Correction Of Astigmatism Research Articles

Evaluation of Intraocular Pressure in Eyes After Femtolasik Surgery

Introduction: Femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) surgery is a surgical procedure performed in the treatment of refractive errors. Given the changes in central corneal thickness, intraocular pressure may be lower and underestimated, which may lead to a late diagnosis of ocular hypertension/glaucoma. Aims: The aim of this study was to evaluate and compare intraocular pressure, by different methods, before and after FS-LASIK, for correction of myopia or myopic astigmatism. Methods: Retrospective and observational study, which included eyes undergoing FS-LASIK surgery (November 2020 to November 2022). The intraocular pressure values were measured (preoperatively, on the 1st, 3rd and 6th postoperative month) using contact tonometry (Goldmann applanation tonometry) and non-contact tonometry (by Corvis®ST according to the formulas: pachymetry – Ehlers, Shah, Dresden, Spoerl – and biomechanics – corrected and uncorrected). The intraocular pressure values obtained at 6 months with the different methods were compared with the Goldmann applanation tonometry intraocular pressure values obtained at baseline. Results: Ninety patients (of a total of 174 eyes) underwent FS-LASIK, with a preoperative spherical equivalent of -3.7±1.7. Preoperatively (mean ± standard deviation) Goldmann applanation tonometry was 15.0±1.9 mmHg; the intraocular pressure values obtained through the Corvis® ST (in mmHg) according pachymetry: Ehlers (13.5±2.6), Shah (14.3±2.3), Dresden (14.5±2.2) and Spoerl (14.5±2.1); and biomechanics: corrected (14.4±1.9) and not corrected (15.3±2.1), respectively. At 6 months postoperatively, all showed statistically significant differences, with the exception of Shah's formula (p=0.074); comparing the preoperative Goldmann applanation tonometry with each of the formulas at the end of the follow-up, the Ehlers formula did not present statistically significant differences (p=0.434), the Shah formula a value of p=0.047 and the others a value of p<0.001. Conclusion: Femtosecond laser-assisted laser in situ keratomileusis surgery underestimates intraocular pressure measurement by contact tonometry. In non-contact tonometry, at 6-month follow-up, the Shah formula appears to be less influenced by this bias. More studies are needed to evaluate the best method to assess I intraocular pressure measurement after FS-LASIK surgery.

Three-Month Clinical Outcomes to Correct Myopia or Myopic Astigmatism Using a Femtosecond Laser for Lenticule Creation With Automated Centration and Cyclotorsion Compensation.

To individually evaluate the clinical outcomes for right and left eyes in the first 3 months after laser-assisted lenticule extraction for myopia and myopic astigmatism with the use of the new ATOS femtosecond laser system (Smart-Sight; SCHWIND eye-tech-solutions). A total of 331 eyes from 168 patients (166 right eyes and 165 left eyes) consecutively treated with SmartSight lenticule extraction were retrospective analyzed after a 3-month follow-up period. Patients' mean age was 26 ± 6 years (range: 18 to 47 years) and mean preoperative spherical equivalent (SEQ) was -5.07 ± 1.92 diopters [D] (range: -1.50 to -11.25 D) with a mean astigmatism of -1.04 ± 0.85 D (range: 0.00 to -4.00 D). At 3 months of follow-up, visual acuity, SEQ and cylinder, safety index, efficacy index, corneal higher order aberrations, and intraocular pressure (IOP) were analyzed. Furthermore, refractive and visual outcomes were also analyzed for the right and left eyes individually. All lenticule extraction treatments were performed with the SmartSight treatment method of the SCHWIND ATOS femtosecond laser. At 3 months after surgery, mean SEQ was -0.12 ± 0.19 D and 98% of eyes were within ±0.50 D of the SEQ. All eyes were within ±1.00 D of the SEQ. Astigmatism of 0.50 D or less was achieved in 99% of eyes. The change in Snellen lines (difference between preoperative corrected distance visual acuity and postoperative uncorrected distance visual acuity) showed a gain of one or more lines in 13% and in 85% of the eyes the same was achieved. There was a loss of one or more lines at 3 months of follow-up in 1.6%. The safety index was 1.03 and efficacy index was 1.02. No significant difference between the right and left eyes was found. The 3-month follow-up data show that SmartSight treatment for correction of myopia and myopic astigmatism with the SCHWIND ATOS is a safe, efficient, and accurate procedure. It provided excellent results in terms of visual recovery, predictability, and higher order aberrations. [J Refract Surg. 2024;40(1):e30-e41.].

Refractive Outcome of Femtosecond Assisted Laser in situ Keratomileusis in 1564 cases of Myopia and Compound Myopic Astigmatism.

To determine the outcomes of Femtosecond Assisted Laser in situ Keratomileusis (Femto LASIK) on eyes with myopia and compound myopic astigmatism in terms of efficacy, safety, accuracy, predictability, and stability of the procedure. Quasi-experimental study. Place and Duration of the Study: Refractive Surgical Department, Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, from January 2014 to August 2019. Participants aged 18 years and above with upto -12D (dioptre of myopia, underwent preoperative detailed work-up with history, ocular examination, subjective refraction and assessment on topography, tomography, and aberrometry. Suitable candidates underwent Femto LASIK and were re-evaluated at 1stpostoperative day, end of 1stweek, 1month, 3 months, 6months and 1year. Results were analysed and represented in form of standard graphs for refractive surgery. Results: Postoperative UDVA (uncorrected distance visual acuity) of 20/40 was achieved in 99% of patients. Efficacy index was 1.02 + 0.15. Safety index was 1.04 + 0.199. None of the patients lost more than one line in postoperative CDVA (corrected distance visual acuity) when compared to preoperative CDVA. All the eyes (100%) were accurately treated within +1.0 DS of intended spherical equivalent (SEQ) range. Mean SEQ showed stability with 1% eyes recorded to have more than 0.5D change or more over 12 months. Femto LASIK is an effective, safe, accurate, predictable, and stable procedure for correction of myopia and compound myopic astigmatism. Femtosecond, Laser in situ Keratomileusis, Refractive surgery, Myopia, Compound myopic astigmatism, Uncorrected distance visual acuity.

On the issue of diagnostic accuracy of methods for analyzing the parameters of regular astigmatism

This study evaluates the diagnostic accuracy of various methods for measuring the parameters of regular astigmatism. The study included 83 patients (122 eyes) with regular astigmatism exceeding 1.0 D. Three groups were formed depending on the type of astigmatism. Spherical and cylindrical (power and axis) components of refraction were determined using automatic refractometry. The results were refined with subjective tests: power and axis tests with a cross-cylinder. The criterion for diagnostic accuracy was the level of corrected visual acuity. To assess the impact of cylinder position on visual acuity, discrete deviations of the axis of trial astigmatic lenses from the correct position (determined based on subjective tests) were modeled at 5, 10, and 15 degrees in both clockwise and counterclockwise directions. In the overall sample of observations, coincidence of results was found only in one-third of cases, with a tendency for discrepancies in data between the two methods in nearly 70% of cases. Statistical processing revealed significant differences only in the magnitude of the cylinder in the group with against-the-rule astigmatism (p<0.0005). An increase in maximum visual acuity corrected based on subjective test data was noted. With a deviation of the cylinder axis from the correct position by 10-15 degrees, regardless of the type of astigmatism, a significant tendency for a decrease in visual acuity was identified. At the same time, with a deviation of the cylinder axis within 5 degrees, a significant decrease in visual acuity was noted only in with-the-rule astigmatism and counterclockwise deviation. To achieve maximum visual acuity in the correction of regular astigmatism, objective method data must be refined with subjective tests. The results of modeling the deviation of the axis of the corrective lens from the proper position can be considered when evaluating the functional outcomes of TIOL implantation.

Tolerance to induced astigmatism of patients with trifocal or extended depth of focus intraocular lens implantation.

Residual astigmatism is common after cataract surgery involving implantation of an intraocular lens, yet the tolerance of presbyopia-correcting intraocular lens to astigmatism of different magnitudes and axes is poorly understood. Here we compared visual acuity and quality in the presence of induced astigmatism after implantation of a trifocal or extended-depth-of-focus (EDOF) intraocular lens, the two widely used presbyopia-correcting intraocular lenses. At least 3 months after implantation of a TFNT00 or ZXR00 intraocular lens, patients were analyzed by slit-lamp examination, non-contact tonometry, subjective refraction, iTrace aberrometry, and corneal topography. After correction of residual astigmatism, astigmatism of different magnitudes on different axes was induced using cylindrical lenses, and overall visual acuity was measured, while objective visual quality was measured using the Optical Quality Analysis System II. Subjects were also asked about subjective visual quality using the Visual Function-14 questionnaire. Comparison of 18 individuals who received a trifocal lens and 19 who received an EDOF lens showed that objective visual quality was better in the EDOF group regardless of the magnitude or axis of the induced astigmatism. In both groups, astigmatism of at least -1.00 DC influenced distant vision more severely when the axis was 45° than 0° or 90°, meanwhile astigmatism of at least -1.50 DC influenced near and intermediate vision more severely when the axis was 45° than 0° or 90°. Trifocal or EDOF intraocular lenses are less tolerant of oblique astigmatism than astigmatism with or against the rule. EDOF lenses may provide better objective visual quality than trifocal lenses in the presence of astigmatism, regardless of its magnitude or axis.

Visual and refractive outcomes of opposite clear corneal incision combined with rotationally asymmetric multifocal intraocular lens implantation.

To evaluate the visual and refractive outcomes of astigmatic cataract patients following opposite clear corneal incision (OCCI) combined with rotationally asymmetric multifocal intraocular lens (IOL) implantation. Department of Ophthalmology, Zhongshan Hospital (Xiamen), Fudan University, People's Republic of China. Retrospective cohort study. This study comprised 58 cataract eyes of 54 patients with corneal astigmatism who underwent phacoemulsification and rotationally asymmetric multifocal IOL implantation which received either OCCI (OCCI group) or a single clear corneal incision (SCCI group). The follow-up period was 3 months after surgery. Distance, intermediate and near visual acuity, refractive outcomes, and corneal anterior keratometry were compared between the two groups. Vector analysis was used to evaluate astigmatism correction. Three months after surgery, the distance, intermediate and near visual acuity, and sphere remained comparable between the two groups, but a significant difference was detected in residual astigmatism and anterior corneal keratometric astigmatism. In the OCCI group, the residual astigmatism and keratometric astigmatism were -0.60 ± 0.29 D and 0.59 ± 0.28 D, respectively, which were lower than those in SCCI groups (-1.18 ± 0.47 D and 1.15 ± 0.45 D, both p < 0.05). In vector analysis, the difference vector (DV), angle of error (AoE), absolute AoE, index of success (IoS) and correction index (CI) were statistically significantly different between the two groups (p < 0.05). OCCI combined with rotationally asymmetric multifocal intraocular lens implantation showed predictable and desirable efficacy in treating cataract patients with astigmatism.

Optimization of Ray-Tracing-Guided LASIK Outcomes: A Prospective Comparative Study of ZZ InnovEyes Strategy versus Automated Strategy.

To evaluate the effectiveness of Zhang and Zheng's InnovEyes (ZZ InnovEyes) strategy for optimizing outcomes of ray-tracing-guided laser in situ keratomileusis (LASIK) compared to the standard automated strategy. A total of 38 patients (71 eyes) undergoing therapeutic refractive surgery at Hangzhou MSK Eye Hospital were randomly assigned to the ZZ InnovEyes and automated groups using double-masked randomization. The study assessed visual acuity, refractive outcomes, and higher-order aberrations preoperatively and at 1-day, 2-week, 1-month, and 3-month follow-ups. Statistical analysis was done with Microsoft Excel and SPSS 19.0. The exposure and control groups comprised 36 and 35 eyes, respectively. The ZZ InnovEyes group demonstrated significant advantages in manifest refraction spherical equivalent (MRSE) correction compared to the automated approach group (0.13 ± 0.30 D vs 0.62 ± 0.40 D, p < 0.001), achieving 97.22% uncorrected distance visual acuity (UDVA) of 20/16 or better compared to 85.71% in the automated group at the 3-month follow-up (p = 0.08), and achieving 50.00% UDVA of 20/12.5 or better compared to 28.57% in the automated group at the 3-month follow-up (p = 0.06). Loss lines from preoperative corrected distance visual acuity to postoperative UDVA were lower in the ZZ InnovEyes group (0.00%) than the automated group (8.57%; p = 0.07). Both groups exhibited similar astigmatism corrections and higher-order aberrations. The ZZ InnovEyes strategy, which incorporates manifest and wavefront refraction for ray-tracing-guided LASIK, demonstrated superior MRSE correction and potential advantages in visual acuity outcomes compared to the standard automated strategy. This study highlights the need for ongoing optimization and research in refractive surgery. ChiCTR2300078709.

Significance of Prescribing Astigmatic Correction in Young Patients having Low Astigmatism with Near Vision Complaints

Astigmatism causes increased difficulty in reading performance like book reading, mobile usage and computer work. Objective: The primary objective was to find out the significance of prescribing astigmatic correction in young patients having low astigmatism with near vision complaints and secondary objective was to find out the most common type of astigmatism affecting near vision. Methods: This was a multicentered, prospective cohort study conducted from April 2022 to Sep 2022. A total of 64 subjects of both genders were selected through non-probability convenient sampling technique. Patients with age between 15-30 years having low astigmatism (0.25-0.75D) with near vision complaints were included. Any amount of astigmatism was corrected with appropriate glasses and subjects were asked for a follow up fortnightly. Follow up improvement in symptoms were recorded and compared with earlier complaints by applying chi square test using SPSS version 23.0. Results: A total of 64 subjects were enrolled in the study. The mean age of patients was 22.44 years including 27 (42%) males and 37 (58%) females. The most common symptom was Eye Strain found in 53 (83%) of the patients. Most common type of astigmatism was Against the Rule astigmatism. 62 (96%) patients improved to 6/6 in both eyes. On follow up, improvement in symptoms was noted and compared with symptoms before the usage of glasses. Conclusions: The study concluded that the treatment for near vision complaints in young patients is prescribing them with proper cylindrical / astigmatic correction in the form of eye glasses.

Astygmatyzm w kontekście operacji usunięcia zaćmy z wykorzystaniem torycznych soczewek wewnątrzgałkowych – aktualny przegląd piśmiennictwa

Assessment and management of astigmatism is often difficult, and one of the specific situations in which this problem must be faced is when a patient with astigmatism is qualified for cataract surgery. A relatively predictable method of astigmatism correction during a single procedure and also the method of choice in the treatment of cataracts accompanied by corneal astigmatism is cataract phacoemulsification with implantation of toric intraocular lenses. The aim of the study is to review the current literature on this topic. The prevalence of corneal astigmatism ≥1.0 D in patients with cataract varies in various studies from 34.8 to 66.9%, which illustrates the scale of demand for this procedure. The paper discusses the key aspects of pre-operative assessment of astigmatism, including the changes that occur with the aging process. The importance of measuring the posterior corneal astigmatism and the consequences of its neglect in the form of deviations in the assessment of total corneal astigmatism and postoperative residual refractive errors were emphasized. Attention was paid to available updates of toric calculators and innovations in cases of irregular astigmatism.

Wybrane zagadnienia dotyczące implantów torycznych wszczepianych podczas operacji usunięcia zaćmy i operacji refrakcyjnej wymiany soczewki

Toric intraocular lens implantation is currently a preferred method of astigmatism correction in patients with cataract and during refractive lens exchange. Astigmatism-correcting lenses enable significant visual acuity improvement and increase patient satisfaction after the surgery. In order to achieve optimal postoperative results, it is required to conduct proper qualification, thorough and reliable keratometry measurements before surgery as well as consider potential contraindications to toric intraocular lens implantation. The aim of this review is to outline current indications and contraindications for toric lens implantation and to introduce toric lens power calculation methods

Strategy of Surgical Treatment of Patients with Pigment Dispersion Syndrome and Myopia

Purpose: to conduct a prospective study of the results of surgical treatment of patients with pigment dispersion syndrome and complex myopic astigmatism. Materials and methods. As a result of a comprehensive examination of 10453 adult primary patients with complex myopic astigmatism, the diagnosis of pigment dispersion syndrome was made in 99 patients (0.94 %). The study group consisted of 22 people, 9 men and 13 women, with an average age of 29.4 ± 9.8. In the case of iridosonular contact, according to ultrasound biomicroscopy, laser basal iridectomy was performed at the first stage. In the case of normal intraocular pressure indicators, laser correction of myopia was made in patients of the study group within 6 months after laser basal iridectomy. Results. During biomicroscopy, a Krukenberg spindle was observed in 34 eyes (77.2 %), exogenous pigment was detected in 20 eyes (45.4 %) on the iris and lens, and sectoral illumination of the iris was detected in 5 (11.4 %). After laser basal iridectomy on 24 eyes (54.5 %) in all the studied meridians, we noted a tendency to deepen the posterior chamber, but the increase was statistically significant only at 12 hours (P &lt; 0.05). The achieved decrease in the angle of the anterior chamber was statistically significant (P &lt; 0.05) in the meridians of 3, 9 and 12 hours and ranged from 3.56 to 8.53 degrees in different meridians. Laser correction of complex myopic astigmatism was performed in 11 patients (22 eyes) using ReLEx® SMILE technology and 10 (20 eyes) patients using FemtoLASIK technology. At the end of the observation period after correction, refraction within ±0.5 dptr of the planned one was achieved in 88.1 % of cases (37 eyes), ±1.0 dptr — in 100 % of cases. The efficiency coefficient was 88.46 %, the safety coefficient was 92.8 %. Postoperative values of corneal-compensated IOP were comparable with preoperative indicators (P &gt; 0.05). Conclusions. The analysis of the of surgical treatment results in the patients with pigment dispersion syndrome and myopia showed the absence of negative dynamics in the course, as well as high efficiency, safety and stability of the results achieved after laser correction. The applied algorithm for the management of patients with combined pathology with pigment dispersion syndrome and myopia is pathogenetically justified, safe, promotes the preservation of visual functions of patients and improves their quality of life.

Toric Monofocal Intraocular Lenses for the Correction of Astigmatism during Cataract Surgery: A Report by the American Academy of Ophthalmology

To review the published literature evaluating the visual and refractive outcomes and rotational stability of eyes implanted with toric monofocal intraocular lenses (IOLs) for the correction of keratometric astigmatism during cataract surgery and to compare those outcomes with outcomes of eyes implanted with nontoric monofocal IOLs and other astigmatism management methods performed during cataract surgery. This assessment was restricted to the toric IOLs available in the United States. A literature search of English-language publications in the PubMed database was last conducted in July 2022. The search identified 906 potentially relevant citations, and after review of the abstracts, 63 were selected for full-text review. Twenty-one studies ultimately were determined to be relevant to the assessment criteria and were selected for inclusion. The panel methodologist assigned each a level of evidence rating; 12 studies were rated level I and 9 studies were rated level II. Eyes implanted with toric IOLs showed excellent postoperative uncorrected distance visual acuity (UCDVA), reduction of postoperative refractive astigmatism, and good rotational stability. Uncorrected distance visual acuity was better and postoperative cylinder was lower with toric IOLs, regardless of manufacturer, when compared with nontoric monofocal IOLs. Correcting pre-existing astigmatism with toric IOLs was more effective and predictable than using corneal relaxing incisions (CRIs), especially in the presence of higher magnitudes of astigmatism. Toric monofocal IOLs are effective in neutralizing pre-existing corneal astigmatism at the time of cataract surgery and result in better UCDVA and significant reductions in postoperative refractive astigmatism compared with nontoric monofocal IOLs. Toric IOLs result in better astigmatic correction than CRIs, particularly at high magnitudes of astigmatism. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The correction of a hyperopic astigmatism with full-toric orthokeratology lenses. Clinical case

Orthokeratology has gained widespread clinical application in the last decade due to accumulated scientifi c data confi rming its effectiveness in inhibiting progressive myopia in children and adolescents. In cases of correction of other refractive errors, such as hypermetropia, mixed astigmatism, specialists inform patients about the possibilities of orthokeratology lenses (OKL) not often. This clinical case demonstrates the possibilities of customized, full-toric OKL to correct complex hyperopic astigmatism in an 11-year-old child. The patient was observed for several years with complex hyperopic astigmatism in ophthalmological clinics and followed the recommendations of specialists to use eyeglass correction. At the stage of transition from preschool to primary school, the child became shy of glasses and refused to wear them. In search of an alternative method of correction, parents sought advice in the special contact lens practice. The patient underwent a complete ophthalmological examination, including corneal topography. Taking into account the features of refraction and the shape of the cornea, the wishes of the child and parents, we have chosen customized orthokeratology lenses (OKL) with a fully toric design (full-toric) as method of correction. The OKL parameters were calculated by using the RGP Designer program. The lenses were made by OKVision Laboratory (Moscow). The fi tting of customized OKL allowed us to solve several tasks at once: the correction of complex hyperopic astigmatism and the freedom from using correction tools in the daytime. Despite the fact that orthokeratology is not the fi rst-line choice for optical correction of hyperopia, in some cases the method may become the only alternative to glasses and soft contact lenses

Clinical outcomes of stromal lenticule rotation to correct mixed astigmatism.

To describe a stromal lenticule rotation surgical technique to correct mixed astigmatism and evaluate the initial clinical outcomes of this innovative approach. This retrospective case series included five eyes from five patients with mixed astigmatism that underwent intrastromal lenticule rotation surgery. The eyes were evaluated for uncorrected visual acuity, corrected distance visual acuity, manifest refraction, central corneal thickness, corneal volume, anterior and posterior K readings, and corneal higher order aberrations (HOAs) (including total HOAs, spherical aberrations, coma, and trefoil) using the Scheimpflug-Placido topographer before and 3 months after surgery. The corneal epithelium and stroma were imaged using anterior segment optical coherence tomography (AS-OCT) postoperatively. A paired-sample t-test was used to analyse the data. Clinical improvement was found in the uncorrected distance visual acuity (0.64 ± 0.11 logMAR vs. 0.20 ± 0.17 logMAR) and spherical and cylindrical diopters (D) (+2.65 ± 1.32 D vs. -0.05 ± 0.51 D and -4.95 ± 0.94 D vs. -1.10 ± 0.78 D, respectively). Anterior flat keratometry readings showed a steep trend (40.65 ± 1.24 D vs. 42.73 ± 0.63 D). Anterior corneal astigmatism decreased from 4.50 ± 0.55 D to 2.05 ± 0.73 D. According to the AS-OCT images, no significant epithelial remodelling was observed postoperatively. Although no significant differences were found among the increased corneal HOAs, the coma and trefoil changed much more than spherical aberrations 3 months postoperatively. The results for these five eyes suggest that the autologous stromal lenticule rotation technique is safe and effective; it may be an economical and feasible surgical option for correcting mixed astigmatism.

Simulation model for advanced astigmatism corrective eyeglasses and contact lenses

Mathematical eye models are crucial for developing treatment strategies for astigmatic eye conditions. Extensive research has been conducted on various treatment techniques, and also various surfaces in glasses and contact lenses. This study aims to address the existing research gap by optimizing mathematical eye models for specific astigmatic conditions. Using Liu and Brennan's model, we simulate the correction of astigmatism with glasses and contact lenses. We optimize toroidal and aspherical lens surfaces to maximize their effectiveness in correcting astigmatism and evaluate image quality using modulation transfer function (MTF), point spread function (PSF), and focal spot diagrams. Our results show that both glasses and contact lenses can effectively treat astigmatism, with glasses providing superior correction. However, individual factors such as oblique vision, decentration, and anterior surface asphericity can influence treatment outcomes. This study contributes to advancing ophthalmology by integrating computational models with clinical data to improve treatment planning and personalization.

Comparison of risk factors for OBL in FS-LASIK and SMILE correction for myopia and myopia astigmatism.

To find out the incidence and risk factors of opaque bubble layer (OBL) in eyes with myopia and myopic astigmatism following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). A total of 1076 eyes from 569 patients who had FS-LASIK or SMILE were included in the retrospective research. For each kind of surgery, eyes were separated into two groups: "OBL" groups and "no OBL" groups. In the FS-LASIK group, eyes that developed OBL were split into "hard OBL" and "soft OBL" groups. The incidence and size of OBL were analyzed after watching the surgical procedure videotaped during the operation and taking screenshots. Surgical parameters, including sphere, cylinder, keratometry, corneal thickness, flap thickness, cap thickness, lenticule thickness, and visual acuity, were compared. In the FS-LASIK surgery, the incidence of OBL was 63.2% (347 eyes). A thicker central corneal thickness (CCT) was the only independent risk factor affecting the OBL area (β = 0.126, P = 0.019). One hundred and thirty of these eyes had hard OBL, and the flap thickness of these eyes was thinner than that of those with soft OBL (P = 0.027). In the SMILE group, 26.6% (140 eyes) developed OBL. A higher flat keratometry (K) and a thicker residual stromal thickness (RST) were risk factors affecting the OBL area (β = 0.195, P = 0.024; β = 0.281, P = 0.001). The incidence of OBL differs between the FS-LASIK surgery and the SMILE surgery. There are differences in the factors influencing OBL between the two surgeries.

Differences Between Keratometry and Total Keratometry Measurements in a Large Dataset Obtained With a Modern Swept Source Optical Coherence Tomography Biometer

This study aimed to explore the concept of total keratometry (TK) by analyzing extensive international datasets representing diverse ethnic backgrounds. The primary objective was to quantify the disparities between traditional keratometry (K) and TK values in normal eyes and assess their impact on intraocular lens (IOL) power calculations using various formulas. Retrospective multicenter intra-instrument reliability analysis. The study involved the analysis of biometry data collected from ten international centers across Europe, the United States, and Asia. Corneal power was expressed as equivalent power and astigmatic vector components for both K and TK values. The study assessed the influence of these differences on IOL power calculations using different formulas. The results were analyzed and plotted using Bland-Altman and double angle plots. The study encompassed a total of 116,982 measurements from 57,862 right eyes and 59,120 left eyes. The analysis revealed a high level of agreement between K and TK values, with 93.98% of eyes exhibiting an absolute difference of 0.25 D or less. Astigmatism vector differences exceeding 0.25 D and 0.50 D were observed in 39.43% and 1.08% of eyes, respectively. This large-scale study underscores the similarity between mean K and TK values in healthy eyes, with rare clinical implications for IOL power calculation. Noteworthy differences were observed in astigmatism values between K and TK. Future investigations should delve into the practicality of TK values for astigmatism correction and their implications for surgical outcomes.

Refractive Surgery Overview

Advancements in technology and techniques are continuously shaping the field of refractive surgery for the correction of myopia, hyperopia, astigmatism, and presbyopia. As a result, more patients are seeking alternatives to spectacles or contact lenses. Clinicians must stay up-to-date with the latest options available for vision correction. This article aims to provide a comprehensive overview of the exciting progress being made in this area of clinical advancements and research.

Single and dual limbal relaxing incisions in correcting corneal astigmatism during cataract surgery

Introduction: Correcting astigmatism during cataract surgery to achieve optimal visual outcomes is important. Various techniques, such as limbal relaxing incisions (LRIs), are used to correct astigmatism. LRIs are effective for mild to moderate astigmatism but have limitations in correcting larger astigmatism. This study aimed to review the effectiveness of single and dual LRI in correcting astigmatism during cataract surgery. Methods: This literature review utilized databases from 2010 until 2022. The keywords “corneal astigmatism”, “limbal relaxing incision”, and “cataract surgery” were used to collect 12 journals that had relevant topics. Results: LRIs are a form of partial-thickness keratotomy used to correct astigmatism during cataract surgery. The incisions for LRIs are made in the peripheral cornea, following a nomogram based on the patient's astigmatism, age, and the location of the steep axis of astigmatism. LRIs can be performed as single or dual incisions, with dual LRIs offering greater astigmatism correction. In the case of irregular astigmatism, LRIs can be adjusted to the topography of the cornea because the lengths of coupled incisions can vary. Conclusion: The effectiveness between single and dual LRIs was the same, but paired LRIs have a superior effect in correcting greater astigmatism. LRIs remain a valuable tool for cataract surgeons to manage astigmatism and improve visual outcomes in cataract surgery patients.

GAMBARAN BESAR KELAINAN REFRAKSI ASTIGMATISME PADA ANAK USIA DINI DI PASIR JAYA TAHUN 2022

This study focuses on how the eye conditions of children suffering from astigmatime are in the Pasirjaya housing complex. The purpose of this research is to provide education about the importance of maintaining eye health. To provide an understanding of astigmatism. To provide knowledge on how to treat astigmatism so that it can be overcome. The research method used in this study is a qualitative method (by developing why atigmatism in children can occur and the factors that can cause astigmatism in children). This study resulted in the findings that patients know about Astigmatism in children as much as 61.7%. It was found that they had astigmatism, while the others had other refractive errors. This was due to the prolonged use of gadgets in carrying out online activities or also known as online. while those who understand the dangers of astigmatism are left at 60.7% so they do protection with astigmatism correction lenses. So that parents especially have to be introspective in seeing the development of children during this pandemic season by monitoring the use of laptops or gadgets in their daily processes by instilling the 20/20/20 theory