteristics of refractive drift, and the selection of the most appropriate IOL formula for glaucoma patients undergoing cataract surgery or cataract surgery after anti-glaucoma surgery or combined glaucoma and cataract surgery.

Comparison of accuracy of intraocular lens calculation formulas in cataract eyes with prior radial keratotomy and axial length longer than 28mm / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the accuracy of different intraocular lens(IOL)calculation formulas in cataract patients with axial length longer than 28mm and a history of radial keratotomy(RK).METHODS: Retrospective study. The medical records of 19 cataract patients(29 eyes)after RK and with axial length longer than 28mm who underwent cataract surgery from January 2011 to July 2020 in Beijing Tongren Hospital were analyzed. The absolute error(AE)of the difference among three different formulas was calculated. AE refers to the absolute value between the actual spherical equivalent after cataract surgery and the spherical equivalent predicted by the IOL formula. The AE values of the three formulas and the percentages of eyes with AE≤0.5, 0.75, 1.0, and 2.0D were calculated and compared.RESULTS: The AE values of the three formulas were significantly different(χ2=8.759, P=0.013). The Barrett True-K formula had the smallest median AE, which was only 0.62(0.20, 1.15)D, followed by the Haigis formula 0.76(0.34, 1.26)D, and the Holladay 1(D-K)formula had the largest 1.01(0.49, 1.62)D. The percentages of affected eyes with AE ≤0.5, 0.75, 1.0, and 2.0D for the Barrett True-K formula were 48%, 59%, 69%, and 93%, which were equal to or higher than the other two formulas.CONCLUSION: The Barrett True-K formula is more recommended among the three formulas for cataract patients after RK and with axial length longer than 28 mm.

Resultados del cálculo de la lente intraocular con fórmula Holladay 2 y Barret Universal 2 / Results of Intraocular Lens Calculation with Holladay 2 and Barret Universal 2 formula

Objetivo: Determinar los resultados refractivos con las fórmulas Holladay 2 y Barret Universal 2 a partir del cálculo de la lente intraocular en pacientes operados de catarata. Métodos: Se realizó un estudio descriptivo prospectivo y longitudinal con 60 ojos de 50 pacientes operados de catarata mediante la técnica de facoemulsificación. Se empleó para el cálculo de la lente el IOL Master 700 y el Pentacam AXL con la fórmula Holladay 2 y Barret Universal 2, respectivamente. Resultados: Predominó el sexo femenino y el grupo etario mayor de 60 años. Los ojos mayores de 26 mm mostraron la mayor diferencia entre el poder dióptrico de la lente intraocular que se implantó según Holladay y en menores de 22 mm según Barret Universal. Ambos grupos presentaron una disminución del equivalente esférico, siendo superior a 7 y 5 dioptrías en ojos mayores de 26 mm en el posoperatorio de ambas fórmulas. Posterior a la cirugía se observó una mejoría en la agudeza visual sin corrección y corregida de más de 4 líneas en la cartilla de Snellen, independiente de la longitud axial, para ambos grupos en estudio. Sin cambios significativos en el cilindro queratométrico. En el 70,0 por ciento de los casos, el resultado refractivo final estuvo en rango de la emetropía para el grupo Holladay 2 y el 66,7 por ciento para el grupo Barret Universal 2. Conclusiones: Ambas fórmulas resultan útiles para el cálculo de la lente intraocular en todos los rangos de longitud axial(AU)

Objective: To determine refractive outcomes with the Holladay 2 and Barret Universal 2 formulas from intraocular lens calculation in cataract surgery patients. Methods: A prospective and longitudinal descriptive study was performed with 60 eyes of 50 patients who underwent cataract surgery by phacoemulsification. The IOL Master 700 and Pentacam AXL with the Holladay 2 and Barret Universal 2 formula, respectively, were used to calculate the lens. Results: Female gender and age group older than 60 years predominated. Eyes larger than 26 mm showed the greatest difference between the dioptric power of the intraocular lens implanted according to Holladay and those smaller than 22 mm according to Barret Universal. Both groups presented a decrease of the spherical equivalent, being higher than 7 and 5 diopters in eyes larger than 26 mm postoperatively in both formulas. Postoperatively, there was an improvement in uncorrected and corrected visual acuity of more than 4 lines in the Snellen chart, independent of axial length, for both groups under study. No significant changes in keratometric cylinder. In 70.0 percent of the cases, the final refractive result was in the emmetropia range for the Holladay 2 group and 66.7 percent for the Barret Universal 2 group. Conclusions: Both formulas are useful for the calculation of the intraocular lens in all axial length ranges(AU)

Optimización de las constantes para el cálculo preciso de cinco modelos de lente intraocular / Optimization of constants for accurate calculation of five intraocular lens models

Objetivo: Optimizar las constantes utilizadas por las fórmulas SRK/T, SRK/T2, Holladay 1 y Hoffer Q para cinco modelos de lentes intraoculares (LIO), implantados durante la cirugía de catarata en el Instituto Cubano de Oftalmología (enero/2006-octubre/2019). Método: Se estudiaron retrospectivamente 47341 pacientes. Las constantes se optimizaron ajustando a cero el error de predicción promedio (EPm) y obteniendo el valor que arrojó el máximo número de ojos con error de predicción absoluto -EP- ≤; 0,25, tanto para la biometría ultrasónica como para la óptica. La eficacia de las constantes optimizadas se verificó mediante el análisis de los errores absolutos medio y mediano (EAM/EAMed) más bajos y el porcentaje de ojos en un intervalo determinado de error de predicción en función del valor de las constantes. También se analizaron el índice de rendimiento de la fórmula de Haigis y un nuevo índice introducido. Resultados: Las constantes optimizadas fueron significativamente diferentes de los valores del fabricante. Los valores obtenidos para EPm = 0 fueron diferentes a los mínimos de EAM y EAMed. El porcentaje de ojos con -EP- ≤ 0,25 y 0,50 D difirió cuando los criterios de optimización fueron diferentes. SRK/T y SRK/T2 mostraron los mejores rendimientos, según ambos índices. Conclusiones: Las constantes optimizadas mejoran los resultados postoperatorios para cada combinación LIO-fórmula. Diferentes criterios de optimización conducen a diferentes resultados. El EAM, el EAMed y el porcentaje de ojos con -EP- ≤; 0,50 D son parámetros válidos para comprobar el rendimiento de las fórmulas, hasta disponer de un índice único, fiable y consensuado(AU)

Objective: To optimize the constants used by the SRK/T, SRK/T2, Holladay 1 and Hoffer Q formulas for five intraocular lens (IOL) models implanted during cataract surgery at the Cuban Institute of Ophthalmology (January/2006-October/2019). Methods: 47341 patients were retrospectively studied. The constants were optimized by adjusting the average prediction error (EPm) to zero and obtaining the value that showed the maximum number of eyes with absolute prediction error -EP- ≤ 0.25, for both ultrasonic and optical biometry. The effectiveness of the optimized constants was verified by analyzing the lowest average and median absolute errors (EAM/EAMed) and the percentage of eyes in a given range of prediction error as a function of the value of the constants. The Haigis formula performance index and a newly introduced index were also analyzed. Results: The optimized constants were significantly different from the manufacturer's values. The values obtained for EPm = 0 were different from the EAM and EAMed minima. The percentage of eyes with -EP- ≤ 0.25 and 0.50 D differed when the optimization criteria were different. SRK/T and SRK/T2 showed the best performances, according to both indexes. Conclusions: Optimized constants improve postoperative outcomes for each IOL-formula combination. Different optimization criteria lead to different results. The EAM, the EAMed and the percentage of eyes with -EP- ≤ 0.50 D are valid parameters to check the performance of the formulas, until a single, reliable and consensual index is available(AU)

Comparison of the Accuracy of Intraoperative Aberrometry in Intraocular Lens Implantation Between Myopic Eyes with Emmetropia and Myopia Targets.

Purpose: To compare the accuracy of intraoperative aberrometry (IA) for predicting postoperative refraction between eyes with emmetropia and myopia targets. Patients and Methods: This retrospective analysis included patients with axial myopia (axial length ≥ 25.0 mm) who underwent uncomplicated phacoemulsification cataract surgery with IA to achieve emmetropia (plano to -0.5 D) or intentional myopia (-2.5 D to -5.0 D). Preoperative ocular biometry was performed in all eyes using an IOLMaster. Refractive prediction errors in IA were compared between eyes with emmetropia and myopia targets. Refractive prediction errors in IA for both groups were also compared with those predicted by intraocular lens power calculation formulas including the SRK/T, Holladay 1, Hoffer Q, Holladay 2, Haigis, and Barrett Universal II formulas. Results: Thirty-nine eyes of 39 patients with a target of emmetropia and 22 eyes of 22 patients with a target of intentional myopia were included in the final analysis. The mean numerical error was significantly different from zero (myopic trend) in myopia-targeted eyes (-0.37 ± 0.54 D, one-sample t-test, P = 0.004, 95% confidence interval: -0.61 to -0.14), while it was close to zero in emmetropia-targeted eyes. The mean absolute error was significantly smaller in emmetropia-targeted eyes (0.28 ± 0.27 D) than in myopia-targeted eyes (0.51 ± 0.41 D, P = 0.01). IA was revealed as the most accurate method for predicting postoperative refraction in eyes with emmetropia target, whereas Barrett Universal II formula was found to be the most accurate for eyes with myopia target. Conclusion: In patients with axial myopia, the performance of IA was altered when targeting intentional myopia compared with emmetropia. Myopic shift in the refractive outcome should be considered when IA is used to target myopia.

Difference between both eyes in the calculation of the dioptre power of the intraocular lens in a series of 7994 patients.

PURPOSE: To analyse the distribution of the difference between both eyes in the calculation of the dioptric power of the intraocular lens in a series of 7994 patients and the biometric variables that determine it. METHODS: The data of patients between 3 and 99 years old, residents of the city of Guayaquil and neighbouring sites, who received ocular biometry by partial optical coherence interferometry between 2004 and 2020 were reviewed. Ocular biometrics, including axial length (AL), anterior chamber depth (ACD), and the mean corneal dioptre power (CD), were measured by partial coherence interferometry. Refraction without or with cycloplegia was recorded in spherical equivalent (SE). The Haigis formula from the IOL Master instrument was used to calculate the dioptric power of the intraocular lens in both eyes. RESULTS: Data from the bilateral optical biometry of 7994 patients were analysed. The mean and standard deviation of AL, CD, ACD and dioptre power of the IOL were 23.66 ±â€¯1.25, 43.70 ±â€¯1.49, 3.34 ±â€¯0.40 and +20.46 ±â€¯3.84, respectively. 2538 (31.7%) patients had equal dioptre power of the IOL between both eyes. 3243 (40.6%) patients had a 0.50 D difference; 1162 (14.5%), 1.0 D; 425 (5.3%), 1.5 D. 626 patients (7.8%) had a difference in IOL dioptre of 2 D or more, with a maximum of 24 D. The asymmetry of AL between OU was ≥0.4 mm in 10.49%, while that of CD reached ≥1 D in 1.9%. CONCLUSIONS: 92.16% of patients had a difference within 1.5 D between both eyes in the calculation of the dioptre power of the intraocular lens. In case an eye is programmed in which it is impossible to perform a reliable biometry, either due to trauma or due to white or brunescent cataract, the calculation of the intraocular lens could be done taking as a reference the biometry of the contralateral eye.

Diferencia entre ambos ojos en el cálculo del poder dióptrico del lente intraocular en una serie de 7.994 pacientes / Difference between both eyes in the calculation of the dioptre power of the intraocular lens in a series of 7994 patients

Objetivo Analizar la distribución de la diferencia entre ambos ojos en el cálculo del poder dióptrico del lente intraocular (LIO) en una serie de 7.994 pacientes y las variables biométricas que la determinan. Métodos Se revisaron los datos de pacientes entre 3 y 99años, residentes en la ciudad de Guayaquil y sitios aledaños, que recibieron biometría ocular por interferometría de coherencia óptica parcial entre 2004 y 2020. La medición incluyó la longitud axial (LA), la profundidad de la cámara anterior (PCA) y la queratometría (Km) media. La refracción sin o con cicloplejia en dioptrías (D) fue registrada en equivalente esférico (EE). La fórmula de Haigis, incluida en el instrumento IOL Master, fue usada para realizar el cálculo del poder dióptrico del LIO en ambos ojos. Resultados Se analizaron los datos de la biometría óptica bilateral de 7.994 pacientes. El promedio y la desviación estándar de LA, Km, PCA y poder dióptrico del LIO fueron 23,66±1,25, 43,70±1,49, 3,34±0,40 y +20,46±3,84, respectivamente. Un total de 2.538 (31,7%) pacientes tuvieron igual poder dióptrico del LIO entre ambos ojos, y 3.243 (40,6%) pacientes tuvieron 0,50D de diferencia; 1,162 pacientes (14,5%), 1,0D; 425 pacientes (5,3%), 1,5D; 626 pacientes (7,8%) tuvieron una diferencia en el poder dióptrico del LIO de ≥2D, con un máximo de 24D. La asimetría de la LA entre ambos ojos fue ≥0,4mm en el 10,49%, mientras que el de la Km alcanzó ≥1D en 1,9%. Conclusiones El 92,2% de los pacientes tuvieron una diferencia dentro de 1,5D entre ambos ojos en el cálculo del poder dióptrico del LIO. En el caso de tratarse de un ojo en que resultara imposible realizar una biometría confiable, ya fuera por traumatismo o por catarata blanca o brunescente, el cálculo del LIO podría hacerse tomando como referencia la biometría del ojo contralateral (AU)

Purpose To analyse the distribution of the difference between both eyes in the calculation of the dioptric power of the intraocular lens in a series of 7994 patients and the biometric variables that determine it. Methods The data of patients between 3 and 99years old, residents of the city of Guayaquil and neighbouring sites, who received ocular biometry by partial optical coherence interferometry between 2004 and 2020 were reviewed. Ocular biometrics, including axial length (AL), anterior chamber depth (ACD), and the mean corneal dioptre power (CD), were measured by partial coherence interferometry. Refraction without or with cycloplegia was recorded in spherical equivalent (SE). The Haigis formula from the IOL Master instrument was used to calculate the dioptric power of the intraocular lens in both eyes. Results Data from the bilateral optical biometry of 7994 patients were analysed. The mean and standard deviation of AL, CD, ACD and dioptre power of the IOL were 23.66±1.25, 43.70±1.49, 3.34±0.40 and +20.46±3.84, respectively. 2538 (31.7%) patients had equal dioptre power of the IOL between both eyes. 3243 (40.6%) patients had a 0.50D difference; 1162 (14.5%), 1.0D; 425 (5.3%), 1.5D. 626 patients (7.8%) had a difference in IOL dioptre of 2D or more, with a maximum of 24D. The asymmetry of AL between OU was ≥0.4mm in 10.49%, while that of CD reached ≥1D in 1.9%. Conclusions 92.16% of patients had a difference within 1.5D between both eyes in the calculation of the dioptre power of the intraocular lens. In case an eye is programmed in which it is impossible to perform a reliable biometry, either due to trauma or due to white or brunescent cataract, the calculation of the intraocular lens could be done taking as a reference the biometry of the contralateral eye (AU)

Changes of ocular biometry in eyes with posterior chamber phakic intraocular lens implantation.

OBJECTIVE: To evaluate changes in biometric variables and intraocular lens (IOL) calculation results after posterior chamber phakic IOL (PCPIOL) implantation. METHODS: This retrospective, observational study included 65 eyes of 38 patients who underwent PCPIOL (EVO Visian ICL) implantation for correction of myopia. Prior to and a minimum of one year (mean 14.9 months) after EVO Visian ICL implantation, biometric variables and IOL calculation results were compared. Optical biometry, including anterior chamber depth, axial length, flat, steep, and mean keratometry values and IOL calculation results for the Holladay 2, Hoffer Q, Haigis, and SRK/T formulas were measured using the IOLMaster 700 SWEPT Source OCT biometer. MAIN RESULTS: The mean anterior chamber depth decreased from 3.70±0.22mm to 3.34±0.39mm, the mean axial length increased from 26.61±1.61mm to 26.71±1.66mm, and the mean flat keratometry changed from 42.82±1.86 D to 42.73±1.83 D. These changes were statistically significant. The mean IOL power calculation also revealed a statistically significant decrease with all four formulas (ranging from 0.19 D to 0.30 D) after PCPIOL implantation. CONCLUSIONS: Biometric variables and IOL calculation results showed statistically significant changes one year after EVO Visian ICL implantations. However, IOL power calculations yielded a decrease of less than 0.50 D, inducing much less refractive deviation in the spectacle plane; and the change was primarily related to an increase in AL measurements. IOL power calculations in eyes with EVO Visian ICL in situ provided satisfactory and reliable results.

Artificial intelligence applications and cataract management: A systematic review.

Artificial intelligence (AI)-based applications exhibit the potential to improve the quality and efficiency of patient care in different fields, including cataract management. A systematic review of the different applications of AI-based software on all aspects of a cataract patient's management, from diagnosis to follow-up, was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All selected articles were analyzed to assess the level of evidence according to the Oxford Centre for Evidence-Based Medicine 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation system. Of the articles analyzed, 49 met the inclusion criteria. No data synthesis was possible for the heterogeneity of available data and the design of the available studies. The AI-driven diagnosis seemed to be comparable and, in selected cases, to even exceed the accuracy of experienced clinicians in classifying disease, supporting the operating room scheduling, and intraoperative and postoperative management of complications. Considering the heterogeneity of data analyzed, however, further randomized controlled trials to assess the efficacy and safety of AI application in the management of cataract should be highly warranted.

Advances in intraocular lens power calculation formulas in high myopia / 中华实验眼科杂志

As the number of cataract patients with high myopia increases, and the cataract surgery shifts from a rehabilitation procedure to a refractive procedure, achieving a good postoperative visual acuity has been the target of cataract patients with high myopia.Because of inaccurate axial length measurement, unpredictable effective lens position and improper selection of intraocular lens (IOL) calculation formulas, the precision of refractive prediction in cataract patients with high myopia remains low, which affects the visual acuity and satisfaction of patients.With the development of IOL calculation formulas, SRK/T, Holladay1 and other thin-lens vergence formulas have been modified in axial length, corneal curvature and other parameters, and the thick-lens vergence formulas such as Barrett Universal Ⅱ have been widely put into use.Meanwhile, new formulas including artificial intelligence-based formulas such as Hill-RBF, ray tracing formulas such as Olsen and OKULIX, and theoretical formulas such as Kane and EVO formulas have been developed.More choices and guarantees are available for refractive prediction after cataract surgery.This paper summarized the optimization and advance of different types of IOL calculation formulas so as to provide different available choices to improve the accuracy of IOL power calculation in cataract patients with high myopia.

Comparación entre las fórmulas SRK/T, Hoffer Q, Barrett Universal y HRBF para el cálculo del lente intraocular / Comparison of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation

Objetivo: Comparar la exactitud de las fórmulas SRK/T, Hoffer Q, Barrett Universal y HRBF en el cálculo del lente intraocular. Métodos: Se realizó un estudio descriptivo longitudinal prospectivo de 70 ojos de 70 pacientes operados de cirugía de catarata con implante de lente intraocular, de junio del año 2018 a junio del 2019, utilizando el IOL Master 700, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Se determinó la exactitud de cada fórmula respecto al error de predicción del equivalente esférico y se compararon entre sí. Resultados: Los pacientes entre 60 y 80 años constituyeron el 70,00 por ciento de los casos y el sexo femenino representó el 61,43 por ciento. Los ojos de tamaño medio representaron el 91,43 por ciento del total. No hubo diferencias en el error de predicción absoluto medio entre de las fórmulas analizadas para el rango total de longitudes axiales. La fórmula de Barrett tuvo el 65,71 por ciento de ojos con un error de predicción dentro de ± 0,50 D. El mayor porcentaje de ojos con un error mayor a 1 dioptría recayó sobre la Hoffer Q (10,00 por ciento). Conclusiones: El grupo etario más representado está entre 60 y 80 años y el sexo femenino es mayoritario. Predominan los ojos de tamaño medio y las mensuraciones biométricas dentro de los valores promedio estándar. Las fórmulas HRBF, SRK/T, Hoffer Q y Barrett predicen el resultado refractivo posoperatorio con una exactitud similar para el rango total de longitudes axiales. La fórmula de Barrett logra el mayor porcentaje de ojos con errores de predicción posoperatorios dentro del rango de la emetropía(AU)

Objective: Compare the accuracy of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation. Methods: A prospective longitudinal descriptive study was conducted of 70 eyes of 70 patients undergoing cataract surgery with intraocular lens implantation from June 2018 to June 2019 at Ramón Pando Ferrer Cuban Institute of Ophthalmology. In all cases IOL Master 700 was used for lens calculation. Determination of the accuracy of each formula in error prediction of the spherical equivalent was followed by a comparison of the formulas. Results: Patients aged 60-80 years were 70.00 percent of the cases; female sex represented 61.43 percent. Medium sized eyes were 91.43 percent of the total eyes examined. Mean absolute prediction error did not show any difference between the formulas analyzed for the total range of axial lengths. The Barrett formula spotted 65.71 percent of the eyes with a prediction error within ± 0.50 D. The highest percentage of eyes with an error greater than 1 diopter corresponded to the Hoffer Q formula (10.00 percent ). Conclusions: The best represented age group was 60-80 years; female sex prevailed. A predominance was found of medium size and biometric measurements within standard mean values. The formulas HRBF, SRK/T, Hoffer Q and Barrett predict the postoperative refractive result with similar accuracy throughout the total range of axial lengths. The Barrett formula achieves the highest percentage of eyes with postoperative prediction errors within the range of emmetropia(AU)

Inter-device measurement variability of vital data parameters for keratorefractive and cataract refractive surgery.

INTRODUCTION: The measurements of corneal white-to-white (WTW) diameter and pupil size are critical for decision making in refractive surgery. Currently, automatic measurement of keratometry, corneal WTW, and pupil size are implemented in several ocular devices. The purpose of this study was to examine the agreement between two commonly used devices, an autorefractor and an optical biometer, for these parameters. METHODS: Measurements were performed with both a Lenstar LS-900 and Nidek ARK-1 by an experienced examiner in random order. The devices were placed in close proximity within the same dimly lit room. RESULTS: The measurements of 65 right eyes were analyzed. The results of the flat, steep, and mean keratometric reading were not significantly different (p = 0.96, p = 0.90, p = 0.93, respectively). Corneal WTW distances showed only moderate agreement between devices and were found to be significantly different (r = 0.8071; p < 0.01). Pupil diameters showed poor agreement between devices and were significantly different (r = 0.4890; p < 0.01). Agreement between implantable contact lens sizing, based on the measurements obtained by the two devices, was achieved for 19 of the 51 eyes (37.3%). CONCLUSION: We found a significant difference in WTW and pupil size measurements between ARK-1 and Lenstar. Results for both of the devices cannot be considered interchangeable for these data parameters.

EFFECT OF PHARMACOLOGICAL PUPIL DILATION ON INTRAOCULAR LENS POWER CALCULATION IN PATIENTS INDICATED FOR CATARACT SURGERY.

PURPOSE: To evaluate the influence of pupil dilation on ocular parameters measured by optical biometry and the influence of pupil dilation on intraocular lens (PC IOL) power calculation by using the third-generation (SRK/T) and the fourth-generation (Haigis) formula. METHODS: 40 eyes of patients indicated for cataract surgery were included in this study. Each patient was examined by optical biometer firstly without artificial mydriasis (AM) and then after AM, which was achieved using local application of short-term acting mydriatics. Biometric data were measured by Lenstar LS 900 optical biometer, we recorded axial length of the eye (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal astigmatism and optical power of cornea. These data we measured were used for calculation of the PC IOL optical power using both the SRK/T and the Haigis formula. The target postoperative refraction was set to emmetropia. Statistical analysis was performed for evaluation of influence of AM on each ocular parameter and influence of AM on the recommended PC IOL power calculated by the SRK/T and the Haigis formula. RESULTS: No statistically significant effect of AM on AL, LT and keratometry was demonstrated. On the contrary we demonstrated significant effect on CCT and ACD. No effect of AM on the PC IOL power calculation using the SRK/T formula was proved - the PC IOL optical power before AM and after AM did not differ in any case. When using the Haigis formula for the PC IOL power calculation, the recommended optical power of the PC IOL changed by +0.5 Dpt in 9 eyes, i.e., 22.5 % of the whole group, but statistical analysis did not show this change as statistically significant. CONCLUSION: Pharmacological dilation of the pupil significantly affects some intraocular parameters measured by optical biometer and in the case of using the Haigis formula it can influence recommended power of the PC IOL. Conversely, when using the SRK/T formula, pharmacological dilation of pupil does not affect the recommended PC IOL power.

Fórmula Barrett True K en pacientes con catarata operados de cirugía refractiva corneal / The Barrett True-K formula in cataract patients undergoing corneal refractive surgery

Objetivo: Determinar los resultados refractivos en pacientes operados de catarata con cirugía refractiva corneal, según el cálculo del poder dióptrico de la lente intraocular con la fórmula Barrett True K. Métodos: Se realizó un estudio pre-experimental, del tipo antes y después, en el cual fueron incluidos 18 pacientes (31 ojos). En ellos se analizaron variables demográficas y clínicas. La principal variable de salida fue la predictibilidad del componente esférico ± 0,50 D, ± 1,0 D según la longitud axial. Resultados: Fueron estudiados pacientes con un promedio de edad de 59,4 años, predominantemente del sexo femenino (66,7 por ciento). El 77,4 por ciento fue operado con queratotomía radial. Con la cirugía de catarata se produjo una mejora ostensible de la agudeza visual no corregida (mediana preoperatoria: 0,12 y mediana posoperatoria: 0,60). Solo el 9,7 por ciento de los ojos analizados presentó una agudeza visual sin corregir de 20/20 y el 90,3 por ciento de 20/40 o más. La cantidad de ojos con un equivalente esférico de ± 0,50 disminuyó en la medida en que aumentó la longitud axial (corta: 100 por ciento; normal: 57,1 por ciento; larga: 22,7 por ciento), no así la predictibilidad del componente esférico de ± 0,50, que aumentó (corta: 50,0 por ciento; normal: 57,1 por ciento; larga: 63,6 por ciento). Conclusiones: La fórmula Barrett True K resulta útil para el cálculo de la lente intraocular en pacientes operados de catarata y cirugía refractiva corneal previa(AU)

Objective: Determine refractive outcomes in patients undergoing cataract corneal refractive surgery based on intraocular lens dioptric power calculation with the Barrett True-K formula. Methods: A pre-experimental before/after study was conducted of 18 patients (31 eyes). Demographic and clinical variables were analyzed. The main output variable was spherical component predictability ± 0.50 D, ± 1.0 D according to axial length. Results: Mean age was 59.4 years; female sex prevailed (66.7 percent). Of the patients studied, 77.4 percent underwent radial keratotomy. Cataract surgery led to notable uncorrected visual acuity improvement (preoperative mean: 0.12; postoperative mean: 0.60). Only 9.7 percent of the eyes examined had an uncorrected visual acuity of 20/20, whereas 90.3 percent had 20/40 or more. The number of eyes with a spherical equivalent of ± 0.50 fell as axial length rose (near: 100 percent; normal: 57.1 percent; far: 22.7 percent), unlike ± 0.50 spherical component predictability, which rose from near: 50.0 percent; normal: 57.1 percent; far: 63.6 percent. Conclusions: The Barrett True-K formula is useful for intraocular lens calculation in patients undergoing previous cataract and corneal refractive surgery(AU)

Accuracy of intraocular lens calculation formulas for eyes with insufficient capsular support.

BACKGROUND: There is no consensus on which intraocular lens (IOL) power calculation formula provides the best refractive prediction in patients with inadequate capsular support whose anterior ocular anatomic structure differs from that of normal subjects. Therefore, the purpose of this study was to analyze the accuracy and performance of IOL calculation formulas (SRK/T, Holladay 1, Hoffer Q, Haigis, and Barrett Universal II) in predicting postoperative refractive prediction error (PE) for this subgroup of patients. METHODS: A total of 110 eyes from 110 patients with insufficient capsular support who underwent scleral fixation of an IOL at the Zhongshan Ophthalmic Center from July 1, 2016 to November 30, 2019 were enrolled in this retrospective study. Preoperative optical biometrics were measured with the IOL Master 500 (Carl Zeiss, Oberkochen, Germany). The performance of each formula in predicting PE was compared, and the effect of keratometry and axial length (AL) on PE was evaluated for each formula using univariate and multivariate linear regression analysis. RESULTS: The mean age of the included participants was 12.54±9.66 years. The Sanders, Retzlaff, and Manus/theoretical (SRK/T) (-0.25 D) and Holladay 1 (-0.28 D) formulas tended to have minimal postoperative PE compared to the Hoffer Q (-0.62 D), Haigis (-0.67 D), and Barrett Universal II (-0.62 D) formulas (P=0.005). All formulas individually resulted in <70% of eyes within ±1.00 D of the PE. Nevertheless, after constants were optimized, these formulas led to 7.3% to 13.6% of increase within ±1.00 D of the PE. Keratometry and AL were significantly associated with PE for each formula, but the relationship was weakest for SRK/T. CONCLUSIONS: In eyes with insufficient capsular support, postoperative PE was minimal for the SRK/T formula, which suggested SRK/T to be the best choice, especially when the keratometry and AL of patients are extremely large or small.

High Agreement between Barrett Universal II Calculations with and without Utilization of Optional Biometry Parameters.

PURPOSE: To examine the contribution of anterior chamber depth (ACD), lens thickness (LT), and white-to-white (WTW) measurements to intraocular lens (IOL) power calculations using the Barrett Universal II (BUII) formula. METHODS: Measurements taken with the IOLMaster 700 (Carl Zeiss, Meditec AG, Jena, Germany) swept-source biometry of 501 right eyes of 501 consecutive patients undergoing cataract extraction surgery between January 2019 and March 2020 were reviewed. IOL power was calculated using the BUII formula, first through the inclusion of all measured variables and then by using partial biometry data. For each calculation method, the IOL power targeting emmetropia was recorded and compared for the whole cohort and stratified by axial length (AL) of the measured eye. RESULTS: The mean IOL power calculated for the entire cohort using all available parameters was 19.50 ± 5.11 diopters (D). When comparing it to the results obtained by partial biometry data, the mean absolute difference ranged from 0.05 to 0.14 D; p < 0.001. The optional variables (ACD, LT, WTW) had the least effect in long eyes (AL ≥ 26 mm; mean absolute difference ranging from 0.02 to 0.07 D; p < 0.001), while the greatest effect in short eyes (AL ≤ 22 mm; mean absolute difference from 0.10 to 0.21 D; p < 0.001). The percentage of eyes with a mean absolute IOL dioptric power difference more than 0.25 D was the highest (32.0%) among the short AL group when using AL and keratometry values only. CONCLUSIONS: Using partial biometry data, the BUII formula in small eyes (AL ≤ 22 mm) resulted in a clinically significant difference in the calculated IOL power compared to the full biometry data. In contrast, the contribution of the optional parameters to the calculated IOL power was of little clinical importance in eyes with AL longer than 22 mm.