PurposeTo systematically review SMILE-based astigmatism correction and influencing factors.MethodsLiterature was screened across eight databases. Pre- and post-SMILE cylinder, difference vector (DV), correction index (CI), magnitude of error (ME), angle of error (AE), and index of success (IOS) were compared. Bias was assessed using Cochrane's Risk of Bias, Quality Assessment of Diagnostic Accuracy Studies, and the Newcastle–Ottawa Scale.ResultsElevated ocular residual astigmatism (ORA) resulted in greater postoperative residual astigmatism, accompanied by increased DV and IOS (p < 0.05), whereas ME, AE, and CI remained unaffected by ORA levels. Postoperative cylinder, DV, ME, AE, CI, and IOS were comparable between eyes (p > 0.05). Correction outcomes were impacted by ocular rotation, astigmatism characteristics, spherical degree, corneal curvature, and patient age.ConclusionsSMILE effectively corrects low, moderate, and high astigmatism, but high ORA patients tend to experience undercorrection. But accuracy requires vector planning.

ABSTRACT Clinical relevance Rigid gas permeable (RGP) contact lenses effectively correct special refractive errors in young children when spectacles fail, supporting visual development. Background To analyse the visual outcomes of young children (under 6 years) with special refractive errors corrected using RGP contact lenses during the visual development. Methods This retrospective study included 50 young children fitted with RGP lenses at Beijing Tongren Eye Centre (2019–2024). Special refractive errors included ultra-high hyperopia due to aphakia, ultra-high myopia (spherical equivalent≤-9.00D), high astigmatism (astigmatism ≥2.00D), and high anisometropia (interocular difference ≥3.00D). Some anisometropia cases had coexisting ocular lesions (myelinated retinal nerve fibres, familial exudative vitreoretinopathy, persistent pupillary membrane). All children were > 4.5 years at final visit with ≥6 months RGP wear. We compared the changes in best-corrected visual acuity (BCVA) before and after RGP contact lens wear in these children and analysed their final visual outcomes. Binocular function was considered ‘good’ if the Worth 4-dot test showed fusion at near and far distances, with stereoacuity ≤100 seconds of arc. Results Median age at RGP initiation was 3.16 years (interquartile range (IQR) 2,4), with a median wear duration of 2 years (IQR 1,3.17). BCVA improved significantly from 1.10 logMAR (IQR 1.23,1.01) to 0.30 logMAR (IQR 0.50,0.10) (p < 0.001). A total of 28 patients (56%) achieved a BCVA of 6/12 or better, with 17 showing good binocular function. The highest binocular function rates were in groups with ultra-high myopia (50%), high astigmatism (67%), and pure high anisometropia (50%). None of the nine patients with coexisting ocular lesions achieved good binocular function. Conclusions RGP lenses significantly improve BCVA in young children with special refractive errors. The best results were observed in cases of refractive errors alone, while those with other ocular lesions showed limited but notable improvements from baseline.

ObjectiveTo quantify the distribution of anterior corneal eccentricity (e value) and identify associated factors in Chinese children and adolescents with astigmatism.MethodsCorneal topography data obtained using the Medmont E300 were retrieved from 961 participants aged 3 to 18 years, with corneal astigmatism (ΔK) ≥ 2.00 D. Data analysis included anterior corneal e values along both flat and steep meridians at 1–10 mm chord lengths, as well as the device-reported mean e values for the flat and steep meridians (9.35 mm chord dimater); anterior corneal keratometry readings (flat/steep K); ΔK; and refractive error. Demographic factors, including age and sex, were also analyzed.ResultsThis study included 961 right eyes (mean age: 7.9 ± 2.9 years; 56% male). The mean e values were 0.73 ± 0.10 for the flat meridian and 0.51 ± 0.21 for the steep meridian. Along the flat meridian, e values decreased and stabilized with increasing chord length, while along the steep meridian, a U-shaped trend was observed. The mean flat e was correlated with the flat K (β = −0.013, P < 0.001) and ΔK values (β = 0.037, P < 0.001), whereas the mean steep e was only associated with sex (β = −0.043, P = 0.001) in multivariate analyses.ConclusionIn Chinese children and adolescents with moderate to high corneal astigmatism, the anterior cornea demonstrates aspheric characteristics with distinct meridional asymmetry. The flat e value may was associated with corneal curvature (flat K and ΔK values), whereas the steep e value was not associated with these parameters.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12886-025-04402-3.

Ray tracing-guided LASIK for high myopia and astigmatism: Initial clinical outcomes.

Background. Modern cataract surgery requires increasingly high standards to achieve excellent visual outcomes at all distances, with mandatory intraoperative correction of corneal astigmatism. In such cases, customized intraocular lenses (IOLs), calculated according to the patient’s specific biometric parameters, are used. This report presents a clinical case of implanting a customized toric multifocal IOL during cataract surgery in a patient with high axial myopia and concomitant corneal astigmatism. Case description. A 45-year-old male with complicated cataract, high axial myopia, and corneal astigmatism underwent phacoemulsification with implantation of a customized multifocal IOL (Lentis Mplus LU-313T). In addition to standard ophthalmological examinations, optical specular endothelial microscopy of the cornea, optical coherence tomography (OCT) of the retina, and Scheimpflug corneal densitometry were performed. Preoperative IOL power calculation was carried out using an online calculator based on IOLMaster and corneal topography data. Postoperatively, uncorrected visual acuity was 1.0 for distance, 0.4 at intermediate, and 0.5 at near. Discussion. Implantation of customized IOLs with rotationally asymmetric optics, with a +2.0 D addition in the dominant right eye (Lentis Mplus LU-313 MF-20T) and a +3.0 D addition in the nondominant left eye (Lentis Mplus LU-313 MF-30TX), eliminated the need for postoperative optical correction at different distances. High uncorrected visual acuity was achieved for distance, intermediate, and near vision. The absence of halo effect after surgery enabled the patient to drive comfortably, including in the evening and at night. Conclusion. This comprehensive surgical approach to treating complicated cataract in eyes with high myopia and corneal astigmatism provided complete visual rehabilitation and eliminated the need for additional optical correction.

SIGNIFICANCE:There is a lack of knowledge on myopic progression in patients with moderate to high astigmatism, which has been compounded by their exclusion from myopia control studies. This study found increased myopia that was linearly associated with age, emphasizing the importance of understanding myopia control treatments in this population.PURPOSE:Moderate to high amounts of astigmatism cause visual blur and may affect myopic progression. However, there is little information as to the effect of cylinder on change in myopia, and the vast majority of myopia control studies have excluded children with significant astigmatism. The purpose of this study was to assess myopic and cylinder changes in children with moderate to high astigmatism.METHODS:Retrospective review of children (2 to 15 years) who presented with astigmatism (>2.00D) and myopic spherical equivalent refraction (SER) to a tertiary care pediatric hospital. Best corrected visual acuity and cycloplegic refraction changes over at least 2 years of follow-up were analyzed. Patients with confounding ocular disease, history of myopia control, or Trisomy 21 were excluded.RESULTS:Two hundred twenty-seven patients presented at 6.6 years (IQR 5.2, 9.1) with a median 0.00D (IQR −2.00, 0.50) sphere, −3.00D (IQR −4.25, −2.50) cylinder, and −1.75 (IQR −3.75, −0.99) SER. Twenty-four percent of patients had amblyopia and 46% had strabismus. At final exam (4.9 [IQR 3.0, 6.7] years), patients were more myopic and had greater cylinder (p<0.001). Hispanic patients were disproportionately represented (64%) but had no difference in refractive parameters versus non-Hispanic patients. Initial age was linearly associated with sphere and SER, and the rate of change in sphere and SER over 2 to 3 years of follow-up. Initial J0 was linearly associated with myopic and cylindrical progression.CONCLUSIONS:Children with moderate to high levels of astigmatism showed myopic and cylindrical progression at follow-up. Amblyopia and strabismus were common in our cohort, but neither amblyopia nor strabismus affected the rates of myopic or cylindrical progression. Patients with moderate astigmatism (−2.00 to −3.00D) had more myopic and cylindrical progression compared with those with higher levels of astigmatism.

Screening Corneal Tomography for the Diagnosis of Keratoconus in Pediatric Patients With Trisomy 21.

Uncorrected astigmatism in children is a major cause of visual impairment, often associated with reduced stereopsis and visual symptoms, which may be further exacerbated by prolonged screen exposure. Objectives: This study aimed to evaluate the effect of full refractive correction on stereopsis in children with moderate-to-high astigmatism and to examine the association between cylindrical error, screen time, and stereoacuity. Methods: A cross-sectional study was conducted among 273 children aged 4–8 years attending the ophthalmology department of KRL hospital, Islamabad. Consecutive sampling was employed. After ethical approval and informed consent, each participant underwent a comprehensive ocular examination, including visual acuity testing with ETDRS charts and stereopsis assessment using vectograph circles. Demographic data, refractive status, screen exposure, and outdoor activity were recorded. Statistical analysis included Spearman’s correlation and the Wilcoxon Signed-Rank Test. Results:The mean uncorrected stereopsis was 141.5 ± 108.1 arc seconds, improving significantly to 66.8 ± 36.6 arc seconds after optical correction (Z=–14.031, p&lt;0.001). A significant positive correlation was found between cylindrical error in the right eye and baseline stereopsis (Spearman’s rho=0.465, p&lt;0.001). Screen time averaged 4.9 ± 1.5 hours/day and was negatively associated with stereopsis levels. Asthenopic symptoms, including frequent blinking (82.4%) and blurred vision (81.0%), were highly prevalent. Conclusion: Full refractive correction significantly improves stereopsis in children with high astigmatism. Excessive screen exposure may further compromise binocular function, underscoring the importance of early detection, timely correction, and lifestyle modifications in pediatric populations.

SIGNIFICANCE:Children with uncorrected astigmatism are often assumed to accommodate to the circle of least confusion. However, empirical evidence in children without a history of refractive correction is lacking. This study found that most children accommodate toward the anterior focal plane, with both focal planes exhibiting a lag of accommodation.PURPOSE:To examine accommodative responses by measuring refractive states of the eye during near viewing in children with uncorrected astigmatism without a history of refractive correction.METHODS:Participants aged 3 to <10 years with no history of refractive correction monocularly viewed a 20/250 letter at a 3-D demand (33 cm) while accommodative responses were measured using open-field autorefraction. Responses were classified based on the focal plane closest to the stimulus: anterior or posterior focal plane, or circle of least confusion. Cycloplegic autorefraction was used to classify participants as having low astigmatism (≤1.50 D) or high astigmatism (>1.50 D). Participants were further subdivided as having hyperopia (≥2.00 D), myopia (≥0.75 D), or emmetropia (less than 0.75 D myopia and 2.00 D hyperopia) based on their spherical cycloplegic refractive error. Chi-square analyses and Fisher exact tests were used to assess the association between accommodative response and cycloplegic refractive error classification.RESULTS:Of the 352 participants, 316 (89.8%) had low astigmatism and 36 (10.2%) had high astigmatism. In both groups, significantly more participants were classified as being focused at the anterior focal plane (low: 98.7%; high: 83.3%) than the posterior focal plane (low: 0.6%; high: 0.0%) or circle of least confusion (low: 0.6%; high: 16.7%; p<0.001). Almost all nonhyperopic participants in the low astigmatism group (99.2%) and hyperopic participants irrespective of astigmatism magnitude (low: 100%; high: 95.2%) accommodated closer to the anterior focal plane with accommodative lags in both meridians. Most nonhyperopic participants with high astigmatism also accommodated to the anterior focal plane (66.7%) and a third to the circle of least confusion (33.3%).CONCLUSIONS:In contrast to the assumption that children with astigmatism accommodate to the circle of least confusion, our findings show that most children accommodated to the anterior focal plane during near-viewing tasks, with accommodative lags in both meridians.

Background/Objectives: This study assessed outcomes between penetrating keratoplasty (PK) and Descemet’s stripping automated endothelial keratoplasty (DSAEK) when combined with cataract surgery as part of the triple procedure. Methods: Retrospective analysis of 727 triple procedures (525 PK and 202 DSAEK) from 2007–2023. Graft survival, visual acuity, and refractive outcomes were analyzed. Kaplan–Meier and Cox regression were used for survival and prognostic analysis. Results: No statistically significant difference in survival was found (PK—42 months; DSAEK—47 months). DSAEK had better visual acuity improvement and refractive stability. PK had higher astigmatism and variability in refractive error. Conclusions: While graft survival was comparable, DSAEK offers superior visual rehabilitation, supporting its use when refractive predictability is important.

To conduct a city-wide survey and investigate the risk factors of ocular disorders among institutionalised adults with intellectual disabilities (ID) in Taipei City. A cross-section city-wide ophthalmic survey was conducted in Taipei City from 2016 to 2017, involving full-day residents with ID aged over 18. Participant characteristics, including age, gender, ID severity and associated diseases, were collected for multiple logistic regression analysis to identify ocular disorder risk factors. A total of 687 participants, comprising 70.9% of the eligible individuals, were included. Refractive errors (73.8%), strabismus (32.6%), ocular hypertension (26.0%) and cataract (15.3%) were the most common ocular disorders. Myopia (73.2%) is the most common refractive error, with 14.6% being high myopia. Down's syndrome (DS) was a common risk factor for developing strabismus (OR, 2.87; 95% confidence interval [CI], 1.54 to 3.35), nystagmus (OR, 6.50; 95% CI, 2.22 to 19.0), high myopia (OR, 2.62; CI, 1.85 to 3.09), high astigmatism (OR, 3.06; CI, 1.65 to 5.69) and cataracts (OR, 8.00; CI, 3.50 to 18.30), while it served as a protective factor against ocular hypertension (OR, 0.14; CI, 0.03 to 0.62). Cerebral palsy (CP) was identified as a common risk factor for strabismus (OR, 2.17; CI, 1.16 to 4.05), nystagmus (OR, 4.22; CI, 1.51 to 11.8) and high myopia (OR, 2.22; CI, 1.04 to 4.73). High prevalence of myopia, strabismus, ocular hypertension and cataract was observed in institutionalised adults with ID. DS and CP were more significant risk factors than ID severity for ocular disorders. Regular ophthalmic exams, particularly monitoring intraocular pressure, are crucial for this population.

Purpose: Pellucid Marginal Degeneration (PMD) is a rare ectatic corneal disorder characterized by inferior peripheral thinning and significant irregular astigmatism. Despite its clinical similarities to keratoconus, PMD presents unique diagnostic and therapeutic challenges. This review aims to provide a comprehensive update on the pathophysiology, clinical features, diagnostic approaches, and management strategies for PMD, emphasizing the latest advancements in treatment options. Methods: A systematic literature search was performed in MEDLINE (via PubMed), Google Scholar, and Scopus up to February 2025 using the terms: "pellucid marginal degeneration," "PMD," "ectatic corneal disorders," "keratoplasty in PMD," "corneal cross-linking in PMD," "ICRS in PMD," "toric IOL PMD" and their Boolean combinations (AND/OR). The search was restricted to English-language studies involving human subjects, including case reports, case series, retrospective studies, clinical trials, and systematic reviews. A total of 76 studies met the inclusion criteria addressing treatment outcomes in PMD. Results: PMD is characterized by a crescent-shaped band of inferior corneal thinning, leading to high irregular astigmatism and reduced visual acuity. Diagnosis relies on advanced imaging techniques such as Scheimpflug-based corneal tomography, which reveals the characteristic "crab-claw" pattern. Conservative management includes rigid gas-permeable (RGP) lenses and scleral lenses, which provide effective visual rehabilitation in mild to moderate cases. Surgical options, such as CXL, ICRS, and toric IOLs, are reserved for advanced cases, with varying degrees of success. Newer techniques such as CAIRS, employing donor tissue instead of synthetic rings, show promising outcomes in corneal remodeling with potentially improved biocompatibility. Penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) remain definitive treatments for severe PMD, though they are associated with significant risks, including graft rejection and postoperative astigmatism. Conclusions: PMD is a complex and progressive corneal disorder that requires a tailored approach to management. Early diagnosis and intervention are critical to optimizing visual outcomes. While conservative measures are effective in mild cases, surgical interventions offer promising results for advanced disease. Further research is needed to refine treatment protocols and improve long-term outcomes for patients with PMD.

To compare the visual outcomes and corneal higher-order aberrations (HOAs) of patients with high or low myopic astigmatism after small incision lenticule extraction (SMILE). A total of 157 eyes of 157 patients who underwent SMILE were included in this retrospective, nonrandomized, comparative study. All the eyes which were with the rule astigmatism were divided into high astigmatism group (HAG; astigmatism ≤-2.00 D, 73 eyes) and low astigmatism group (LAG; astigmatism ≥-1.00 D, 84 eyes). Visual and refractive examinations were performed, HOAs of the anterior surface, posterior surface, and total cornea of the eyes were evaluated preoperatively and 6mo postoperatively. At the postoperative 6-month follow-up, uncorrected distance visual acuity of 20/20 or better was achieved in 97% and 100% eyes in HAG and LAG respectively and 74% and 100% eyes were within -0.50 D. Vector analysis revealed no significant differences in the correction index (P=0.066), angle of error (P=0.091) or flattening index (P=0.987) between two groups. The magnitude of error was -0.37±0.31 D in HAG and -0.04±0.19 D in LAG (P<0.001). Index of success (IOS) was 0.22±0.09 in the HAG and 0.50±0.46 in the LAG (P<0.001). HOAs of most anterior, posterior and total cornea significantly increased after SMILE, especially the spherical aberration and coma. For HAG, the SMILE procedure induced significantly higher anterior, posterior and total cornea horizontal coma and total corneal total HOAs compared with LAG (P<0.001) and these surgically induced HOAs predominantly originated from the anterior surface of the cornea. SMILE surgery induces more HOAs and a mild under-correction of astigmatism in eyes with high astigmatism. The increment in HOAs after SMILE is related to preoperative astigmatism.

Purpose: To investigate the long-term changes in astigmatism and identify factors associated with its progression in children with high astigmatism.Methods: We retrospectively reviewed the medical records of pediatric patients aged 2-10 years with astigmatism &gt; 2.0 diopters (D) who were followed for more than 5 years. Refractive errors were measured at the initial visit and at 1, 3, and 5 years thereafter. Patients were categorized into two groups based on changes in astigmatism over the first 3 years. Those who exhibited an increase in astigmatism &gt; 1.0 D were categorized in the progressive group, whereas the remaining patients were categorized in the stationary group. Factors related to astigmatism progression were analyzed.Results: In total, 93 eyes from 93 patients were included, with an average age of 4.6 ± 1.7 years. Of the patients, 42 were male and 51 were female. In all patients, significant progression was observed in both myopia and astigmatism between the initial visit and the 5-year follow-up. In patients with myopia and relatively low initial astigmatism, astigmatism significantly increased over time. The risk of astigmatism progression was higher in patients with epiblepharon than in others.Conclusions: A significant progression of astigmatism was noted in children with myopia and those with relatively low initial astigmatism. Additionally, epiblepharon was associated with astigmatism progression. Therefore, the presence of epiblepharon should be considered in the management of children with high astigmatism.

PurposeWe evaluated the efficacy of small incision lenticule extraction (SMILE), femtosecond-assisted laser in situ keratomileusis (FS-LASIK), and toric implantable collamer lens (TICL) implantation for correcting myopia with high astigmatism by vector analysis.MethodsThis retrospective study included 155 patients (155 eyes) with myopia and high astigmatism who underwent SMILE, FS-LASIK, or TICL implantation at our hospital. Patients were selected and divided into three groups based on the surgical procedure. The safety and effectiveness of three methods in correcting high astigmatism were compared, and the efficacy on high astigmatism were compared using Alpins’ vector analysis.ResultsSix months after surgery, operative safety and effectiveness did not differ significantly among the implantation types. Postoperative cylinder and SE were higher in the SMILE and FS-LASIK groups compared to the TICL group (P < 0.05). Among the three groups, significant differences were observed in surgically-induced astigmatism (1.91 ± 0.46D vs. 2.14 ± 0.56D vs. 1.89 ± 0.63D), difference vector (0.43 ± 0.28 vs. 0.34 ± 0.24 vs. 0.80 ± 0.52), correction index (0.96 ± 0.15 vs. 1.02 ± 0.15 vs. 0.87 ± 0.21), angle of error (-3.38 ± 5.87°vs. -0.54 ± 4.04° vs. -7.23 ± 10.09°), flattening effect (1.87 ± 0.47 vs. 2.13 ± 0.57 vs. 1.74 ± 0.64), flattening index (0.93 ± 0.14 vs. 1.01 ± 0.15 vs. 0.80 ± 0.22), and index of success (0.23 ± 0.16 vs. 0.16 ± 0.12 vs. 0.38 ± 0.24) (P < 0.05).ConclusionsSMILE, FS-LASIK, and TICL implantation are all safe and effective for correcting myopia with high astigmatism. FS-LASIK demonstrated the best correction effect on high astigmatism, followed by SMILE and TICL implantation.

To report the incidence, indications, and clinical outcomes of repeat deep anterior lamellar keratoplasty (DALK) in keratoconus patients. Case series. This retrospective study included all repeat DALK procedures for keratoconus performed at King Khaled Eye Specialist Hospital (KKESH) between 2016 and 2024. Patient demographics, surgical techniques, complications, and outcomes were analyzed. Among 2136 primary DALK procedures, only 0.66% (14 eyes) required repeat keratoplasty. The mean age at the time of repeat DALK was 32 and the mean follow-up duration was 30 months. Indications included lipid keratopathy (28.6%), persistent epithelial defect with severe immune reaction (14.3%), high irregular astigmatism (14.3%), and stromal scarring (7.1%). Graft exchange alone was sufficient in most cases (64%), while larger trephination and further dissection (22%) were performed for stromal scars or host rim ectasia. Postoperative complications (43%) included loose sutures (36%), elevated intraocular pressure (7%), and cataract formation (7%). The overall graft survival rate was 93%, with one failure due to poor compliance with postoperative steroids and follow-ups. Visual recovery was favorable, with 57% achieving 20/40 or better. Repeat DALK is a safe and effective alternative to penetrating keratoplasty (PK) for failed primary DALK, offering high graft survival and favorable visual outcomes while minimizing immune-related complications. Postoperative adherence and timely steroid management are critical for optimizing success. Further studies comparing repeat DALK and repeat PK are needed to assess long-term endothelial health and visual stability.

Relevance. Modern cataract surgery has acquired a distinct refractive focus, which is particularly relevant given population aging and the growing need for presbyopia correction. Patients now expect not only cataract removal but also complete spectacle independence, including cases of high ametropia where laser correction is contraindicated. Multifocal intraocular lenses (MIOLs) address this need by providing high visual acuity at all distances. However, the correction of high hyperopia using MIOLs remains understudied, despite these patients’ strong potential for successful implantation. Key contributing factors include: early-onset presbyopia, anatomical features (short axial length, narrow anterior chamber angle) predisposing to angle-closure glaucoma, and high motivation for spectacle independence. In this context, the 2023-approved trifocal IOL Triphobic HD True Trifocal Hydrophobic MICL (EYEOL UK LIMITED, UK) with its extended diopter range (up to +40.0 D sphere and +6.0 D cylinder) is of particular importance. The limited publications on its use underscore the relevance of this clinical case. Purpose. To analyze clinical and functional outcomes of Triphobic HD Toric True Trifocal Hydrophobic MICL implantation in a patient with high hyperopia and corneal astigmatism. Material and Methods. We present a case of a 42-year-old male with OU high hyperopia and corneal astigmatism, OS amblyopia. History: multifocal spectacle correction and exhibiting refractive instability. The patient underwent refractive lens exchange with Triphobic HD Toric True Trifocal Hydrophobic MICL implantation. Results. The postoperative course was uneventful. At 1-month followup, visual acuity was: OD: 1.0 (distance), 1.0 (66 cm), 0.5 (33 cm); OS: 0.7 (distance), 0.6 (66 cm), 0.4 (33 cm); OU: 1.0 (near/intermediate distance). The patient reported minor optical phenomena without discomfort. VF-14 satisfaction score was 100 points. Conclusion. This analysis demonstrates the efficacy and safety of Triphobic HD Toric True Trifocal Hydrophobic MICL implantation in high hyperopia. The results confirm modern MIOLs’ potential in refractive surgery by providing: high functional visual acuity at all distances, significant quality-of-life improvement, stable postoperative outcomes. Key success factors included: comprehensive diagnostic evaluation using modern equipment, precise IOL power calculation, strict surgical protocol adherence, personalized treatment approach Keywords: cataract surgery; high hyperopia; multifocal IOL; presbyopia

Purpose: Astigmatism is one of the most common forms of refractive error and can affect visual acuity as well as stereopsis. The aim of this study was to examine the influence of uncorrected symmetrical mixed astigmatism on binocular visual acuity and stereo threshold in different axis orientations. Material and Methods: In a non-randomized cross-sectional study, 40 participants were examined in two age groups (18 - 30 years and over 50 years). Using trial lenses, symmetrical mixed astigmatism was simulated in three axis orientations (90°, 0°, 45°) and two magnitudes (0.5 D and 1.0 D). Binocular visual acuity was determined as an interpolated logMAR value, while the stereo threshold was measured using the Stereo Acuity Test D10. Data were analyzed using repeated-­measures ANOVA and non-parametric tests. Results: Binocular visual acuity significantly decreased with an increasing magnitude of simulated astigmatism (p &lt; 0.001). Visual acuity was significantly worse at 1.0 D compared to 0.5 D. The stereo threshold also significantly increased with higher astigmatism (p &lt; 0.01), indicating a decrease in stereopsis. The axis orientation of astigmatism had a significant effect on stereopsis: Against-the-rule and oblique astigmatism caused greater impairments than with-the-rule astigmatism. The effect of age was significant only for with-the-rule astigmatism at 1.0 D (p = 0.019), with older participants showing greater deterioration in stereopsis than younger ones. Conclusion: Uncorrected mixed astigmatism leads to a significant decrease in binocular visual acuity and stereopsis, with the impact varying depending on axis orientation and astigmatism magnitude. The results suggest that even low levels of astigmatism should be corrected, particularly in individuals with limited accommodative ability.

Background/Objectives: Post-keratoplasty astigmatism can limit visual recovery even after successful corneal transplantation. Femtosecond laser-assisted arcuate keratotomy (FSAK) has emerged as a method to reduce high residual astigmatism and enhance visual outcomes. This study aimed to evaluate the outcome of FSAK in treating astigmatism following keratoplasty. Methods: This retrospective study included 32 eyes from 31 patients who underwent FSAK after keratoplasty. Inclusion required complete suture removal, regular corneal topography, and the absence of additional ocular pathology or prior intraocular surgery. Data collected included uncorrected (UCVA) and best-spectacle-corrected visual acuity (BSCVA), manifest refraction, and tomographic parameters. The primary outcomes were changes in visual, refractive, and tomographic measures across the entire cohort, with further subgroup analysis between penetrating keratoplasty (PKP) and lamellar keratoplasty (LKP) eyes. Secondary outcomes were documentation of complications. Results: UCVA improved significantly from 0.92 ± 0.33 to 0.58 ± 0.39 LogMAR (p < 0.001). BSCVA showed a non-significant trend toward improvement from 0.32 ± 0.21 to 0.26 ± 0.22 LogMAR (p = 0.158). The manifest cylinder reduced significantly from -6.15 ± 2.75 D to -4.49 ± 2.92 D (p = 0.037). Corneal topography revealed significant postoperative steepening in keratometric values. While overall outcomes were comparable between the subgroups, LKP eyes demonstrated a greater myopic shift and a higher rate of overcorrection, whereas PKP eyes tended toward undercorrection. Conclusions: FSAK appears to be an effective approach for reducing post-keratoplasty astigmatism and improving uncorrected visual acuity. Given the biomechanical differences between graft types, individualized treatment planning based on graft characteristics may enhance surgical predictability and optimize outcomes.

To compare the efficacy of toric implantable collamer lens (Toric-ICL) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia correction in patients with moderate to high myopia complicated with astigmatism. We retrospectively collected data from 64 patients (aged 18-42 years) with moderate to high myopia complicated with astigmatism (128 eyes) undergoing either Toric-ICL (28 patients/56 eyes) or FS-LASIK (36 patients/72 eyes) at our department between January, 2019 and December, 2020. The changes of uncorrected distance visual acuity (UCVA), spherical equivalent (SE), mean astigmatism correction index (CI), corneal endothelial cell density (ECD) and intraocular pressure (IOP) following the procedures were compared between the two groups. In FS-LASIK group, all the eyes (72/72) achieved an UCVA≥1.0, similar to the rate in Toric-ICL group (55/56 eyes; P=0.2374). The postoperative SE was also comparable between FS-LASIK and Toric-ICL groups [0.43±0.06 D (range: -1.0 to 1.50 D) vs 0.38±0.05 D (range: -0.75 to 1.00 D); P=0.56]. The mean astigmatism CI was significantly higher in FS-LASIK group than in Toric-ICL group (0.8561 vs 0.7176; P<0.0001), and 88.89% of the eyes in FS-LASIK group and 69.64% in Toric-ICL group had postoperative astigmatism ≤0.50 D. No significant changes were observed in postoperative corneal ECD in FS-LASIK group, whereas ECD decreased significantly after the procedure in Toric-ICL group (P=0.0057). The patients undergoing Toric-ICL exhibited no significant changes of postoperative IOP, but the patients receiving FS-LASIK had significantly reduced IOP after the procedure (P<0.001). Although the patients included in Toric-ICL group had higher myopia and astigmatism, Toric-ICL still showed better predictability and efficacy for astigmatic correction in Toric-ICL group. Toric-ICL is an effective and safe equivalent of FS-LASIK for correcting moderate myopia but can be more advantageous for correcting high myopia with astigmatism.