Residual Astigmatism Research Articles

Head-to-Head Comparison of Intermediate Vision of Two Monofocal Intraocular Lenses.

To compare intermediate visual outcomes in patients previously implanted with bilateral Clareon monofocal IOLs versus bilateral Eyhance IOLs. This was a non-interventional, single-center, examiner-masked, comparative study. Participants were cataract patients presenting at least 3 months after uncomplicated, bilateral implantation of either Clareon or Eyhance non-toric and toric IOLs. Outcomes measures included binocular distance-corrected intermediate visual acuity (DCIVA), binocular corrected distance visual acuity (CDVA), binocular best-corrected defocus curve, postoperative mean residual spherical equivalent (MRSE), and residual astigmatism. A total of 620 eyes of 310 subjects (155 subjects per group) were evaluated. The mean difference in DCIVA was 0.05 logMAR between the Eyhance and Clareon IOLs which was significant (p < 0.01), but within the 0.1 logMAR non-inferiority margin. Mean CDVA of the Clareon group was 0.01 ± 0.03 logMAR compared to 0.02 ± 0.03 logMAR of the Eyhance Group (p > 0.05). Defocus curves from +1.0 D to -3.0 D were not clinically nor statistically different between the Clareon and Eyhance groups (p > 0.05). The results of this study show that bilateral implantation of Clareon monofocal IOLs and Eyhance monofocal IOLs lead to similar distance and intermediate visual outcomes.

Comparison of myopic astigmatic correction after cross-assisted SMILE, FS-LASIK, and transPRK.

To compare astigmatic correction among cross-assisted small-incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and transepithelial photorefractive keratectomy (transPRK). The Eye Hospital of Wenzhou Medical University, Zhejiang, China. Prospective comparison study. 154 right eyes of 154 patients with astigmatism of -1.00 to -2.75 diopters (D) were included in this study. 64 eyes, 42 eyes, and 48 eyes were receiving SMILE, FS-LASIK, and transPRK, respectively. The SMILE group used cross-axial alignment for head positioning for astigmatism correction. In the FS-LASIK and transPRK groups, static and dynamic cyclotorsion control were used. Changes in ocular parameters and vector analysis were assessed at 6 months postoperatively. The safety and efficacy indices were comparable among the 3 groups at 6 months postoperatively. Residual astigmatism was smallest in the SMILE group (-0.23 ± 0.25 D) compared with that in FS-LASIK (-0.40 ± 0.28 D, P = .009) and transPRK groups (-0.42 ± 0.32 D, P = .001). 53 (82.8%), 36 (85.7%), and 37 (77.1%) eyes achieved an angle of error within ±5 degrees, respectively ( P = .55). Notably, vector analysis showed that the difference vector, the magnitude of the error, and its absolute value were significantly smaller in the SMILE group than those in the other groups ( P < .05). In addition, the higher-order aberrations, especially coma, were significantly induced postoperatively in each group ( P < .001). Residual astigmatism magnitude was smallest by cross-assisted SMILE, followed by FS-LASIK and transPRK, and the astigmatism axial correction was comparable among groups.

Repositioning Rates of Toric IOLs Implanted in Cataract Surgery Patients: A Retrospective Chart Review.

To determine the incidence of postoperative repositioning of toric intraocular lenses (IOLs) due to clinically significant rotation. This study included consecutive cataract patients with pre-existing astigmatism who had undergone cataract surgery with toric IOL implantation by a single experienced surgeon. Case records of patients who were recommended to undergo toric IOL repositioning surgery due to clinically significant postoperative IOL rotation from the implanted axis were identified. The need for a secondary intervention to manage residual astigmatism was based upon postoperative residual astigmatic error ≥0.75 D, the patient's qualitative dissatisfaction with the level of postoperative distance vision, dilated post-op examination, and confirmation of the significant potential for astigmatism reduction. Case records of 993 eyes implanted with AcrySof toric (N = 362), Tecnis Toric I (N = 53), Tecnis Toric II (N = 308), or enVista Toric IOLs (N = 270) were included. Postoperative toric IOL repositioning was recommended in 16 eyes (1.6%). The repositioning rate was highest in the eyes implanted with Tecnis Toric I (5.7%), followed by AcrySof Toric (2.2%), enVista Toric IOLs (1.1%), and Tecnis Toric II (0.6%). This real-world analysis of eyes implanted with toric IOLs revealed that the rate of surgical IOL repositioning due to clinically significant IOL rotation was lower than 2% for enVista and Tecnis Toric II IOLs. When needed and with appropriate planning, toric IOL repositioning can be very successful.

Effect of astigmatism on visual outcomes after multifocal intraocular lens implantation: a systematic review and meta-analysis

PurposeTo investigate the effects of postoperative astigmatism on the visual outcomes following presbyopia-correcting surgery with multifocal intraocular lens implantation.MethodsA comprehensive literature search was conducted using PubMed, Embase, and Web of Science for articles published until January 2023. Additionally, we included retrospective case series and prospective comparative studies. The combined mean difference (MD) with 95% confidence intervals (CI) and odds ratio (OR) with 95% CI were used to express continuous and categorical outcomes, respectively. All statistical analyses were performed using Review Manager (version 5.4.1).ResultsWe included nine eligible studies that analyzed 3,088 eyes. The proportion of eyes with useful postoperative visual acuity (logMAR ≤ 0.20) and residual astigmatism significantly differed with respect to the magnitude of astigmatism and presence/absence of blurred vision (p &amp;lt; 0.001 for both). Additionally, the mean uncorrected distance visual acuity (MD, 0.14; 95% CI, 0.06 to 0.21; p = 0.0003) and uncorrected intermediate visual acuity (MD, 0.07; 95% CI, 0.00 to 0.13; p = 0.04), but not the uncorrected near visual acuity (MD, 0.02; 95%CI-0.01 to 0.05; p = 0.17), significantly differed according to the magnitude of astigmatism.ConclusionAstigmatism, even at low levels (≥ 0.5D), has a significant effect on visual outcomes, especially on UDVA and UIVA, following multifocal intraocular lens implantation. Accurate preoperative and postoperative evaluation of astigmatism is important.

Comment on: Outcomes of peripheral corneal relaxing incisions for residual astigmatism in patients after cataract surgery.

Comment on: Outcomes of peripheral corneal relaxing incisions for residual astigmatism in patients after cataract surgery.

Cost-Effectiveness Analysis of Light Adjustable Lens Compared to Monofocal Intraocular Lens in Cataract Surgery.

To analyze the cost-effectiveness of the Light Adjustable Lens (LAL; RxSight) in comparison to a monofocal intraocular lens (IOL) for individuals undergoing cataract surgery in both eyes. A cost-effectiveness analysis was performed using a Markov model that simulated the patient outcomes and costs associated with undergoing cataract surgery with the LAL or monofocal IOL. Cost-effectiveness was determined using the incremental cost-effectiveness ratio (ICER), a measure that quantifies the incremental cost in dollars per quality-adjusted life year (QALY) gained. Treatments with the ICER below the willingness-to-pay threshold (WTP) of $50,000/QALY were considered cost-effective. The model was also evaluated for the impact of uncertainties in parameters using one-way sensitivity and probabilistic sensitivity analyses. The cost-effectiveness analysis showed that the LAL is cost-effective compared to monofocal IOLs in patients undergoing cataract surgery, with ICERs of $9,792/QALY (health care perspective) and $10,072/QALY (societal perspective) both significantly below the WTP. The model was most sensitive to patient age, market cost of the LAL, and proportion of patients with residual astigmatism following cataract surgery. The probabilistic sensitivity analysis showed that cataract surgeries in patients starting at age 65 years were cost-effective in 94% of the simulations at a WTP of $50,000/QALY. From both health care and societal perspectives, the study shows cataract surgeries performed with the LAL are cost-effective when compared to those performed with a monofocal IOL. More studies are needed to compare the LAL to other premium lenses that also provide patients with excellent visual outcomes at a higher cost. [J Refract Surg. 2023;39(11):777-782.].

Intraocular Lenses for Cataract Surgery

What Is the Issue?&#x0D; &#x0D; 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.&#x0D; Premium lenses, including lenses to correct astigmatism (called toric lenses), are available but may not be covered by public or private health plans.&#x0D; 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.&#x0D; &#x0D; What Did We Do?&#x0D; &#x0D; 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.&#x0D; 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.&#x0D; &#x0D; What Did We Find?&#x0D; &#x0D; 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.&#x0D; 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).&#x0D; 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.&#x0D; 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.&#x0D; 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.&#x0D; &#x0D; What Does it Mean?&#x0D; &#x0D; 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.&#x0D; 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.&#x0D; 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.&#x0D;

Residual astigmatism calculation method in implantation of a monofocal non-toric intraocular lens

BACKGROUND: Nowadays, phacoemulsification with monofocal non-toric intraocular lens (IOL) implantation is a most common procedure in cataract surgery. Residual astigmatism has an important impact on uncorrected visual acuity. Therefore, development of residual astigmatism assessment method is relevant and may expand indications for toric IOL implantation.&#x0D; AIM: To develop a method for calculating residual astigmatism in cases when non-toric monofocal IOL is implanted.&#x0D; MATERIALS AND METHODS: The study included 351 patients (391 eyes, 105 men and 246 women, mean age 75.3 8.5 years) who underwent phacoemulsification with non-toric monofocal IOL implantation. Biometry was performed by IOL-Master 500, postoperative refraction was assessed by autorefractometer Topcon-8800.&#x0D; RESULTS: Using regression analysis, where the depended variable was residual astigmatism, and preoperative corneal astigmatism and steep corneal meridian axis location served as covariates, we revealed a significant relation (p 0.001) with medium strength (R2 = 0.51) between these parameters, which formed residual astigmatism calculation formula for monofocal non-toric IOL implantation: Ast = KAst 0.71 0.62 sinKax + 0.73.&#x0D; CONCLUSIONS: This formula may allow to evaluate the residual astigmatism and justify a decision on the advisability of toric IOL implantation.

Accuracy of Astigmatism Calculation with the Barrett, Panacea, and enVista Toric Calculators.

To evaluate residual refractive astigmatism using the Panacea and enVista toric calculators, compared to the gold-standard Barrett toric calculator. A retrospective and comparative study was conducted in one center. We reviewed the medical records of all patients with a diagnosis of senile cataracts and regular corneal astigmatism, without previous corneal or intraocular surgery, who underwent phacoemulsification with implantation of a toric intraocular lens, who had pre- and postoperative corneal topography, biometry, and refraction measurements. The frequency of preoperative astigmatism according to the axis was 70 (84%) eyes showing with-the-rule (WTR) astigmatism, 9 (14%) eyes with against-the-rule (ATR) astigmatism, and 1 (2%) eye with oblique astigmatism. Regarding astigmatism prediction errors, there were statistically significant differences between the enVista and Panacea calculators (median of 0.39, 0.18, and 0.52 for Barrett, enVista, and Panacea, respectively). The residual astigmatism prediction error centroid was similar for the Barrett and enVista toric calculators, and both were lower compared to the Panacea calculator (x-component p < 0.001). The enVista toric calculator incorporating the Emmetropia Verifying Optical (EVO) toric calculator provides similar results to the gold-standard Barrett calculator.

Premium Intraocular Lenses in Glaucoma-A Systematic Review.

The incidence of both cataract and glaucoma is increasing globally. With increasing patient expectation and improved technology, premium intraocular lenses (IOLs), including presbyopia-correcting and toric IOLs, are being increasingly implanted today. However, concerns remain regarding the use of premium IOLs, particularly presbyopia-correcting IOLs, in eyes with glaucoma. This systematic review evaluates the use of premium IOLs in glaucoma. A comprehensive search of the MEDLINE database was performed from inception until 1 June 2023. Initial search yielded 1404 records, of which 12 were included in the final review of post-operative outcomes. Studies demonstrated high spectacle independence for distance and good patient satisfaction in glaucomatous eyes, with positive outcomes also in post-operative visual acuity, residual astigmatism, and contrast sensitivity. Considerations in patient selection include anatomical and functional factors, such as the type and severity of glaucomatous visual field defects, glaucoma subtype, presence of ocular surface disease, ocular changes after glaucoma surgery, and the reliability of disease monitoring, all of which may be affected by, or influence, the outcomes of premium IOL implantation in glaucoma patients. Regular reviews on this topic are needed in order to keep up with the rapid advancements in IOL technology and glaucoma surgical treatments.

Rotational stability of plate haptic toric intraocular lenses after combined 25-gauge vitrectomy and cataract surgery.

To evaluate the postoperative intraocular lens (IOL) rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL. In this retrospective case series, 32 eyes of 32 patients underwent a combined 25-gauge vitrectomy and phacoemulsification for vitreoretinal diseases and cataract with regular corneal astigmatism of at least 1 diopter (D). A plate haptic toric IOL (AT Torbi 709M, Carl Zeiss Meditec AG) was implanted in all eyes. The outcome measures were rotational stability and refractive astigmatism up to 6mo postoperatively as well as the best corrected visual acuity (BCVA). Preoperative refractive astigmatism was 2.14±1.17 D, which was significantly reduced to 0.77±0.37 D six to eight weeks postoperatively and remained stable throughout the observation period (0.67±0.44 D at three months and 0.75±0.25 D at six months; for all groups: P<0.0001 compared to baseline). BCVA improved significantly from 0.36±0.33 logMAR preoperatively to 0.10±0.15 logMAR following surgery (P=0.02). Mean IOL axis deviation from the target axis was 3.4°±2.9° after six to eight weeks and significantly decreased over time (2.4°±2.6° six months after surgery; P=0.04). In one patient IOL, re-alignment was performed. Corneal astigmatism is significantly reduced following combined 25-gauge vitrectomy and cataract surgery. The plate haptic toric IOL position and axis remain stable during the observation period of six months.

Ocular residual astigmatism (ORA) does not seem to correlate with baseline refractive error among refractive surgery candidates.

Ocular residual astigmatism (ORA) is defined as the difference between refractive astigmatism and anterior corneal astigmatism. A high ORA may be correlated with poorer results in patients undergoing corneal-based laser surgery. Is a high baseline refractive error related to a higher degree of ORA? This was a retrospective analytical study including 181 right eyes of an equal number of refractive surgery candidates. Manifest subjective refraction was measured, along with a Pentacam AXL Wave corneal tomography. Via a vector analysis with this methodology, subjective cylinder was translated into the corneal plane and a vectorial subtraction was performed in order to measure ORA. Spearman's rank order test, one-way ANOVA and Chi-square were used to determine whether different levels of baseline refractive error correlate with different levels of ORA. Mean age was 28.33 ± 4.71years with a female preponderance (65.7%). Mean ORA was 0.74 ± 0.39 D, with 33.1% of eyes having an ORA ≥ 0.90 D. There was not a correlation between ORA and level of myopia (rho = - 0.022; p = 0.764), nor between ORA and spherical equivalent (rho = 0.009; p = 0.903). Refractive astigmatism did not demonstrate to be correlated with ORA level either (rho = 0.078; p = 0.329). One-way ANOVA tests failed to demonstrate an association between different classifications of refractive error and level of ORA. In the studied population, ORA is not correlated with baseline refractive error. Every patient presenting for possible corneal-based laser refractive surgery should be evaluated for a possible high level of ORA, irrespective of their baseline ametropia level.

Outcomes of peripheral corneal relaxing incisions for residual astigmatism in patients after cataract surgery.

To evaluate the outcomes of peripheral corneal relaxing incisions (PCRIs) for correcting residual astigmatism in eyes after cataract surgery. Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. Retrospective case series. Retrospectively, we reviewed all consecutive cases that had previous cataract surgery and subsequent PCRIs by 1 surgeon. The PCRI length was determined according to a nomogram based on age and manifest refractive astigmatism. Visual acuity and manifest refractive astigmatism before and after the PCRIs were compared. Vector analysis was performed, and net refractive changes along the incision meridian were calculated. Criteria were met by 111 eyes. After the PCRIs, mean uncorrected visual acuity was significantly improved, and the percentage of eyes with uncorrected distance visual acuity of ≥20/20 increased significantly by 36%; the mean refractive astigmatism magnitude decreased significantly, and the percentages of eyes with refractive cylinder of ≤0.25 diopters (D) and ≤0.50 D increased significantly by 63% and 75%, respectively (all P < .05). The vector magnitude difference between pre- and post-operative refractive astigmatism was 0.88 ± 0.38 D. The postoperative refractive astigmatism had significantly smaller centroid and variance values than the preoperative refractive astigmatism ( P < .05). PCRIs are an effective approach for correcting low amounts of residual astigmatism in patients after cataract surgery.

Refractive outcomes of toric intra-ocular lens implantation in cases of high posterior corneal astigmatism.

To evaluate whether the toric intra-ocular lens (IOL) power calculation based on total corneal astigmatism (TCA) in eyes with high posterior corneal astigmatism (PCA) could result in a systematic over-correction or under-correction after operation. The present study included a mono-centric retrospective study design. The data were collected from 62 consecutive eyes during uncomplicated cataract surgery by a single surgeon with a measured PCA of 0.50 diopters (D) or higher. Toric IOL calculations were made using TCA measurements. The eyes were grouped as either "with-the-rule" (WTR) or "against-the-rule" (ATR) on the basis of the steep anterior corneal meridian. The post-operative refractive astigmatic prediction error was analyzed 1 month post-operatively using the vector analysis by the Alpins method and double-angle plots method. The correction indexes were 1.14 ± 0.29 in the ATR eyes and 1.25 ± 0.18 for the WTR eyes, indicating a tendency toward over-correction. The mean over-correction was 0.22 ± 0.52D in the ATR group and 0.65 ± 0.60D in the WTR group. The magnitude of error (ME) values were significantly different from the ideal value of zero in both groups (ATR: P = 0.03; WTR: P = 0.00). No significant difference in mean absolute error (MAE) in predicted residual astigmatism was found between ATR and WTR groups (0.61 ± 0.42 D versus 0.64 ± 0.39 D; P = 0.54). The ATR group yielded better results, with 48% <0.50D prediction error in the main analysis. The results suggested that in cases of high PCA, the toric IOL calculation, which was performed using TCA, may cause a potential over-correction in the ATR and WTR eyes. For ATR eyes, over-correction led to slight disruption of post-operative visual quality because of the "with-the-rule" residual astigmatism after operation. Therefore, we suggested using TCA for toric IOL calculation in ATR eyes.

Effects of atropine 0.01% on refractive errors in children with myopia

BackgroundLittle is known about changes in astigmatism during atropine treatment. We aimed to explore the effects of atropine 0.01% eye drops on both spherical and cylindrical refractive errors in myopic children. MethodsChildren aged 6–14 years with myopia ≥ −6.00 D and < −0.50 D, and total astigmatism > −2.00 D in at least one eye were enrolled. Subjects were randomised either to receive atropine 0.01% once nightly with single-vision lenses or simply to wear single-vision lenses and were followed up at 3-month intervals. Cycloplegic refraction and axial length were measured. The magnitude and direction of total astigmatism (TA), corneal astigmatism (CA), and residual astigmatism (RA) were evaluated. ResultsOverall, 119 eyes (69 eyes in the atropine group and 50 eyes in the control group) were included in the final analyses after 9 months. Atropine-treated eyes showed significantly less progression of myopia than did control eyes (spherical equivalent: −0.35 ± 0.33 vs. −0.56 ± 0.49 D, p = 0.001; axial length: 0.20 ± 0.19 vs. 0.33 ± 0.19 mm, p < 0.001). Compared with control eyes (−0.04 ± 0.23 D), a significant increase in TA was observed in the atropine-treated eyes (−0.14 ± 0.29 D); this was mainly attributed to the increase in CA (−0.17 ± 0.26 D) rather than the minor decrease in RA (0.02 ± 0.32 D). ConclusionsAtropine 0.01% was effective in preventing myopia progression, whereas 9 months of atropine treatment resulted in a clinically small, but statistically significant increase in TA in myopic Chinese children.

Ultra-compact dual band imaging spectrometer with freeform prisms.

Wide spectrum and miniaturization are the main challenges in the imaging spectrometer design. In this paper, we propose an ultra-compact dual band imaging spectrometer (CDBIS) with cemented freeform prisms, which works at both the visible-near-infrared (VNIR) from 400nm to 1000nm and the shortwave-infrared (SWIR) from 1000nm to 1700nm. The imaging spectrometer is only composed of three cemented prisms, a primary prism and two triangular prisms. And a freeform surface characterized by the Zernike polynomial is introduced in each prism. The CDBIS is dispersed by a diffraction grating, which is designed on the second surface of the primary prism. Based on vector aberration theory (VAT), the relationship among the astigmatism generated by the introduced freeform surfaces, the wavelength, and the field of view is studied. Accordingly, a wideband is realized by introducing the freeform surfaces after the diffraction grating. Furthermore, through optimizing the coefficients of Zernike polynomial terms, residual astigmatism at different wavelengths is well balanced. An imaging spectrometer with a volume of only 100c m 3 is obtained, with a spectral resolution of 1.45nm at VNIR and 2.40nm at SWIR, respectively. It has a huge potential for broadband space exploration.

The Association Between Ocular Residual Astigmatism and the Efficacy of Astigmatism Correction Via Small Incision Lenticule Extraction (SMILE).

Astigmatism correction after small-incision lenticule extraction (SMILE) surgery is affected by several factors, including ocular residual astigmatism (ORA), which accounts for the vector difference between refractive and corneal astigmatism. Previous studies revealed the relationship between ORA and astigmatism correction after laser-assisted in situ keratomileusis (LASIK). However, in SMILE surgery, no comprehensive study exploring the link between these two variables has been performed. We have therefore assessed the association between ORA and astigmatism correction after SMILE. This was a retrospective, single-centered study. Patients with myopia or myopic astigmatism who underwent SMILE surgery using the 500-kHz Visumax laser platform and were followed up for at least 3 months were included. Patients' demographic and clinical characteristics, such as visual acuity, refractive status and corneal tomography, were recorded. ORA was calculated using Alpins Statistical System for Ophthalmic Refractive Surgery Techniques (ASSORT) Ocular Residual Astigmatism calculator. A total of 888 eyes (408 eyes from males and 480 eyes from females) from 444 patients (mean age [standard deviation] 32.4 ± 7.1years) were included in our study. Mean (± SD) preoperative sphere and cylinder were -5.45 ± 1.98 (range -10.00-0.00) diopter (D) and -0.89 ± 0.70 (range -4.00-0.00) D, respectively. Calculated mean ORA was 0.68 ± 0.35 (range 0.07-3.53) D. Postoperative logMAR uncorrected visual acuity was 0.03 ± 0.31. Mean postoperative sphere and cylinder were -0.10 ± 0.56 (range -1.5 to 1.0) D and -0.51 ± 0.37 (-1.5 to 0.0) D, respectively. The Pearson correlation test revealed preoperative sphere, steep keratometry (steep-K) and ORA were statistically correlated with the amplitude of astigmatism correction (P < 0.001), and the generalized estimating equations analysis showed that ORA was negatively correlated with the amplitude of astigmatism correction (P < 0.001). The results of our study suggest that preoperative higher ORA may be associated with a lower magnitude of astigmatism correction after SMILE surgery in patients with all levels of astigmatism preoperative. ClinicalTrials.gov: NCT05604872. Registered 3 November 2022-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT05604872.

A clinical case of a combined method for correcting irregular post-keratoplastic astigmatism in a patient with cataract

Using the example of a clinical case, a clinical and functional analysis of a combined method for correcting irregular post-keratoplastic astigmatism in a patient with cataract is presented.&#x0D; Patient, aged 50, complained of low vision and fog in front of the left eye during the last 3 years. For the left eye, the diagnosis was made: Irregular post-keratoplastic astigmatism of a high degree, condition after penetrating keratoplasty, posterior capsular cataract. To correct the irregular post-keratoplastic astigmatism, the patient underwent the MyoRing implantation into the corneal graft. Then, 1 year later, the patient underwent cataract phacoemulsification with a toric intraocular lens implantation for the simultaneous correction of residual corneal astigmatism. The follow-up period after phacoemulsification was 1 year. One year after the MyoRing implantation into the corneal graft, uncorrected visual acuity and corrected visual acuity increased from 0.02 to 0.05, corneal astigmatism decreased by 4.46 D and became significantly more regular. 1 month after phacoemulsification with toric intraocular lens implantation, uncorrected visual acuity increased from 0.05 to 0.8, corrected visual acuity from 0.05 to 1.0; spherical and cylindrical components of refraction amounted to 0.5 D each and did not change anymore.&#x0D; The combined method of irregular post-keratoplastic astigmatism correction in a patient with cataract showed a high refractive result, stability and safety in the late postoperative period.

Effect of postoperative residual astigmatism on visual outcomes after trifocal intraocular lens implantation.

The aim of this study was to evaluate the effect of residual astigmatism on postoperative visual outcomes after trifocal intraocular lens implantation. In this prospective observational study, we divided 156 eyes into two groups according to postoperative astigmatism measured by subjective optometry and followed them up for 3 months. Visual acuity, modulation transfer function (MTF) curves, Strehl ratio (SR), Visual Function Index-14 scores, and photic phenomena were compared. Linear regression analysis revealed a weak correlation between residual astigmatism and uncorrected distance visual acuity (UDVA) (r = 0.190, P = 0.016) at 3 months and a significant between-group difference at 1- and 3-month postoperative UDVA (P = 0.038, P = 0.018, respectively). MTF curve values and SR (MTF-10 total, MTF-10 cornea, MTF-30 total, MTF-30 cornea, SR Total, and SR cornea) were significantly worse (P < 0.001), and the Visual Function Index-14 scores were lower in the 0.5 < astigmatism ≤ 1.25 D group (P < 0.05) than in the astigmatism ≤ 0.5 D group. No significant differences were found in the frequency, severity, and bothersomeness of photic phenomena (P > 0.05). Postoperative residual astigmatism affects the UDVA of the trifocal intraocular lens-implanted eyes. Although we found no significant differences in uncorrected intermediate and near visual acuity, both objective and subjective visual quality were affected, suggesting the need for surgical planning when the anticipated postoperative astigmatism is >0.5 D.

Stereopsis after bilateral implantation of Toric intraocular lenses in high myopic cataract patients with astigmatism

PurposeTo evaluate near, intermediate, distance visual acuity and stereopsis after bilateral implantation of Toric intraocular lenses (IOLs) in high myopic patients with astigmatism. MethodsBilateral Toric or non-Toric IOL implantation (n ​= ​40 eyes each) was performed on high myopic cataract eyes with astigmatism. Best-corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), uncorrected near visual acuity (UCNVA), residual refractive astigmatism (RRA), and near, intermediate, and distance stereoacuity were measured postoperatively at 7 days, 1 month, and 3 months. ResultsThe three-month postoperative BCDVA, UCIVA, and UCNVA of the Toric group were 0.08 ​± ​0.07, 0.30 ​± ​0.11, and 0.23 ​± ​0.14 LogMAR. All improved over the preoperative assessments (P ​< ​0.05). The RRA, UCIVA, and UCNVA were significantly better in the Toric group than the non-Toric group at all follow-up examinations (all P ​< ​0.05). At 3 months, the median near and intermediate stereoacuity of the Toric group were 100 (range 40 – 400) and 120 (range 50 – 400) arcsec, which were better than the non-Toric group (both P ​< ​0.05). Fine near stereopsis ≥100 arcsec was present in 65% of the Toric patients, and 50% had good intermediate stereopsis of ≥100 arcsec. However among non-Toric patients, only 15% and 5% achieved fine near and intermediate stereopsis. The postoperative BCDVA and best-corrected distance stereoacuity were similar in the two groups (P ​> ​0.05). ConclusionsIn bilateral high myopic cataract patients with astigmatism, Toric IOLs not only improved UCIVA, UCNVA, and RRA, but also enhanced near and intermediate stereopsis acuity.