Toric Intraocular Lens Research Articles

Accuracy of the Goggin Nomogram for 0.50 D Steps in Toric IOL Cylinder Power Calculation.

To examine the accuracy of the cylinder power choice for toric intraocular lenses (IOLs) using the Goggin Nomogram, which adjusts anterior keratometric astigmatic power values for the likely effect of posterior corneal and non-corneal, non-lenticular astigmatism. A consecutive, retrospective case series was based at the Queen Elizabeth Hospital and Ashford Advanced Eye Care in Adelaide, Australia. A total of 586 consecutive eyes of 586 patients underwent phacoemulsification surgery with implantation of a Zeiss AT TORBI 709MP or AT LISA Tri Toric 939 MP toric IOL, calculated using the Goggin Nomogram. The median absolute magnitude of error and geometric mean astigmatic correction index in consecutive eyes with toric IOL cylinder powers of 1.00 to 3.00 diopters (D) were analyzed. Overall, all eyes receiving IOL cylinder powers of 1.00 to 3.00 D inclusive had a median magnitude of error value of 0.19 D (IQR: 0.31) and astigmatic correction index value of 1.03 (IQR: 0.33). For eyes with with-the-rule, against-the-rule, and oblique astigmatism, the median magnitude of error was 0.18 D (interquartile range [IQR]: 0.29), 0.19 D (IQR: 0.31), and 0.17 D (IQR: 0.39), respectively, and the astigmatic correction index was 1.06 (IQR: 0.28), 1.01 (IQR: 0.35) and 1.08 (IQR: 0.32), respectively. Goggin Nomogram adjusted keratometry provided optimal refractive astigmatic outcome in IOL cylinder powers of 1.00 to 3.00 D in eyes with with-the-rule, against-the-rule, and oblique astigmatism. Goggin Nomogram adjusted keratometry compensates for both posterior corneal astigmatism and any other source of ocular astigmatism. [J Refract Surg. 2022;38(5):298-303.].

Refractive Outcomes of Non-Toric and Toric Intraocular Lenses in Mild, Moderate and Advanced Keratoconus: A Systematic Review and Meta-Analysis.

Background: To perform a systematic review and meta-analysis of the refractive outcomes of non-toric and toric intraocular lenses (IOLs) in keratoconus (KC) using different IOL power calculation formulas. Methods: A systematic search was conducted to identify studies that report on refractive outcomes of different IOL power calculation formulas in KC patients undergoing cataract surgery. Inclusion criteria were primary posterior chamber non-toric and toric monofocal intraocular lens implantation, data on the degree of KC, explicit mention of the formula used for each stage of KC, and the number of eyes in each category. We calculated and compared the absolute and mean prediction errors, percentage of eyes within 0.5 D and 1 D from target, and the weighted absolute prediction errors of IOL formulas, all were given for KC degrees I–III. Results: The bibliographic search yielded 582 studies published between 1996 and 2020, 14 of which (in total 456 eyes) met the criteria: three studies on non-toric IOL (98 eyes), eight studies on toric IOLs (98 eyes) and three studies of unknown separation between non-toric and toric IOLs (260 eyes). The lowest absolute prediction error (APE) for mild, moderate, and advanced KC was seen with Kane’s IOL power formula with keratoconus adjustment. The APE for the top five IOL power formulas ranged 0.49–0.73 diopters (D) for mild (83–94%) of eyes within 1 D from the target), 1.08–1.21 D for moderate (51–57% within 1 D), and 1.44–2.86 D for advanced KC (12–48% within 1 D). Conclusions: Cataract surgery in eyes with mild-to-moderate KC generally achieves satisfactory postoperative refractive results. In patients with advanced KC, a minority of the eyes achieved spherical equivalent refraction within 1 D from the target. The Kane’s formula with keratoconus adjustment showed the best results in all KC stages.

Tilt and decentration with various intraocular lenses: A narrative review.

We find that tilt and decentration of intraocular lens (IOL) commonly cause visual quality deterioration after cataract surgery. Multiple factors affect IOL tilt and decentration in the pre-, mid-, and post-operation phases. Moreover, the tilt and decentration of 1-piece IOL are less correlated with internal ocular HOAs than those of 3-piece IOL. Aspherical IOLs are more sensitive to decentration or tilt than spherical IOLs. Furthermore, the optical performance of toric IOLs with an accurate axis remains stable irrespective of tilt and decentration. The optical quality of asymmetric multifocal IOLs varies significantly after decentration and tilt in different directions. The image quality enhances or deteriorates in the direction of the decentered IOL. An extended depth of focus IOL can achieve good visual acuity in the distant, intermediate, and near range. Additionally, its tilt and decentration have less impact on the vision than bifocal and trifocal IOL. This is the first review that compares the effect of IOL tilt and decentration on image quality for various IOL designs. The result indicates that a deeper understanding of tilt and decentration of various IOLs can help achieve a better visual effect to visually improve refractive cataract surgery.

Factors associated with corneal astigmatism change after ptosis surgery.

To evaluate the predictive factors of postoperative corneal astigmatism change in ptosis patients who underwent ptosis surgical repair. Patients who underwent levator resection at Oculoplastic service of the Department of Ophthalmology, Naresuan University Hospital, Thailand between September 2017 and August 2019 were retrospectively evaluated. Changes in degree and axis of corneal astigmatism after ptosis surgery were compared based on patient factors consisting of age at operation, sex, preoperative margin-reflex distance (MRD) 1, and preoperative degree and axis of corneal astigmatism. Forty-two eyes of 28 patients were included in the study. Wilcoxon signed ranks test showed a significant postoperative corneal astigmatism change only in a subgroup of eyes with preoperative astigmatism of ≥1.5 diopters (D; P=0.006). Furthermore, 72.2% (13/18) of the eyes with preoperative astigmatism of ≥1.5 D showed a reduction of astigmatism after eyelid surgery, with the mean astigmatic change of 0.65 D. Majority of preoperative eyes demonstrated with-the-rule astigmatism pattern (45.2%), of which 57.9% showed a reduced degree of astigmatism. In patients undergoing ptosis surgery, the data demonstrate for the first time the association between postoperative corneal astigmatism change and a preoperative corneal astigmatism of ≥1.5 D. Thus, we encourage considering severity of corneal astigmatism prior to cataract or refractive surgery planning in ptosis patients, especially with toric-intraocular lens, to avoid the possibility of calculation error.

Хирургический подход к лечению аметропии у пациентов с кератоконусом и катарактой

Purpose. To develop a two-stage surgical technique to the treatment of ametropia in patients with keratoconus and concomitant cataract. Material and methods. 33 patients (35 eyes) with stages II–III of non-progressive keratoconus and concomitant cataracts of various stages of maturity were operated on. The average age of the patients was 46.5±2.7 (41–63). The operations were performed according to our proposed two-stage method of treating ametropia in patients with KC and cataracts (Patent of the Russian Federation No. 2748634 of 28.05.2021). The first stage was the implantation of FE RRARA intrastromal corneal ring segments (ICRS) with thickness from 150 to 350 µm. To correct residual refractive error in 5–7 months after the 1st stage, patients underwent stage 2: cloudy lens was removed and replaced with toric posterior chamber intraocular lens (TIOL) – AcrySof IQ Toric (Alcon, USA), T-flex Toric RayOne (Rayner, UK). Results. After the first stage of the operation (ICRS implantation), the uncorrected visual acuity (NCVA) was 0.2±0.03, the best corrected visual acuity (BCVA) was 0.4±0.02. In 1 month after the 2nd stage (phacoemulsification + TIOL) NCVA was 0.64±0.11 and BCVA was 0.74±0.12. During the entire follow-up period after the surgery visual functions, refraction, and rotational stability of TIOL were stable. Conclusion. Conducting a two-stage surgical intervention in patients with keratoconus and cataracts allows to stop the progression of the disease and effectively correct the ametropia concomitant with keratoconus. Key words: keratoconus, cataract, intracorneal segments, ametropia, toric intraocular lenses

Comparison of Visual Outcomes Between Toric Intraocular Lenses and Clear Corneal Incisions to Correct Astigmatism in Image-Guided Cataract Surgery.

PurposeTo compare the astigmatism correction effects of toric intraocular lenses (IOL) and clear corneal incisions during image-guided cataract surgery.MethodsAll patients with regular corneal astigmatism of 0.75–1.5 D underwent cataract surgery and astigmatism correction using the Callisto eye image-guided system. One group had implantation of an AcrySof toric IOL. Another group had implantation of aspheric IOL with 3.0 mm single clear corneal incision (SCCI) on the steep axis. Uncorrected and best-corrected spectacle visual acuity, refraction, and toric IOL axis were evaluated at 1, 4, and 12 weeks postoperatively.ResultsSixty-eight eyes of 68 patients were included. The mean residual refractive cylinder was 0.34 ± 0.40 D in the toric group and 0.64 ± 0.57 D in the SCCI group. There were no significant differences in residual refractive cylinder, spherical equivalent, uncorrected distance visual acuity (UDVA), and best-corrected spectacle visual acuity (BCSVA) between groups. The percentage of the residual cylinder within ± 0.50 D was 75 and 56% for toric and SCCI cases, respectively (p > 0.1). The mean surgical induced astigmatism vector was 0.61 ± 0.29 D in the SCCI group and 1.04 ± 0.38 D in the toric group. The mean magnitude of error was negative (−0.54 ± 0.48 D) and the correction index was <1.0 (p < 0.05) in SCCI group. At 3 months, all toric IOL alignment errors were within 5 degrees from the intended axis.ConclusionsBoth toric IOL and SCCI can correct low and medium astigmatism effectively with the help of a precise image-guided system.

Comment on: Laser corneal enhancement after trifocal intraocular lens implantation in eyes that had previously undergone photoablative corneal refractive surgery.

We congratulate Mayordomo-Cerdá et al. on their valuable observations in a large group of patients after sequential trifocal intraocular lens (IOL) implantation and laser corneal enhancement (LCE) after primary laser corneal refractive surgery (LCRS) for hyperopia or myopia.1 This is an increasingly frequent clinical problem as more patients with prior LCRS develop presbyopia and/or cataract yet still seek spectacle independence. We highlight some points of discussion, which may benefit the design of further studies aimed at optimizing outcomes in this challenging group. The reported rate of dissatisfaction of 10% to 20% is higher than that typically observed in studies of primary trifocal IOL implantation (∼2%).2 It would be interesting to know to what extent this disparity relates to residual refractive error or higher-order aberrations (HOAs): both are more likely after LCRS. Separating these factors may identify the main source of dissatisfaction and guide onward management of individual patients. A diffractive trifocal IOL adds negative spherical aberration to eyes with a wider defocus curve, which may be further modified by the original LCRS and subsequent LCE. While this may be desirable after myopic laser in situ keratomileusis (LASIK), it can have an adverse effect on quality of vision after hyperopic LCRS. The presentation of defocus curves may have facilitated the understanding of the presented outcomes, particularly in this relatively complex optical system. Furthermore, certain LCE techniques may be better suited to the original LCRS method used. Consequently, it would be of interest to know how HOAs varied between myopic and hyperopic subgroups after sequential treatments and correlation with final visual outcomes. As the number of post-LCRS patients with presbyopia and/or cataract increases, data on visual outcomes and safety are likely to increase across a range of treatment options such as monovision, small-aperture IOLs, or combination of trifocal and low-addition bifocal IOLs, with or without LCE.3 Alternatively, in the absence of cataract (45% in this study), additional LCE with or without presbyopic protocols may be considered instead of presbyopic refractive lens exchange. Since some degree of corneal multifocality is present after LASIK, especially with older laser protocols and myopic treatments, individuals with larger pupils may benefit from the spherical aberration–induced increased depth of focus. Current studies may yield more favorable results simply because lens technology has developed (ie, toric trifocal IOLs are now available), laser platforms have improved, and IOL calculation formulas for post-LCRS eyes have evolved.4,5 This study reported quite high cylindrical refractive error after primary LCRS for which toric trifocal IOL implantation may have prevented the need for subsequent LCE. The predominant method of LCE was photorefractive keratectomy (PRK) (72%), which is more likely to delay recovery with postoperative haze and ocular surface symptoms. Some surgeons favor LASIK or small-incision lenticule extraction for laser retreatments for these reasons. The preferred LCE protocol (topography-guided vs wavefront-guided treatment) is not clarified in the study, which could aid the interpretation of postoperative satisfaction. Information on LCE modality according to the type of primary treatment (myopic vs hyperopic) would also add further value to this welcome and valuable study.

Accuracy of astigmatism correction with toric intraocular lens implantation in eyes with previous radial keratotomy.

To evaluate refractive outcomes of toric intraocular lens (IOL) implantation in eyes with previous radial keratotomy (RK). Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. Retrospective case series. Consecutive cases with previous RK and had undergone cataract surgery with toric IOL implantation and met the following criteria were retrospectively reviewed: (1) regular bowtie corneal astigmatism within the central 3.0 mm zone, (2) difference in corneal regular astigmatism magnitude between the IOLMaster and Lenstar of ≤ 0.75 diopters (D), (3) difference in the regular astigmatism meridians from the 2 biometers of ≤15 degrees, and (4) available postoperative manifest refraction at ≥ 8 weeks with corrected distance visual acuity of 20/30 or better. Vector analysis was used to assess the preoperative corneal and postoperative refractive astigmatism. In 40 eyes of 31 patients with previous RK, preoperatively, the mean magnitude of corneal regular astigmatism was 2.10 ± 0.98 D; 1 (3%) and 2 (10%) eyes had anterior corneal regular astigmatism ≤0.5 D and ≤1.0 D, respectively; and the centroid value was 1.14 D @ 179 degrees ± 2.05 D. Postoperatively, the mean magnitude of refractive regular astigmatism was 0.46 ± 0.44 D; 29 (73%) and 35 (88%) of eyes had refractive regular astigmatism ≤0.5 D and ≤1.0 D, respectively (P < .05); and the centroid value was 0.12 D @ 173 degrees ± 0.63 D (P < .05). Toric IOLs can be used successfully to treat corneal regular astigmatism in eyes with previous RK.

Late-onset toxic anterior segment syndrome after possible aluminum-contaminated and silicon-contaminated intraocular lens implantation.

To describe an outbreak of late-onset toxic anterior segment syndrome (TASS) after the implantation of a specific hydrophilic acrylic intraocular lens (IOL). University Hospitals of Leuven, Belgium. Retrospective, single-center, observational study. All eyes undergoing cataract surgery with a monofocal, toric, or enhanced depth-of-focus (EDoF) Synthesis (Cutting Edge) IOL between August 2019 and March 2020 were reviewed. Data were collected on the surgical procedure, postoperative course, time until onset of symptoms, clinical features, and additional treatments. A laboratory surface analysis of all 3 IOL subtypes was performed in the Intermountain Ocular Research Center at the University of Utah, USA. Furthermore, other possible causes of prolonged postoperative inflammation rather than the IOL itself were investigated. Among the 203 eyes included, 28 TASS cases were identified (13.8%), among which 25 received a monofocal IOL, and 3 received an EDoF IOL. The mean time until onset was 28.9 (±19.9) days. Patients presented with anterior chamber cells (92.9%), deposits on the IOL (57.1%), or fibrinous inflammation (35.7%). 4 eyes (14.3%) underwent a surgical intervention, whereas 24 eyes showed a resolution of inflammation with topical therapy alone. Laboratory analysis showed the presence of both aluminum and silicon particles on the monofocal IOL, silicon particles only on the EDoF IOL, and no particles on the toric IOL surface. This report describes an outbreak of atypical, late-onset TASS after cataract surgery, possibly correlated with aluminum and silicon contamination of the IOL surfaces.

Changes in visual outcomes and ocular morphometrics after foldable myopic and toric intraocular lens implantation: 5-year results.

To evaluate the refractive, visual, and morphometric changes after implantation with a foldable iris-fixated phakic intraocular lens (pIOL) to correct myopia or astigmatism. University Eye Clinic Maastricht, the Netherlands. Prospective case series. We evaluated patients implanted with the Artiflex Myopia Toric (Ophtec B.V.) iris-fixated pIOL as of January 2004. Measurements were performed annually and reported after 1 and 5 years. The study included 481 eyes (277 patients; age 39.8 ± 10.9 years [SD]). 5 years postoperatively, 91% of eyes were within ±1.0 diopter (D) of target, and the mean myopization over a 5-year period was 0.22 D (P < .001). The logMAR corrected distance visual acuity (CDVA) increased by a mean 0.015 (P = .015) over 5 years; 88% of eyes had a CDVA of 20/20 or better, and 5.5% lost 2 or more lines of CDVA. Mean uncorrected distance visual acuity (UDVA) increased by 0.045 logMAR over 5 years (P < .001); 96% reached an UDVA of 20/40 or more. Anterior chamber depth (ACD) decreased by 0.04 mm (P < .001), and axial length (AL) increased by 0.23 mm (P < .001) over 5 years. Chronic endothelial cell loss showed a 5-year decline of 320 cells/mm2 in the myopic and 310 cells/mm2 in the toric subgroups (P < .001). Cataract resulted in pIOL explantation in 4.0% of eyes (mean survival 59.0 ± 40.0 months); higher preoperative age (hazard ratio [HR], 1.13; P < .001) and smaller ACD (HR, 6.80; P = .035) were risk factors for shorter survival due to cataract formation. Over 5 years, logMAR CDVA and UDVA decreased significantly due to myopization caused by lenticular changes and AL elongation.

Refractive outcomes of toric intraocular lens in combined trabecular micro bypass stent implantation and cataract surgery in glaucomatous eyes.

To evaluate the impact of trabecular micro bypass stents (iStent Inject) on refractive outcomes with toric intraocular lens (IOL) in glaucomatous eyes. We identified glaucomatous eyes receiving a toric IOL between October 2017 and December 2020. Eyes with iStent implantation were included in the study group and eyes undergoing isolated phacoemulsification served as controls. Corrected and uncorrected visual acuity, manifest refraction, intraocular pressure (IOP), and number of hypotensive drugs three months after surgery were evaluated. 26 eyes comprised the study group and 41 eyes the control group. Mean postoperative refractive cylinder was 0.26D in the control and 0.11D in the iStent group, with 63% and 85% of eyes with a cylinder of 0 and 85% and 92% of eyes with a cylinder ≤ 0.5D respectively. The mean absolute difference between target and outcome spherical equivalent was 0.26D in the control and 0.22D in the iStent group, with all eyes within 0.75D of target. LogMar uncorrected postoperative vision in eyes targeted for emmetropia was 0.04 in the control and 0.03 in the iStent group. There was a statistically significant reduction in IOP and number of hypotensive drugs in both groups, with a mean decrease in IOP of 8.6% in the control and 15.7% in the iStent group. The number of hypotensive drugs dropped from 1.63 ± 0.80 to 1.34 ± 0.91 in the control group and from 2.12 ± 0.65 to 0.44 ± 0.71 in the iStent group. Toric IOLs provide predictable refractive outcomes in glaucomatous eyes undergoing combined phacoemulsification with iStent implantation, reducing postoperative spectacle dependence.

Comparison of clinical outcomes of astigmatic correction using toric intraocular lens

AIM: To compare the clinical effects of two brands of Toric intraocular lens used in surgical correction of cataract with corneal astigmatism. METHODS: Totally 35 patients (50 eyes) with corneal astigmatism who underwent ophthalmic surgery from April 2019 to July 2019 were retrospectively analyzed. Among them, 25 eyes of 20 patients were implanted with Rayner 623T, while 25 eyes of 15 patients with Alcon AcrySof Toric intraocular lens (IOL). Three months after surgery, the uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), residual astigmatism, rotational degree of intraocular lens, contrast sensitivity, objective visual quality and the National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25) scale score were compared. Vector analysis was performed using the Alpins method. RESULTS: The mean postoperative UCDVA and BCDVA (logMAR) in the Rayner group were 0.17±0.20 and 0.08±0.15, respectively (P&gt;0.05), while those in the Alcon group were 0.21±0.16 and 0.10±0.11, respectively (P&gt;0.05). The mean residual astigmatism in the Rayner group was -0.57±0.24 D while that in the Alcon group was -0.50±0.28 D (P&gt;0.05). There was no statistically significant difference between the two groups in IOL rotational stability, vector analysis parameters, contrast sensitivity and objective visual quality (P&gt;0.05). The NEI VFQ-25 scale score was 85.16±5.91 in the Rayner group while it was 82.08±6.16 in the Alcon group (P&gt;0.05). CONCLUSION: The two brands of toric intraocular lens-Rayner 623T and Alcon AcrySof toric show no significant difference in their clinical outcomes.

Live surgery outcomes in cataract surgery.

To evaluate and compare the outcomes of live surgery (LS) and no-live surgery (NLS) on cataract surgery with implantation of different types of intraocular lenses (IOLs). Retrospective, contralateral eye, case series of patients that underwent cataract surgery in live or non-live view during two consecutive editions of national meetings. Both eyes of the same patients were implanted with the same IOL, one in LS and the other in NLS. 108 eyes of 54 patients, aged between 50 and 82 (72 ± 8.2) and implanted with different types of IOLs, were reviewed. Both eyes in each patient were well matched at baseline in terms of intraocular biometric characteristics, corneal curvature and endothelial cell density (ECD) (p > 0.05). There are no statistically significant differences between the biometric and topographic parameters, aberrometric data and the loss of ECD in the post-operative outcomes (p > 0.05). However, comparing the different types of IOLs, there is a significant loss of ECD in eyes implanted with a toric IOL during LS (p = 0.0014 and p = 0.04, in 2017 and 2018 edition respectively). In this series of live cataract surgery, eyes operated in LS or NLS have comparable outcomes, underlying the importance and the benefits of live view in terms of medical education and the low-risk of complications. Nevertheless, we have found a significant increase in ECD loss in patients implanted with toric IOLs during LS.

Association between axial length and toric intraocular lens rotation according to an online toric back-calculator.

To assess the relationship between axial length (AL) and intraocular lens (IOL) rotation among eyes receiving a toric IOL and subsequently entered into an online toric back-calculator database. Retrospective analysis of data collected online via astigmatismfix.com, a freely available online toric back-calculator where surgeons enter pre- and post-operative information to help manage residual postoperative astigmatism. Included records were deemed valid with entry of AL and IOL orientation between January 2017 and March 2019. Rotation was determined by a difference of ≥5° between pre-operative intended IOL orientation and actual post-operative IOL orientation. Frequency and magnitude of rotation are presented with means and associated standard deviation (SD). Linear regression models of this association are presented. Records of 6752 eyes were included in the analysis, of which 74.8% were determined to have a rotated IOL. The magnitude of rotation increased with each millimeter (mm) increase in AL with a mean rotation of 13.3° (SD: 12.8°) for eyes with AL 20-20.9 mm and a maximum mean rotation of 30.6° (SD: 30.3°) among eyes with AL 29-29.9 mm. General linear modeling demonstrated a significant association (P<0.0001) with a parameter estimate of 1.19 (standard error: 0.159) and R 2 of 0.0083. Analysis from an online database indicates that toric IOLs inserted into eyes with longer AL are more likely to rotate and to rotate more degrees from the target axis. The findings from this study are clinically relevant for surgeons implanting toric IOLs.

Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wave front guided surface ablation

BackgroundThis study aimed to evaluate toric intraocular lens to correct of pre-existing astigmatism at the time of phacoemulsification compared to using of spherical intraocular lens followed by wavefront guided surface ablation.ResultsThe patients were classified into three groups: Group A with 20 eyes of 19 patients having phacoemulsification with spherical intraocular lens only as a control group, group B with 20 eyes of 14 patients had phacoemulsification with toric intraocular lens and group C with 20 eyes of 16 patients had phacoemulsification with spherical intraocular lens and wavefront guided PRK three months later. Comparison pre-operative data for all groups showed no statistically significant difference regarding UCVA, BCVA, MRSE, and refractive astigmatism (P>0.05). Post operatively, there was a statistically significant difference for UCVA, BCVA, MRSE, and refractive astigmatism for group A compared to group B (P<0.05) and group A compared to group C but there was no statistically significant difference for group B compared to C regarding all these parameters (P>0.05).ConclusionIn this study, we found similar effects for both techniques in astigmatism corrected groups while both differed from the control group that was not corrected. Correcting preexisting astigmatism during cataract surgery should be in mind in every case to improve visual outcomes. Longer period of follow up are required to evaluate stability of these techniques and possibility of regression.

Measured Corneal Astigmatism Versus Pseudophakic Predicted Refractive Astigmatism in Cataract Surgery Candidates

To compare standard and total corneal astigmatism measurements to the predicted pseudophakic (nontoric) refractive astigmatism in candidates for cataract surgery. A retrospective, cross-sectional study. A single-center analysis of consecutive eyes measured with a swept-source optical coherence tomography biometer at a large tertiary medical center between February 2018 and June 2020. Corneal astigmatism was calculated based on standard keratometry astigmatism (KA), total corneal astigmatism (TCA), and predicted refractive astigmatism (PRA) for a monofocal nontoric intraocular lens (IOL) implantation calculated by the Barrett toric calculator using the predicted posterior corneal astigmatism (PRA(Predicted-PCA)) and the measured posterior corneal astigmatism (PRA(Measured-PCA)) options. Separate analyses were performed for each eye. Ophthalmology Department, Shaare Zedek Medical Center, Jerusalem, Israel. In total, 8152 eyes of 5320 patients (4221 right eyes [OD] and 3931 left eyes [OS], mean age 70.6±12.2 years, 54.2% females) were included in the study. The mean vector values (centroid) for KA, TCA, PRA(Predicted-PCA), and PRA(Measured-PCA) were 0.07 diopters [D] at 19.5°, 0.27 D at 7.5°, 0.44 D at 2.9°, and 0.43 D at 179.3°, respectively (P < .01), for OD and 0.02 D at 150.3°, 0.23 D at 169.7°, 0.40 D at 179.4°, and 0.42 D at 169.5°, respectively (P < .01), for OS. More than 73% of eyes had a PRA >0.5 D. Standard and total corneal astigmatism measurements differ significantly from the PRA by the Barrett toric calculator. The PRA, rather than the KA or TCA, should be used as the reference guide for astigmatism correction with toric IOL implantation.

Effect of decentration, tilt and rotation on the optical quality of various toric intraocular lens designs: a numerical and experimental study.

Toric intraocular lenses (T-IOLs) may lose their optical quality if they are not correctly positioned inside the capsular bag once implanted. In this work, T-IOLs with cylinder powers of +1.50, +4.50 and +7.50 D and differing degrees of spherical aberration have been designed, manufactured and tested in vitro using a commercial optical bench that complies with the requirements of standard ISO 11979-2. Moreover, the effect of tilt and rotation on optical quality was assessed by means of numerical ray tracing on an astigmatic eye model, while the effect of decentration was evaluated numerically and experimentally.

Visual and refractive outcomes of monofocal toric intraocular lens implantation in amblyopic eyes.

To evaluate the visual and refractive outcomes of monofocal toric intraocular lens (IOL) implantation after cataract surgery in amblyopic eyes. Our center's database was used to identify patients who had undergone bilateral cataract surgery between 2016 and 2020 with the implantation of a toric IOL in their amblyopic eye. Exclusion criteria were the presence of strabismus, ocular pathologies other than cataract or intra-surgical complications. The outcomes analysed were uncorrected distance visual acuity (UDVA), subjective refraction and corrected distance visual acuity (CDVA) one month after surgery. Ninety patients were included, with a mean age of 68.96 ± 7.81years. CDVA was lower for the amblyopic eye, both before and after surgery. There was a mean improvement in CDVA of 0.23 ± 0.21 LogMAR for the dominant eye and of 0.39 ± 0.33 for the amblyopic eye, p < 0.001 in both cases. Postoperative subjective refractive cylinder was higher in the amblyopic eye (-0.24 ± 0.39 D versus -0.10 ± 0.25 D, p < 0.01), as well as mean cylinder prediction error (-0.30 ± 0.47 D versus 0.02 ± 0.42 D, p < 0.01), compared to the dominant eye. There was a statistically significant correlation between preoperative and postoperative CDVA in amblyopic eyes (Spearmańs Rho = 260, p = 0.013). Mean postoperative UCVA was 0.15 ± 0.25 for amblyopic and 0.03 ± 0.12 for dominant eyes. Only one patient required distance spectacle correction due to residual astigmatism. Cataract surgery with toric IOL implantation in amblyopic eyes leads to an improvement in visual acuity and to spectacle independence in almost all cases, even in the presence of a higher cylinder prediction error.

Do limbal relaxing incisions during cataract surgery still have a role?

BackgroundThough Limbal Relaxing Incisions (LRI) were used widely to correct pre-existing corneal astigmatism during cataract surgery, they have been replaced recently with the more expensive methods like the use of toric Intra Ocular Lenses (IOL) and femtosecond during cataract surgery. We conducted our study to re-evaluate the role of (LRI) in correcting pre-existing moderate corneal astigmatism during cataract surgery in settings where other options are neither available nor affordable.MethodsRetrospective analysis of all consecutive cases of LRI performed by a single surgeon at the time of cataract surgery to correct moderate corneal astigmatism (1.5-3D) in a community hospital over a period of 6 months. Corneal astigmatism, uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (CDVA) were recorded pre-operatively, 4 weeks and 3 months post-operatively. Data on age, intraocular lens (IOL) power, predictive refraction and post-operative spherical equivalent was also collected and analyzed. The number and position of LRI was determined based on the pre-existing corneal astigmatism using online calculator.Results29 eyes of 25 patients with the mean age of 73.6 years (range: 46 to 90 years) and corneal astigmatism between 1.5 to 3D were included. Statistically significant reduction in the mean corneal astigmatism was recorded from 2.05 ± 0.45D preoperatively to 0.85 ± 0.56D postoperatively (P < 0.0001). All eyes showed reduction in astigmatism; 83% of eyes had < 1.0D post-operatively and 66% of eyes had < 0.75D. UDVA of 6/9 or better was recorded in 80% of eyes post-operatively (CDVA of 6/9 or better in 100%). The spherical equivalent was within 1.0D of the predictive refraction postoperatively in nearly all eyes (97%) and within 0.5D in 86% of the eyes. There were no peri-operative or post-operative complications were recorded in any case.ConclusionCombining LRI and cataract surgery to address moderate degrees of corneal astigmatism is a safe, reliable and predictable option especially in areas where more expensive methods such as toric IOL or excimer laser are not available or affordable. LRI has no significant effect on the spherical equivalent and is an excellent tool in reducing patient’s spectacle dependence.

Immediately sequential bilateral cataract surgery: an academic teaching center's experience.

To evaluate the safety and outcomes of immediately sequential bilateral cataract surgery (ISBCS) at a Canadian academic teaching center. Tertiary university teaching hospital of Laval University, Quebec City, Canada. Retrospective cohort study. 2003 consecutive patients (4006 eyes) who underwent ISBCS under topical anesthesia from January 2019 to December 2019 were included. All charts were retrospectively reviewed. Outcome measures included intraoperative and postoperative complications, postoperative uncorrected distance (UCVA) and pinhole (PHVA) visual acuities, and autorefraction measurements. 4006 eyes from 1218 (60.8%) female and 785 (39.2%) male patients with a mean age of 74 ± 8 years had a mean preoperative visual acuity of 0.503 logMAR (Snellen 20/63). The mean axial length was 23.53 ± 1.37 mm. Most eyes had monofocal intraocular lenses (IOLs) implanted (n = 3738, 93.3%) followed by toric (n = 226, 5.6%), multifocal (n = 25, 0.6%), and multifocal toric (n = 17, 0.4%) IOLs. Intraoperative complications included 14 (0.3%) posterior capsule ruptures with 5 (0.1%) requiring sulcus IOL placement, and 7 (0.2%) partial zonulysis, with 3 requiring capsular tension rings (0.07%). There were no cases of endophthalmitis or toxic anterior segment syndrome. Mean 5-week postoperative UCVA was 0.223 (Snellen 20/33), PHVA was 0.153 (Snellen 20/28) with a mean spherical equivalent of -0.21 diopters. ISBCS performed following International Society of Bilateral Cataract Surgeons recommended guidelines is a safe procedure. This cohort of 4006 eyes had very few complications, with none attributable to the surgery being done bilaterally. The UCVA, PHVA, and refractive outcomes were good.