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Purpose: To describe a novel technique for preparing multiple corneal allogeneic ring segments (CAIRS) from a single corneal graft using femtosecond laser technology., Methods: This is a case series of 10 eyes from 10 patients with keratoconus who underwent FS-assisted CAIRS implantation using corneas from 4 donors at the Hospital Foundation Adolphe de Rothschild-Noémie de Rothschild institute. A preoperative and postoperative examination was performed at 1 day, 1 week, and 1 month. Anterior segment OCT and corneal tomography with aberrometric and pachymetric analyses were performed at each visit. Visual, refractive, and topographic parameters were extracted. The thickness and width of implanted CAIRS were analyzed., Results: Patients were classified according to keratoconus severity: group A (maximal keratometry Kmax <75D) and group B (Kmax >75D). At 1 month postoperatively, both groups A and B showed a significant decrease in mean keratometry by 4.78 ± 1.57D and 12.87 ± 4.62D, respectively. Total and higher order aberrations decreased by 5.66 ± 4.55 and 0.65 ± 1.54 in group A and by 9.45 ± 9.15 and 0.49 ± 1.39 in group B, respectively. The corrected distance visual acuity improved by 4.8 ± 1.7 lines in group A. Visual improvement was not significant in group B. One eye in group B exhibited acute rejection and required explantation., Conclusions: FS-assisted multiple CAIRS implantation using a single corneal graft maximizes the utilization of viable corneal tissue. CAIRS implantation is an effective and biocompatible therapeutic alternative, particularly in cases of moderate to advanced keratoconus with Kmax <75D., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To evaluate the safety and efficacy of different time-point combinations of intrastromal corneal ring segment (ICRS) implantation using femtosecond technology) and corneal collagen crosslinking (CXL) for the treatment of moderate-to-severe keratoconus (KCC)., Methods: This study included 69 eyes of 69 patients with keratoconus who underwent ICRS and CXL treatment at an Eye Hospital between March 2020 and March 2023. The patients were divided into two groups: Group 1 (n = 33 eyes of 33 patients), which received ICRS and CXL treatment in one session, and Group 2 (n = 36 eyes of 36 patients), which included treatment with ICRS for at least 6 months following CXL application. Preoperative and postoperative evaluations included visual acuity, autorefractometer refraction, corneal tomographic measurements using the Sirius (CSO) Scheimpflug camera and the TONOREF™ III device, and documentation of observed complications. Uncorrected visual acuity (UCVA) and best-corrected spectacle visual acuity (BCVA) were measured in each eye individually, and visual acuity was assessed using the logarithm of the minimum angle of resolution (logMAR)., Results: In Group 1, mean UCVA improved from 0.81 ± 0.34 to 0.45 ± 0.25 (p < 0.01), and mean BCVA improved from 0.76 ± 0.35 to 0.38 ± 0.20 (p < 0.01). In Group 2, mean UCVA improved from 0.71 ± 0.32 to 0.43 ± 0.30 (p < 0.01), and mean BCVA improved from 0.65 ± 0.25 to 0.31 ± 0.23 (p < 0.01). Both groups showed significant reductions in manifest spherical and cylindrical refraction (p < 0.01). Group 1 exhibited greater reductions in maximum keratometry (Kmax), flat keratometry (K1), steep keratometry (K2) (p < 0.05), and astigmatic aberration compared with group 2 (p < 0.01). The use of simultaneous or separate CXL and ICRS does not significantly increase the incidence of complications., Conclusions: Both combined and separate CXL and ICRS treatments resulted in significant improvement in UCVA and BCVA and reduced manifest refraction. Although improvements were observed in groups 1 and 2 in terms of K1, K2, and Kmax at 6 months, the improvements were more pronounced in Group 1. These results highlight the potential benefits of simultaneous ICRS + CXL treatment and underscore the importance of optimising the timing of CXL treatment to achieve the best visual outcomes., (© 2024. The Author(s).)

This study aims to observe the clinical efficacy and safety of rigid gas permeable corneal contact lenses (RGP-CLs) wearing after femtosecond laser-assisted minimally invasive lamellar keratoplasty (FL-MILK) in progressive and advanced keratoconus eyes. Twenty-five patients (27 eyes) fitted with RGP-CLs after FL-MILK were enrolled, and 22 grading-matched keratoconus patients (23 eyes) as a control group. Corneal morphological data, diopter, best corrected vision, corneal endothelium, non-invasive tear film rupture time (NIBUT), corneal perception and comfort questionnaire were analysed before and after wearing RGP-CLs. In the FL-MILK group, the flat K, steep K and Kmax of the corneal anterior surface were decreased by 3.05D, 3.48D and 7.17D respectively after surgery (P = 0.011, 0.004 and 0.007). The central corneal thickness increased by 175.29 μm (P < 0.001). The basic curve of RGP-CLs after surgery was about 0.23 mm flatter than that before surgery (P = 0.013). There was no statistical difference in the best corrected vision and the comfort of wearing RGP-CLs before and after FL-MILK (P = 0.923, 0.391). Compared with the control group, there was no significant difference in vision improvement by RGP-CLs (P = 0.669). During the follow-up, the comfort of wearing RGP-CLs in the two groups was good, and no obvious adverse events were observed. This study showed MILK significantly increases corneal thickness and flattens corneal curvature, achieving good RGP-CLs corrected vision., (© 2024. The Author(s).)

Purpose: To identify preoperative predictors of big bubble (BB) formation during deep anterior lamellar keratoplasty (DALK) in patients with keratoconus (KC)., Methods: DESIGN: Retrospective cohort study in an Italian tertiary centre., Study Population: Consecutive patients with KC undergoing DALK from January 2021 to July 2023., Observation Procedure: Tomographic and topographic data including K-max, K-mean, keratometric astigmatism, thinnest point, mean peripheral corneal thickness, difference between the mean peripheral corneal thickness and the thinnest point (peripheral-minimal corneal thickness), position (central/paracentral) and cone area (%), Amsler-Krumeich classification and anterior segment optical coherence tomography (AS-OCT) analysis to assess the severity stage., Main Outcome Measures: Rate of BB formation and type; multivariate logistic regression analysis was used to analyse all preoperative parameters in patients with BB formation versus failure., Results: Pneumatic dissection succeeded in 98 of 140 eyes (70.0%), with 94 type 1 bubbles (67.1%) and four type 2 bubbles (2.9%). BB formation succeeded more frequently in patients with lower K-max (p=0.032), lower K-mean (p=0.010), higher thinnest point (p=0.017), lower peripheral-minimal corneal thickness (p=0.009) and lower Amsler-Krumeich stages (p=0.021). According to the AS-OCT analysis, BB formation was more frequent in the lower stages (p<0.001). After the logistic regression (pseudo-R²=0.176, constant=3.21, 95% CI 1.14 to 5.29, p=0.002), AS-OCT classification was found to be the only factor that predicted BB formation (coefficient=-0.81, 95% CI -1.18 to -0.43, p<0.001)., Conclusions: AS-OCT classification is a reliable predictor for BB formation. Tomographic and topographic analyses indicated that a steeper and more ectatic cornea is more prone to BB failure., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The purpose of this study was to investigate corneal stiffening after epithelium-off accelerated corneal cross-linking (CXL; 9 mW/cm²) in progressive keratoconus (KC) with different methods of epithelial debridement., Methods: This was a retrospective, interventional, and non-randomized study. In group 1, the epithelium was removed using a hockey knife (N = 45). In group 2 (N = 39) and group 3 (N = 22), the epithelial thickness was measured by optical coherence tomography (OCT) and the epithelium was ablated by excimer laser, but, in group 3, stromal ablation was performed additionally to correct high order aberrations (HOAs). Corneal biomechanics (integrated invers radius [IIR], stress-strain index [SSI]) and corneal tomography (thinnest corneal thickness [TCT]) were assessed with Corvis ST and Pentacam prior to and 1 month after CXL., Results: Corneal tomography did not differ among the groups preoperatively (P > 0.05). TCT decreased significantly in all groups after surgery (all P < 0.05). Nonetheless, corneal biomechanical stiffening was found in all three groups indicated by a decreased IIR and an increased SSI (all P < 0.05). For group 3, the HOA improved significantly (P < 0.001). Among the groups, there were no significant differences in changes of biomechanical parameters, but TCT was significantly reduced after laser ablation., Conclusions: Corneal stiffening after CXL is independent from epithelial removal. In particular, despite the removal of stromal tissue to correct HOA, a stiffening effect was achieved in keratoconic corneas, even it was less pronounced compared to mechanical epithelial removal. The reduction in HOA indicates a possible improvement in visual acuity., Translation Relevance: Cross-linking stiffens the keratoconus independent of epithelial debridement technique and may compensate minor stromal laser ablation.

Purpose: This study examines the incidence of infection and resistance associated with Intracorneal Ring Segment (ICRS) implantation, a common outpatient surgical treatment for correcting refractive errors and corneal ectatic diseases. Although ICRS procedures are typically safe and reversible, there is a low but notable risk of microbial infections, which require prompt and sometimes invasive treatment., Methods: Three electronic databases, PubMed, Web of Science (WoS), and Scopus, were utilised to search for literature according to PRISMA guidelines to identify infections related to the implantation of ICRS in the cornea between January 2000 and December 2022., Results: Gram-positive organisms were involved in 86% of cases: 35.7% S. aureus, 25% coagulase-negative staphylococci species, 17.8% streptococci and 7.1% Nocardia species. Less commonly recorded were Gram-negative bacteria (14%), with Pseudomonas aeruginosa ( circa 10%) and Klebsiella pneumonia (4%) being the most common Gram-negative bacteria. In rare cases, fungi have also been reported. ICRS-related bacterial infections can be categorised into early or late onset. Early onset infection typically manifests within the first few weeks after implantation and is often associated with contamination during surgery, unhygienic practices, or inadequate sterilisation techniques. On the other hand, late-onset infection may develop months or even years after the initial procedures and may be associated with persistent bacterial colonisation, secondary infections, or prolonged use of prophylactic antibiotics. S aureus is encountered in both early and late-onset infections, while Nocardia species and K. pneumoniae have generally been reported to occur in late-onset infections. In addition, vision recovery from S. aureus infections tends to be poor compared to other bacterial infections., Conclusion: S. aureus is a predominant pathogen that often requires surgical intervention with poor outcomes. Early infections result from incision gaps and ring segment rubbing, while late infections are linked to prolonged antibiotic use. Further research is needed on novel antimicrobial ICRS to procure the vision.

Purpose: The aim of this study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) and compare it with penetrating keratoplasty (PKP) in keratoconic eyes with Descemet membrane (DM) rupture., Methods: In this comparative retrospective case series, 33 keratoconic eyes with a history of hydrops underwent DALK and 27 received PKP. Baseline and postoperative visual acuity, corneal astigmatism, mean keratometry, endothelial cell density, and complication rates were measured., Results: The median follow-up of patients who underwent DALK was 45 months (range, 4-76 months) and that of patients who underwent PKP was 84 months (range, 4-136 months). Both procedures had comparable postoperative visual acuity, astigmatism, and mean keratometry. Significantly higher endothelial cell densities were observed in DALK than in PKP at 2, 3, and 5 years postsurgery (2043 ± 767 vs. 1165 ± 683 cell/mm 2 , P = 0.007, n = 12 in both groups at 2 years). Intra-DALK, 15 perforations occurred (44.12%) and 1 (2.94%) was converted to PKP. Graft rejection was diagnosed in 1 (3.03%) DALK procedure versus 8 (29.63%) PKP ( P = 0.008), and other long-term complication rates were equivalent. Kaplan-Meier survival analysis also revealed a higher rejection-free survival rate for the DALK group ( P = 0.012). Subgroup analysis within both groups based on the severity of preoperative DM rupture revealed no significant difference in any major 2-year outcomes., Conclusions: DALK showed similar beneficial visual outcome and safety but significantly better endothelial protection over PKP in eyes with keratoconus and previous hydrops. Therefore, DALK is recommended in posthydrops cases irrespective of the DM rupture severity., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To compare the postoperative outcomes following implantation of KERATACx ring segments (Imperial Medical Technologies Europe GmbH) in patients having eccentric keratoconus with three different topographic patterns., Methods: This retrospective cohort study was conducted at Maadi Eye Subspeciality Center, Cairo, Egypt. The study included patients with keratoconus who had implantation of KERATACx ring segments. Three groups were segregated based on topographic keratoconus patterns using the Sirius CSO Topographer (CSO Italia): type I ectasia where the cone coincides with the corneal flat axis, type II ectasia in which the cone coincides with neither the steep nor the flat axis and lies between the two axes, and type II ectasia for cones coinciding with the corneal steep axis. The visual and topographic outcomes were compared preoperatively and postoperatively for the three enrolled groups., Results: This study enrolled 92 eyes of 92 patients and had a mean ± standard deviation follow-up of 16.9 ± 9.2 months. The patients' medical records revealed that night vision complaints and halos around the light were experienced the most by the type III ectasia group (31.25%). For the type III ectasia group, four topographic indices and one visual parameter did not show statistically significant differences between the preoperative and postoperative data (inferior-superior difference at 2- and 4-mm diameter, coma aberration, higher order aberrations, and uncorrected distance visual acuity), contrary to the type I and II ectasia groups, which showed significant improvements in all evaluated parameters., Conclusions: The type III morphological pattern of ectasia is the least likely to benefit from KERATACx ring segments implantation. [ J Refract Surg . 2024;40(9):e625-e634.] .

Background: To evaluate the results of corneal allogenic intrastromal ring segment (CAIRS) implantation in keratoconus., Methods: The medical records of patients with keratoconus who underwent CAIRS implantation were reviewed. The CAIRS, prepared by trephination from the donor cornea, was implanted into a tunnel created using the femtosecond laser. The depth of the tunnel was 200 μ; the inner diameter of the tunnel was 4.5 mm; and the outer diameter was 7 mm. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), keratometry, minimum corneal thickness (CT), endothelial cell density (ECD), and high order aberration values were recorded preoperatively and at the 1st, 3rd, and 6th months postoperatively., Results: A total of 23 eyes of 23 patients were included in the study. Preoperative UCVA (0.08 ± 0.01) and BCVA (0.25 ± 0. 11) values improved postoperatively and reached 0.40 ± 0.05 and 0.68 ± 0.09, respectively, at the end of the 6-month follow-up period (p 1  < 0.001, p 2  = 0.016; respectively). A statistically significant flattening of all keratometric values was observed in the postoperative period compared to preoperatively (p < 0.001 for all). There were no statistical differences between CT and ECC values at the preoperative and postoperative visits (p 1  = 0.654, p 2  = 0.769; respectively). In addition, coma aberration values were lower than the preoperative values at all postoperative visits (p < 0.05 for all)., Conclusions: These results suggest that CAIRS implantation is a safe treatment option with good visual and keratometric outcomes for suitable patients with keratoconus., (© 2024 The Author(s). Clinical & Experimental Ophthalmology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Ophthalmologists.)

Background: Both the anterior chamber and posterior chamber phakic intraocular lenses (pIOLs) implantation are acceptable refractive surgical approaches in keratoconus patients with high anisometropia, contact lens intolerance, or who prefer spectacle and contact lens independent. They are beneficial for correcting anisometropia in stable keratoconus cases or following corneal procedures such as intrastromal corneal ring segments (ICRS), collagen cross-linking (CXL), and keratoplasty. They are suitable for eyes without advanced keratoconus with acceptable best-corrected distance visual acuity (BCDVA) or without highly irregular astigmatism, high comma, and higher-order aberrations (HOAs). Combined procedures for irregular astigmatism reduction and corneal regularization with either ICRS or topography/wavefront-guided transepithelial PRK (with or without CXL) can be associated in advance with pIOLs implantation to improve BCDVA in these cases., Aim: To study and report the evidence regarding the safety and efficacy of pIOLs for KC patients' visual and refractive rehabilitation, we have analyzed the scientific evidence published within the last 10 years (from 2012 onwards)., Results: No randomized controlled trials but only eleven retrospective case series and two prospective case series were identified. Satisfactory visual rehabilitation was achieved regarding uncorrected and corrected distance visual acuity (CDVA) and predictability of the refractive correction. Both types of pIOL (iris claw and posterior chamber pIOLs) offer very good results in terms of safety and efficacy with indexes close to or even exceeding 1., Conclusion: pIOLs implantation is a valid refractive therapeutic approach for correcting stable keratoconus with moderate-to-high refractive errors, especially anisometropia associated with regular or mildly irregular astigmatism, and good CDVA., Competing Interests: Declaration of conflicting interestsThe authors have no financial interest in any product or or instrument, or drug mentioned in this article. The authors have not received any contribution as consultants, reviewers for any of the devices, or instruments mentioned in this article.

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., Competing Interests: Declaration of Competing Interest On behalf of all authors and as the corresponding author, I hereby declare that there has been no conflicting interests of any type, at any time during the conduction of this project., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this review was to summarize the different surgical approaches combining photorefractive keratectomy (PRK) and corneal crosslinking (CXL), present each protocol template in a simple format, and provide an overview of the primary outcomes and adverse events., Methods: A literature review was conducted as outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Eight different databases were searched. Papers were included if PRK was immediately followed by CXL., Results: Thirty-seven papers met the inclusion criteria of a total yield of 823. The latest research into simultaneous PRK and CXL has been shown to not only stabilize the cornea and prevent keratoconus progression but also improve the visual acuity of the patient. Improvements in uncorrected distance visual acuity and (spectacle) corrected distance visual acuity were found to be significant when considering all protocols. There were also significant reductions in K1, K2, mean K, Kmax, sphere, cylinder, and spherical equivalent. Random-effects analysis confirmed these trends. Corrected distance visual acuity was found to improve by an average of 0.18 ± 1.49 logMAR (Cohen's D [CD] 0.12; P <0.02). There was also a significant reduction of 2.57 ± 0.45 D (CD 5.74; P <0.001) in Kmax. Cylinder and spherical equivalent were also reduced by 1.36 ± 0.26 D (CD 5.25; P <0.001) and 2.61 ± 0.38 D (CD 6.73; P <0.001), respectively., Conclusions: Combining the 2 procedures appears to be of net benefit, showing stabilization and improvement of ectatic disease, while also providing modest gains in visual acuity. Since customized PRK and CXL approaches appear superior, a combination of these would likely be best for patients., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

This case series reports eight eyes with keratoconus treated with laser implantation of one or two segments of progressive thickness corneal intrastromal ring (PT-ICRS). In this case series, it was evident that the insertion of PT-ICRS induces more pronounced corneal flattening at the thickest point, causing a reduction in distortion (coma) and lower astigmatism, resulting in a remarkable improvement in vision. Compared to the implementation of traditional intrastromal rings, the PT-ICRS variant showed superior results despite the small sample size. However, the same degree of asymmetry enhancement was not observed in cases in which a 330° PT-ICRS was implanted, despite the improvement in visual results when replacing a 320° traditional ring with a 330° PT-ICRS. These conclusions are limited as this is a case series with few cases., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

BACKGROUND: Corneal transplantation in keratoconus (KC) patients is generally considered to be successful with a high grade of patient satisfaction. Long-term studies suggest a 6% to 11% probability of KC recurrence manifested by keratometric instability and progressive corneal ectasia. METHODS: We propose to review the frequency, risk factors for the development, and the surgical options for the correction of high irregular astigmatism due to late graft ectasia following penetrating keratoplasty (PK). RESULTS: Post-keratoplasty ectasia is characterized by increasing corneal steepening with myopic shift and high irregular astigmatism, developing years or decades after PK, mostly occurring in KC patients. Contact lenses may adequately improve the visual acuity; however, because these patients are often elderly and intolerant to hard contact lenses, ultimately a surgical correction is proposed to the patient. Compressive suture and corneal wedge resection may improve corneal astigmatism, but the outcomes are unpredictable and often temporary. For this reason, a larger PK graft is often proposed for surgical rehabilitation with the consequence of removing more of the recipient's healthy endothelium and exposing the patient to a renewed immunogenic stimulus and short-term graft failure for endothelial decompensation. More recently, lamellar keratoplasty using various techniques has been proposed as an alternative to PK in order to maximize the visual outcomes and minimize the complications. CONCLUSIONS: Management of advanced corneal ectasia is a significant challenge for corneal surgeons. Many surgical approaches have been developed, so there is a large arsenal of surgical operations to correct post-PK ectasia. Among them, large-diameter anterior lamellar keratoplasty may be a viable, safer, and effective alternative to PK for the correction of post-keratoplasty ectasia. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to explore the optimal shape of customized lenticules for stromal lenticule addition keratoplasty (SLAK) for off-centered ectasia., Methods: Two different methods to create ex vivo models of eccentric-keratoconus were investigated. Twelve human corneas were used to create model 1 by a hyperopic photorefractive keratectomy (PRK), and model 2 by masked phototherapeutic keratectomy (PTK) on the anterior corneal surface, whereas both types received myopic ablation of the posterior surface. Keratoconus models underwent a modified femtosecond laser (FSL) flap-cut to create stromal pockets. Sixteen human corneas underwent FSL dissection to obtain four lenticule types: type I (planar) and type II (negative) lenticules were used without modifications, whereas type III (customized-planar), and type IV (customized-negative) lenticules underwent further masked-PRK to obtain an asymmetric bow-tie shape. Topographic, aberrometric analysis, and anterior segment optical coherence tomography (AS-OCT) were performed in all recipient corneas before and after lenticule implantation., Results: Keratoconus model was successfully reproduced. Tomographic analysis showed a significant inferiorly decentered corneal steepening with coherent stromal thinning. Model 2 reproduced better the curvature of real keratoconus. Lenticules type I implantation induced a homogeneous corneal thickening, type III produced higher thickening in the inferior half of the cornea. Type II determined a maximal peripheral pachymetric increase, with a gradual reduction toward the center, and type IV presented an asymmetric peripheral thickening. Topographic assessment showed a cone apex flattening in all cases, but it was significantly higher in types II and IV. Customized lenticules improved significantly corneal surface regularity regarding types I and II., Conclusions: The approach of customizing lenticules by increasing their asymmetry and tailoring the re-shaping effects, may improve SLAK outcomes in eccentric keratoconus.

BACKGROUND Acute corneal hydrops, a rare complication of keratoconus, is characterized by sudden onset of corneal stroma edema. It typically manifests as an acute decrease in visual acuity, accompanied by pain and photophobia. Prompt recognition and interventions are critical for effective resolution of hydrops and prevention of corneal vascularization. Herein, we present a case of a patient with keratoconus who developed corneal hydrops, successfully managed using full-thickness compression sutures and intracameral air injection. CASE REPORT A woman in her early 30s, with a history of keratoconus, presented with symptoms of acute hydrops in her left eye. On presentation, best corrected visual acuity was hand motion. Slit-lamp examination revealed marked corneal edema with multiple stromal clefts. The decision was made to perform full-thickness compression sutures combined with intracameral air injection to expedite edema resolution and prevent neovascularization. Three full-thickness sutures were placed across Descemet membrane breaks, and an air bubble was left, filling 50% of the anterior chamber. At 3-month follow-up, a clear, compact cornea was noted, with no evidence of vascularization. The patient was scheduled for penetrating keratoplasty for visual rehabilitation. CONCLUSIONS The combination of full-thickness compression sutures and intracameral air seems to be an effective and safe method for preventing corneal angiogenesis following hydrops. As corneal scaring is often an inevitable complication of acute corneal hydrops, keratoplasty is necessary for improving visual acuity. Hence, the prevention of corneal vascularization should be the major aim in the management of corneal hydrops to ensure successful keratoplasty.

Background: Recently a new surgical technique for intracorneal ring-segments (ICRS) assisted by femtosecond laser (FSL) called ByLimB was developed, involving the creation of the incision from a paralimbic region. This study aims to evaluate the safety and efficacy of the ByLimb technique following one year of follow-up., Methods: A prospective, single-center study was conducted at the Zaldivar Institute in Buenos Aires, Argentina. Keratoconus patients with indication for ICRS-FSL assisted procedure, operated with the ByLimb technique were included. By using the ByLimb technique, the ICRS are placed without affecting the tunnel's roof, and the end of the ICRS is always away from the incision area. Visual acuity, topographic astigmatism, and the occurrence of complications were evaluated. Safety index was the main outcome and efficacy indes was a complimentary outcome., Results: A total of 17 eyes completed the 12-month follow-up period. The safety index was 1.10 (mean postoperative corrected distance visual acuity (CDVA) in decimal: 0.76/preoperative CDVA: 0.69), while the efficacy index was 0.89 (mean postoperative uncorrected distance visual acuity UDVA in decimal: 0.62/preoperative CDVA: 0.69). Mean preoperative astigmatism was 5.3 ± 2.3, decreasing twelve months after surgery at 2.1 ± 1.2 (p < 0.001). No eye loss lines of vision and no intraoperative complications were observed. During the first month after surgery, an improper positioning of the ICRS based on topographic assessment was detected in five cases. A second procedure was performed, which consisted of opening the incision and introducing a Sinsky hook, through which the ICRS was mobilized and placed in its correct position. No incisional alterations, signs of infection, anterior segment anomalies, or fundus alterations were observed., Conclusion: FSL-assisted ICRS implantation through the perilimbal region has demonstrated an adequate safety index one year post-surgery. Additionally, this technique has facilitated accurate realignment of ICRS during secondary surgical interventions within one-month post-surgery. While the current findings are promising, continued follow-up of these cases is warranted., (© 2024. The Author(s).)

To evaluate the impact of excimer laser-assisted deep anterior lamellar keratoplasty (Exc-DALK) and excimer laser-assisted penetrating keratoplasty (Exc-PKP) on subfoveal choroidal thickness (SFCT) in eyes with advanced keratoconus. A retrospective comparative clinical study, which compares the outcomes of 24 eyes treated with Exc-DALK (G1) against matched group of 43 eyes treated with Exc-PKP (G2) at both 2 months (T1) and 2 years (T2) postoperatively. Main outcomes included best-corrected visual acuity (BCVA), central macular thickness (CMT), and SFCT. Preoperatively, there were no significant differences between both groups regarding BCVA, CMT or SFCT (p > 0.05). There were no significant differences between both groups regarding BCVA at both follow-ups (p > 0.05). There were no significant differences between both groups regarding CMT at both follow-ups (p > 0.05). SFCT was higher in G2 than G1 at both follow-ups (p < 0.01). Compared to preoperative SFCT, there were no significant changes in SFCT in G1 at both follow-ups (p > 0.05). In G2, SFCT increased significantly at T1 (p < 0.01) and did not differ significantly at T2 (p = 0.17). SFCT increased significantly after Exc-PKP but not after Exc-DALK, which might indicate that Exc-DALK affects the choroid less and thus could represent a less traumatic approach to ocular tissue than Exc-PKP., (© 2024. The Author(s).)

Purpose: This study aimed to report the long-term results of combined topography-guided photorefractive keratectomy (PRK) and accelerated corneal collagen cross-linking (CXL) for keratoconus using the Zeiss refractive coordinated system., Methods: A prospective interventional study was conducted in a tertiary eye care hospital in South India. Patients with mild-to-moderate progressive keratoconus and corneal pachymetry greater than 450 µm were included. They underwent customized topography-guided PRK followed by CXL. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and keratometry readings and complications were evaluated at 1, 3, 6, 12, and 24 months postoperatively., Results: Thirty patients (30 eyes) were included in the study. All study parameters showed a statistically significant improvement postoperatively over baseline values. At 24 months, the mean UDVA improved from 0.8 ± 0.180 logarithm of the minimum angle of resolution (logMAR) to 0.38 ± 0.118 logMAR ( P -value <0.001) and CDVA improved from 0.467 ± 0.142 logMAR to 0.227 ± 0.078 logMAR ( P -value <0.001). The mean flat, steep, and maximum keratometry values were significantly reduced by 2.133, 3, and 4.54 diopters, respectively, at the last follow-up examination ( P -value <0.001)., Conclusion: The combined topography-guided PRK and accelerated CXL procedure seem to be a promising treatment alternative for early keratoconus. This is the first such study on the Zeiss refractive coordinated system. However, further studies with a larger study population and longer follow-up periods are required to draw final conclusions about the benefits of this procedure in keratoconus., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: To evaluate the association between donor-related factors and the risk of rejection in patients undergoing penetrating keratoplasty (PKP) for keratoconus., Methods: A retrospective review was performed of keratoconus patients with no corneal neovascularization who underwent PKP from November 2014 to December 2016 and completed at least two years of follow-up. Preoperative, donor, operative, and postoperative data were collected and analyzed to identify factors leading to corneal graft rejection., Results: A total of 201 eyes (of 201 patients) that underwent PKP for keratoconus were included. Of these, 22.9% (95% CI 17.6-29.2%) had an episode of graft rejection. The overall graft survival rate was 98.5%. Receipts with a history of corneal transplant in the fellow eye (IRR 1.69, 95% CI 1.01, 2.80; p = 0.044) and those with postoperative stromal neovascularization (IRR 2.51, 95% CI 1.49, 4.21; p = 0.001) had a significantly higher incidence of rejection than those without these features. In univariate analysis, death-to-surgery time and death-to-excision time (DET) showed a weak association with graft rejection (p 0.05 and 0.08 respectively); However, in the multivariable analysis, this significance was lost. Grafts with a death-to-excision time (DET) greater than 8 h had a 0.53X lower risk of rejection compared with grafts with DET within 8 h or less (p = 0.05). Rejection was higher in patients receiving grafts with a preservation time within 7 days or less compared with preservation time greater than 7 days (30.6% vs. 21.2%, respectively, p = 0.291)., Conclusion: In the multivariable analysis, none of the donor-related factors were significantly associated with graft rejection; however, short death-to-surgery time may be associated with rejection after PKP. Recipients with a history of PKP in the fellow eye and those who developed corneal neovascularization were also at increased risk of developing rejection after keratoplasty., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: The aim of this study was to analyze changes in corneal biomechanical properties after implantation of intracorneal ring segments (ICRSs) in keratectasia., Methods: This retrospective single-center study included 112 patient eyes that underwent femtosecond laser-assisted ICRS implantation (Intacs SK; Addition Technology Inc, Des Plaines, IL) for keratectasia. Biomechanical analysis was performed using the Ocular Response Analyzer (ORA; Reichert Inc, Depew, NY), with determination of corneal resistance factor, corneal hysteresis, and Keratoconus Match Index, as well as by Corvis ST (OCULUS, Wetzlar, Germany), with determination of stiffness parameter A1, Ambrosio relational thickness to the horizontal profile (Arth), integrated radius, deformation amplitude ratio, and stress-strain index as well as Corvis Biomechanical Index and Tomographic Biomechanical Index. Data collection was performed preoperatively and 6 months postoperatively for ORA and Corvis ST and additionally after 1 and 2 years for ORA., Results: The corneal resistance factor decreased significantly postoperatively (5.8 ± 1.7 mm Hg) compared with preoperatively (6.75 ± 3.7 mm Hg; P = 0.021) and increased again during follow-up (6.2 ± 1.9 mm Hg; P = 0.024), without regaining preoperative values. Corneal hysteresis and Keratoconus Match Index did not change significantly. Stiffness parameter A1 ( P = 0.045) increased significantly after ICRS implantation and Arth decreased significantly from 181 ± 85 to 150 ± 92 ( P = 0.016). However, there was no significant postoperative change for others Corvis parameters., Conclusions: Corneal biomechanical properties showed inconsistent changes after ICRS implantation. Classical corneal biomechanical parameters (using single central air-puff tonometers) do not seem to be suitable for follow-up after ICRS implantation., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Corneal deformations caused by keratoconus produce high levels of optical aberration (OA). Despite appropriate optical correction, these alter the quality of vision and diminish the patient's quality of life, especially since the affected population is predominantly young and of working age. When thinning is too severe or corneal transparency too impaired, a corneal transplant may be considered. In this study, we compare the quality of life of patients with keratoconus in the early (stages 1 and 2) or advanced (stages 3 and 4) stages of the Krumeich classification, as well as patients who have had keratoconus treated by keratoplasty. Quality of life was assessed using the NEI-VFQ 25 questionnaire, the most widely used for keratoconus. An aberrometric examination (OQAS®; HD Analyser, Visiometrics, Terrassa, Spain) was also performed to assess patients' quality of vision. Our results show that keratoplasty provides an improvement in quality of life compared with advanced-stage keratoconus in the areas of distance (p=0.0083) and near vision (p=0.029) activities. This improvement also applies to Best-Corrected Visual Acuity (BCVA) (p=0.032) and transparency (OSI) (p=0.049). Our study shows that keratoplasty improves corneal transparency, and it is interesting to note that it improves patients' quality of life over the long term., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Purpose: To compare the outcomes of deep anterior lamellar keratoplasty (DALK) using dehydrated versus standard organ culture-stored donor corneas for eyes with keratoconus., Design: Prospective, randomized, single-center trial conducted in Italy., Participants: Adult patients (age ≥ 18 years) with keratoconus scheduled for elective DALK., Methods: Patients undergoing successful type 1 bubble pneumatic dissection using a standard DALK technique were randomized during surgery to receive either dehydrated (n = 30) or standard organ culture-stored (n = 30) donor corneas., Main Outcome Measures: The primary study outcome was best spectacle-corrected visual acuity (BSCVA) 12 months after surgery. Secondary outcomes were refractive astigmatism (RA), endothelial cell density (ECD), and complication rates., Results: Postoperative BSCVA did not significantly differ between groups at both time points: mean difference at 6 months was 0.030 logarithm of the minimum angle of resolution (logMAR; 95% confidence interval [CI], -0.53 to 0.10 logMAR; P = 0.471) and at 12 months was -0.013 logMAR (95% CI, -0.10 to 0.08 logMAR; P = 0.764). No significant differences between groups were observed in terms of postoperative RA and ECD at all time points. In the first 3 days after DALK, an epithelial defect was present in 10 patients (33%) in the organ culture cornea group and in 29 patients (97%) in the dehydrated cornea group. Complete re-epithelialization was achieved by day 7 in all patients (100%) in both groups., Conclusions: The study provides evidence that the use of dehydrated corneas is noninferior to the use of standard organ culture donor corneas for DALK. Corneal tissue dehydration represents a viable solution that can allow long-term cornea preservation and avoid wastage of unused corneas., Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article., (Copyright © 2023 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To report a case of ulcerative keratopathy following implantation of acellular porcine corneal stroma (APCS) in a patient with keratoconus (KC)., Methods: A 58 year-old patient initially presented with an ulcerative keratopathy in the left eye. Previously, several corneal procedures (including radial keratotomy, laser-in-situ keratomileusis, crosslinking) were performed for KC. Eight months ago, an APCS lenticule (Xenia corneal implant, Gebauer Medizintechnik GmbH, Neuhausen, Germany) was implanted into a stromal pocket because of progressive keratectasia. Visual acuity was hand movement. Anterior segment optical coherence tomography showed a space between the APCS lenticule and the host stroma. Excimer laser-assisted penetrating keratoplasty (PKP, 8.0/8.1 mm) was performed in the left eye. The corneal explant was investigated by light and transmission electron microscopy., Results: Best-corrected visual acuity was 20/40 six weeks after PKP. Light microscopy demonstrated a stromal ulceration down to the APCS lenticule. No stromal cells could be found within the APCS lenticule eight months after implantation. The APCS lenticule did not show a green stain of the collagens with Masson-Goldner staining and exhibited a strong Periodic acid-Schiff positive reaction. Electron microscopy of the APCS lenticule revealed cross-linked collagen lamellae without cellular components. Close to the interface, corneal collagen lamellae of the host cornea were disorganized. Few vital keratocytes were present on the surface of the lenticule and appeared to cause mechanical disruption of the host stroma along the lenticule-stroma interface., Conclusion: APCS implantation may lead to severe complications such as ulcerative keratopathy in otherwise uncomplicated KC corneas. In such cases, excimer laser-assisted PKP or Deep Anterior Lamellar Keratoplasty are the methods of choice to restore visual acuity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To assess the accuracy of intraocular lens (IOL) power formulas, namely, SRK/T, Haigis, Barrett Universal II, Barrett True-K for keratoconus, Kane formula, and Kane formula for keratoconus, for cataract with keratoconus in Japanese eyes., Setting: Five surgical sites in Japan., Design: A retrospective case series., Methods: Eyes with keratoconus undergoing cataract surgery were included. Postoperative refraction was compared with the prediction by the formulas. Visual acuity, manifest spherical equivalent, prediction error (PE), and mean absolute errors (MAEs) were determined 1 month postoperatively. The PE within 0.50 diopter (D), 1.00 D, and 2.00 D were compared between IOL formulas. Subgroup analysis based on the steepest keratometry (stage 1, ≤ 48 D; stage 2, > 48 D and ≤ 53 D; and stage 3, > 53 D) was performed. The relationship between PE and preoperative biometric data were assessed., Results: Fifty eyes were included. The MAE of the Barrett True-K for keratoconus, Kane keratoconus, and Kane formulas were significantly lower than that of Haigis. A statistically significant difference in the prediction accuracy within ± 0.50 D was found between Kane keratoconus and Haigis. The prediction accuracy of the Barrett True-K for keratoconus, SRK/T, and Kane within ± 1.00 D was statistically significant compared with that of Haigis. In stage 3, the Barrett True-K for keratoconus had a significantly lower MAE than SRK/T and Haigis., Conclusion: Keratoconus-specific formulas were more accurate than existing formulas in Japanese eyes. The Barrett True-K formula for keratoconus had higher prediction accuracy in severe keratoconus., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Competing Interests: The authors have no conflicts of interest to disclose.

Purpose: To analyze the clinical outcomes after Bowman layer (BL) onlay grafting for the treatment of progressive, advanced keratoconus., Design: Prospective, interventional case series., Methods: Twenty-one eyes underwent BL onlay grafting. After removing the epithelium, a single or double BL graft was "stretched" onto the corneal surface, allowed to dry-in, and a soft bandage lens was placed until the graft was re-epithelialized. Best spectacle- and/or best contact lens-corrected visual acuity (BSCVA/BCLVA), corneal tomography, and postoperative complication rates were analyzed for the total group and 2 subgroups (group 1: preoperative maximum keratometry [Kmax] <69 diopters [D; n = 7); group 2: preoperative Kmax ≥69 D [n = 14]). Follow-up ranged from 6 to 36 months (mean 21 ± 11 months)., Results: All 21 surgeries were uneventful. Overall, Kmax changed from 76 ± 12 D preoperatively to 72 ± 9 D at 6 to 36 months postoperatively (P = .015). Kmax decreased by 6 D in group 2 (P = .002) but did not change in group 1. Average BSCVA remained stable for group 1 and improved from preoperatively 0.8 ± 0.4 to 0.4 ± 0.2 logarithm of the minimum angle of resolution postoperatively in group 2 (P = .032); BCLVA remained stable (P > .05). Within the first postoperative weeks, 2 eyes required BL graft repositioning after inadvertent bandage lens removal and 4 eyes underwent BL retransplantation for incomplete re-epithelialization. One eye underwent BL regrafting 12 months postoperatively after traumatic corneal erosion. All eyes showed a completely re-epithelialized graft at the last available follow-up., Conclusions: BL onlay grafting is a completely extraocular, minimally invasive surgical technique, providing up to -6 D of corneal flattening in eyes with advanced progressive keratoconus, allowing for continued (scleral) contact lens wear and therefore preserving the BCLVA., (Copyright © 2023. Published by Elsevier Inc.)

Lamellar surgeries have revolutionized our understanding and practice of keratoplasties. However, the learning curve in deep anterior lamellar keratoplasty (DALK) makes it daunting for novice surgeons. This paper describes a unique intraoperative sign - the radial "spike sign," which heralds the commencement of a big bubble in some cases of advanced keratoconus in eyes that have not undergone any previous surgery. The spike sign was noted during big bubble DALK surgery and was then retrospectively looked for in recorded DALK surgical videos and correlated with the formation of a big bubble. The movement of air after injection was classified into the direct formation of a big bubble, stromal emphysema with no big bubble, and emphysema with the spike sign followed by a big bubble. In total, 104 surgical videos of big bubble attempts were evaluated and classified as such. The spike sign helps reduce the number of unnecessary attempts at big bubble formation during DALK, thus improving surgical outcomes., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: To compare the effects of corneal allogenic intrastromal ring segment (CAIRS) implantation on topographical measurements and visual outcomes of patients with keratoconus with and without corneal cross-linking (CXL) prior to the time of implantation., Methods: Sixty-seven eyes with corneal allograft intrastromal ring segment implantation (KeraNatural; Lions VisionGift) due to advanced keratoconus were included in the study. Thirty-seven eyes had no CXL and 30 eyes had had CXL before being referred to the authors. The changes in spherical equivalent (SE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), steep keratometry (K1), flat keratometry (K2), mean keratometry (Kmean), maximum keratometry (Kmax), and thinnest pachymetry were retrospectively analyzed 6 months after the implantation., Results: The median age was 29 years in the CXL group and 24.0 years in the non-CXL group ( P > .05), respectively. All topographical and visual parameters before implantation were similar in both groups ( P > .05 for all parameters). At 6 months, CDVA, K1, and Kmean showed higher improvement in the non-CXL group than the CXL group ( P = .030, .018, and .039, respectively)., Conclusions: CAIRS surgery has a flattening effect on both the corneas with and without CXL. The cornea with prior CXL treatment had less flattening effect due to the stiffening effect of prior CXL. [ J Refract Surg . 2024;40(6):e392-e397.] .

Purpose: The aim of this study was to describe a new technique of selective corneal stromal transplantation for keratoconus treatment, donut-shaped CAIRS (corneal allogeneic intrastromal ring segment)., Methods: A donut-shaped corneal graft is obtained using a double-bladed trephine. Descemet membrane, endothelium, and epithelium are all removed from the graft. Only stromal tissue is transplanted. A wide 360-degree intrastromal tunnel is created using the femtosecond laser, with a 30-degree angulation. The diameter is from 5.4 mm to 8 mm optical zone. After dehydration, the corneal graft is inserted into the tunnel. We report the clinical and tomographic outcomes after the procedure in 3 patients., Results: The mean follow-up time after donut-shaped CAIRS was 6.01 ± 1.02 months. In case 1, best spectacle-corrected visual acuity improved from 20/150 to 20/40. In case 2, it improved from 20/400 to 20/40, and in case 3 from 20/200 to 20/40. The mean preoperative K was 57.3 ± 4.5 D and reduced to 44.2 ± 2.5 D after donut-shaped CAIRS. The mean spherical equivalent decreased from -9.8 ± 3.2 preoperatively to -3.2 ± 2.2 postoperatively. No intraoperative or postoperative complications were observed. Anterior segment OCT showed a mid-stroma implant, fusiform in shape, equidistant from the epithelium and endothelium., Conclusions: Donut-shaped CAIRS is a variation of the traditional CAIRS technique and showed to be an alternative option for keratoconus treatment, especially in moderate to advanced cases with a central clear cornea without scars. The technique is minimally invasive, and the visual axis remains untouched., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: This retrospective longitudinal study evaluated the biomechanical E-staging in KC corneas before and after intracorneal ring segment (ICRS) implantation (Intacs® SK, Addition Technology, Illinois, United States)., Methods: Biomechanical E-staging for ectatic corneal diseases was applied retrospectively on 49 KC corneas of 41 patients who underwent ICRS implantation. The main outcome parameters included the Corvis Biomechanical Factor (CBiF, the linearized Corvis Biomechanical Index and the biomechanical parameters included), the resulting biomechanical E-staging, the stress-strain index, thinnest corneal thickness (TCT), maximal anterior keratometry (Kmax), and the anterior radius of curvature (ARC). They were evaluated at 1.9 ± 1.1 months preoperatively and postoperatively after 2.8 ± 0.7, 5.8 ± 1.0, and 10.6 ± 2.3 months., Results: The CBiF decreased (4.9 ± 0.5 | 4.7 ± 0.5, P = 0.0013), and the E-staging increased significantly (2.8 ± 0.8 | 3.1 ± 0.9, P = 0.0012, paired t-test) from preoperatively to the first postoperative follow-up. The difference remained significant after 6 months; however, there was no more difference after 11 months. TCT was stable, whereas Kmax and ARC significantly decreased after ICRS implantation (TCT: 464 ± 49, 470 ± 51, 467 ± 38, 461 ± 48; Kmax: 56.3 ± 4.5, 54.7 ± 4.5, 54.2 ± 4.8, 54.1 ± 4.3; ARC: 51.5 ± 3.4, 48.3 ± 3.8, 48.6 ± 3.0, 48.6 ± 3.2 preoperatively and 3, 6, and 11 months postoperatively, respectively). Besides Kmax and ARC, Ambrósio's relational thickness to the horizontal profile (ARTh) was the only parameter that was significantly lower than preoperatively at any follow-up (P ≤ 0.0024, Wilcoxon matched-pairs test)., Conclusion: Intacs® SK implantation results in an increasing biomechanical E-staging in the first postoperative months with stabilization near preoperative values after 1 year. Significantly lower ARTh values at any follow-up document the ICRS effect and contribute to a slightly higher postoperative biomechanical E-staging value., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: The aim of this study was to describe the safety and efficacy of the Tel-Aviv Protocol (epithelial photorefractive keratectomy and corneal cross-linking) as a treatment for postrefractive surgery corneal ectasia., Methods: This study includes 8 eyes from 7 patients, each diagnosed with postrefractive surgery ectasia years after refractive surgery and treated with the Tel-Aviv Protocol. The procedure included transepithelial PRK using the EX500 excimer laser, a 50-μm laser ablation of the epithelium and anterior stroma, delivered on the visual axis with cyclotorsion correction, treating up to 50% of refractive astigmatism. After the epithelial photorefractive keratectomy, all patients underwent corneal cross-linking., Results: The mean keratometry (K) and maximal K both decreased [from 43.37 ± 2.23 to 41.84 ± 2.01 ( P = 0.03) and from 44.95 ± 3.08 to 42.78 ± 2.19 ( P = 0.03), respectively]. Astigmatism was significantly reduced (from 3.53 ± 2.36 to 0.88 ± 0.89 diopter; P = 0.02). Uncorrected visual acuity improved significantly in all patients from a mean of 0.56 ± 0.32 to 0.15 ± 0.14 logMAR ( P = 0.01). Best-corrected visual acuity improved from 0.22 ± 0.24 to 0.06 ± 0.06 logMAR ( P = 0.07; 1-tail P = 0.04). All patients maintained visual acuity during the follow-up period, up to 25 months, mean = 329 days. The Tel-Aviv Protocol was found to be safe [mean safety index: 1.63 ± 1.03 (range: 1.00-4)] and effective [mean efficacy index: 1.29 ± 0.66 (range: 0.71-2.1)]., Conclusions: The Tel-Aviv Protocol, developed initially for keratoconus treatment, is a safe and promising procedure to stop postrefractive surgery ectasia progression while significantly improving vision, thereby avoiding keratoplasty., Competing Interests: Conflicts of interest statement: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Corneal crosslinking (CXL) is used for treating keratoconus and post-laser in situ keratomileusis ectasia. However, refractive surgery is not usually performed with prophylactic CXL. Therefore, we performed a meta-analysis comparing outcomes of refractive surgeries with vs without prophylactic CXL. We systematically searched databases for studies comparing refractive surgeries for myopic correction with vs without prophylactic corneal crosslinking. Review Manager 5.4.1 was used to perform statistical analysis. We included 2820 eyes from 28 studies. Compared with refractive surgery alone, surgery with prophylactic CXL resulted in decreased central corneal thickness, corrected distance visual acuity logMAR, and safety and efficacy indices. There were no significant differences in postoperative uncorrected distance visual acuity of 20/20 or better at ≥12 months and other visual outcomes among both groups. More randomized controlled trials with standard crosslinking protocols are needed to analyze the prophylactic use of crosslinking with refractive surgeries., (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Purpose: To assess the outcomes of deep anterior lamellar keratoplasty or penetrating keratoplasty at the scar and the edema stages., Methods: Forty-five patients (45 eyes) with keratoconus scar stage (scar group, n=26; penetrating keratoplasty a subgroup, n=7; deep anterior lamellar keratoplasty b subgroup, n=19) and keratoconus edema stage (edema group, n=19; penetrating keratoplasty c subgroup, n=12; deep anterior lamellar keratoplasty d group, n=7) who received penetrating keratoplasty or deep anterior lamellar keratoplasty from 2000 to 2022 were retrospectively studied. At 1, 6, and 12 months after surgery, the best-corrected visual acuity, astigmatism, spherical equivalent, corneal endothelial cell density, and complications were analyzed., Results: The best-corrected visual acuity and average corneal endothelial cell loss rate were not significantly different between the scar and edema groups (p>0.05). At 6 and 12 months after surgery, the astigmatism and spherical equivalent in the scar group were significantly lower than those in the edema group (p<0.05). The spherical equivalent of the deep anterior lamellar keratoplasty b subgroup was lower than that of the penetrating keratoplasty a subgroup in the scar group 6 months after surgery (p<0.05). In the edema group, there was no significant difference in spherical equivalent between subgroups (p>0.05). There were no significant differences in best-corrected visual acuity and astigmatism between subgroups within the two groups (p>0.05). In comparison to the scar group, the edema group experienced more complications. According to a survival analysis, there was no statistically significant difference between the scar group and the edema group regarding the progression of vision., Conclusions: In terms of the outcomes and prognosis for vision after keratoplasty with edema stage and scar stage, deep anterior lamellar keratoplasty may be as effective as penetrating keratoplasty.

We present the case of a 65-year-old man with bilateral keratoconus and history of bilateral penetrating keratoplasty (PK) who developed gradual visual decline in the left eye due to cataract formation. Following successful left eye cataract surgery and monofocal, non-toric intraocular lens (IOL) in-the-bag implantation, the patient experienced persistently low uncorrected distance visual acuity (UDVA) due to high residual refractive error and intolerance to contact lenses. A supplementary toric IOL was placed in the ciliary sulcus, but subsequent rotational instability of the lens required repeated realignment. Despite two attempts at IOL repositioning, the rotational instability persisted, necessitating the replacement of the original Sulcoflex IOL with a toric, implantable Collamer lens. Following the implantation of the toric ICL, the patient achieved excellent UDVA with no adverse events over a 4-year follow-up period. This case highlights the potential rotational instability associated with toric piggyback IOLs in keratoconic, post-PK, pseudophakic eyes and the special considerations on choosing the type of piggyback lens in these eyes., (Copyright ©2024. All rights reserved. Reproduction in whole or in part in any form or medium without expressed written permission of the Digital Journal of Ophthalmology is prohibited.)

Purpose: The aim of this study was to investigate the effect of the implementation of corneal collagen crosslinking (CXL) on the frequency of corneal transplants among patients with keratoconus (KC) in the same region., Methods: Before the introduction of CXL in 2007, 55 primary corneal transplants had been conducted in patients with KC (2005 and 2006) at the Department of Ophthalmology, Oslo University Hospital, Norway. We collected data from our corneal transplant registry for 2021 and 2022. The primary outcome was the number of corneal transplants performed in patients with KC. Age, sex, visual acuity (logarithm of the minimal angle of resolution), KC stage according to the Amsler-Krumeich classification system, and steepest keratometry reading (maximum keratometry, Pentacam, HR) were recorded. Furthermore, we registered the annual number of CXL treatments conducted from 2007 to 2022., Results: A total of 352 corneal transplants were performed in 2021 and 2022. Among them, 11 (3.1%) were transplants for patients with KC. All included patients were male; further, 90.1% and 9.1% of the patients were graded stages 4 and 3, respectively. The mean maximum keratometry was 79.0 diopter (range 61.0-109). The mean best-corrected visual acuity (logarithm of the minimal angle of resolution) was 1.3 (range 0.2-3.0). In 2021 to 2022, 431 CXL treatments were performed., Conclusions: There was a significant decrease in the number of corneal transplants performed in patients with KC 15 years after the introduction of CXL. This indicates that the availability of CXL treatment over many years may considerably reduce the need for keratoplasties in this group of patients., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To compare long-term outcomes of simultaneous accelerated corneal crosslinking (CXL) with intrastromal corneal ring segments (CXL-ICRS) with simultaneous accelerated CXL with topography-guided photorefractive keratectomy (CXL-TG-PRK) in progressive keratoconus (KC)., Setting: Kensington Eye Institute and Bochner Eye Institute, Toronto, Canada., Design: Prospective nonrandomized interventional study., Methods: The change in visual and topographical outcomes of CXL-ICRS and CXL-TG-PRK 4 to 5 years postoperatively were compared using linear regression models adjusted for preoperative corrected distance visual acuity (CDVA) and maximum keratometry (Kmax)., Results: 57 eyes of 43 patients with progressive KC who underwent simultaneous accelerated (9 mW/cm 2 , 10 minutes) CXL-ICRS (n = 32) and CXL-TG-PRK (n = 25) were included. Mean follow-up duration was 51.28 (9.58) and 54.57 (5.81) months for the CXL-ICRS and CXL-TG-PRK groups, respectively. Initial mean Kmax was higher in the CXL-ICRS group compared with the CXL-TG-PRK group (60.68 ± 6.81 diopters [D] vs 57.15 ± 4.19 D, P = .02). At the last follow-up, change (improvement) in logMAR uncorrected distance visual acuity (UDVA) compared with that preoperatively was significant with CXL-ICRS (-0.31 ± 0.27, P < .001, which is equivalent to approximately 3 lines) and not significant with CXL-TG-PRK (-0.06 ± 0.42, P = .43). The logMAR CDVA improved significantly with CXL-ICRS (-0.22 ± 0.20, P < .001), but not with CXL-TG-PRK (-0.05 ± 0.22, P = .25). Adjusting for baseline Kmax and CDVA, the improvement in UDVA was significantly greater with CXL-ICRS than with CXL-TG-PRK (-0.27, 95% CI, 0.06-0.47, P = .01). Improvement in CDVA was not significantly different., Conclusions: In this cohort of progressive KC with long-term follow-up, UDVA showed more improvement with accelerated CXL-ICRS than with CXL-TG-PRK., (Copyright © 2023 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Purpose: To evaluate spherical intraocular lens (IOL) implantation for cataracts in keratoconic eyes followed by optional refractive toric lens exchange to improve uncorrected visual acuity., Methods: This retrospective study evaluated cataract surgery outcomes in keratoconic eyes. Eyes treated with a spherical IOL targeted for -2.00 diopters (D) either achieved acceptable manifest refraction and desired exchange with a toric IOL (Group 1); achieved satisfactory manifest refraction and chose to use spectacles or contact lenses (Group 2); or did not achieve acceptable refraction and used contact lenses (Group 3). Group 4 had single-stage toric IOL implantation with plano target. Corrected and uncorrected distance visual acuity (CDVA and UDVA) and keratometry were analyzed., Results: Groups 1 to 4 had 18, 23, 18, and 26 eyes, respectively. A staged toric exchange resulted in significantly better ( P = .02) UDVA (mean: 0.15 logMAR; 20/25 Snellen) than initial toric IOL implantation (0.24 logMAR; 20/30 Snellen). All toric IOL exchange eyes achieved 20/30 or better CDVA and 94% had 20/40 or better UDVA. Mean manifest cylinder significantly decreased from 3.39 D before lens exchange to 1.10 D postoperatively., Conclusions: Initial implantation of a spherical IOL in keratoconic eyes allows basing toric calculations on the manifest refraction, which may be more reliable than keratometry measurements in keratoconic eyes. UDVA after staged toric IOL exchange was significantly better than after initial toric IOL implantation. Importantly, by staging use of toric lenses, the authors avoided cases where patients required a rigid contact lens after a toric IOL was implanted. [ J Refract Surg . 2024;40(4):e207-e217.] .

Competing Interests: Aylin Kiliç is on the Scientific Advisory Board of KeraNatural and may have financial conflicts. The remaining authors have no funding or conflicts of interest to disclose.

This review analyzed all pertinent articles on keratoconus (KCN) and cataract surgery. It covers preoperative planning, intraoperative considerations, and postoperative management, with the aim of providing a simplified overview of treating such patients. Preoperatively, the use of corneal cross-linking, intrastromal corneal ring segments, and topo-guided corneal treatments can help stabilize the cornea and improve the accuracy of biometric measurements. It is important to consider the advantages and disadvantages of traditional techniques such as penetrating keratoplasty and deep anterior lamellar keratoplasty, as well as newer stromal augmentation techniques, to choose the most appropriate surgical approach. Obtaining reliable measurements can be difficult, especially in the advanced stages of the disease. The choice between toric and monofocal intraocular lenses (IOLs) should be carefully evaluated. Monofocal IOLs are a better choice in patients with advanced disease, and toric lenses can be used in mild and stable KCN. Intraoperatively, the use of a rigid gas permeable (RGP) lens can overcome the challenge of image distortion and loss of visual perspective. Postoperatively, patients may need updated RGP or scleral lenses to correct the corneal irregular astigmatism. A thorough preoperative planning is crucial for good surgical outcomes, and patients need to be informed regarding potential postoperative surprises. In conclusion, managing cataracts in KCN patients presents a range of challenges, and a comprehensive approach is essential to achieve favorable surgical outcomes., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: To present the clinical, genetic, and histopathological features of the ninth family affected by congenital stromal corneal dystrophy (CSCD) to date., Methods: Twelve cases of a Spanish family affected by CSCD were analyzed regarding history, visual acuity (VA, decimal scale), an ophthalmologic exam and specular microscopy. Five eyes were treated by deep anterior lamellar keratoplasty (DALK), and thirteen eyes by penetrating keratoplasty (PK). In the two last generations, a genetic study was performed., Results: Most of the patients affected were born with opaque corneas except for three, whose corneas were clear at birth. Biomicroscopy showed a whitish diffuse stromal opacity with an unaltered epithelium, causing poor VA (from hand motions to 0.4). Patients treated with PK presented mean postoperative VA of 0.19±0.20 over a follow-up time of 235.3±101.4months with 38% recurrences. Patients who underwent DALK experienced VA improvement to 0.17±0.11 over a follow-up time of 10.8±2.6months without signs of recurrence. In the latter, the big bubble technique was not achieved, so a manual technique was performed. The genetic study showed heterozygosis for a 1-bp deletion at nucleotide 962 in exon 8 of the decorin gene., Conclusions: CSCD is a rare entity, which should be treated by DALK whenever possible, obtaining better results than PK. Close monitoring of children of affected individuals is important, because CSCD can progress during the early years of life., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Purpose: The purpose of this study is to determine the incidence of suture-related complications, their risk factors, and effects on the clinical outcomes after deep anterior lamellar keratoplasty (DALK) for keratoconus., Methods: In this retrospective, comparative, interventional study, the records of consecutive patients with keratoconus who underwent DALK were reviewed for suture-related complications. Univariate analyses were used to identify risk factors for suture complications. We compared groups with and without suture-related complications to evaluate the effects of these complications on clinical outcomes after DALK., Results: Of the 633 DALKs, 438 eyes (69.2%) developed suture complications including loose sutures (32.7%), spontaneous suture rupture (30%), sterile suture abscesses (22.8%), suture tract vascularization (16.4%), suture erosion (10.3%), and suture cheese wiring (6.8%). Vernal keratoconjunctivitis increased the incidence of sterile suture infiltration, premature suture loosening, and suture tract vascularization. Loose suture was observed more commonly in larger graft size, while spontaneous suture rupture was associated with late suture removal. There was no statistically significant difference in postoperative outcomes including visual acuity, refraction, graft rejection, and failure in eyes with and without suture complications. However, suture-related complications were directly associated with sight-threatening ocular morbidities, including graft rejection (39 eyes), ulcer (1 eye), and failure (2 eyes)., Conclusion: Suture-related complications frequently occurred after DALK for keratoconus. Ocular surface inflammation, large grafts, and late suture removal increased the risk of suture-related complications. While these complications had no negative impact on clinical outcomes in the majority of cases, some of them led to sight-threatening morbidity, underlining the importance of early diagnosis and treatment., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Acute corneal hydrops (ACH) is a rare but sight-threatening complication of corneal ectasias. We aim to review the current literature on etiopathogenesis, histology, role of ancillary investigations, management, and outcomes of ACH by classifying the various management strategies based on their site of action and the underlying mechanism. A review of the literature was conducted by searching the following databases: PubMed (United States National Library of Medicine), Embase (Reed Elsevier Properties SA), Web of Science (Thomson Reuters), and Scopus (Elsevier BV) till April 2023. The literature search used various combinations of the following keywords: acute corneal hydrops, keratoconus, ectasia, management, keratoplasty. Nine hundred eighty-three articles were identified based on the above searches. Case reports which did not add any new modality of treatment to the existing literature, articles unrelated to management, those with no full text available, and foreign-language articles with no translation available were excluded. Eventually, 75 relevant articles that pertained to the management of ACH were shortlisted and reviewed. Recent studies have described newer surgical interventions like full-thickness or pre-Descemetic sutures, thermokeratoplasty, and plasma injection that aim to close the posterior stromal break. Posterior lamellar keratoplasties act by replacing the posterior torn Descemet's membrane (DM), and early deep anterior lamellar keratoplasty (DALK) has been attempted to combine the correction of the anatomical defect and visual rehabilitation in a single surgery. These surgical interventions may help by reducing the scarring and increasing the number of patients who can be visually rehabilitated with contact lenses rather than keratoplasty., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: We describe the management of a case of severe corneal melting after corneal cross-linking (CXL) treated with a staged approach using a conjunctival flap followed by deep anterior lamellar keratoplasty (DALK)., Methods: A 12-year-old male developed severe corneal melting with pending perforation after an accelerated epithelium-off CXL protocol. We initially treated the patient with a conjunctival flap to prevent perforation. Three months later, we performed DALK to restore vision., Results: Conjunctival flap surgery allowed us to avoid corneal perforation and penetrating keratoplasty (PK) à chaud. Once the inflammation had resolved, we recessed the conjunctiva and performed DALK for optical purposes. Twelve months later, the graft was clear and the corrected visual acuity was 20/25 (Snellen). No complications occurred after surgery., Conclusions: Although CXL is considered a safe procedure, in rare cases it can lead to serious complications, such as corneal haze, infectious and non-infectious keratitis, stromal melting and perforation. Corneal melting and perforation are usually managed by emergency PK. Herein we suggest a staged approach involving an emergency conjunctival flap followed by DALK at a later time that allowed us to avoid PK à chaud., (© 2024. The Author(s).)

Purposes: This study aims to assess and compare the postoperative visual and topographic outcomes, complications, and graft survival rates following deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with macular corneal dystrophy., Methods: In this study we enrolled 59 patients (23 male; and 36 female) with macular corneal dystrophy comprising 81 eyes. Out of these, 64 eyes underwent penetrating keratoplasty, while 17 eyes underwent deep anterior lamellar keratoplasty. The two groups were analyzed and compared based on best-corrected visual acuity, corneal tomography parameters, pachymetry, complication rates, and graft survival rates., Results: After 12 months, 70.6% of the patients who underwent deep anterior lamellar keratoplasty (DALK) and 75% of those who had penetrating keratoplasty (PK) achieved a best-corrected visual acuity of 20/40 or better (p=0.712). Following surgery, DALK group showed lower front Kmean (p=0.037), and Q values (p<0.01) compared to the PK group. Postoperative interface opacity was observed in seven eyes (41.2%) in the DALK group. Other topography values and other complications (graft rejection, graft failure, cataract, glaucoma, microbial keratitis, optic atrophy) did not show significant differences between the two groups. The need for regrafting was 9.4% and 11.8% in the PK and DALK groups, respectively (p=0.769). Graft survival rates were 87.5% and 88.2% for PK and DALK; respectively (p=0.88 by Log-rank test)., Conclusion: Both PK and DALK are equally effective in treating macular corneal dystrophy, showing similar visual, topographic, and survival outcomes. Although interface opacity occurs more frequently after DALK the visual results were comparable in both groups. Therefore, DALK emerges as a viable surgical choice for patients with macular corneal dystrophy without Descemet membrane involvement is absent.

Background/aims: Ectasia of the cornea can occur decades after penetrating keratoplasty (PK), especially in keratoconus eyes. The purpose of this study was to characterise ectasia after PK by morphological findings in anterior segment optical coherence tomography (AS-OCT)., Methods: In this retrospective, single-centre case series, 50 eyes of 32 patients with a history of PK at an average of 25±10 years earlier were included. The eyes were classified either as ectatic (n=35) or as non-ectatic (n=15). The main parameters included central corneal thickness (CCT), lowest corneal thickness at the interface (LCTI), anterior chamber depth, graft-host interface angle at the thinnest point and host cornea-iris angle. Furthermore, steep and flat keratometry readings obtained by AS-OCT (CASIA-2, Tomey) and Scheimpflug tomography (Pentacam, Oculus) were assessed. OCT findings were correlated with clinical grading of ectasia., Results: There was a highly significant difference in LCTI, graft-host interface angle and anterior chamber depth (in pseudophakic eyes) between the groups. The ratio calculated by the quotient of LCTI divided by CCT was significantly lower in ectatic than non-ectatic eyes (p<0.001). In eyes with an LCTI/CCT ratio of ≤0.7, the OR for the occurrence of a clinical detectable ectasia was 2.4 (CI 1.5 to 3.7). Steep keratometry values were significantly higher in ectatic eyes., Conclusion: AS-OCT is a helpful tool to recognise and quantify ectasia in post-PK eyes objectively., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Corneal biomechanics is an emerging field and the interest into physical and biological interrelations in the anterior part of the eye has significantly increased during the past years. There are many factors that determine corneal biomechanics such as hormonal fluctuations, hydration and environmental factors. Other factors that can affect the corneas are the age, the intraocular pressure and the central corneal thickness. The purpose of this review is to evaluate the factors affecting corneal biomechanics and the recent advancements in non-destructive, in vivo measurement techniques for early detection and improved management of corneal diseases., Methods: Until recently, corneal biomechanics could not be directly assessed in humans and were instead inferred from geometrical cornea analysis and ex vivo biomechanical testing. The current research has made strides in studying and creating non-destructive and contactless techniques to measure the biomechanical properties of the cornea in vivo., Results: Research has indicated that altered corneal biomechanics contribute to diseases such as keratoconus and glaucoma. The identification of pathological corneas through the new measurement techniques is imperative for preventing postoperative complications., Conclusions: Identification of pathological corneas is crucial for the prevention of postoperative complications. Therefore, a better understanding of corneal biomechanics will lead to earlier diagnosis of ectatic disorders, improve current refractive surgeries and allow for a better postoperative treatment., (© 2024. The Author(s).)

Abstract: Corneal allogeneic intrastromal ring segments (CAIRS) refer to the placement of allogeneic rings and segments in intrastromal channels within the cornea. Currently, a deepithelialized donor cornea is used as the allogeneic source for CAIRS and the cut ring is turned sideways and implanted so that the thickness can be varied by varying the distance between the concentric trephine blades. In addition, to obtain a greater effect, CAIRSs are preferred to be implanted with the Bowman layer (BL) facing the corneal apex and posterior stroma facing limbally. Being flexible tissue, it is, however, important to prevent twisting and to maintain correct orientation. We describe a simple technique of marking the BL with a gentian violet surgical marker to simplify CAIRS insertion. BL marking allows easy visibility of twists and helps identify improper orientation, thus allowing correct insertion of CAIRS., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)