Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
What Is the Issue? A cataract is an opacity of the lens and is the leading cause of reversible visual impairment worldwide. There are no medical treatments for cataracts but surgical procedures that replace the lens with a synthetic lens (called an intraocular lens [IOL]) have shown to be effective for restoring vision. Premium lenses, including lenses to correct astigmatism (called toric lenses), are available but may not be covered by public or private health plans. Given that there is an increased cost associated with toric lenses, there is a need to evaluate their effectiveness compared to other available corrective options, including glasses. What Did We Do? To inform decisions about the appropriate use of astigmatism-correcting IOLs, CADTH sought to identify and summarize literature that evaluates the clinical effectiveness of toric lenses against other corrective options. An information specialist conducted a search of peer-reviewed and grey literature sources. One reviewer screened citations, and selected and critically appraised the included studies. What Did We Find? One systematic review (SR), 3 randomized controlled trials (RCTs), 1 prospective nonrandomized study, and 6 retrospective nonrandomized studies were identified that evaluated the clinical effectiveness of toric versus nontoric IOLs implanted during cataract surgery, including 1 with a pediatric focus. Toric IOLs may be better than nontoric IOLs for postoperative astigmatism, but this may be dependent on the measurement of astigmatism evaluated (e.g., corneal astigmatism, residual refractive astigmatism, subjective refraction astigmatism, autorefraction astigmatism, spherical equivalent astigmatism, cylinder astigmatism, surgically induced astigmatism). Toric IOLs may be better than nontoric IOLs for postoperative uncorrected visual acuity (VA), but it is unclear if this results in a clinically meaningful difference to the patient. None of the studies reported on spectacle independence. Patient-centred outcomes were seldomly reported across the studies, and rarely used validated tools, making it difficult to conclude if there were patient-centred outcome differences between toric and nontoric IOLs. Harms were reported across the studies through intraoperative complications, postoperative complications, and adverse events. Postoperative complications were statistically higher in the toric group in the SR, but there were not statistically significant differences in harms reported in the primary studies. What Does it Mean? It is difficult to draw conclusions across the studies and outcomes due to the variation in how outcomes were reported or because few studies report on these outcomes. A proposed minimum set of core outcomes for cataract surgery was published in 2015. The studies included in this report did not align with this minimum set of outcomes. For example, as VA is not synonymous with improved visual functioning for patients, evaluating patient-reported visual functioning with a patient-reported outcome measure (PROM) tool is part of the minimum set of core outcomes. Future research should incorporate core outcomes, including PROMs. Although toric IOLs statistically improved uncorrected VA, when compared to nontoric lenses, statistical significance does not imply a difference that is clinically meaningful to a patient.
What Is the Issue? A cataract is an opacity of the lens and is the leading cause of reversible visual impairment worldwide. There are no medical treatments for cataracts but surgical procedures that replace the lens with a synthetic lens (called an intraocular lens [IOL]) have shown to be effective for restoring vision. Premium lenses, including lenses to correct astigmatism (called toric lenses), are available but may not be covered by public or private health plans. Given that there is an increased cost associated with toric lenses, there is a need to evaluate their effectiveness compared to other available corrective options, including glasses. What Did We Do? To inform decisions about the appropriate use of astigmatism-correcting IOLs, CADTH sought to identify and summarize literature that evaluates the clinical effectiveness of toric lenses against other corrective options. An information specialist conducted a search of peer-reviewed and grey literature sources. One reviewer screened citations, and selected and critically appraised the included studies. What Did We Find? One systematic review (SR), 3 randomized controlled trials (RCTs), 1 prospective nonrandomized study, and 6 retrospective nonrandomized studies were identified that evaluated the clinical effectiveness of toric versus nontoric IOLs implanted during cataract surgery, including 1 with a pediatric focus. Toric IOLs may be better than nontoric IOLs for postoperative astigmatism, but this may be dependent on the measurement of astigmatism evaluated (e.g., corneal astigmatism, residual refractive astigmatism, subjective refraction astigmatism, autorefraction astigmatism, spherical equivalent astigmatism, cylinder astigmatism, surgically induced astigmatism). Toric IOLs may be better than nontoric IOLs for postoperative uncorrected visual acuity (VA), but it is unclear if this results in a clinically meaningful difference to the patient. None of the studies reported on spectacle independence. Patient-centred outcomes were seldomly reported across the studies, and rarely used validated tools, making it difficult to conclude if there were patient-centred outcome differences between toric and nontoric IOLs. Harms were reported across the studies through intraoperative complications, postoperative complications, and adverse events. Postoperative complications were statistically higher in the toric group in the SR, but there were not statistically significant differences in harms reported in the primary studies. What Does it Mean? It is difficult to draw conclusions across the studies and outcomes due to the variation in how outcomes were reported or because few studies report on these outcomes. A proposed minimum set of core outcomes for cataract surgery was published in 2015. The studies included in this report did not align with this minimum set of outcomes. For example, as VA is not synonymous with improved visual functioning for patients, evaluating patient-reported visual functioning with a patient-reported outcome measure (PROM) tool is part of the minimum set of core outcomes. Future research should incorporate core outcomes, including PROMs. Although toric IOLs statistically improved uncorrected VA, when compared to nontoric lenses, statistical significance does not imply a difference that is clinically meaningful to a patient.
Various novel intraocular lens (IOL) power calculation formulas have been described to increase refractive precision following cataract surgery. These include the Barrett Universal II, Emmetropia Verifying Optical (EVO), Kane, Naeser 2, Olsen, Panacea, Pearl DGS, Radial Basis Function (RBF), T2, and VRF formulas. With a few notable exceptions, historical and regression formulas—first- and second-generation IOL formulas like Sanders, Retzlaff, Kraff (SRK), Binkhorst, Hoffer, and SRKII—are generally regarded as outdated. The effective lens position (ELP) is accounted for in third- and fourth-generation formulas which include more biometric data. A possible alternative that has shown to be remarkably accurate when used with the Olsen method is ray tracing. Artificial intelligence-derived IOL formulas are becoming increasingly common and may yield better lens power prediction accuracy. Despite improvements in surgical technique, biometry measurements, and IOL calculations, some clinical circumstances continue to challenge cataract surgeons to determine the appropriate IOL power. These unique situations include pediatric eyes, post-refractive eyes, and corneal ectasias. The obstacles to reliability include unrepeatable measurements and inaccurate biometry examinations. Researchers have tried to identify the most accurate IOL estimations for these challenging clinical scenarios to overcome these obstacles.
Astigmatism, a prevalent refractive error caused by an irregular curvature of the cornea or lens, can significantly affect visual acuity and the quality of life. Correcting astigmatism during cataract surgery is essential for achieving optimal postoperative visual outcomes. This comprehensive review examines recent innovations in astigmatism correction methods and their impact on cataract surgery. It provides an in-depth analysis of advancements such as toric intraocular lenses (IOLs), femtosecond laser-assisted cataract surgery (FLACS), and new IOL technologies designed to address astigmatism with greater precision. The review also evaluates clinical outcomes, including visual acuity improvements, patient satisfaction, and safety considerations associated with these innovations. Additionally, it explores the cost-effectiveness of various techniques and highlights emerging trends and future directions in the field. By synthesizing current evidence, this review aims to offer valuable insights for clinicians and inform best practices in astigmatism management during cataract surgery.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.