Search Results (21)

Purpose: Pellucid Marginal Degeneration (PMD) is a rare ectatic corneal disorder characterized by inferior peripheral thinning and significant irregular astigmatism. Despite its clinical similarities to keratoconus, PMD presents unique diagnostic and therapeutic challenges. This review aims to provide a comprehensive update on the pathophysiology, clinical features, diagnostic approaches, and management strategies for PMD, emphasizing the latest advancements in treatment options. Methods: A systematic literature search was performed in MEDLINE (via PubMed), Google Scholar, and Scopus up to February 2025 using the terms: “pellucid marginal degeneration,” “PMD,” “ectatic corneal disorders,” “keratoplasty in PMD,” “corneal cross-linking in PMD,” “ICRS in PMD,” “toric IOL PMD” and their Boolean combinations (AND/OR). The search was restricted to English-language studies involving human subjects, including case reports, case series, retrospective studies, clinical trials, and systematic reviews. A total of 76 studies met the inclusion criteria addressing treatment outcomes in PMD. Results: PMD is characterized by a crescent-shaped band of inferior corneal thinning, leading to high irregular astigmatism and reduced visual acuity. Diagnosis relies on advanced imaging techniques such as Scheimpflug-based corneal tomography, which reveals the characteristic “crab-claw” pattern. Conservative management includes rigid gas-permeable (RGP) lenses and scleral lenses, which provide effective visual rehabilitation in mild to moderate cases. Surgical options, such as CXL, ICRS, and toric IOLs, are reserved for advanced cases, with varying degrees of success. Newer techniques such as CAIRS, employing donor tissue instead of synthetic rings, show promising outcomes in corneal remodeling with potentially improved biocompatibility. Penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) remain definitive treatments for severe PMD, though they are associated with significant risks, including graft rejection and postoperative astigmatism. Conclusions: PMD is a complex and progressive corneal disorder that requires a tailored approach to management. Early diagnosis and intervention are critical to optimizing visual outcomes. While conservative measures are effective in mild cases, surgical interventions offer promising results for advanced disease. Further research is needed to refine treatment protocols and improve long-term outcomes for patients with PMD. Full article

Background and Clinical Significance: Brittle cornea syndrome (BCS) is a rare, autosomal recessive connective tissue disorder characterized by extreme corneal thinning, high myopia, and increased risk of spontaneous or trauma-induced ocular rupture. It is primarily caused by mutations in the ZNF469 or PRDM5 genes, which regulate extracellular matrix integrity. Early recognition and diagnosis of BCS are crucial to prevent severe visual impairment. This report presents two genetically confirmed cases of BCS in Albanian siblings, emphasizing the diagnostic value of whole-exome sequencing and individualized surgical management strategies. Case Presentation: Two siblings—a 28-year-old male and a 25-year-old female—presented with progressive visual deterioration and marked corneal thinning (<200 µm). Both had a history of spontaneous ocular rupture following minor trauma in the contralateral eye. Detailed ophthalmologic evaluation revealed keratoglobus, high myopia, and irregular astigmatism. Genetic testing identified the homozygous pathogenic variant c.974delG (p.Cys325LeufsX2) in the PRDM5 gene in both cases. The male underwent penetrating keratoplasty (PKP), achieving a best-corrected visual acuity (BCVA) of 20/30. The female initially underwent deep anterior lamellar keratoplasty (DALK), which was converted to PKP intraoperatively due to central endothelial perforation, resulting in a BCVA of 20/25. Both patients remained complication-free over a 7-year follow-up period. Conclusions: These cases highlight the importance of early genetic diagnosis and a tailored surgical approach in managing BCS. Long-term monitoring and protective strategies are essential to prevent complications. Incorporating genetic testing into clinical practice can enhance diagnostic accuracy and guide personalized treatment plans in patients with hereditary corneal dystrophies. Full article

Background/Objectives: The aim of this study was to review the therapeutic and prognostic factors influencing Acanthamoeba Keratitis (AK) management. Methods: A systematic search was performed across MEDLINE^® (via PubMed), Web of Science^®, and Scopus^®, following the PRISMA 2020 guidelines, and registered in PROSPERO (CRD420251010774). Studies reporting AK treatment regiments and prognostic factors were included. After extracting the data from the included articles, the relevant aspects of the treatment and the prognostic factors were compared and summarized. Results: Sixty-one articles were included: nine were prospective, including 3 randomized controlled trials (RCTs), and fifty-two were retrospective. The findings suggest that therapeutic epithelial debridement (TED), followed by an association with biguanides, diamidines, and an antibacterial agent, is a strong initial treatment option. An adjunctive medical treatment with topical voriconazole 1% or oral miltefosine may also be considered. Surgical approaches were also assessed when the pharmaceutical therapy failed, with Deep Anterior Lamellar Keratoplasty (DALK) playing an important role in the cases without a deep stroma involvement. Early Therapeutic Penetrating Keratoplasty (TPK) should be used as a salvage therapy and Optical Penetrating Keratoplasty (OPK) should be used for rehabilitation purposes. Key prognostic factors include older age, delayed diagnosis, corticosteroid use before prompt diagnosis, poor initial best corrected visual acuity (BCVA), and AK stage at presentation. Conclusions: The initial treatment with TED, biguanides, and diamidines remains the foundation of treatment. Surgical options can be considered in advanced cases. An early diagnosis, age, and initial BCVA are prognosis factors that should be considered. Future research may focus on improvement of protocols and searching for novel agents. Full article

Objective: To evaluate the clinical outcomes of cornea transplantation (penetrating keratoplasty, Descemet membrane endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty, and deep anterior lamellar keratoplasty) using donor corneas stored in Eusol-C hypothermic storage medium compared to corneas stored in organ-culture. Methods: The clinical outcomes of 92 patients who underwent corneal transplantation with human donor corneas stored in Eusol-C medium at 2–8 °C were retrospectively evaluated. The control group consisted of 169 patients who received corneas organ-cultured at 31 °C. Donor age, sex, death-to-preservation time, and storage time were recorded. Endothelial cell (EC) density (ECD), EC mortality, and EC morphology scores were evaluated during storage in both groups. Complication rates, visual outcomes, and corneal transparency were monitored for up to six months. Results: The mean storage in Eusol-C time was 7.7 ± 2.5 days, while organ-culture time was 14.2 ± 4.0 days. In the Eusol-C group, ECD was 2398 ± 354 cells/mm², with an average EC morphology score of 3.4 ± 0.7/4. Approximately 28% of the corneas in the Eusol-C group had no EC mortality. In the organ-culture group, ECD was 2256 ± 328 cells/mm², with an average EC morphology score of 3.5 ± 0.5/4, and 42% were devoid of EC mortality. No complications, such as re-bubbling, were observed in both groups during surgery. Transparent corneas were achieved in 81.3% of the Eusol-C group the day after surgery. Mean corrected distance visual acuity (CDVA) at 3 and 6 months was 4.5 ± 4.0/10 and 5.4 ± 3.7/10 for the Eusol-C group and 5.0 ± 2.9/10 and 5.7 ± 2.8/10 for the organ-culture group, with no statistical differences observed between the groups. No graft failure was observed up to three months. Graft rejection occurred in the Eusol-C group and in the organ-culture group in, respectively, one and two cases at the six-month follow-up. Conclusions: Comparable surgical outcomes were achieved with donor corneas stored in both hypothermic Eusol-C and organ-culture media. Full article

We describe retrospectively the indications and outcomes of nine patients who present with varying degrees of deep posterior stromal scarring or endothelial failure following deep anterior lamellar keratoplasty (DALK). These patients underwent a surgical strategy coined Intraoperative Optical Coherence Tomography Guided Femtosecond Laser-Assisted Descemet Membrane Endothelial Keratoplasty (iFAD). This strategy can be used to address suboptimal visual outcomes following primary DALK. Patients undergoing iFAD first had femtosecond laser-assisted trephination of the underlying posterior lamella using the liquid keratoplasty system on the Femto LDV Z8 platform (Zeimer Ophthalmic Systems AG, Port, Switzerland). A Descemet Membrane Endothelial Keratoplasty (DMEK) graft was subsequently transplanted in place of the removed lamella. Out of nine cases, major indications for seven included post-infective, blepharokeratoconjunctivitis (BKC) and deep stromal scarring related to stromal dystrophy. The remaining two had endothelial failure following primary DALK. The main benefits of this surgical approach are (1) Utilization of integrated real-time iOCT on the femtosecond laser platform allows for precise calibration of a wide range of vertical posterior trephination depths (96–329 microns) from the endothelial surface. (2) Femtosecond laser trephination utilizing a non-applanation liquid interface preserves trephination geometries and maximises precision-based surgical outcomes. (3) iFAD is a viable and straightforward technique for surgeons addressing patients who might otherwise require complex surgery to address residual deep stromal scars post-DALK. Full article

Background: The aim of this study was to evaluate the intraoperative complications and visual outcomes of manual deep anterior lamellar keratoplasty (mDALK) in patients who underwent previous radial keratotomy (RK) for myopia. Methods: The notes of patients who underwent mDALK after RK at three different hospitals—San Giovanni Addolorata Hospital (Rome, Italy), Mount Saint Joseph Hospital (Vancouver, Canada), and Tor Vergata University Hospital (Rome, Italy)—were retrospectively reviewed. We analyzed the manual dissection success rate and conversion to penetrating keratoplasty (PK), the residual recipient stromal thickness, the postoperative corrected distance visual acuity (CDVA), postoperative refraction, and topographic astigmatism. Results: Thirteen eyes of eleven patients were included in the analysis (male 7/11, 63.6%). Preoperatively, mean topographic astigmatism was 5.4 ± 3.5 D (range 1.6–14.8 D), and mean CDVA was 0.47 ± 0.2 logMAR (range 0.3–1.0 logMAR) [Snellen equivalent 20/50]. Manual dissection was performed in all cases. None of the examined eyes were converted to PK. An improvement in both topographic astigmatism (2.8 ± 0.9 D, p = 0.0135) and CDVA (0.23 ± 0.2 LogMAR, p = 0.0122) was recorded at 12-month follow-up. Conclusions: mDALK is a safe and effective surgical technique when applied to eyes previously treated with RK, with an observed improvement in CDVA and topographic astigmatism. Full article

Herpes simplex virus (HSV) is one of the most common etiologic agents of corneal disease and a significant cause of corneal blindness worldwide. Although most cases can be successfully managed with medical therapy, HSV keratitis associated with visually significant stromal scarring often requires corneal transplantation for visual rehabilitation. While penetrating keratoplasty (PK) represented the traditional keratoplasty technique, the past few decades have seen a shift towards lamellar keratoplasty procedures, including deep anterior lamellar keratoplasty and mushroom keratoplasty. This paper describes the current surgical techniques and perioperative antiviral prophylaxis regimen for herpetic keratitis and reviews their postoperative clinical outcomes. Full article

The aim of our study is to investigate the feasibility and outcomes of using a femtosecond laser (FSL) platform (Ziemer LDV Z8) for deep anterior lamellar keratoplasty (DALK), enabling the creation of mushroom-shaped graft–host junctions, lamellar cuts, and intrastromal tunnels, to facilitate the big bubble, in one step. We included wet lab experiments on nine porcine eyes to assess the laser accuracy and cuts depth using an anterior segment (AS) OCT. This was followed by an interventional prospective case series on 10 eyes with variant corneal pathologies. The Z8 system, with in-built intraoperative optical coherence tomography (iOCT), guided corneal scans and directed the cuts. ASOCT showed visible mushroom configurations, lamellar cuts, and tunnels. Deviations from the target were 1.6%, 2.6%, and 3.5%. Anterior lamellar removal was easy in all clinical cases, including corneal scarring. The intrastromal tunnel was found at the preset location and the mushroom configuration was acquired. A big bubble was achieved in all cases. Type 1, 2, and 3 bubbles were formed in eight, one, and one case, respectively. We describe a new approach to DALK in which the in-built iOCT-guided FSL enables safe, precise, controlled, and reproducible desired cuts in one step. The preliminary clinical outcomes were favorable. Full article

Background: Anterior lamellar keratoplasty (ALK) is a less invasive procedure than PK, and thus avoids many of the intraocular complications associated with PK. DALK can be performed using several different techniques, with either a manual dissection, a keratome or femtosecond-laser assisted dissection, or with a big bubble technique. To analyse the outcomes and compare the results of three deep anterior lamellar keratoplasty (DALK) techniques. Methods: This study included 105 DALK cases performed at Queen Victoria Hospital, East Grinstead, UK, in the period between January 2016 and May 2022. Cases were classified into four groups based on technique: BB-DALK, manual DALK, FS-DALK and ‘converted to PK group’. Results: There was significant improvement in VA and Kmax compared to the preoperative values in all groups. There was no significant difference detected in VA and Kmax between all groups. Conclusions: Performing DALK surgery with any suitable technique (manual, big-bubble or femtosecond-assisted) is effective and causes significant improvements in VA and Kmax, even in cases where a conversion to penetrating keratoplasty is required. However, every technique has its pros and cons and should be tailored according to surgeon preference and individual case pathology. Full article

Partial-thickness corneal transplants using a deep anterior lamellar keratoplasty (DALK) approach has demonstrated better patient outcomes than a full-thickness cornea transplant. However, despite better clinical outcomes from the DALK procedure, adoption of the technique has been limited because the accurate insertion of the needle into the deep stroma remains technically challenging. In this work, we present a novel hands-free eye mountable robot for automatic needle placement in the cornea, AutoDALK, that has the potential to simplify this critical step in the DALK procedure. The system integrates dual light-weight linear piezo motors, an OCT A-scan distance sensor, and a vacuum trephine-inspired design to enable the safe, consistent, and controllable insertion of a needle into the cornea for the pneumodissection of the anterior cornea from the deep posterior cornea and Descemet’s membrane. AutoDALK was designed with feedback from expert corneal surgeons and performance was evaluated by finite element analysis simulation, benchtop testing, and ex vivo experiments to demonstrate the feasibility of the system for clinical applications. The mean open-loop positional deviation was 9.39 µm, while the system repeatability and accuracy were 39.48 µm and 43.18 µm, respectively. The maximum combined thrust of the system was found to be 1.72 N, which exceeds the clinical penetration force of the cornea. In a head-to-head ex vivo comparison against an expert surgeon using a freehand approach, AutoDALK achieved more consistent needle depth, which resulted in fewer perforations of Descemet’s membrane and significantly deeper pneumodissection of the stromal tissue. The results of this study indicate that robotic needle insertion has the potential to simplify the most challenging task of the DALK procedure, enable more consistent surgical outcomes for patients, and standardize partial-thickness corneal transplants as the gold standard of care if demonstrated to be more safe and more effective than penetrating keratoplasty. Full article

Background: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. Objectives: The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. Search Methods and Selection Criteria: A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record’s reference list. Data Extraction: Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. Data Statistical Analyses: The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for p-values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I², chi-square (χ²), and tau-squared. Main Results: We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK. Full article

Background: Traumatic injuries in eyes previously treated with Deep Anterior Lamellar Keratoplasty (DALK) can lead to ruptures in the Descemet Membrane (DM) and damage to the corneal endothelium, a crucial layer for maintaining corneal clarity. Due to cell cycle constraints, the human corneal endothelium cannot proliferate; instead, it compensates for injury through cell enlargement and migration from adjacent areas. Methods: This study examines a notable case of corneal endothelial cell migration following a penetrating eye injury in a patient previously treated with DALK for keratoconus, supplemented by a review of relevant literature to contextualize the regenerative response. Results: A 39-year-old male with a history of DALK suffered a traumatic eye injury, resulting in damage to the Descemet Membrane and loss of the crystalline lens. After primary repair and considerations for further surgery, the patient’s cornea cleared remarkably, with an improved visual acuity. This demonstrates the DM’s potential for self-repair through endothelial cell migration. Conclusions: The outcomes suggest that delaying corneal transplant surgery for up to 3 months following Descemet Membrane injury due to ocular trauma could be advantageous. Allowing time for natural healing processes might eliminate the need for further invasive surgeries, thereby improving patient recovery outcomes. Full article

This study aimed to compare the efficacy of robot-assisted and manual cannula insertion in simulated big-bubble deep anterior lamellar keratoplasty (DALK). Novice surgeons with no prior experience in performing DALK were trained to perform the procedure using manual or robot-assisted techniques. The results showed that both methods could generate an airtight tunnel in the porcine cornea, and result in successful generation of a deep stromal demarcation plane representing sufficient depth reached for big-bubble generation in most cases. However, the combination of intraoperative OCT and robotic assistance received a significant increase in the depth of achieved detachment in non-perforated cases, comprising a mean of 89% as opposed to 85% of the cornea in manual trials. This research suggests that robot-assisted DALK may offer certain advantages over manual techniques, particularly when used in conjunction with intraoperative OCT. Full article

Purpose: The purpose of this paper is to report the clinical manifestations, diagnostic evaluation, management and outcomes of microsporidial keratitis in post-keratoplasty eyes. Methods: This is a retrospective review of three patients diagnosed with microsporidial stromal keratitis in post-keratoplasty eyes between January 2012 and December 2021 at a tertiary referral center (Ospedali Privati Forlì “Villa Igea”, Forlì, Italy). Results: All patients presented with fine multifocal granular infiltrates following keratoplasty for a presumed herpetic keratitis. No microorganisms were isolated from the corneal scrapings and no clinical response was observed with broad-spectrum antimicrobial therapy. In all cases, confocal microscopy demonstrated spore-like structures. The histopathologic examination of the excised corneal buttons confirmed the diagnosis of microsporidial stromal keratitis. Following therapeutic keratoplasty and treatment with an initial high dose and extended taper of topical fumagillin, clinical resolution was achieved in all eyes. The Snellen visual acuities at the final follow-up were 20/50, 20/63 and 20/32. Conclusions: Prior to definitive surgery, confocal microscopy can be employed for the in vivo detection of pathogenic microorganisms such as Microsporidium. In post-keratoplasty eyes, therapeutic keratoplasty and an initial high dose of topical fumagillin with extended taper can allow the resolution of microsporidial stromal keratitis with a satisfactory visual prognosis. Full article

Astigmatism is a visually significant condition that can develop after keratoplasty. The management of post-keratoplasty astigmatism can be performed both when transplant sutures are in place and when they have been removed. Fundamental for astigmatism management is its identification and characterization in terms of type, amount, and direction. Commonly, post-keratoplasty astigmatism is evaluated through corneal tomography or topo-aberrometry; however, many other techniques can be used in case these instruments are not readily available. Here, we describe several low-tech and high-tech techniques used for post-keratoplasty astigmatism detection in order to quickly understand if it contributes to low vision quality and to determine its characteristics. The management of post-keratoplasty astigmatism through suture manipulation is also described. Full article