Introduction and objectives Refractive lens exchange (RLE) with presbyopia-correcting intraocular lenses (IOLs) can provide high levels of spectacle independence, but the procedure is unforgiving. Small residual refractive errors, ocular surface instability, undiagnosed corneal or macular disease, capsule-related IOL malposition, and mismatched expectations are common pathways to postoperative dissatisfaction. The literature on multifocal and extended-range optics is now complemented by consensus documents and functional classification frameworks that help standardize terminology and reduce “marketing-driven” decision making. Materials and methods This narrative review aims to define practical indications for multifocal IOL use in RLE, clarify borderline cases, summarize the level of evidence supporting current recommendations, and present a staged algorithm for management of dissatisfaction. Priority was given to international consensus statements, systematic reviews/meta-analyses, randomized or comparative studies, large contemporary cohorts, and focused case series dealing with dissatisfaction, neuroadaptation failure, and IOL exchange. The literature was organized around the terms refractive lens exchange, refractive lensectomy, multifocal intraocular lens, trifocal, extended depth of focus, enhanced monofocal, dysphotopsia, neuroadaptation failure, and lens exchange, with emphasis on contemporary evidence available up to January 2026. Results The evidence can be translated into two clinic-ready workflows. The first is a preoperative selection pathway that starts with patient goals, prioritizes optical quality, treats astigmatism aggressively, and reserves range-first optics for eyes and expectations that can tolerate their trade-offs. The second is a symptom-first rescue pathway built on a strict reversible-first and YAG-last sequence. Borderline eyes are best handled with conservative category selection or deferred surgery. Contemporary exchange series show that persistent neuroadaptation failure may be successfully managed either by exchange to monofocal optics or by exchange to another multifocal platform with a different optical profile, provided that refraction, ocular surface disease, posterior-segment pathology, and IOL position have already been addressed. Conclusion Multifocal IOLs remain valuable in RLE, but success depends more on indication discipline and rescue sequencing than on lens marketing labels. A structured algorithm, clear counseling, and explicit documentation of rescue options improve safety, readability, and everyday clinical usefulness.

PURPOSE:To evaluate the long-term safety, stability, and visual outcomes of diagonal haptic capture (DHC) of a 4-haptic hydrophilic acrylic intraocular lens (Akreos adapt, Bausch&Lomb) in eyes with posterior capsule deficiency and an intact anterior capsulorhexis. SETTING:Single tertiary referral center. DESIGN:Retrospective interventional case series. METHODS:Medical records were reviewed for patients who underwent cataract surgery complicated by posterior capsule rupture and in whom DHC was used for IOL fixation between 2015 and 2023. Twenty eyes of 20 patients were identified. Fellow eyes with uneventful in-the-bag implantation of the same IOL model served as controls. RESULTS:Median follow-up was 2 years (mean 2.6±2.1 years; range 0-6 years) based on data from referring ophthalmologists, and 8 years (mean 6.0±2.8 years; range 2-9 years) for patients examined at the study center. Mean postoperative corrected distance visual acuity did not differ significantly between DHC eyes and fellow eyes (p>0.4). Refractive predictability and intraocular pressure were comparable between groups. All IOLs remained well centered with normal tilt throughout follow-up. No cases of pigment dispersion glaucoma, uveitis-glaucoma-hyphema syndrome, pseudophacodonesis, or late IOL dislocation were observed. In a subset of eyes, anterior segment optical coherence tomography demonstrated adequate clearance between the IOL and posterior iris without evidence of iris chafing. CONCLUSIONS:Diagonal haptic capture of a 4-haptic hydrophilic acrylic IOL provided stable long-term fixation, satisfactory visual and refractive outcomes, and a low incidence of complications. However, these results may be IOL-specific.

PurposeTo evaluate the long-term outcomes of a simultaneous lenticule rotation and excimer laser ablation for high hyperopic astigmatism, a technique addressing otherwise untreatable refractive errors.MethodsA 41-year-old female patient with a high refractive error (+3.75/-5.50 D) in her left eye underwent femtosecond laser-assisted FLEx, lenticule rotation, and excimer laser ablation. The procedure was performed to correct high astigmatism, which could not be treated with standard laser correction or phakic IOL implantation. Treatment parameters were adjusted to compensate for myopic shift due to centripetal lenticule shrinkage. Postoperative evaluations occurred at 3 months, 1 year, and 2 years.ResultsRefractive astigmatism was reduced by >5.0 D, with corneal astigmatism decreasing by 3.7 D. The lenticule integrated well without distortions. Minor epithelial remodeling occurred, but no structural complications were observed. The patient achieved stable visual acuity and high satisfaction over 2 years.ConclusionThis technique provides a stable, reversible alternative for high hyperopic astigmatism, preserving accommodation and avoiding refractive lens exchange. Corneal lenticule surgery may offer a viable option for patients with extreme hyperopic astigmatism. Further clinical studies are warranted to confirm its long-term efficacy.

Background/Objectives: The purpose of this study was to investigate the variation in subjective manifest refraction measures in a patient cohort screened for myopic refractive surgery. Methods: In this retrospective non-randomised cross-sectional single-centre study, we evaluated a dataset containing sequences of three refraction measurements performed by four experienced optometrists in 175 eyes screened for refractive corneal or lens surgery for myopia or myopic astigmatism. Refraction was converted from sphere (SPH), cylinder (CYL) and axis to power vector components (spherical equivalent SEQ and cylinder projections C0 and C45). The mean power vectors of the three repeat measurements (MEAN) and the deviations (DEV) of the repeat measurements from the MEAN were evaluated. Results: MEAN values for SPH/CYL/SEQ/C0/C45 were −5.93/0.99/−5.44/−0.47/0.02 D and the corresponding standard deviations were 0.20/0.16/0.17/0.17/0.16 D. DEV of both SEQ and CYL correlated significantly with patient age (Spearman R = 0.16 and 0.20). DEV of CYL correlated with mean (myopic) SEQ (R = −0.22) and CYL (R = 0.27) whereas DEV of SEQ showed no significant correlation with mean SEQ or CYL. Conclusions: The variation in subjective manifest refraction with repeat measurements is in a range of ±0.16 to ±0.20 D for SPH, CYL and the power vector components SEQ, C0 and C45. If reliable subjective refraction measurements are mandatory, e.g., for planning refractive surgery procedures or for formula constant optimisation, repeat refractometry measures could help to ensure representative data and to estimate the intraindividual variations.

SMILE (kurz für „Small Incision Lenticule Extraction“) ist ein minimalinvasives intrastromales und praktisch schmerzfreies neueres Verfahren zur refraktiven Korrektur an der Hornhaut. Es ist jedoch nicht frei von möglichen Komplikationen. In diesem Kapitel werden die Vorteile und Grenzen von SMILE dargelegt, um ein Verständnis für die Genese möglicher Komplikationen zu vermitteln, und dann einige Strategien vorgeschlagen, um Komplikationen von vornherein zu vermeiden oder sie zu bewältigen, wenn sie trotz gebührender Sorgfalt auftreten. Des Weiteren stellen wir einige Einflüsse auf das refraktive Ergebnis und auch die stromale Geweberotation dar.

Purpose: To evaluate corneal densitometry changes in the eyes 3 years after allograft corneal inlay (ACI) implantation for refractive treatment of presbyopia. Methods: This retrospective case series included 32 nondominant eyes of 32 patients who underwent allograft corneal lenticle implantation. Corneal densitometry was performed preoperatively and postoperatively at 1, 3, 6, 12, and 36 months using a Scheimpflug tomography device. The results were analyzed in four different layers and four different zones of the cornea. Results: The mean age of the 32 included patients was 49.8±3.3 (range 45–56) years. The densitometric changes measured at 36 months were more prominent in zones 1 and 2, especially in the anterior layer (AL). The AL mean baseline densitometry values were 19.02±2.20 grayscale unit (GSU) for zone 1 and 17.50±1.89 for zone 2. Densitometry values increased significantly at 1-month (to zone 1:23.37±3.71 GSU, P <0.001 and zone 2:18.90±2.39 GSU, P =0.001) and 3-month follow-up (to zone 1:23.68±4.35 GSU, P <0.001 and zone 2:18.80±2.46 GSU, P =0.006). Between the 3-month and 6-month follow-up periods, the densitometry values returned to baseline levels and remained constant throughout the 36-month follow-up (to zone 1:19.98±1.96 GSU, P =0.414 and zone 2:18.11±2.13 GSU, P =1.000). No significant densitometric changes were observed in zone 3 at any time. Densitometric values returned to baseline levels in all layers and zones at 6 months postoperatively. Conclusion: These results support the notion that ACI implantation is relatively safe regarding corneal transparency.

Die refraktive Chirurgie ist eines der sich am schnellsten entwickelnden Gebiete der Augenheilkunde. Ihre Methoden haben sich mit der Einführung des Excimer-Lasers grundlegend weiterentwickelt und ersetzten in sehr kurzer Zeit Hornhautschnitte für Routinefälle. Darüber hinaus hat die Einführung des Femtosekundenlasers zur LASIK-Flap-Erzeugung zur weiteren Erhöhung der Sicherheit und Wirksamkeit refraktiver Verfahren beigetragen. In diesem Kapitel diskutieren wir die LASIK mit mechanischem Mikrokeratom und die Femtosekundenlaser-LASIK mit einem Fokus auf den verschiedenen Ablationsprofilen, ihrer klinischen Durchführung, Vorteilen, Komplikationen und Nachsorge sowie ihren Grenzen. Auch technische Aspekte wie Eyetracking werden dargestellt.

AimsRefractive lens exchange (RLE) is becoming a popular refractive solution for patients ineligible for corneal surgeries or phakic intraocular lenses. However, concerns regarding retinal detachment (RD) risk persist.MethodsA systematic literature review and meta-analysis was performed in Medline and Scopus.The final search was updated on 30 March 2024.ResultsOf 2415 full-text screening reports, 40 studies met inclusion criteria, encompassing 8 592 380 eyes. This included 20 264 eyes that underwent RLE and 8 572 116 eyes that underwent cataract surgery. In the RLE surgery subgroup, the RD incidence for follow-up <12 months was 0.00016% (0.00000%; 0.00034%), for follow-up between 12 and 24 months was 0.0000% (0.0000%; 0.03102%), and for follow-up >24 months was 0.02312% (0.00984%; 0.03640%) (p<0.01). In the cataract surgery subgroup, the incidence for follow-up >24 months was 0.01244% (0.00655%; 0.01832%), and for missing follow-up was 0.00429% (0.00221%; 0.00637%).ConclusionsWe found that the incidence of RD after RLE was approximately double that observed after cataract surgery with at least 24 months (median 4 years) follow-up. Thus, RD may be classified as rare complication after cataract surgery (1/1000) and an uncommon complication after RLE (1/500). It must be noted that the heterogeneity of the subgroups after RLE was low. While some limitations, such as the lack of long-term follow-up in certain studies and incomplete reporting of factors like axial length or PVD status, may slightly influence the interpretation, these findings provide valuable insights. Acknowledging the inherent uncertainty in interpreting these results, additional studies are recommended.PROSPERO registration numberCRD42023431420.

Background Corneal and epithelial thickness maps obtained with high-frequency ultrasound were first used to diagnose keratoconus. Anterior segment OCT has recently become widely used in many conditions especially in preoperative planning before refractive surgery, keratoconus diagnosis, keratoconus progression monitoring, hydrops formation, and epithelial healing monitoring. We compare epithelial and pachymetric thickness-based parameters from two different Fourier-domain optical coherence tomography (OCT) devices as to whether they can be used interchangeably. Methods Retrospective, comparative chart review. This study comprises 24 normal consecutive eyes and 32 consecutive post-SMILE eyes with corneal thickness and epithelial thickness maps obtained using two different OCT devices (Cirrus 5000, Carl Zeiss Meditec, Germany and Avanti RTVue 100, OptoVue Inc., USA). The following common parameters in the print-out of the two OCT devices were examined: minimum corneal thickness (Pachy min), minimum corneal thickness minus median corneal thickness (Pachy min−med), average corneal thickness of the superonasal octant minus the average corneal thickness of the inferotemporal octant (Pachy SN−IT), average corneal thickness of the superior octant minus average corneal thickness of the inferior octant (Pachy S−I), minimum epithelial thickness (Epi min), and maximum epithelial thickness (Epi max). Results Pachy min and Epi max measurements matched well between the two devices (ICC at 0.906 and 0.839, respectively). We found a significant correlation in Pachy min (p = 0.040), Pachy min−med (p = 0.033), and Epi max (p < 0.001) in the normal eye group. Only Pachy min and Epi max measurements (p < 0.001 for both) exhibited a significant correlation between the two devices in the post-SMILE group. Conclusion Anterior segment OCT is a valuable method for evaluating quantitative corneal and epithelial thickness measurements. However, measurements may differ between devices, and they should not be used interchangeably.

Purpose: To assess the performance of a hybrid Transformer-based convolutional neural network (CNN) model for automated detection of keratoconus in stand-alone Scheimpflug-based dynamic corneal deformation videos (DCDVs). Methods: We used transfer learning for feature extraction from DCDVs. These feature maps were augmented by self-attention to model long-range dependencies before classification to identify keratoconus directly. Model performance was evaluated by objective accuracy metrics based on DCDVs from two independent cohorts with 275 and 546 subjects. Results: The model’s sensitivity and specificity in detecting keratoconus were 93% and 84%, respectively. The AUC of the keratoconus probability score based on the external validation database was 0.97. Conclusion: The hybrid Transformer-based model was highly sensitive and specific in discriminating normal from keratoconic eyes using DCDV(s) at levels that may prove useful in clinical practice.

Purpose: To develop and evaluate a novel artificial intelligence (AI)–derived metric for detection of early ectasia (E) by leveraging spatiotemporal biomechanical data derived from dynamic cornea videos only. Design: Multicenter cross-sectional case-control retrospective study. Participants: A total of 451 eyes from 451 patients from 2 centers with both Scheimpflug tomography and dynamic corneal deformation examinations. Methods: The training data set included 167 normal (N) patients with stable eyes postlaser vision correction, 83 NT eyes with VAE (VAE-NT), and better eyes from 64 patients with bilateral keratoconus (ie, mild KC [MKC]). The external validation data set included 68, 33, and 36 patients from the N, VAE-NT, and MKC groups, respectively. Extensive spatial and temporal pixel-level analysis of corneal displacement, stromal gray scale changes, and thickness variations from Corvis ST video frames was performed to identify a novel risk score with best detection of early E (combined VAE-NT and MKC). Findings were further validated using various approaches based on the external data set. Main Outcome Measures: Area under the receiver operating characteristics curve (AUC), accuracy, specificity, and sensitivity for detecting early E. Results: The novel AI-derived index achieved an AUC of 0.995 with accuracy, sensitivity, and specificity of 96%, 97%, and 96%, respectively, outperforming all Scheimpflug tomographic and dynamic deformation combined indices such as Belin/Ambrósio Enhanced Ectasia Display, Corvis Biomechanical Index (CBI), and Tomographic and Biomechanical Index (TBI). Conclusions: The AI-derived index based on spatiotemporal corneal biomechanical data outperformed existing instrument's topographic, tomographic, and biomechanical indices, in detecting E. This novel metric offers a clinically meaningful enhancement in early diagnosis and management of corneal E disease. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Background: Keratorefractive lenticule extraction (KLEx) has been shown to be safe and effective for the correction of myopia and myopic astigmatism. Residual refractive errors reduce the uncorrected postoperative visual acuity leading to patient dissatisfaction and increased retreatment rates. Aim of the study: The aim was to assess the potential influence of the recommendations of the Committee for Refractive Surgery (KRC) on the likelihood of retreatment and to compare the results of various methods for retreatment after KLEx for myopia. Methods: Retrospective study of eyes with myopia and myopic astigmatism in which KLEx (SMILE, Visumax 500, Carl Zeiss Meditec, Jena, Germany) was performed between April 2015 and December 2022. Results: A total of 2462 eyes from 1278 patients were analyzed. Of the eyes 3.05% (n = 75) were retreated within 24 months. Eyes in the recommended treatment range (corrections up to -8.0 dpt in the stronger main section) had a 50% lower risk of retreatment than eyes within the borderline range (corrections between -8.0 dpt and -10.0 dpt in the stronger main section). Retreatment was predominantly performed using the advanced surface ablation (ASA n = 44) or the Circle program (transformation of a SMILE cap into a flap, n = 29). The postoperative results of both methods after 3 months were comparably safe and effective; however, visual recovery was significantly faster with Circle. A second KLEx treatment in two eyes (one patient) resulted in a residual refractive error, which impaired the uncorrected visual acuity even 1.7 years later. Conclusion: There was a significantly lower retreatment rate in the recommended treatment range than in the borderline range according to the KRC recommendations. In addition, the ASA and Circle proved to be equally predictable but with different healing processes. These results can help with the education and selection of patients.

Keratorefraktive Lentikelextraktion (KLEx) hat sich als sicher und effektiv zur Korrektur von Myopie und myopem Astigmatismus erwiesen. Verbleibende Refraktionsfehler mindern die unkorrigierte postoperative Sehschärfe, was zu Unzufriedenheit der Patienten und zu Nachbehandlungen führt. Ziel war es, den potenziellen Einfluss der Empfehlungen der KRC auf die Wahrscheinlichkeit einer Nachbehandlung zu beurteilen und die Ergebnisse unterschiedlicher Methoden zur Nachbehandlung nach myoper KLEx zu vergleichen. Es erfolgte eine retrospektive Studie von Augen mit Myopie und myopem Astigmatismus, bei denen zwischen April 2015 und Dezember 2022 eine KLEx (SMILE, Visumax 500, Carl Zeiss Meditec, Jena, Deutschland) durchgeführt wurde. Insgesamt wurden 2462 Augen von 1278 Patienten analysiert. Davon wurden 3,05

Torische Intraokularlinsen (IOL) sind inzwischen sehr bewährt zum Ausgleich eines vorbestehenden kornealen Astigmatismus, besonders im Rahmen einer Kataraktoperation. Als Indikation gelten im Allgemeinen reguläre Hornhautastigmatismen ab einer Dioptrie. Das Prinzip der torischen IOL lässt sich mit monofokalen und multifokalen Optiken kombinieren. Wenn noch keine Katarakt vorliegt, können torische IOL auch in ein phakes Auge implantiert werden. Eine additive torische IOL kann auch nach bereits stattgehabter Kataraktoperation zur refraktiven Feinkorrektur in den Sulcus ciliaris implantiert werden. Essenziell für den Operationserfolg ist eine genaue Untersuchung mit Berücksichtigung des posterioren kornealen Astigmatismus. Der exakten – und dauerhaften – Ausrichtung der Torusachse auf den steilen Meridian kommt eine hohe Bedeutung bei; schon geringe Abweichungen von der Zielachse können zu signifikanten visuellen Beschwerden führen. Eine Alternative zu torischen IOL kann – vor allem bei irregulären Astigmatismus – ein Implantat sein, welches das Lochblenden-/Small-aperture-Prinzip nutzt. Besonders bei geringen Astigmatismen können limbal relaxierende Inzisionen eine weitere Option darstellen.

PURPOSE: To evaluate the impact of refractive couplings in myopia and myopic astigmatism with two different keratorefractive lenticule extraction (KLEx) systems. METHODS: This was a retrospective evaluation of refractive outcomes with two different lasers studying 2,841 eyes undergoing small incision lenticule extraction (SMILE) (VisuMax 500; Carl Zeiss Meditec) and 2,528 eyes undergoing SmartSight (ATOS; SCHWIND eye-tech-solutions GmbH). Coupling effects (derived from the ratio between partial slopes) were determined for sphere and cylinder and for spherical equivalent, cardinal, and oblique astigmatism separately. RESULTS: Statistically significant coupling effects were observed for both the VisuMax and ATOS systems, as indicated by P values less than .05. For the VisuMax, a coupling effect of 8% of cylinder into sphere and a 2% coupling of sphere into cylinder was found. For the ATOS, the coupling effect of sphere into cylinder was 1%. A 3% coupling effect of oblique astigmatism into cardinal astigmatism in the VisuMax, and conversely, a 0.1% coupling effect of defocus into oblique astigmatism in the ATOS were found. In cases with no astigmatism plan, sphere had a 2% effect on induced astigmatism in the VisuMax and 0.6% in the ATOS. In high astigmatism plans, sphere had a significant 16% impact on cylinder in the VisuMax. Additionally, the effect of defocus on cardinal astigmatism was 6% in the VisuMax and 0.8% on oblique astigmatism in the ATOS. CONCLUSIONS: Despite the P values less than .05 indicating statistical significance, the observed coupling effects were consistently low, with magnitudes below 10%, even for astigmatism exceeding 2.50 diopters. These couplings may be partly attributed to cross-effects of torsional eye movements. Coupling values for KLEx were markedly lower than those reported for non-aspheric excimer laser ablations. The results suggest that surgical results may be refined further by optimizing nomograms to mitigate coupling effects.

Purpose: To identify potential risk factors that increase the likelihood of re-treatment following keratorefractive lenticule extraction (KLEx) for myopia and myopic astigmatism. Methods: This was a retrospective study of patients with myopia and myopic astigmatism who underwent KLEx using the VisuMax 500 laser (Carl Zeiss Meditec) between April 2015 and December 2020. Patients were assigned to one of two groups: the control group and the re-treatment group (if they had additional refractive surgery within 2 years of the primary treatment). The effect of different preoperative, intraoperative, and postoperative parameters on the re-treatment rate was analyzed. Results: Overall 1,822 eyes of 938 patients were analyzed. In total, 2.96% of eyes (n = 54) underwent re-treatment. The re-treated patients were more likely to be women and have high myopia, high astigmatism, steep corneas, higher ocular residual astigmatism, and residual myopic and/or astigmatic refractive error. In contrast, no significant correlation was found between re-treatment rate and age, chord µ, type of astigmatism, and corneal thickness. Conclusions: Factors associated with higher rates of retreatment after KLEx included female gender, manifest refractive high myopia (> −5.00 diopters [D]), astigmatism (> 2.00 D), spherical equivalent (> 6.00 D), ocular residual astigmatism, steeper corneas, and postoperative residual myopic and astigmatic refractive errors. This study may help to preoperatively detect patients at risk for re-treatment, improve preoperative patient counseling, and optimize patient selection to reduce future re-treatment rates. [ J Refract Surg . 2024;40(6):e362–e370.]

Purpose. Assessing the applicability of an algorithm developed for keratoconus detection in adolescents. This algorithm relies on optical coherence tomography (OCT) and incorporates features related to corneal pachymetric and epithelial thickness alterations. Methods. We retrospectively reviewed charts of patients under the age of 18 and divided them into four groups according to the Belin-Ambrosio display (Pentacam): normal, manifest, and subclinical keratoconus, as well as very asymmetric eye with normal topography and tomography (VAE-NTT). Corneal and epithelial thickness maps (Cirrus 5000 HD-OCT, Carl Zeiss Meditec, Germany) were evaluated by a human grader. In the first step, if at least one of four parameters (pachymetry minimum (pachy min), pachy minimum-median (min-med), pachy superonasal-inferotemporal (SN-IT), or epithelial (epi SN-IT)) exceeded its cut-off value, the eye was considered as suspect. In the second step, the combined presence of coincident thinning of total cornea and epithelium as well as concentric epithelial thinning lead to the diagnosis of keratoconus. Receiver operating characteristic (ROC) curves were generated to determine area under the curve (AUC), sensitivity, and specificity for the parameters. Results. The study involved 19 pediatric patients diagnosed with keratoconus, comprising 29 manifest keratoconic eyes, 3 eyes with subclinical keratoconus, and 5 VAE-NTT eyes. In addition, 22 eyes from 11 normal adolescents were included in the analysis. The AUC values of parameters in step 1 were 0.889 for pachy min, 0.997 for pachy min-med, 0.893 for pachy SN-IT, and 0.998 for epi SN-IT. When both steps were performed, this algorithm captured all manifest and subclinical pediatric keratoconic eyes. When all eyes of the keratoconus patients were combined, step 1 had 97.3% sensitivity and step 2 had 100% specificity. Conclusion. Using this OCT-based approach in adolescents yielded a high level of agreement with the current gold standard, tomography. Using them together, potentially also with other examinations may improve the diagnostic accuracy of KC in the pediatric population. Integration of this approach into the software of the device to facilitate automated evaluations is desired.