Equivalence of two optical quality metrics to predict the visual acuity of multifocal pseudophakic patients

This article studies the relationship between two metrics, the area under the modulation transfer function (MTFa) and the energy efficiency (EE), and their ability to predict the visual quality of patients implanted with multifocal intraocular lenses (IOLs). The optical quality of IOLs is assessed in vitro using two metrics, the MTFa and EE. We measured them for three different multifocal IOLs with parabolic phase profile using image formation, through-focus (TF) scanning, three R, G, B wavelengths, and two pupils. We analyzed the correlation between MTFa and EE. In parallel, clinical defocus curves of visual acuity (VA) were measured and averaged from sets of patients implanted with the same IOLs. An excellent linear correlation was found between the MTFa and EE for the considered IOLs, wavelengths and pupils (R2 > 0.9). We computed the polychromatic TF-MTFa, TF-EE, and derived mathematical relationships between each metrics and clinical average VA. MTFa and EE proved to be equivalent metrics to characterize the optical quality of the studied multifocal IOLs and also in terms of clinical VA predictability

Visual acuity of pseudophakic patients predicted from in-vitro measurements of intraocular lenses with different design

The optical quality of a set of IOLs (modeling set: one monofocal and two bifocals) was assessed through focus by the area under the modulation transfer function (MTFa) metric and related to the visual acuity (VA) defocus curves of pseudophakic patients implanted with said IOLs. A non-linear relationship between the MTFa and clinical VA was obtained with an asymptotic limit found to be the best VA achievable by the patients. Two mathematical fitting functions between clinical VA and MTFa were derived with high correlation coefficients (R-2 >= 0.85). They were applied to the MTFa obtained from a different set of IOLs with advanced designs (trial set: one extended range of vision -ERV-, one trifocal ERV and one trifocal apodized) to predict VA versus defocus of patients implanted with these IOLs. Differences between the calculated VA and the clinical VA for both fitting models were within the standard deviation of the clinical measurements in the range of -3.00 D to 0.00 D defocus. thus proving the suitability of the MTFa metric to predict clinical VA performance of new IOL designs. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Visual acuity of pseudophakic patients predicted from in-vitro measurements of intraocular lenses with different design

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Comparison of visual and optical quality of monofocal versus multifocal intraocular lenses

Objective: To compare visual quality in patients implanted with Tecnis ® monofocal (ZCB00) and multifocal (ZMB00) intraocular lenses taking into account their optical quality measured in vitro with an eye model. Methods: In total, 122 patients participated in this study: 44 implanted with monofocal and 78 with multifocal intraocular lenses. Measurements of visual acuity and contrast sensitivity were performed. The optical quality of the intraocular lenses was evaluated in three image planes (distance, intermediate and near) using an eye model on a test bench. The metric considered was the area under the curve of the modulation transfer function. Results: Optical quality at the far focus of the monofocal intraocular lens (area under the curve of the modulation transfer function = 66.97) was considerably better than that with the multifocal lens (area under the curve of the modulation transfer function = 32.54). However, no significant differences were observed between groups at the distance-corrected visual acuity. Distance-corrected near vision was better in the multifocal (0.15 ± 0.20 logMAR) than that in the monofocal group (0.43 ± 0.21 logMAR, p < 0.001), which correlated with the better optical quality at near reached by the multifocal intraocular lens (area under the curve of the modulation transfer function = 29.11) in comparison with the monofocal intraocular lens (area under the curve of the modulation transfer function = 5.0). In intermediate vision, visual acuity was 0.28 ± 0.16 logMAR (multifocal) and 0.36 ± 0.14 logMAR (monofocal) with p = 0.014, also in good agreement with the values measured in the optical quality (area under the curve of the modulation transfer function = 10.69 (multifocal) and 8.86 (monofocal)). The contrast sensitivity was similar in almost all frequencies. Pelli–Robson was slightly better in the monofocal (1.73) than in the multifocal group (1.64; p = 0.023). Conclusion: Patients implanted with multifocal ZMB00 achieved a distance visual acuity similar to those implanted with monofocal ZCB00, but showed significantly better intermediate and near visual acuity. A correlation was found between intraocular lenses’ optical quality and patients’ visual acuity. Contrast sensitivity was very similar between the multifocal and monofocal groups

Efectos de la exposición prenatal a alcohol, tabaco y otras drogas de abuso sobre el desarrollo retiniano

Objetivo Evaluar la estructura retiniana mediante tomografía de coherencia óptica (OCT) en niños con antecedentes de exposición prenatal a tóxicos. Métodos Se exploraron 49 niños expuestos a tóxicos prenatalmente, de edades comprendidas entre 5 y 18 años. De ellos, 25 tenían antecedentes de exposición prenatal a tabaco, 20 fueron expuestos durante el embarazo a alcohol y 4 a otras drogas de abuso. Todos los niños fueron sometidos a una exploración oftalmológica completa incluyendo la realización de una OCT. Se realizó una comparación frente a un grupo control, pareado por edad, de 25 niños con embarazos controlados sin exposición a tóxicos. Resultados Los niños expuestos prenatalmente a tóxicos presentan una reducción significativa del espesor medio de la capa de fibras nerviosas de la retina (CFNR) en comparación con los no expuestos (81, 5 vs. 99, 7; p < 0, 005), así como de sus cuatro cuadrantes (CFNR superior: 97, 5 vs. 127, 5; p < 0, 005; CFNR nasal: 61, 5 vs. 72, 3; p = 0, 005; CFNR inferior: 99, 8 vs. 128, 6; p< 0, 005, CFNR temporal: 58, 3 vs. 68, 2; p < 0, 005). También se objetivó una disminución significativa en el espesor medio de la capa de células ganglionares (72, 9 vs. 85, 9; p < 0, 005). De las diferentes exposiciones prenatales estudiadas, en los niños expuestos a drogas de abuso se encontró la mayor disminución en el grosor de CFNR (CFNR espesor medio = 72), seguidos de los expuestos a alcohol (CFNR espesor medio = 72, 9) y, en tercer lugar, el grupo de expuestos a tabaco durante el embarazo (CFNR espesor medio = 94, 6). Conclusiones La exposición a tóxicos durante la gestación interfiere en el desarrollo de la retina. Estos resultados refuerzan la evidencia de las recomendaciones acerca de evitar el consumo de cualquier tipo de tóxicos durante el embarazo. Purpose: To assess structural changes in the retina using optical coherence tomography (OCT) in children prenatally exposed to toxic substances. Methods: The study included a total of 49 infants, aged between 5 and 18 years, exposed to toxic substances during pregnancy. Among the exposed children, 25 were exposed to tobacco, 20 were exposed to alcohol, and 4 children were exposed to other drugs of abuse. All children underwent a complete ophthalmology examination, including an OCT. The results were compared against a control group composed of 25 infants, age matched with controlled pregnancy, and not exposed to toxic substances. Results: Children prenatally exposed to toxic substances showed significantly thinner average retinal nerve fibre layer (RNFL) compared with control children (81.5 vs. 99.7 µm; P <.005), as well as RNFL thinning in its four quadrants (superior RNFL: 97.5 vs. 127.5 µm; P <.005; nasal RNFL: 61.5 vs. 72.3 µm; P <.005; inferior RNFL: 99.8 vs. 128.6 µm; P <.005, temporal RNFL: 58.3 vs. 68.2 µm; P <.005). Exposed children also exhibited a thinner ganglion cell layer (72.9 vs. 85.9; P <.005). Greater RNFL thinning was observed in children exposed to drugs of abuse (RNFL thinner average = 72), followed by children exposed to alcohol (RNFL thinner average = 72.9), and finally the least affected were those children exposed to tobacco during pregnancy (RNFL = 94.6). Conclusion: Toxic substances during pregnancy interfere in retinal development. These results strengthen the evidence about the avoidance of any toxic substance during pregnancy

Influence of ocular biometric factors on the defocus curve in an enlarged depth-of-focus intraocular lens

Background: To assess the influence of biometric measurements on the defocus curve after the implantation of enlarged depth-of-focus (EDoF) intraocular lens (IOL). Methods: Patients who underwent cataract surgery with bilateral implantation of Tecnis Symfony IOL were enrolled. Preoperatively, axial length (AL), corneal keratometry (K), pupil size and corneal aberrations were measured. 1 month after surgery, distance, intermediate, and near visual acuities (VA) were recorded. At 3 months, monocular and binocular corrected contrast sensitivities under photopic and mesopic lighting conditions were measured with CSV-1000E test. At 6-months, the defocus curve between −5.00 to + 3.00 diopters (D) was assessed in steps of 0.50 D, and NEI-RQL-42 questionnaire was administered. Results: One hundred thirty one eyes of 66 patients were included. Binocular logMAR VA better than 0.1 for intermediate vision was obtained in 90% of patients, whereas only 17.7% obtained that result in near vision. The rate of satisfaction was high (96%) and most of them (85.5%) had no or little difficulties in near vision. The mean amplitude of the defocus curve was 2.35D ± 0.73D, and smaller AL, smaller pupils, younger age, and male sex were associated with wider range of clear vision. Conclusions: Tecnis Symfony IOL enables functional vision at all distances, but demographic variables and preoperative biometric measurements like AL and pupil size influence the postoperative amplitude of the defocus curve. These parameters could be used to predict the performance of EDoF IOLs

Influence of cardiovascular condition on retinal and retinal nerve fiber layer measurements

Objective To assess changes in the retinal nerve fiber layer (RNFL) and macula in subjects with cardiovascular risk factors or subclinical ischemia. Design Prospective and observational study. Methods A total of 152 healthy men underwent cardiovascular examination, including quantification of subclinical atheroma plaques by artery ultrasound scans, blood analysis, and a complete ophthalmic evaluation, including spectral-domain optical coherence tomography. The variables registered in cardiovascular examination were quantification of classic major risk factors, subclinical atheroma plaques by artery ultrasound scans, and analytical records. The ophthalmic evaluation registered RNFL and macular thickness. Results Mean subject age was 51.27±3.71 years. The 40 subjects without classic cardiovascular risk factors did not show differences in RNFL and macular thicknesses compared with the 112 subjects with at least one risk factor (except in sector 9 that showed higher thicknesses in subjects with 1 risk factor). Comparison between the group of subjects with and without atheroma plaques revealed no differences in RNFL and macular thicknesses. The sub-analysis of subjects with subclinical atheroma plaques in the common carotid artery revealed a significant reduction in central macular thickness in the left eye compared with the right eye (p = 0.016), RNFL in the superior quadrant (p = 0.007), and the 11 o’clock sector (p = 0.020). Comparison between smokers and nonsmokers revealed that smokers had significant thinning of the central macular thickness (p = 0.034), the nasal RNFL quadrant (p = 0.006), and the 3 and 5 o’clock sectors (p = 0.016 and 0.009). Conclusions Classic cardiovascular risk factors do not cause RNFL or macular thickness reduction, but tobacco smoking habit reduces nasal RNFL thickness. Subclinical atherosclerosis in the common carotid artery associates a reduction in central macular and nasal RNFL quadrant thicknesses in the left eye compared with the right eye

Comparison of visual and optical quality of monofocal versus multifocal intraocular lenses

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