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Journal of Clinical Medicine Jun 2024: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical... (Review)
Review
: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. : The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record's reference list. Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for -values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I, chi-square (χ), and tau-squared. We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK.
PubMed: 38893017
DOI: 10.3390/jcm13113306 -
Journal of Cataract and Refractive... May 2024Rotational stability is key for optimizing postoperative visual outcomes as even a small degree of rotation of a toric intraocular lens (IOL) from its target axis can...
Rotational stability is key for optimizing postoperative visual outcomes as even a small degree of rotation of a toric intraocular lens (IOL) from its target axis can result in a significant reduction of astigmatic correction. This systematic review and meta-analysis evaluated the rotational stability of toric IOLs of different lens models and haptic designs. All published studies and clinical trials that investigate postoperative rotation of toric IOLs were searched and evaluated. Quality of studies was assessed using the Methodological Index for Nonrandomized Studies (MINORS) scale. A single-arm meta-analysis was performed in R4.3.1 software with subgroup analysis performed based on lens model and haptic design. Fifty-one published studies of 4863 eyes were included in the meta-analysis. The pooled mean absolute rotation of all toric IOLs was 2.36° (95% CI: 2.08-2.64). Postoperative rotation is dependent on many aspects of lens material and design. Modern commercially available toric IOLs exhibit exceptional rotational stability.
PubMed: 38768060
DOI: 10.1097/j.jcrs.0000000000001486 -
Survey of Ophthalmology May 2024Advancements in diagnostic methods and surgical techniques for keratoconus (KC) have increased non-invasive treatment options. Successful surgical planning for KC... (Review)
Review
Advancements in diagnostic methods and surgical techniques for keratoconus (KC) have increased non-invasive treatment options. Successful surgical planning for KC involves a combination of clinical science, empirical evidence, and surgical expertise. Assessment of disease progression is crucial, and halting the progression should be the focus if it is progressive. While surgeons used to rely on experience alone to decide the surgical method, comparing the network of primary factors, such as visual acuity, across studies can help them choose the most appropriate treatments for each patient and achieve optimal outcomes. Meticulous tabulation methods facilitate interpretation, highlighting the importance of selecting the correct surgical and rehabilitation approach based on each patient's condition and stage of the disease. We detail the outcomes of a comprehensive network meta-analysis comparing the effectiveness of various combined therapeutic refractive treatments for KC at identical stages of the disease, spanning 4 distinct follow-up intervals. Additionally, the comprehensive analysis suggests that for corneas with optimal best corrected visual acuity (BCVA) preoperatively (classified as regular), combining phakic intraocular lenses with intracorneal ring segments (ICRS) and corneal cross-linking (CXL) could offer the best therapeutic approach provided the disease stage does not exceed stage 3. For irregular corneas, although initial follow-ups show a significant difference in BCVA with surface ablation, longer-term follow-ups recommend combining surface ablation with ICRS and CXL, especially at higher stages.
PubMed: 38710236
DOI: 10.1016/j.survophthal.2024.04.008 -
Frontiers in Medicine 2024To examine the causes and factors that lead to high order aberration (HOA) during the treatment of myopia using small incision lenticule extraction (SMILE), as well as...
OBJECTIVE
To examine the causes and factors that lead to high order aberration (HOA) during the treatment of myopia using small incision lenticule extraction (SMILE), as well as the differences between SMILE and other corneal refractive surgeries through a systematic review and meta-analysis.
METHODS
A systematic search was conducted from January 2015 to February 2023 in Pubmed, Embase, Web of Science, and Google Scholar databases to gather relevant studies on SMILE and HOA. Studies meeting specific criteria were chosen, and clinical data was retrieved for analysis.
RESULTS
This meta-analysis resulted in the inclusion of 19 studies involving 1,503 eyes. Pooled results showed significant induction of total HOA (tHOA, = -0.21, < 0.001), spherical aberration (SA, = -0.11, < 0.001) and coma aberration (CA, = -0.18, < 0.001) after SMILE compared to pre-SMILE, while no significant change in trefoil aberration (TA) was observed ( = -0.00, = 0.91). There was a significantly lower induction of tHOA after SMILE compared to femtosecond laser-assisted keratomileusis (FS-LASIK, = 0.04, < 0.001), and no significant difference was observed compared to wavefront aberration-guided (WFG) refractive surgery ( = 0.00, = 0.75). There was also a significant association between different levels of myopia and astigmatism, duration of follow-up, lenticule thickness, and preoperative central corneal thickness (CCT) on the induction of tHOA after SMILE ( < 0.05), while the higher preoperative myopia group (sphere > -5D), lower preoperative astigmatism group (cylinder ≤ -1D), larger lenticule thickness group (lenticule thickness > 100 μm), shorter follow-up group (follow-up 1 month postoperatively) and the thicker CCT group (CCT > 550 μm) brought a significant induction of tHOA compared to the opposite comparison group ( < 0.001).
CONCLUSION
While SMILE can induce HOA significantly, it induces less HOA than FS-LASIK. Postoperative HOA following SMILE can be affected by factors such as myopia, astigmatism, lenticule thickness, CCT, and duration of follow-up. Future research should continue to explore techniques to decrease the induction of HOA by using this methodology.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/.
PubMed: 38601117
DOI: 10.3389/fmed.2024.1274101 -
The British Journal of Ophthalmology Apr 2024To compare the refractive and visual outcomes of femtosecond laser-assisted astigmatic keratotomy (FSAK) and toric intraocular lens (IOL) implantation for correcting...
Femtosecond laser-assisted astigmatic keratotomy versus toric IOL implantation for correcting astigmatism in cataract patients: a systematic review and meta-analysis with trial sequential analysis.
AIMS
To compare the refractive and visual outcomes of femtosecond laser-assisted astigmatic keratotomy (FSAK) and toric intraocular lens (IOL) implantation for correcting astigmatism in cataract patients.
METHODS
Studies were retrieved from the Ovid-Medline, EMBASE, Cochrane Central Register of Controlled Trials and Scopus which compared FSAK and toric IOL for astigmatism correction in cataract patients. Outcome measures included postoperative refractive cylinder, correction index, uncorrected distance visual acuity (UDVA), the proportion of patients achieving a residual refractive cylinder of 1.00 dioptre or less, target-induced astigmatism (TIA) and surgically induced astigmatism (SIA). The trial sequential analysis (TSA) was used to collect firm evidence supporting our conclusion.
RESULTS
9 studies encompassing 590 participants were analysed. The meta-analysis revealed that toric IOLs could result in less postoperative refractive cylinder and provide better UDVA compared with FSAK. The TSA disclosed strong evidence of lower postoperative refractive cylinder in the toric IOL group compared with that of the FSAK group. FSAK showed a smaller correction index and lower mean TIA and SIA compared with toric IOLs.
CONCLUSIONS
For cataract patients, both FSAK and toric IOLs are effective methods for correcting astigmatism. However, toric IOLs offer less postoperative astigmatism and result in better postoperative UDVA compared with FSAK. In vector analysis of astigmatism, toric IOLs can also produce higher TIA and SIA. Additionally, neither method is associated with severe untreatable complications. Therefore, the conclusion is that toric IOLs are the preferred choice for astigmatism correction in cataract patients and FSAK serves as a viable alternative when toric IOLs are contraindicated.
PubMed: 38575199
DOI: 10.1136/bjo-2024-325195 -
American Journal of Ophthalmology Mar 2024To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation. (Review)
Review
PURPOSE
To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation.
METHODS
We investigated how current IOLs influence peripheral visual function, peripheral optical quality, and visual perception and performance, in patients following cataract surgery. Peripheral vision is described as vision outside the central foveal region of the eye (beyond 4-5° of eccentricity). We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and gray literature for relevant references. Randomized controlled trials and observational studies were eligible for inclusion. Finally, 47 studies with a total of 5963 participants were eligible for this review, of which 15 were included in the meta-analysis.
RESULTS
Regarding visual fields, the meta-analysis showed that the pooled estimate of mean deviation (MD) measured with perimetry tests (standard automated perimetry [SAP], short-wavelength automated perimetry [SWAP], and frequency doubling technology [FDT]) appears to be lower than the mean of healthy age-matched controls, regardless of IOL design. Results for pooled estimate show that localized defects (pattern standard deviation [PSD]) were higher than those in the healthy age-matched controls for FDT. We also collected evidence demonstrating that pseudophakia increases peripheral astigmatism and a myopic shift from 20° onward, leading to decreased peripheral image quality compared with that in phakic eyes. Patient-reported outcomes on peripheral vision showed a pooled score estimate of 95.19, indicating high satisfaction, and for the Steps & Stairs questions, a pooled score estimate at 0.23, indicating no to little difficulty seeing steps and stairs.
CONCLUSIONS
Peripheral image quality is degraded in eyes after cataract surgery. Nevertheless, whether this degradation leads to impaired visual function in the periphery requires further investigation.
PubMed: 38521156
DOI: 10.1016/j.ajo.2024.03.016 -
Therapeutic Advances in Ophthalmology 2024New developments in artificial intelligence, particularly with promising results in early detection and management of keratoconus, have favorably altered the natural... (Review)
Review
BACKGROUND
New developments in artificial intelligence, particularly with promising results in early detection and management of keratoconus, have favorably altered the natural history of the disease over the last few decades. Features of artificial intelligence in different machine such as anterior segment optical coherence tomography, and femtosecond laser technique have improved safety, precision, effectiveness, and predictability of treatment modalities of keratoconus (from contact lenses to keratoplasty techniques). These options ingrained in artificial intelligence are already underway and allow ophthalmologist to approach disease in the most non-invasive way.
OBJECTIVES
This study comprehensively describes all of the treatment modalities of keratoconus considering machine learning strategies.
DESIGN
A multidimensional comprehensive systematic narrative review.
DATA SOURCES AND METHODS
A comprehensive search was done in the five main electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane), without language and time or type of study restrictions. Afterward, eligible articles were selected by screening the titles and abstracts based on main mesh keywords. For potentially eligible articles, the full text was also reviewed.
RESULTS
Artificial intelligence demonstrates promise in keratoconus diagnosis and clinical management, spanning early detection (especially in subclinical cases), preoperative screening, postoperative ectasia prediction after keratorefractive surgery, and guiding surgical decisions. The majority of studies employed a solitary machine learning algorithm, whereas minor studies assessed multiple algorithms that evaluated the association of various keratoconus staging and management strategies. Last but not least, AI has proven effective in guiding the implantation of intracorneal ring segments in keratoconus corneas and predicting surgical outcomes.
CONCLUSION
The efficient and widespread clinical translation of machine learning models in keratoconus management is a crucial goal of potential future approaches to better visual performance in keratoconus patients.
TRIAL REGISTRATION
The article has been registered through PROSPERO, an international database of prospectively registered systematic reviews, with the ID: CRD42022319338.
PubMed: 38516169
DOI: 10.1177/25158414241232258 -
Ophthalmology and Therapy May 2024Small incision lenticule extraction (SMILE) has made notable advancements in addressing myopic astigmatism. Nevertheless, the potential impact of cyclotorsion on...
INTRODUCTION
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.
METHODS
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.
RESULTS
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.
CONCLUSION
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.
PubMed: 38498276
DOI: 10.1007/s40123-024-00921-2 -
Journal Francais D'ophtalmologie Apr 2024To evaluate the safety, efficacy and postoperative visual quality of small incision lenticule extraction (SMILE) and Wavefront-Guided Laser in situ keratomileusis... (Meta-Analysis)
Meta-Analysis
PURPOSE
To evaluate the safety, efficacy and postoperative visual quality of small incision lenticule extraction (SMILE) and Wavefront-Guided Laser in situ keratomileusis (WFG-LASIK) and to analyze their efficacy in correcting astigmatism.
METHODS
A systematic literature search was performed using Cochrane Collaboration methodology. Databases searched included PubMed, Embase, the Cochrane Library and Web of Science. RevMan software version 5.3.0 was used for meta-analysis.
RESULTS
A total of 976 eyes were included in 8 studies, of which 539 eyes underwent SMILE and 437 eyes underwent WFG-LASIK. There were no statistically significant differences in the proportion of eyes achieving uncorrected distance visual acuity of 20/20 or better (P=0.18), the proportion of eyes within±0.50 diopter of target refraction postoperatively (P=0.10), or the postoperative magnitude of cylinder (P=0.10). Regarding the Alpins vector analysis of astigmatism, there was no statistically significant difference in the surgical magnitude of error (P=0.09) between the two groups. WFG-LASIK has a lower surgical angle of error (P= 0.002) and higher surgical correction index of cylinder (P=0.03) than SMILE. In terms of aberrations, higher order aberrations (P=0.46), spherical aberrations (P=0.22) and trefoil (P=0.56) were not statistically different, while WFG-LASIK induced less coma than SMILE surgery (P=0.02).
CONCLUSION
Both SMILE and WFG-LASIK are safe and effective ways to correct myopia and astigmatism. Compared with SMILE, WFG-LASIK has a lower surgical angle of error, higher surgical correction index of cylinder and induces less coma.
Topics: Humans; Keratomileusis, Laser In Situ; Astigmatism; Coma; Lasers, Excimer; Prospective Studies; Refraction, Ocular; Cornea; Corneal Stroma; Myopia; Surgical Wound; Treatment Outcome
PubMed: 38377878
DOI: 10.1016/j.jfo.2024.104085 -
Frontiers in Medicine 2023To investigate the effects of postoperative astigmatism on the visual outcomes following presbyopia-correcting surgery with multifocal intraocular lens implantation.
PURPOSE
To investigate the effects of postoperative astigmatism on the visual outcomes following presbyopia-correcting surgery with multifocal intraocular lens implantation.
METHODS
A comprehensive literature search was conducted using PubMed, Embase, and Web of Science for articles published until January 2023. Additionally, we included retrospective case series and prospective comparative studies. The combined mean difference (MD) with 95% confidence intervals (CI) and odds ratio (OR) with 95% CI were used to express continuous and categorical outcomes, respectively. All statistical analyses were performed using Review Manager (version 5.4.1).
RESULTS
We included nine eligible studies that analyzed 3,088 eyes. The proportion of eyes with useful postoperative visual acuity (logMAR ≤ 0.20) and residual astigmatism significantly differed with respect to the magnitude of astigmatism and presence/absence of blurred vision ( < 0.001 for both). Additionally, the mean uncorrected distance visual acuity (MD, 0.14; 95% CI, 0.06 to 0.21; = 0.0003) and uncorrected intermediate visual acuity (MD, 0.07; 95% CI, 0.00 to 0.13; = 0.04), but not the uncorrected near visual acuity (MD, 0.02; 95%CI-0.01 to 0.05; = 0.17), significantly differed according to the magnitude of astigmatism.
CONCLUSION
Astigmatism, even at low levels (≥ 0.5D), has a significant effect on visual outcomes, especially on UDVA and UIVA, following multifocal intraocular lens implantation. Accurate preoperative and postoperative evaluation of astigmatism is important.
PubMed: 38089878
DOI: 10.3389/fmed.2023.1214714