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Purpose: The aim of this study was to investigate the outcome of the meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) in corneal regularization and thickness., Methods: Patients waiting for deep anterior lamellar keratoplasty for advanced keratoconus with an intolerance to contact lenses (CLs) underwent the MS-SLAK procedure by FSL 80 kHz ablation (VICTUS, Technolas Perfect Vision, DE). Customized positive meniscus-shaped stromal lenticules were obtained and implanted. Examination was performed at baseline and at 3-, 6-, and 12-month follow-up and included corrected distance visual acuity both with spectacles and CLs (spectacle CDVA and CL-CDVA), manifest refraction spherical equivalent, slit-lamp examination, anterior segment optical coherence tomography, corneal topography, and in vivo confocal microscopy., Results: Fifteen patients completed the study. Statistical increases in corneal thickness values were found from the first follow-up ( P < 0.001). Improvement in the Surface Asymmetry Index ( P = 0.04), Symmetry Index ( P = 0.02), spherical aberration ( P < 0.001), coma ( P = 0.18), high-order aberration ( P = 0.37), and anterior asphericity index (Q) ( P = 0.31) were found at 12 months. At the 12-month follow-up, no improvement were found in spectacle CDVA ( P = 0.23); however, all patients reported CL wearing tolerance recovery, and significant improvement in CL-CDVA ( P = 0.002) was found. The confocal microscopy at 12 months showed a significant increase in keratocyte density within the lenticule and absence of fibrotic reactions in both anterior and posterior interfaces., Conclusions: MS-SLAK seems to be effective in regularizing the corneal surface as showed by the significant improvement in topographic symmetry indices, coma, and high-order aberration. The corneal regularization is also confirmed by the results in anterior Q and the recovery of the CL wearing tolerance., Competing Interests: Conflicts of interest statement: The authors have no funding or conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To evaluate corneal biomechanical changes after meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) performed for the treatment of keratoconus., Methods: This interventional study included patients affected by advanced keratoconus (stage III and IV) who underwent examination with a dynamic Scheimpflug analyzer and non-contact tonometer (Corvis ST; Oculus Optikgeräte GmbH) at baseline and 12 months after MS-SLAK. The biomechanical parameters evaluated in this study were integrated inverse radius (1/R), deformation amplitude ratio (DA ratio), stiffness parameter at first applanation (SP-A1), biomechanical intraocular pressure (bIOP), central corneal thickness (CCT), and stress-strain index (SSI)., Results: Sixteen patients were enrolled in the study. The analysis was ultimately conducted on 15 patients. Comparative analyses showed an increase in corneal stiffness as demonstrated by a rise in SSI ( P < .0001) and SP-A1 ( P < .0001) and a decrease in DA ratio ( P < .0001) and 1/R ( P = .01). A significant increase in CCT was found ( P < .0001). No statistically significant modification was found for bIOP ( P = .43)., Conclusions: The corneal biomechanical analyses evaluated by the Corvis ST showed that MS-SLAK for advanced keratoconus is able to increase corneal overall stiffness. This result is explained by the significant increase in thickness induced by MS-SLAK. [ J Refract Surg . 2023;39(7):499-504.] .

Purpose: To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus., Methods: We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest., Results: Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty., Conclusions: Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.

To evaluate the effect of donor-to-recipient sex mismatched (male donor corneas to female recipients) on the incidence of rejection episodes and failures up to 1 year after corneal transplantation. Prospective observational cohort study, with donor corneas randomly assigned and surgeons blind to the sex of donor. A unique eye bank retrieved and selected the donor corneas transplanted in 4 ophthalmic units in patients with clinical indication for primary or repeated keratoplasty for optical reasons, perforating or lamellar, either anterior or posterior. Rejection episode defined as any reversible or irreversible endothelial, epithelial or stromal sign, with or without development of corneal edema, and graft failure as a permanently cloudy graft or a regraft for any reason detected or acknowledged during a postoperative ophthalmic visit at any time up to 1 year after surgery were recorded.156 (28.6%) patients resulted donor-to-recipient gender mismatched for H-Y antigen (male donor to female recipient). During the 12 months follow-up, 83 (14.7%, 95% CI 12.0-17.9) grafts showed at least 1 rejection episode and 17 (3.2%, 95% CI 2.0-5.0) failed after immune rejection, among 54 (9.6%, 95% CI 7.4-12.3) grafts failed for all causes. No significant differences between matched and mismatched patients were found for cumulative incidence of both rejection episodes (15.2% and 13.5%) and graft failures following rejection (3.2% and 2.6%), respectively. Multivariable analyses showed that H-Y matching either is not a predictive factor for rejection or graft failure nor seems to influence incidence of failures on respect to patient's risk category. The lack of influence of donor-to-recipient mismatched on the rate of rejections and graft failures resulting from this study do not support the adoption of donor-recipient matching in the allocation of corneas for transplantation.

Purpose: To investigate the feasibility of intrastromal lenticule insertion to restore corneal shape in a model of ectatic human cornea., Methods: For this experimental ex vivo study on 34 human corneas unsuitable for transplantation, 17 corneas were thinned by decentralized posterior excimer laser ablation to 200 μm thickness and 6.5 mm diameter and then inflated up to 100 mm Hg to expose the ectasias (recipient corneas). Pachimetry and topography were obtained. Stromal lenticules of the same diameter and thickness as the ectasias were shaped with a femtosecond laser from the remaining 17 donor corneas. An intrastromal pocket was created with femtosecond laser within the ectatic recipient corneas and the donor lenticule was inserted inside it. Changes in corneal architecture and profile were evaluated by means of corneal topography and anterior segment optical coherence tomography., Results: All stromal lenticules were successfully implanted. Tomography confirmed regularity of the lenticule profile within the stromal pocket. Corneal thickness was significantly increased after the procedure (P < 0.0001). Maximal posterior elevation from the best-fitted toric ellipsoid was significantly reduced (P < 0.0001). Significant flattening of posterior K1 and K2 was also obtained (P = 0.041 and P = 0.004, respectively). Anterior and posterior astigmatism, anterior and posterior asphericity, and spherical aberration did not differ significantly after the procedure., Conclusions: Femtosecond laser-assisted stromal lenticule addition is feasible for restoring corneal thickness to an ectatic area and for regularizing posterior corneal elevation. The technique opens new perspectives for the treatment of corneal ectasias.

Purpose: To compare the refractive outcomes following penetrating keratoplasty and deep anterior lamellar keratoplasty in fellow eyes in patients with keratoconus., Methods: This is an observational retrospective review of consecutive patients with keratoconus first managed with penetrating keratoplasty in one eye and then with lamellar keratoplasty in the fellow eye, between 2002 and 2007. Data collection was based on patients' hospital records. Information related to assessment before surgery and at 1, 3, 6, 12, 24, and 48 months after keratoplasty were retrieved and considered in the analysis. Clinical evaluations included patients' medical histories and diagnosis of keratoconus, uncorrected and best corrected visual acuity, spherical equivalent, refractive cylinder, topographic cylinder, and high-order aberrations, complications, and adverse reactions. Data on contrast sensitivity, central corneal thickness, and central residual bed thickness (only for lamellar keratoplasty) were retrieved from anterior segment optical coherence tomography observation performed at 48 months., Results: Sixteen patients (32 eyes), 7 males and 9 females, were included in the analyses. After 4 years from transplantation, at the end of follow-up, no statistically significant differences were found in visual acuity and refractive measures between the two keratoplasties. Perforating keratoplasty showed significant differences for contrast sensitivity at 6 cpd with maximum glare (p = 0.026) and without glare (p = 0.015). Deep anterior lamellar keratoplasty showed a negative correlation between central residual bed thickness and best corrected visual acuity (R = -0.414, p < 0.001)., Conclusions: The manual pre-descemetic deep anterior lamellar keratoplasty used in this study showed refractive and visual results comparable to those obtained with penetrating keratoplasty. Such results indicated that leaving healthy stroma attached to Descemet's membrane does not compromise the clinical outcome in the short and long term after surgery.

This study aims to examine evolving indications and changing trends for corneal transplantation in Italy. Corneal transplantations performed with donor tissues distributed by the Veneto Eye Bank Foundation between 2002 and 2008 were prospectively evaluated. Of the 13,173 keratoplasties performed on 11,337 patients, 10,742 (81.5%) were penetrating (PK), 1644 (12.5%) were anterior lamellar (ALK), and 787 (6.0%) were endothelial (EK). Keratoconus (42.5%), regraft (18.9%), and pseudophakic bullous keratopathy (PBK, 11.9%) were the leading indications for PK, with keratoconus (69.6%) and regraft (6.5%) showing higher indications for ALK, whereas pseudophakic bullous keratopathy (50.1%) and regraft (18.7%) were the major indications for EK. There was an overall decrease observed in corneal grafting for keratoconus (P = .0048) and an increase for PBK (P = .0653) and regrafting (P = .0137). These indications differed by age and gender. The number of keratoplasties over 7 years was stable (P = .2394), although the annual number of PKs declined by 34.0% (P = .0250), ALKs began to rise from 2005 (P = .0600), whereas EKs showed a huge growth, with their number tripling in 2007 and further doubling in 2008 (P = .0004). Leading indications for keratoplasty showed similar data that have been reported elsewhere for Western countries over the past few decades, albeit with a higher percentage of keratoconus. However, the overall number of keratoplasties for keratoconus was in decline, whereas regraft keratopathy and PKs increased due to the application of the newer surgical techniques for corneal grafting. This highlights an important shift in managing corneal diseases toward the application of selective and more conservative surgeries and changes in indications in corneal transplantation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: To evaluate the safety and efficacy of customized transepithelial photorefractive keratectomy (PRK) for the correction of iatrogenic ametropia after penetrating keratoplasty (PKP) or deep lamellar keratoplasty., Setting: Eye Clinic, Department of Neurological and Visual Sciences, University of Verona, Verona, Italy., Methods: This study comprised 9 patients who had irregular astigmatism from 2.0 to 8.0 diopters (D) after PKP or deep lamellar keratoplasty. The ametropia was corrected with customized transepithelial PRK and the Corneal Interactive Programmed Topographic Ablation (CIPTA) software program (LIGI). Complete ophthalmic examinations were performed before and after surgery., Results: The mean age of the patients was 39.2 years (range 31 to 59 years). All patients gained at least 2 Snellen lines of uncorrected visual acuity; 2 patients had an increase of at least 5 lines, and 3 patients had an increase of 8 lines. The mean refractive spherical equivalent changed from -2.98 D +/- 3.11 (SD) (range -7.25 to +3.00 D) before PRK to -0.58 +/- 0.84 D (range 0 to -2.50 D) at the last follow-up visit. One patient presented with grade 1 haze that did not improve with topical steroid therapy. No patient lost best spectacle-corrected visual acuity., Conclusion: Customized transepithelial PRK with the CIPTA software was a safe and effective treatment for irregular astigmatism after PKP or deep lamellar keratoplasty.

Objective: To evaluate the clinical findings, visual outcomes, and confocal microscopic corneal features of a surgical technique for manual deep lamellar keratoplasty (DLKP) with intentional sparing of the most posterior stroma., Design: Noncomparative, prospective, 12-month interventional study., Participants: Forty-six eyes of 45 patients who had corneal pathologic features without endothelial abnormalities and requiring corneal graft were treated by DLKP by manual stromal delamination. They were examined clinically after surgery and using in vivo confocal microscopy at 2 weeks and 1, 3, 6, and 12 months., Intervention: The surgical technique consisted of an intracorneal deep manual stromal dissection through a 4-mm limbal incision at 50 mum from Descemet's membrane (DM). After trephination, an endothelial free graft was sutured., Main Outcome Measures: Topographic parameters, interface depth and reflectivity, and anterior and postinterface keratocyte density; visual acuity was correlated with these parameters., Results: Two eyes had rupture of the DM. Two eyes that had delayed epithelial healing because of graft override with stromal inflammation underwent a second surgery (penetrating keratoplasty). Mean uncorrected logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity and logMAR best-corrected visual acuity (BCVA) improved from preoperative values (1.342+/-0.239 and 0.923+/-0.226, respectively) to 0.421+/-0.122 and 0.104+/-0.068, respectively, at 12 months. Mean topographic astigmatism was 3.09+/-1.30 diopters (D) at 3 months after suture adjustment, and 2.87+/-0.92 D at 12 months after suture removal. Average interface depth was 64.2+/-6.7 microm at 15 days and showed no significant changes up to 12 months. Mean interface reflectivity was highest at 15 days (95.5+/-15.7 light reflectance units [LRU]) and showed a progressive decrease over time of 55.3+/-8.7 LRU at 12 months. A significant negative correlation was observed between BCVA and topographic astigmatism up to 1 month and between BCVA and interface reflectivity starting from 6 months after surgery., Conclusions: Deep lamellar keratoplasty by intracorneal dissection provides visual and clinical results comparable with that of other DLKP techniques. Visual recovery is slow and progressive, taking up to 1 year. Confocal microscopy enables precise evaluation of corneal features, interface morphologic features, and reflectivity, demonstrating a negative correlation between interface reflectivity and BCVA showing that the progressive recovery over months of the interface transparency is correlated with the increase in visual acuity after 6 months.