Correction Of Myopic Astigmatism Research Articles

Seven-year refractive outcomes comparing small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis for myopia and myopic astigmatism.

This study aimed to compare the seven-year refractive outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for correction of myopia and myopic astigmatism. This retrospective cohort study included 97 eyes of 53 patients who had undergone SMILE or FS-LASIK for myopia seven years prior. Measured parameters included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction. There were no significant differences between the SMILE and FS-LASIK groups in logMAR UDVA, cylinder, and logMAR CDVA at 7 years postoperatively (P>0.05). However, there were significant differences between the two groups in sphere and spherical equivalent (P=0.035 and P=0.016, respectively). UDVA was better than or equal to 20/20 in 81% of the eyes after SMILE and in 63% after FS-LASIK (P = 0.045). The efficacy indices of the SMILE and FS-LASIK groups were 1.04 ± 0.23 and 0.97 ± 0.23 (P=0.405), and the safety indices were 1.18 ± 0.19 and 1.10 ± 0.17 (P=0.543), respectively. This study demonstrates the good predictivity of both SMILE and FS-LASIK. SMILE could offer superior refractive outcomes than FS-LASIK during a 7-year follow-up in correcting myopia and myopic astigmatism.

Ten-year evaluation on efficacy, safety and predictability of femtosecond laser corneal small incision lenticule extraction for correction of myopia and myopic astigmatism: A case series

Objective: To evaluate the 10-year long-term outcomes of patients undergoing small incision lenticule extraction (SMILE). Methods: In this continuous case series, we enrolled a total of 113 patients (208 eyes) who underwent SMILE 10 years prior. Measured parameters included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), cycloplegia spherical equivalent error (SER). Results: 113 patients were enrolled in this study. Patients’ age ranged from 18 to 44 years (mean: 30.2 years). 193 eyes (92.8%) and 176 eyes (84.6%) had an UCVA≥20/20 at 3 months and 10 years postoperatively. The mean efficacy index, measured at 3 months and 10 years postoperatively, were 1.041 and 1.023, respectively; the difference was not statistically significant.Three months after operation, best-corrected visual acuity (BCVA) decreased by 1 line in 19 eyes (9.1%), remained unchanged in 158 eyes (76.0%), increased by ≥1 line in 31 eyes (14.9%). Ten years after operation, BCVA decreased by 2 lines in 15 eyes (7.2%) and by 1 line in 35 eyes (16.8%); remained unchanged in 142 eyes (68.3%); increased ≥1 line in 16 eyes (7.7%). The mean safety index, measured at 3 months and 10 years postoperatively, were 1.147 and 1.331, respectively; the difference was not statistically significant. The mean SER at 3 months and 10 years postoperatively was -0.112 and -0.276, respectively; the difference was statistically significant. Conclusion: There was a decrease in SER 10 years after SMILE surgery compared with 3 months postoperatively, there was no significant decrease in the efficacy index or safety index.

12-Month Visual and Refractive Outcomes of Topography-guided Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism.

To report 12-month visual and refractive outcomes following topography-guided femtosecond laser-assisted laser in situ keratomileusis (LASIK) for myopia and compound myopic astigmatism correction. This prospective, single-center observational study was conducted in an outpatient clinical practice at the Stanford University Byers Eye Institute in Palo Alto, California. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, 5% and 25% contrast sensitivity CDVA, and manifest refraction following topography-guided femtosecond laser-assisted LASIK were assessed. Refractive measurements were used to perform a vector analysis. Sixty eyes of 30 patients (mean age: 32.8 ± 7.0 years; range: 23 to 52 years) undergoing topography-guided LASIK for the correction of myopia and compound myopic astigmatism were analyzed. Mean postoperative UDVA was -0.09 ± 0.10 logarithm of the minimum angle of resolution (logMAR) at 12 months. Mean preoperative CDVA was -0.09 ± 0.09 and -0.13 ± 0.08 logMAR at postoperative 12 months. At 12 months, 26.9% of eyes had gained one or more lines of postoperative UDVA compared to baseline CDVA. Mean pre-operative 5% contrast sensitivity CDVA was 0.68 ± 0.07 and 0.64 ± 0.12 logMAR at 12 months (P = .014) following LASIK. Topography-guided LASIK for myopia and myopic astigmatism correction provided excellent visual and refractive outcomes that were predictable, precise, and stable up to 12 months postoperatively. [J Refract Surg. 2024;40(9):e595-e603.].

Comparison between 80-microns versus 100-microns flap femtosecond LASIK for correction of myopia and myopic astigmatism.

This study aimed to compare the safety, efficacy, and visual outcomes of 80-microns LASIK versus 100-microns LASIK in managing myopia and myopic astigmatism. The study was conducted at a tertiary care hospital in North India. This was a prospective contralateral eye study that included patients with myopia and myopic astigmatism seeking refractive correction. The eligibility criteria included normal corneal topography, an epithelial thickness less than 60 microns, a calculated percentage tissue ablation (with 100-microns flap) less than 40%, a calculated residual stromal bed thickness (with 100-microns flap) more than 300 microns, and willingness to participate and follow up. Patients with glaucoma, cataracts, other visually disabling ocular pathologies, and a history of past ocular surgery were excluded. All patients underwent LASIK with 80-microns LASIK in one eye and 100-microns LASIK in the other eye. The patients were followed up for 6 months, and the results were analyzed. The study included 216 eyes of 108 patients. The mean preoperative spherical equivalent in the 80-microns group and the 100-microns group was -3.53 ± 1.81 and -3.69 ± 1.32 diopters, respectively (P = 0.78). The mean 6 months decimal postoperative UCVA was 0.98 ± 0.13 in the 80-microns group and 0.97 ± 0.14 in the 100-microns group (P = 0.99). The postoperative change in the higher-order aberration profile was comparable in both groups (P = 0.78). The percentage tissue ablation was significantly lower in the 80-microns group (P = 0.002). The incidence of flap micro striae and OBL was higher in the 80-microns group, while neither of these had any visual implications. The study concluded that 80-microns LASIK is an efficacious and safe alternative to 100-micron LASIK, especially useful in patients with higher myopia.

Refractive outcomes after V4c Toric collamer lens implantation over 1y of follow-up.

To evaluate refractive outcomes and corneal astigmatism changes after Toric implantable collamer lens with a central port (V4c T-ICL) implantation over 1y of follow-up. A retrospective study was performed including 50 eyes of 50 patients that underwent V4c T-ICL implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, refractive and corneal astigmatism changes and corneal coupling correction were evaluated preoperatively, 1 and 12mo postoperatively. Vector analysis was used for astigmatism changes. Coefficient of adjustment (CAdj) was calculated for corneal coupling analysis. The mean UDVA achieved was 0.03 logMAR at 1mo and remained unchanged throughout the whole follow-up (P=0.193). At the last visit, 84% of the eyes achieved a CDVA of 0.00 logMAR or better. Regarding spherical equivalent refraction (SEQ), 96% of eyes were ranges of ±1.00 D and 84% of them within ±0.50 D. Also, 94% of eyes had a remaining refractive cylinder within ±1.00 D and 78% of them within ±0.50 D. Both, SEQ and refractive cylinder, remain stable over the postoperative follow-up (P=1.000 and P=0.660, respectively). In terms of surgically induced astigmatism (SIA), no statistically significant differences were found over the follow-up (P=0.102) and under correction was found with a correction index lower than the unit at each visit. A keratometric astigmatism induced of 0.59±0.53 (vector mean: 0.26×73°) D was reached at the last visit. No significant changes in terms of corneal astigmatism orientation were reported over post-surgery visits (P=0.129 and P=0.097 at 1 and 12mo respectively). No clinical significance was found for CAdj on with-the-rule astigmatism. No postoperative complications resulting from the surgery were found. Refractive outcomes suggest that the V4c T-ICL implantation for correction of myopic astigmatism was satisfactory in terms of effectiveness, safety, and stability during 1y of follow-up. Corneal astigmatism induced by the incision around 0.5 D is achieved according to the remaining refractive cylinder found at one-year post-surgery. Corneal coupling analysis results in no unexpected spherical change.

Клинический случай докоррекции остаточной аметропии после выполненной фемтолазерной лентикулярной коррекции миопии и миопического астигматизма по технологии CLEAR

A clinical case of post-correction of residual ametropia after femtolaser lenticular correction of myopia and myopic astigmatism using CLEAR technology T.S. Kuznetsova, V.D. Antonuk Gazprom Eye Microsurger y Clinic, Moscow, Russian Federation N.I. Pirogov National Medical Surgical Center, Moscow, Russian Federation Purpose. To present a clinical case of Trans-PRK surgery for the purpose of correcting residual ametropia after previously performed femtolaser lenticular correction of myopia using CLEAR technology. Methods. As a result of femtolaser lenticular correction of myopia, the patient revealed residual myopia in the left eye in early postoperative period. At the request of the patient, it was decided to carry out additional correction using Trans-PRK technology in order to preserve the type «flap-free» laser correction. The post-correction on the left eye was performed 11 months after the previous CLEAR operation. Results. The operation was performed without complications, according to the standard protocol. A high functional result was achieved. However, in postoperative period, haze 0–1 degree was detected in the left eye. Conservative treatment with corticosteroid drug was performed to a standard decreasing scheme. Conclusion. Post-correction after femtolaser lenticular correction of myopia using Trans-PRK technology is possible. There is a risk to developing haze in the postoperative period. Key words: femtolaser lenticular correction, myopia, myopic astigmatism, post-correction, Trans-PRK, CLEAR

Implantation of phakic intraocular lenses in patients with stabilized keratoconus

To date, extensive experience has been accumulated in the correction of high myopia and myopic astigmatism through the implantation of additional negative lenses (phakic intraocular lenses). However, the use of this method in patients with anatomically altered corneas due to keratoconus remains unresolved.Purpose: to assess the effectiveness and safety of correcting high myopia combined with myopic astigmatism by implanting phakic intraocular lenses in patients with stabilized keratoconus at stages 1–2.Materials and methods. The study encompassed results from 27 surgeries involving the implantation of phakic intraocular lenses in patients with high myopia and myopic astigmatism (12.63 ± 4.25 D). These patients had thin corneas and were diagnosed with stage 1–2 keratoconus after undergoing corneal collagen crosslinking treatment – this constituted the main group. The control group comprised 35 surgeries performed on patients with subclinical non-progressive keratoconus (Forme Fruste). All participants underwent evaluations for visual acuity dynamics and refractive stability of spherical and cylindrical components before surgery, immediately post-surgery, and then at 1, 6, and 12 months after implantation. Additional assessments included intraocular pressure measurements, gonioscopy, ultrasonic echobiometry, ultrasonic ophthalmoscopy, biomicroscopy, ophthalmoscopy, endothelial microscopy, vision character and stereopsis determination, ultrasound biomicroscopy, anterior segment optical coherence tomography, electrophysiological studies, and statistical analysis. An IPCL (a type of phakic intraocular lenses made from hydrophilic acrylic) was implanted, capable of correcting myopia up to 30 D and astigmatism up to 10 D.Results. All patients achieved high uncorrected visual acuity 0.86 ± 0.11. Astigmatism correction was successful in 96% of cases. The average postoperative vault – the distance from the back surface of the phakic intraocular lenses to the anterior lens capsule – was 527.5 ± 40.27 μm (range 460–600 μm), and the intraocular pressure was 11.7 ± 2.08 mm Hg. There was a minor decrease in corneal endothelial cell count from 2599 ± 157.3 to 2375 ± 125.3 cells/mm² in the first group and from 2614 ± 104.8 to 2375 ± 43.3 cells/mm² in the second group respectively (p > 0.05), which falls within the acceptable loss range of 4–7% from preoperative values for both groups. Throughout the observation period, there were no cases of cataract development, pigmentary glaucoma, pupillary block, or other vision-threatening complications.Conclusions. Implantation of phakic intraocular lenses in patients with early-stage stabilized keratoconus and subclinical non-progressive keratoconus provides an effective and practically safe means of correcting high myopia and astigmatism.

Outcomes of astigmatic correction with and without two different cyclotorsion compensation methods in small incision lenticule extraction surgery

PurposeTo compare the astigmatic correction outcomes of small incision lenticule extraction (SMILE) surgery with or without two different cyclotorsion compensation methods. MethodsThis is a prospective randomized clinical trial. Patients with myopic astigmatism that underwent SMILE surgery were randomly divided into static cyclotorsion compensated group (SCC group), slit-lamp group and control group. In the SCC and slit-lamp groups, the intraoperative cyclotorsion was manually compensated with different limbal marking methods. In the control group, the cyclotorsion was not compensated. Visual acuity and manifest refraction were measured preoperatively and postoperatively. Astigmatic outcomes were estimated with vector analysis. ResultsA total of 94 eyes from 94 patients were analyzed postoperatively at the 3-month follow-up. Their mean preoperative cylinder was -1.56±0.86 D (range: -4.25 to -0.25 D). The mean preoperative spherical equivalent was -5.95±1.72 D (range: -10.50 to -2.75 D). All groups showed favorable results in the correction of myopic astigmatism. No statistically differences were found among three groups in postoperative visual acuity, refractive outcomes or vector parameters. ConclusionCyclotorsion compensation with two different manual limbal marking methods was helpful in aligning the surgical position in SMILE, but it was not as effective as expected for the correction of myopic astigmatism under well controlled surgical positioning.

Comparison of Outcomes after Wavefront-optimized and Topography-guided Transepithelial Photorefractive Keratectomy.

To evaluate the outcomes of wavefront-optimized (WFO) and topography-guided (TG) transepithelial photorefractive keratectomy (transPRK) in the treatment of myopia and myopic astigmatism. Patients who underwent transPRK using the WaveLight EX500 excimer laser for the correction of myopia and myopic astigmatism between January 2022 and March 2023 were divided into groups of WFO transPRK (77 eyes of 36 patients) or TG transPRK (63 eyes of 31 patients) in this retrospective, observational cohort study. The preoperative and postoperative 3-month refractive and visual outcomes of the two groups were analyzed. In both groups, the uncorrected distance visual acuity was 0.0 logarithm of the minimum angle of resolution or better in 95% of eyes 3 months postoperatively, and the mean manifest refraction spherical equivalent was within ±1.0 diopter in 90% of eyes. No significant differences were observed between the groups in terms of the uncorrected distance visual acuity or astigmatism. A significant induction of higher order aberrations (HOAs) was observed in both groups. However, the induction of total corneal HOAs (p = 0.014) and spherical aberrations (p < 0.001) was significantly lower in the TG group than that in the WFO group. WFO and TG transPRK effectively improved the visual and refractive outcomes; however, the induction of total corneal HOAs and spherical aberration was lesser following the TG ablation.

Технология CLEAR. Клинико-функциональные результаты более 1000 коррекций миопии и миопического астигматизма

Abctract CLEAR technology. Clinical and functional results of more than 1000 corrections of myopia and myopic astigmatism T.S. Kuznetsova, V.D. Antonuk, S.Yu. Shchukin, I.V. Drozdov, O.I. Kuranova Gazprom Eye Microsurgery Clinic, Moscow Purpose. To evaluate the clinical and functional results of correction of myopia and myopic astigmatism using CLEAR technology. Material and methods. In Eye Microsurgery Gazprom Clinic, 1252 CLEAR surgeries (626 patients) were performed on the platform of the LDV Z8 femtosecond laser (Ziemer) in the period from October 2021 to May 2023. Gender distribution: 219 males (35%) and 407 females (65%). The follow-up period was from 4 months to 12 months. The age of the patients ranged from 16 to 49 years (32.04±6.74 years). Sph from –0.25 to –9.0 D (–3.76±1.48 D), cyl from –0.0 to –2.25 D (–0.53±0.34 D), uncorrected visual acuity was 0.07±0.06, and best corrected visual acuity ranged from 0.8 to 1.0 (0.99±0.01). Central corneal thickness (CCT) (according to ultrasound keratopachimetry) ranged from 487 to 634 microns (552.9±28.7 microns). Horizontal diameter of the cornea was from 10.9 to 13.4 mm (12.1±0.37 mm). Average curvature of the cornea in the center (Average K) ranged from 39.5 to 47.25 D (43.39±1.32 D). Results. Uncorrected visual acuity at 1st day after surgery (1252 eyes) was 0.93±0.2, sph –0.11±0.5 D, cyl –0.4±0.5 D; uncorrected visual acuity after 4–6 months (323 eyes) 1.05±0.24, sph –0.16±0.5 D, cyl –0.4±0.5D; uncorrected visual acuity after 9–12 months (44 eyes) 1.04±0.2, sph –0.11± 0.4D, cyl –0.5±0.6D. Safety index 1.0, efficiency index 1.05. Percentage of intraoperative and early postoperative period complications was less than 1%. Conclusion. Correction of myopia and myopic astigmatism using CLEAR technology is a predictable, safe, effective technology. Key words: femtolaser lenticular correction, myopia, myopic astigmatism, CLEAR technology

Clinical outcomes of topography-guided versus wavefront-optimized LASIK for correction of myopia and compound myopic astigmatism.

To compare the safety, efficacy, and visual outcomes of topography-guided (TG) LASIK ablation versus advanced ablation algorithm (AAA) on Zeiss Mel 90 on virgin eyes. A tertiary care hospital in north India. A retrospective comparative study. Case sheets of 30 patients who underwent TG LASIK and 45 patients who underwent AAA LASIK between January 2021 and September 2022 were retrieved and reviewed. The TG group included 60 eyes of 30 patients, and the AAA group included age- and sex-matched 90 eyes of 45 patients. Both groups were compared for visual outcomes, residual refraction, and root-mean-square higher-order aberrations (rms HOA) at 1 week, 1 month, 3 months, and 6 months postoperatively and using unpaired t-test and Mann-Whitney U test. The mean preoperative spherical equivalent in the TG group and AAA group was - 3.12 (1.67) and - 3.19 (1.61), respectively. The safety and efficacy of the treatment were 100% in both groups. The postoperative increase in rms HOA was comparable in both groups (P = 0.55). The ablation duration was significantly longer in topo-guided LASIK (P = 0.001). AAA LASIK on MEL 90 is comparable to topography-guided LASIK for the management of low myopia and myopic astigmatism.

Femtosecond laser-assisted in situ keratomileusis versus small-incision lenticule extraction: current approach based on evidence.

Laser keratorefractive surgery achieves excellent visual outcomes for refractive error correction. With femtosecond laser, small incision lenticule extraction (SMILE) is an increasingly viable alternative to laser-assisted in situ keratomileusis (LASIK). Comparative studies demonstrate similar efficacy and predictability between SMILE and LASIK, making it difficult for clinicians to choose which to use. This review thus compares femtosecond-LASIK (FS-LASK) and SMILE in various scenarios, to assist clinicians in deciding which refractive surgery procedure to recommend. SMILE may be superior for highly myopic eyes due to a smaller decrease in functional optical zone. SMILE further induces less spherical aberration and less overall higher order aberrations in mesopic conditions. SMIILE also has less postoperative dry eye, making it suitable those with preexisting dry eye. For low to moderate myopic astigmatism correction, FS-LASIK has less undercorrection compared to SMILE. Lastly, SMILE has not yet received Food and Drug Administration or Conformité Européenne approval for hyperopic correction, rendering FS-LASIK the choice of procedure for hyperopic correction. Both FS-LASIK and SMILE demonstrate good efficacy and predictability. Understanding specific clinical scenarios where one may be superior to the other will aid clinicians in choosing the most suitable procedure for personalized care.

Comparative visual outcomes of the first versus second eye following small-incision lenticule extraction (SMILE)

BackgroundThis study aimed to compare the visual outcomes of the first operated eyes with those of the second operated eyes following small-incision lenticule extraction (SMILE).MethodsA total of 202 patients (404 eyes) underwent SMILE using the tear film mark centration method for myopia and myopic astigmatism correction. Baseline characteristics, objective optical quality, decentered displacement, induced corneal aberrations, and modulation transfer function (MTF) values were assessed. Linear regression analyzed the relationship between decentration and visual quality parameters, including corneal aberrations and MTF values.ResultsNo significant difference was observed in objective visual quality, efficacy, and safety indexes between the two groups (all P > 0.05). The average decentered displacement for the first and second surgical eyes was 0.278 ± 0.17 mm and 0.315 ± 0.15 mm, respectively (P = 0.002). The horizontal coma in the first surgical eyes were notably lower than in the second (P = 0.000). MTF values at spatial frequencies of 5, 10, 15, and 20 cycles/degree (c/d) were higher in the first surgical eyes compared to the second (all P < 0.05). Linear regression indicated that high-order aberrations (HOAs), root mean square (RMS) coma, spherical aberration, horizontal coma, vertical coma, and eccentric displacement were all linearly correlated. Furthermore, MTF values exhibited a linear relationship with eccentric displacement across these spatial frequencies.ConclusionsThere was no discernible difference in visual acuity, efficacy, or safety between the two operated eyes. Nonetheless, the first operated eyes exhibited reduced decentered displacement and demonstrated superior outcomes in terms of horizontal coma and MTF values compared to the second operated eyes following SMILE. The variations in visual quality parameters were linearly correlated with decentered displacement.

Bibliometric and visualized analysis of posterior chamber phakic intraocular lens research between 2003 and 2023.

Myopia is causing a major public health concern, with its prevalence increasing globally. This study aimed to discuss posterior chamber phakic intraocular lens (pIOL) research publication trends and hotspots over the past 20 years. Bibliometric analysis was performed using the Web Science Core Collection to investigate posterior-chamber pIOL research publication trends. The extracted records were analyzed, and a knowledge map was built using VOSviewer v.1.6.20. The analysis included visualizing the annual publication count, countries/regions distribution, international and institutional collaborations, author productivity, and journal contribution, in addition to identifying knowledge bases and hotspots. Burst keywords were extracted using CiteSpace v.6.1.R. In total, 791 articles on posterior chamber pIOLs published between 2003 and 2023 were retrieved. China had the highest number of publications, whereas Japanese papers received the most citations. Fudan University had the highest number of publications, with articles from Kitasato University having the highest number of citations. Regarding individual research, Xingtao Zhou has published the most significant number of articles, and Shimizu Kimiya had the highest number of citations. The top productive/influential journal was 'Journal of Cataract & Refractive Surgery'. The top cited references primarily focused on reporting the clinical outcomes of implantable collamer lens (ICL) for individuals with moderate to high myopia. The keywords primarily formed four clusters: posterior chamber pIOL clinical outcomes for myopic astigmatism correction, posterior chamber pIOL implantation complications, ICL size selection and postoperative vault predictions, and postoperative visual quality following posterior chamber pIOL implantation. This study presents the first bibliometric analysis of research trends in posterior chamber pIOL over the past two decades. We investigated the current state and emerging trends of global collaboration and research focal points in this field, offering fresh insights and guidance for researchers.

Современные технологии рефракционной экстракции лентикулы

Purpose. To present modern literature data on the main aspects of refractive lenticular extraction technology. Material and methods. To perform the review, the search for literature sources on PubMed abstract databases was analyzed using the keywords “keratorefractive surgery”, “corneal lenticular”, “femtosecond laser” and data from Russian publications on the topic of the article for the period up to and including 2023. Results. According to the literature data, the strengths and weaknesses of the implementation of each of the existing technologies of keratorefractive surgery have been studied, and the postulates of choosing the optimal method for correcting ametropia have been formulated individually for each patient. Conclusion. Today, keratorefractive surgery is a high-tech industry in ophthalmology and provides a predictable, high-precision and stable refractive result in patients with a wide range of refractive disorders. The analysis of accumulated scientific and clinical experience has shown that one of the most pathogenetically oriented technologies in keratorefractive surgery, minimally affecting the reduction of the biomechanical properties of the cornea, not inducing dry eye syndrome, providing a highly predictable postoperative result in the correction of myopia and myopic astigmatism is refractive lenticular extraction, opening a new era in laser vision correction. Keywords: ametropy, keratorefractive surgery, refractive lenticular extraction

Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis.

Small incision lenticule extraction (SMILE) has made notable advancements in addressing myopic astigmatism. Nevertheless, the potential impact of cyclotorsion on surgical outcomes cannot be overlooked. This study aims to assess the effectiveness of cyclotorsion compensation technology in SMILE surgery for the correction of myopic astigmatism, examining its influence on postoperative visual quality. A systematic review and meta-analysis were conducted. A comprehensive literature search was performed using databases, including PubMed, Web of Science, EMBASE, Cochrane Library, EBSCO, Scopus, CNKI, VIP, and Wan Fang. Studies meeting the criteria were selected and included. Data were independently extracted by three authors. Clinical outcome parameters were analyzed using Review Manager version 5.3. This meta-analysis included ten studies. The results showed that, compared with the control group (cyclotorsion compensation was not performed in SMILE), the following indicators in the cyclotorsion compensation group were: residual astigmatism (RA) [weighted mean difference (MD) = 0.73, 95% confidence interval (CI) + 0.26 to + 1.19, P = 0.002], spherical equivalent (SE) (MD = 1.99, 95% CI + 0.77 to + 3.21, P = 0.001), coma (MD = -0.06, 95% CI -0.08 to -0.04, P < 0.00001), higher-order aberrations (HOAs) (MD = -0.04, 95% CI -0.06 to -0.02, P < 0.0001), follow-up 6-month angle of error (AE) (MD = -2.67, 95% CI -3.71 to -1.63, P < 0.00001), and follow-up 6-month uncorrected distance visual acuity (UDVA) (MD = -0.05, 95% CI -0.08 to -0.01, P = 0.005), and the differences in results were statistically significant. However, the differences among correction index, index of success (IOS), targeted induced astigmatism (TIA), magnitude of error (ME), and spherical aberration (SA) were not statistically significant. Cyclotorsion compensation proves to be effective and predictable for correcting myopic astigmatism. The cyclotorsion compensation group demonstrated advantages over the control group in terms of postoperative residual astigmatism, and it induced fewer coma aberrations. Whether cyclotorsion compensation can lead to better visual quality remains to be seen, and further research on correcting myopic astigmatism through cyclotorsion compensation is warranted.

Refractive results of photorefractive keratectomy comparing trans-PRK and PTK−PRK for correction of myopia and myopic astigmatism

PurposeTo compare refractive outcomes after transepithelial photorefractive keratectomy (tPRK) and combined phototherapeutic keratectomy (PTK−PRK) procedure using two different excimer laser platforms for correction of myopia and myopic astigmatism.MethodsIn this retrospective multicenter study, we compared the results of two different PRK methods. The first group received a tPRK treatment with the Amaris750 excimer laser (Schwind eye-tech solutions). The second group received a combined PTK−PRK treatment with the MEL90 excimer laser (Carl Zeiss). Only healthy eyes with no previous surgery and a spherical equivalent (SE) of −1 to −8 diopters (D) were included. Preoperative spherical equivalent (SE), age, and sex were matched among the two groups. All treatments were performed by the same surgeon in different clinics. This study was approved by the local Ethics Committee (No. 2022–1980).ResultsWe included 154 eyes of 86 patients in our study. There was no difference in predictability of SE between the two groups. Efficacy and safety indices were equally high in both groups. Similarly, no significant differences were seen in change of higher order aberrations (HOA) between the two groups (p > 0.05). No complications occurred.ConclusionBoth investigated methods provide safe and effective refractive results. The combination of PTK with PRK may be a suitable option to the already used one-step tPRK for the correction of myopia.

VISUAL AND REFRACTIVE OUTCOME OF NEW GENERATION SMALL INCISION LENTICULE EXTRACTION (SMILE) IN MYOPIA AND MYOPIC ASTIGMATISM

Introduction: Two main options for the surgical correction of high myopia and myopic astigmatism are corneal refractive surgery and implantation of phakic intraocular lens (IOL). Small Incision Lenticule Extraction (SMILE) is becoming more popular technique which includes a minimally invasive flap-free procedure. The aim of this study is to evaluate the visual and refractive outcome of New Generation SMILE in myopia and myopic astigmatism. Methods: This is an observational retrospective study in patients who underwent SMILE using Visumax 800 Femtosecond laser procedure at Undaan Eye Hospital in period December 2022 to February 2023. Pre and post operative uncorrected visual acuity (UCVA), spherical equivalent (SE), astigmatism value, keratometry and intra ocular pressure (IOP) were evaluated at 1 day, 1 week and 1 month follow-up. Results: The study comprised 30 eyes of 15 patients age from 18 to 32 years old. The mean post operative UCVA was significantly improved to 0.03 ± 0.06 logMAR at 1-day, 0.02 ± 0.04 logMAR at 1-week and -0.01 ± 0.02 logMAR at 1-month follow-up compared to preoperative UCVA 1.35 ± 0.23 logMAR (p&lt;0.001). The mean refractive spherical equivalent was significantly changed from -4.60 ± 1.47 D preoperatively to -0.57 ± 0.38 D at 1-month follow up (p &lt; 0.001). The mean refractive astigmatism decreased from -1.02 ± 0.66 D preoperatively to -0.34 ± 0.25 D at 1- month follow up (p&lt;0.001). Conclusion: New Generation of SMILE has shown good visual and refractive outcome for the correction of myopia and myopic astigmatic eyes since the early phase after surgery.

Ray-Tracing Customization in Myopic and Myopic Astigmatism LASIK Treatments for Low and High Order Aberrations Treatment: 2-Year Visual Function and Psychometric Value Outcomes of a Consecutive Case Series.

The safety and long-term efficacy of automated ray-tracing customized myopic and myopic astigmatic femtosecond laser-assisted LASIK. This consecutive case series retrospective analysis, of 20 subjects (40 eyes) treated with automated raytracing named Wavelight Plus, to include low and high order aberrations based on a three-dimensional custom virtual eye for each case-calculated from interferometry data-obtained from a single diagnostic device that also provides Hartman-Shack Wavefront and Scheimpflug tomography data. We evaluated before and after the customized LASIK procedure: visual acuity, refractive error, high order aberrations, contrast sensitivity, and psychometric post-operative visual function data. At 24 months, the comparison of the pre-operative to the post-operative refractive and visual function value changes in average were: subjective manifest refraction from -4.38 ± 2.54 diopters (D) (range -9.75 to -1.25 D) to +0.11 ± 0.19 D; subjective manifest refractive astigmatism from -0.76 ± 0.91 D (range -2.75 to 0 D) to -0.13 ± 0.16 D, corneal astigmatism from -1.16 ± 0.64 D (range -0.2 to -2.8) to -0.47 ± 0.11 D. 65% of the eyes studied demonstrated an increase of at least one line of vision, while from the same group 38% demonstrated 2 lines of increase. High order aberrations, contrast sensitivity as well as the subjective psychometric input based on the VFQ-25 questionnaire demonstrated actual improvement. This longer-term follow-up, single-arm retrospective consecutive case series documents LASIK treatment customization that appears to be safe and effective in the correction of myopia and myopic astigmatism. Markedly improved objective and subjective visual function post-operatively, underlying the potential importance of simultaneously attempting to correct high order aberrations and improving the spatial alignment of total, measured human eye optics.

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&lt;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.