Insights into the rotational stability of toric intraocular lens implantation: diagnostic approaches, influencing factors and intervention strategies.

Toric intraocular lenses (IOLs) have been developed to enhance visual acuity impaired by cataracts and correct corneal astigmatism. However, residual astigmatism caused by postoperative rotation of the toric IOL is an important factor affecting visual quality after implantation. To decrease the rotation of the toric IOL, significant advancements have been made in understanding the characteristics of toric IOL rotation, the factors influencing its postoperative rotation, as well as the development of various measurement techniques and interventions to address this issue. It has been established that factors such as the patient's preoperative refractive status, biological parameters, surgical techniques, postoperative care, and long-term management significantly impact the rotational stability of the toric IOL. Clinicians should adopt a personalized approach that considers these factors to minimize the risk of toric IOL rotation and ensure optimal outcomes for each patient. This article reviews the influence of various factors on toric IOL rotational stability. It discusses new challenges that may be encountered to reduce and intervene with rotation after toric IOL implantation in the foreseeable future.

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction.

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Descemet membrane endothelial keratoplasty combined with presbyopia-correcting and toric intraocular lenses - a narrative review.

Fuchs endothelial corneal dystrophy (FECD) is the leading indication for EK and may coexist with cataract and presbyopia. Notably, the outcomes of phacoemulsification in FECD patients are not as favorable as those in eyes without this condition. Historically, only monofocal intraocular lenses (IOLs) were recommended for these patients. However, recent reports have described the implantation of Premium-IOLs (such as Multifocal IOLs, Enhanced Depth of Focus IOLs, and Toric IOLs) in FECD eyes undergoing cataract surgery and Descemet membrane endothelial keratoplasty (DMEK). While the results are encouraging, they are not as optimal as those from unoperated eyes, especially when comparing simultaneous procedures to sequential ones. It's advised to perform the DMEK first to improve the accuracy of IOL calculations. Still, even successfully operated eyes may experience secondary graft failure or graft rejection after DMEK. The success rate of a secondary DMEK is typically lower than that of the initial procedure. Furthermore, if the postoperative thickness after DMEK is less than anticipated, laser enhancements might not be an option. There's a pressing need for more controlled and randomized clinical trials to ascertain the safety and effectiveness of Premium-IOLs for FECD eyes. This narrative review aims to collate evidence on the use of Premium IOL technologies in eyes receiving EK and to underscore key points for surgeons performing EK combined with cataract surgery.

Rotational stability of Toric intraocular lenses.

BACKGROUND: A prospective study to evaluate the rotational stability of toric intraocular lenses (IOLs). METHODS: A prospective study of 30 eyes in 29 patients. All patients with regular astigmatism of range 0.75-4 D were included in the study. Exclusion criteria included irregular corneal astigmatism, post-refractive surgery and corneal dystrophies. All patients underwent uncomplicated phacoemulsification cataract surgery by the same surgeon. Three eyes with corneal astigmatism of 0.75-1.5 D were implanted with the AcrySof SA60T3 IOL, eight eyes with astigmatism between 1.5 and 2.0 D received the SA60T4 IOL and eight eyes with astigmatism between 2.0 and 2.50 D received the SA60T5 and rest with astigmatism of 2.5 D and higher received SA60T6 and above models. Main outcome measure was the post-operative position of the lens, assessed at day 1, 1 week, 1 month and 6 months, using toric marker and the slit lamp. RESULTS: There was no significant rotation of IOL observed during a follow-up period of 6 months. Overall, the post-operative rotation was within 5° in 95% of cases. There was no trend for either clockwise or anti-clockwise rotation. However, IOL rotation happens mostly within the first month of surgery, and if it is significant, it requires early repositioning. CONCLUSION: Toric IOLs are very effective and consistent in correcting astigmatism during the cataract surgery. Once placed to its position, toric IOLs demonstrate rotational stability in the capsular bag.

The Castrop formula for calculation of toric intraocular lenses.

PURPOSE: To explain the concept behind the Castrop toric lens (tIOL) power calculation formula and demonstrate its application in clinical examples. METHODS: The Castrop vergence formula is based on a pseudophakic model eye with four refractive surfaces and three formula constants. All four surfaces (spectacle correction, corneal front and back surface, and toric lens implant) are expressed as spherocylindrical vergences. With tomographic data for the corneal front and back surface, these data are considered to define the thick lens model for the cornea exactly. With front surface data only, the back surface is defined from the front surface and a fixed ratio of radii and corneal thickness as preset. Spectacle correction can be predicted with an inverse calculation. RESULTS: Three clinical examples are presented to show the applicability of this calculation concept. In the 1st example, we derived the tIOL power for a spherocylindrical target refraction and corneal tomography data of corneal front and back surface. In the 2nd example, we calculated the tIOL power with keratometric data from corneal front surface measurements, and considered a surgically induced astigmatism and a correction for the corneal back surface astigmatism. In the 3rd example, we predicted the spherocylindrical power of spectacle refraction after implantation of any toric lens with an inverse calculation. CONCLUSIONS: The Castrop formula for toric lenses is a generalization of the Castrop formula based on spherocylindrical vergences. The application in clinical studies is needed to prove the potential of this new concept.

Astigmatism Management with Intraocular Lens Surgery.

Corneal astigmatism is common. More than 40% of patients undergoing cataract surgery have 1 diopter (D) power or more of astigmatism, which left untreated is visually significant. Because toric intraocular lenses (IOLs) are available, the current standard of care is to offer treatment of astigmatism at the time of cataract surgery. PubMed, MEDLINE, Embase databases, and the Cochrane Library were systematically searched from inception to October 2019. Search words included astigmatism, corneal astigmatism, toric IOLs, alignment, and IOL calculation. Studies evaluated included review articles regarding the origin and history of astigmatism, the diagnosis and management of the disease, and the history of surgical management options for astigmatism. Other studies evaluated in this review included clinical trials, meta-analyses, and retrospective analysis of surgical refractive outcomes. Prediction of refractive outcomes was evaluated with a review of IOL calculators and their use in lens prediction for cataract surgery. Evaluation of these articles also showed improved uncorrected visual acuity with the use of toric IOLs in patients undergoing cataract surgery. New diagnostic technology, new toric IOLs, updated lens formulas, intraoperative guidance, and advanced imaging technology and software have contributed to improvements in the surgical correction of astigmatism.

[Correction of corneal astigmatism in femtosecond laser-assisted cataract extraction surgery]. / Korrektsiya rogovichnogo astigmatizma pri femtolazer-assistirovannoi ekstraktsii katarakty.

PURPOSE: To perform a comparative analysis of clinical and functional results and efficiency of corneal astigmatism correction after femtosecond laser-assisted cataract surgery (FLACS) with implantation of toric intraocular lens (TIOL) and in combination with arcuate keratotomy (FL-AC). MATERIAL AND METHODS: The examination included 60 patients (60 eyes). The first group consisted of 30 patients (30 eyes) who underwent FLACS with implantation of TIOL (Acrysof IQ Toric, Alcon, U.S.A.); the second group consisted of 30 patients (30 eyes) who underwent FLACS in combination with FL-AC. The examination was carried out before the operation, on the 3rd day and 3 months after surgery. Corneal astigmatism correction efficiency was analyzed using the Alpins method and graphical vector analysis. RESULTS: Uncorrected visual acuity (UCVA) indices increased to 0.70±0.24 and 0.66±0.31 in the FLACS with TIOL and FLACS with FL-AC groups, respectively, without statistically significant differences between the groups (p=0.03). The value of the residual cylinder was significantly lower in the FLACS with TIOL group (-0.77±0.58 and -0.80±0.39) compared with FLACS with FL-AC (-1.08±0.81 and -1.18±0.63) both on day 3 (p=0.02), and 3 months after surgery (p=0.02). In the FLACS with TIOL group, a higher correction index (0.99±0.18) and a smaller difference vector (0.77±0.64) were achieved compared to the FLACS with FL-AC group (0.78±0.35 and 1.05±0.76, respectively). Corneal higher-order aberrations (HOA) significantly differed on the 3rd day after surgery in the 3.0 mm (p=0.04) and 5.0 mm (p=0.04) zones between the groups. Endothelial cells density was 2460.50±328.40 and 2526.125±196.74 cl/mm2 after 3 months of observation in the FLACS with TIOL and FLACS with FL-AC groups, respectively (p=0.61). CONCLUSION: Both methods had comparable visual acuity results (p=0.03). FLACS with TIOL provided more effective correction of the cylindrical component of refraction to 3.0 D.

Astigmatismo y cirugía de catarata / Astigmatism and cataract surgery

RESUMEN La catarata es la primera causa de ceguera curable en el mundo y se produce por la opacidad del cristalino, con una disminución gradual, lenta y progresiva de la agudeza visual. La cirugía para extraer el cristalino es la única forma de curar esta discapacidad visual. La facoemulsificación ha evolucionado con el fin de lograr su perfección y el objetivo de restablecer la visión de los pacientes con la mayor calidad y cantidad en el menor tiempo posible. El desarrollo científico ha estado encaminado a controlar o eliminar el astigmatismo preoperatorio o inducido por la cirugía, y para esto se ha incluido en la actualidad el empleo de los lentes intraoculares trifocales flexibles tóricos y las incisiones menores a dos milímetros en la córnea clara, así como las incisiones relajantes limbares, las incisiones opuestas en la córnea clara, la cirugía refractiva fotoablativa y el láser de femtosegundo. Para lograr un resultado refractivo en la cirugía de catarata es imprescindible minimizar al máximo el astigmatismo inducido por el procedimiento. Este éxito se logra con un estudio personalizado preoperatorio exhaustivo, que permita satisfacer las necesidades visuales del paciente y su reincorporación temprana a sus tareas. De ahí la motivación para realizar una búsqueda de los últimos diez años de diversos artículos publicados, con el objetivo de describir los principios para evaluar el astigmatismo medio inducido posterior a la cirugía del cristalino, y su repercusión en la calidad visual y de vida de los pacientes. Se utilizó la plataforma google, específicamente la Biblioteca Virtual de Salud, con todos sus buscadores(AU)

ABSTRACT Cataract is the leading cause of curable blindness worldwide. It results from opacity of the crystalline lens with gradual, slow and progressive visual acuity reduction. Surgery for removal of the crystalline lens is the only cure for this visual impairment. Phacoemulsification technique has evolved to achieve perfection and the aim of restoring patients' vision with the greatest quality and quantity in the shortest possible time. Scientific development has been aimed at either controlling or eliminating preoperative or surgically induced astigmatism. To achieve this aim, recent inclusion has been made of the use of flexible toric trifocal intraocular lenses and minor incisions at two millimeters in the clear cornea, as well as limbal relaxing incisions, opposite incisions in the clear cornea, photoablative refractive surgery and femtosecond laser. To obtain a good refractive result in cataract surgery it is indispensable to minimize the astigmatism induced by the procedure. Such success is accomplished through an exhaustive personalized preoperative study allowing to meet the visual needs of patients and their early reincorporation to daily activities. Hence the motivation to conduct a search of a variety of papers published in the last ten years with the purpose of describing the principles applied to evaluate mean induced astigmatism after crystalline lens surgery and its effect on the patients' visual acuity and quality of life. Use was made of the Google platform, particularly the Virtual Health Library with all its search engines(AU)

Evaluation of axis alignment and refractive results of toric phakic IOL using image-guided system.

AIM: To evaluate accuracy of axis alignment and refractive results of toric phakic intraocular lens (IOL) implantation using a digital imaging system. METHODS: This retrospective study investigated toric implantable collamer lens (ICL) implantation in 30 eyes of 21 patients with myopic astigmatism more than 2.0 D guided with digital imaging system. Data were collected during the first week after phakic IOL implantation. RESULTS: Thirty eyes of 21 patients were included in our study. Patients includes 9 males and 12 females. The mean age of the patients was 26.5±7.1 (range 21-44)y. The mean preoperative manifest astigmatism was 3.2±1.7 (range from 2.25 to 4.75) D. The mean postoperative uncorrected distance visual acuity (UCDVA) were 0.07±0.07 (range from 0.1 to 0.0) logMAR. The mean postoperative residual refractive cylinder was 0.25±0.29 (range 0-0.75) D. Eyes with postoperative residual refractive cylinder of 0.5 D or less represented 80% (24 eyes). The mean postoperative toric IOL misalignment measured by the OPD scan III was 1.9°±1.45° (range from 0 to 5°). CONCLUSION: Image guided system allows accurate alignment of toric ICL. This is associated with good postoperative visual acuity and low residual refractive astigmatism which correlates with the precision of toric phakic IOL alignment.

Comparison of Toric Intraocular Lens Alignment Using Image-Guided System and Manual Marking Technique.

OBJECTIVES: The aim of this study was to compare the accuracy of an image-guided system (Callisto eye; Carl Zeiss, Oberkochen, Germany) with the manual marking technique in the positioning of a toric intraocular lens (IOL). METHODS: A total of 80 eyes of 80 patients who underwent cataract surgery with a monofocal, single-piece, hydrophobic, biconvex, toric, aspheric IOL (Acrysof IQ SN6AT, Alcon Laboratories, Inc., Fort Worth, TX, USA) implantation were included. Before surgery, all of the patients underwent a complete eye examination that included evaluation of uncorrected (UCVA) and corrected distance visual acuity (CDVA), spherical equivalent (SE), astigmatic refraction (AR), keratometry, biometry, as well as meridian registration with the IOLMaster 700 (Carl Zeiss, Oberkochen, Germany), slit lamp examination, intraocular pressure measurement, and dilated retinal examination. The diopter of the toric IOL was calculated with an online calculator (Alcon, Fort Worth, TX, USA). At 3 months post surgery, the UCVA, CDVA, SE, and residual astigmatism were recorded, and the pupils of all of the patients were fully dilated to determine the toric IOL marker positions. RESULTS: Group 1, the Callisto eye system group, comprised 45 eyes, and Group 2, the manual marking technique group, was composed of 35 eyes. The preoperative values of both groups were statistically similar in terms of the SE, corneal cylinder, axial length, logMAR UDVA, and logMAR CDVA. At postoperative 3 months, there were no significant differences between the 2 groups in the logMAR UDVA, logMAR CDVA, degree of misalignment of toric IOL, or mean deviation from target-induced astigmatism values. The mean deviation degree from the intended axis was 2.04±1.84 in the Callisto eye system group (Group 1) and 3.24±2.64 in the manual marking technique group (Group 2). However, this difference did not have any effect on the logMAR UDVA. CONCLUSION: The image-guided markerless system was found to be as effective as manual marking in the positioning of toric IOLs.

Image-guided lens extraction surgery: a systematic review.

A systematic review of the recent literature regarding the current image-guided systems used for cataract surgery or refractive lens exchange was performed based on the PubMed and Google Scholar databases in March 2018. Literature review returned 21 eligible studies. These studies compared image-guided systems with other keratometric devices regarding their accuracy, repeatability and reproducibility in measurement of keratometric values, astigmatism magnitude and axis, as well as in IOL power calculation. Additionally, the image-guided systems were compared with conventional manual ink-marking techniques for the alignment of toric IOLs. In conclusion, image-guided systems seem to be an accurate and reliable technology with measurements of high repeatability and reproducibility regarding the keratometry and IOL power calculation, but not yet interchangeable with the current established and validated keratometric devices. However, they are superior over the conventional manual ink-marking techniques for toric IOL alignment.

Health policy regulations pertaining to advanced surgical devices-their socio-economic effects on ophthalmology practice.

The Israel Ministry of Health enacted regulations that aim to reduce private expenditure on healthcare services and mitigate social inequality. According to the modified rules, which went into effect in the second half of 2016, patients who undergo surgery in a private hospital and are covered by their healthcare provider's supplemental insurance (SI) make only a basic co-payment.The modified regulations limited the option of self-payment for advanced devices not covered by national health basket, meaning that patients for whom such devices are indicated had to pay privately for the entire procedure. These regulations applied to all medical and surgical devices not covered by national health insurance (NHI).Toric intraocular lenses (IOLs) are a case in point. These advanced lenses are implanted during cataract surgery to correct corneal astigmatism and, in indicated cases, obviate the need for complex eyeglasses postoperatively. Toric IOL implantation has been shown to be highly cost-effective in both economic and quality-of-life terms. Limitations of the use of these advanced IOLs threatened to increase social inequality.In 2017, further adjustments of the regulations were made which enabled supplemental charges for these advanced IOLs, performed through the SI programs of the healthcare medical organizations (HMOs). Allowing additional payment for these lenses at a fixed pre-set price made it possible to apply a supplemental part of the insurance package to the surgery itself. In mid 2018 these IOLs were included without budget in the national health basket, allowing for self-payment for the additional cost in addition to the basic coverage for all patients with NHI.This case study suggests that, in their efforts to enhance health care equity, policymakers may benefit if exercising due caution when limiting the extent to which SI programs can charge co-payments. This is because, when a service or product is not available via the basic NHI benefits package, limiting SI co-payments can sometimes result in a boomerang effect - leading to an increase in inequality rather than the sought-after decrease in inequality.

Comparative evaluation of two toric intraocular lenses for correcting astigmatism in patients undergoing phacoemulsification.

PURPOSE: To compare the efficacy of AT-TORBI plate haptic toric intraocular lens (IOL) (Carl Zeiss Meditec AG, Jena, Germany) and AcrySof loop haptic toric IOL (Alcon Laboratories, Inc., Fort Worth, TX, USA) for correcting preexisting astigmatism of ≥1 diopters (D) in patients undergoing phacoemulsification and to compare the rotational stability of these two toric IOLs. METHODS: In this prospective randomized controlled trial. Forty-two eyes of 42 cataract patients with preexisting astigmatism of 1 D or more were randomized to receive plate haptic toric (AT TORBI) or loop haptic toric (AcrySof) IOLs, with 21 in each group. Postoperative evaluation was done at day 1, 1 week, 1 month, and 3 months. Uncorrected distance visual acuity (UDVA), best corrected visual acuity (VA), and IOL position were noted in both the groups. RESULTS: At 3 months postoperatively, the mean log MAR UDVA was 0.23 ± 0.20 and 0.20 ± 0.13 in Groups I and II, respectively (P = 0.7), the mean residual cylindrical refractive error in plate haptic toric group was 0.40 ± 0.31 D and in loop haptic group was 0.45 ± 0.33 D (P = 0.64). The mean IOL rotation at 3 months follow-up in plate haptic group was found to be 3.52 ± 3.84° and in loop haptic group was 2.05 ± 2.56° (P = 0.25). CONCLUSION: Both types of toric IOLs were equally efficacious for attaining good uncorrected VA and correcting preexisting astigmatism between 1-5 D. Both of them were rotationally stable at 3 months follow-up.

Efficacy of Toric intraocular lens implantation in eyes with high myopia: A prospective, case-controlled observational study.

The present prospective clinical observational study aimed to evaluate the efficacy of Toric intraocular lenses (IOL) to achieve rotational stability and astigmatism correction in eyes with high myopia. A total of 27 consecutive cataract patients (39 eyes) with pre-existing corneal astigmatism (1.5-3.5 D) were divided into two groups according to their refractive status: One group of 18 eyes with high myopia -(12.5-6.0 D) and another group consisting of 21 eyes with emmetropia or low myopia (-3.0-0.0 D). All eyes underwent cataract phacoemulsification surgeries by the same surgeon, with the implantation of an AcrySof® Toric IOL at the pre-designed degree. Uncorrected visual acuity, best corrected visual acuity and phoropter examination results were recorded at the 1st day, 1st week, 1st month and 3rd month after the surgery. By analyzing digital images from slim-lamp photography with a self-designed software, the rotational stability was observed. The contrast sensitivity was also measured. No significant difference in the baseline and post-operative residual astigmatism was identified between the two groups (P>0.05). In addition, no significant difference in the degree of rotation was observed between the two groups. All patients had significantly improved visual quality after the surgery (P<0.05). In conclusion, the present study observed an equal astigmatism-correction efficiency and rotational stability in the two groups. A second auxiliary spot-penetrating incision, removal of visco-elastic substances and tight adherence of the IOL to the posterior capsular membrane are essential for a successful surgery.

[Predictability of residual astigmatism after implantation of posterior chamber toric lenses]. / Prognostizierbarkeit des Restastigmatismus nach torischer Hinterkammerlinsenimplantation.

BACKGROUND: The objective of the study was to examine the predictability of residual astigmatism after cataract surgery and implantation of the posterior chamber aspheric toric lens TECNIS® ZCT, Abott Medical Optic (Ettlingen, Deutschland). MATERIAL AND METHODS: The retrospective study included a total of 88 patient eyes undergoing a cataract operation with a toric lens implantation between March 2014 and October 2015. The inclusion criteria were a regular astigmatism of at least 0.75 dpt. Posterior chamber toric lenses (model Tecnis ZCT) were exclusively implanted. Post-surgery check-ups were performed after 1 day, 1 month and 2 months. Main study outcome was best-corrected visual acuity (BCVA), spherical and astigmatic aberration and the difference between expected and actual residual astigmatism after cataract surgery. RESULTS: The median reduction of corneal astigmatism was from -2.50 dpt (±1.06 dpt) to -0.75 dpt (±0.51 dpt) (p ≤ 0.05). The median BCVA increased from 0.37 logMAR (±0.25 logMAR) before surgery to 0.09 logMAR (±0.10 logMAR) after surgery. The spherical equivalent was reduced from +3.50 dpt (±1.11 dpt) (presurgery) to -0.56 dpt (±0.51 dpt) (postsurgery) in hyperopic patients and from -2.44 dpt (±3.03 dpt) to -0.69 dpt (±0.81 dpt) in myopic patients. By using the power vector analysis no significant deviation from the expected target values was observed; however, the median discrepancy between the expected and actual residual astigmatism was -0.50 dpt despite a surgical orientation of the intraocular lens (IOL) within 5° of the desired axis. The IOL showed a median rotation of 3.00° (±4.46°). CONCLUSION: Implantation of the aspheric toric intraocular lens Tecnis ZCT is a predictable, effective and reproducible tool in cataract surgery to account for regular corneal astigmatis; however, despite an optimal surgical orientation of the toric IOL, a small and rarely a large discrepancy might occur between expected and actual residual astigmatism.

Do evidence-based guidelines change clinical practice patterns?

In 2013, the Danish Health and Medicines Authorities published a National Clinical Guideline on the treatment of age-related cataracts. The guideline provided evidence-based recommendations on the indication for cataract surgery, cataract surgery in patients with age-related macular degeneration, on the use of toric intraocular lenses (IOLs) to correct preoperative corneal astigmatism, the use of intracameral and topical antibiotics to prevent endophthalmitis, choice of anti-inflammatory medication to control postoperative inflammation and prevent cystoid macular oedema, the use of immediate sequential bilateral cataract surgery and on the postoperative check-up of patients. A questionnaire was sent to all members of the Danish Ophthalmological Society before and after publication of the guideline. The responses showed that the guideline had changed practice patterns so that surgeons were more likely to prescribe non-steroidal anti-inflammatory eye drops and to not prescribe topical antibiotic eye drops after the guideline was published. Other parameters, most notably the use of toric IOLs and use of postoperative examinations were more guided by reimbursement standards than by evidence-based medicine. Thus, evidence-based guidelines do change practice patterns unless they are counteracted by the reimbursement system.

Correction of low corneal astigmatism in cataract surgery.

AIM: To evaluate and compare aspheric toric intraocular lens (IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions (LRI) to manage low corneal astigmatism (1.0-2.0 D) in cataract surgery. METHODS: A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes (102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III (Nidek Co, Japan). Follow-up lasted 6mo. RESULTS: The mean uncorrected distance visual acuity (UCVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group (P<0.01). No difference was observed in the postoperative endothelial cell count between the two groups. CONCLUSION: The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision.

Diagnóstico y control del astigmatismo en la cirugía del cristalino / Diagnosis and control of astigmatism in the crystalline surgery

Se realizó una revisión bibliográfica con el objetivo de conocer las opciones quirúrgicas para la corrección del astigmatismo preoperatorio y posoperatorio en la cirugía de catarata. Fueron abordados tópicos como los estudios preoperatorios detallados que nos permiten realizar una planificación quirúrgica personalizada, así como las diferentes soluciones quirúrgicas actuales, tanto las incisiones anastigmáticas en la facoemulsificación, como las incisiones relajantes limbares combinadas o no con las lentes intraoculares tóricas y los procederes con excímer láser. Se consultaron investigaciones que abarcan varios años hasta el presente para conocer los diferentes resultados de la utilización de estos procederes quirúrgicos hasta llegar a técnicas más novedosas en estudio como el láser femtosecond y las lentes intraoculares ajustables con la luz. Todo esto puede maximizar la corrección refractiva total y lograr en el paciente una óptima calidad visual y una mejor calidad de vida. La corrección refractiva total no es fácil de lograr; no obstante, es posible y debe ser la meta de cada cirujano de catarata(AU)

The present literature review was aimed at finding out the surgical options for the preoperative and postoperative correction of astigmatism in the cataract surgery. The addressed topics were detailed preoperative studies that allow customized surgical planning as well as several current solutions including anartigmatic incisions in phacoemulsification and relaxing limbal incisions either combined or not and Excimer laser procedures. Several research studies comprising various years up to the present were consulted to learn about different results from the use of these surgical methods as well as the most state-of-the-art techniques under study such as fentosecond laser and light-adjustable intraocular lenses. All this may maximize the total refractive correction and achieve optimal visual quality and better quality of life for the patient. It is not easy to reach complete refractive correction but it is possible and should be the goal to be accomplished by every cataract surgeon(AU)

Diagnóstico y control del astigmatismo en la cirugía del cristalino / Diagnosis and control of astigmatism in the crystalline surgery

Se realizó una revisión bibliográfica con el objetivo de conocer las opciones quirúrgicas para la corrección del astigmatismo preoperatorio y posoperatorio en la cirugía de catarata. Fueron abordados tópicos como los estudios preoperatorios detallados que nos permiten realizar una planificación quirúrgica personalizada, así como las diferentes soluciones quirúrgicas actuales, tanto las incisiones anastigmáticas en la facoemulsificación, como las incisiones relajantes limbares combinadas o no con las lentes intraoculares tóricas y los procederes con excímer láser. Se consultaron investigaciones que abarcan varios años hasta el presente para conocer los diferentes resultados de la utilización de estos procederes quirúrgicos hasta llegar a técnicas más novedosas en estudio como el láser femtosecond y las lentes intraoculares ajustables con la luz. Todo esto puede maximizar la corrección refractiva total y lograr en el paciente una óptima calidad visual y una mejor calidad de vida. La corrección refractiva total no es fácil de lograr; no obstante, es posible y debe ser la meta de cada cirujano de catarata(AU)

The present literature review was aimed at finding out the surgical options for the preoperative and postoperative correction of astigmatism in the cataract surgery. The addressed topics were detailed preoperative studies that allow customized surgical planning as well as several current solutions including anartigmatic incisions in phacoemulsification and relaxing limbal incisions either combined or not and Excimer laser procedures. Several research studies comprising various years up to the present were consulted to learn about different results from the use of these surgical methods as well as the most state-of-the-art techniques under study such as fentosecond laser and light-adjustable intraocular lenses. All this may maximize the total refractive correction and achieve optimal visual quality and better quality of life for the patient. It is not easy to reach complete refractive correction but it is possible and should be the goal to be accomplished by every cataract surgeon(AU)

Surgical management of astigmatism with toric intraocular lenses / Uso de lentes intraoculares tóricas no tratamento cirúrgico de astigmatismo

Correction of corneal astigmatism is a key element of cataract surgery, since post-surgical residual astigmatism can compromise the patient's uncorrected visual acuity. Toric intraocular lenses (IOLs) compensate for corneal astigmatism at the time of surgery, correcting ocular astigmatism. They are a predictable treatment. However, accurate measurement of corneal astigmatism is mandatory for choosing the correct toric IOL power and for planning optimal alignment. When calculating the power of toric IOLs, it is important to consider anterior and posterior corneal astigmatism, along with the surgically induced astigmatism. Accurate toric lens alignment along the calculated meridian is also crucial to achieve effective astigmatism correction. There are several techniques to guide IOL alignment, including the traditional manual marking technique and automated systems based on anatomic and topographic landmarks. The aim of this review is to provide an overview on astigmatism management with toric IOLs, including relevant patient selection criteria, corneal astigmatism measurement, toric IOL power calculation, toric IOL alignment, clinical outcomes and complications.

O tratamento do astigmatismo corneal é um fator importante na cirurgia de catarata, uma vez que o astigmatismo residual pode comprometer a acuidade visual não corrigida do paciente após a cirurgia. Lentes intraoculares (LIOs) tóricas compensam o astigmatismo corneal no momento da cirurgia, corrigindo o astigmatismo ocular. Ademais, constituem um tratamento previsível. Entretanto, é necessário obter uma medida precisa do astigmatismo corneal para selecionar o poder correto da LIO tórica e para planejar o melhor alinhamento da mesma. No cálculo do poder da LIO tórica, é importante considerar o astigmatismo das superfícies anterior e posterior da córnea, além do astigmatismo induzido na cirurgia. O alinhamento da lente tórica no meridiano planejado é essencial para se obter uma correção efetiva do astigmatismo. Há várias técnicas para guiar o alinhamento da LIO, incluindo a técnica de marcação manual tradicional e sistemas que se baseiam em pontos de referência anatômicos e topográficos. O objetivo desse artigo de revisão é discutir o uso de LIOs tóricas no tratamento de astigmatismo corneal, incluindo os critérios de seleção dos pacientes, a medida do astigmatismo corneal, o cálculo do poder da LIO tórica, o alinhamento da LIO tórica, os resultados clínicos e as complicações.