Clinical outcomes and significance of postoperative ultrasound biomicroscopy in patients with Boston type 1 keratoprosthesis

ABSTRACT Purpose: To determine the clinical outcomes in patients after type 1 Boston keratoprosthesis surgery and the significance of ultrasound biomicroscopy imaging for postoperative follow-up. Methods: This retrospective analysis included 20 eyes of 19 patients who underwent corneal transplantation with type 1 Boston keratoprosthesis between April 2014 and December 2021. Data on patient demographics, preoperative diagnosis, visual acuity, and postoperative clinical findings were analyzed. Results: Type 1 Boston keratoprosthesis implantation resulted in intermediate- and long-term positive outcomes. However, blindness and other serious complications such as glaucoma, retroprosthetic membrane formation, endophthalmitis, or retinal detachment also occurred. The use of ultrasound biomicroscopy imaging allowed for better evaluation of the back of the titanium plate, anterior segment structures, and the relationship of the prosthesis with surrounding tissues, which provided valuable postoperative information. Conclusion: Regular lifetime monitoring and treatment are necessary in patients who undergo Boston type 1 keratoprosthesis implantation for high-risk corneal transplantation. ultrasound biomicroscopy imaging can be a valuable imaging technique for the evaluation of patients with Boston type 1 keratoprosthesis, providing important information on anterior segment anatomy and potential complications. Further studies and consensus on postoperative follow-up protocols are required to optimize the management of patients with Boston type 1 keratoprosthesis.

[EndoArt®: results in patients with glaucoma drainage devices]. / EndoArt®: Ergebnisse bei Patienten mit Glaukom-Drainage-Implantaten.

BACKGROUND: EndoArt® (Eye Yon Medical, Ness Ziona, Israel) is a novel artificial corneal inner layer transplant and an innovative treatment alternative for patients at high risk for graft failure after posterior lamellar corneal transplantation (EK). AIM OF THE STUDY: We present the initial results of the EndoArt® implantation in patients with glaucoma drainage devices (GDD). PATIENTS AND SURGICAL PROCEDURE: In this study 12 eyes with GDD were retrospectively evaluated. All had a high risk of transplant rejection in cases of EK (previous other glaucoma surgery in addition to GDD, n = 8, condition following Descemet membrane endothelial keratoplasty, DMEK, n = 9, uveitis, n = 2, or synechiae, n = 2). The EndoArt® was secured with a gas bubble and one to three holding sutures. The preoperative and postoperative best spectacle-corrected visual acuity (BSCVA) and central corneal thickness (CCT) were determined. The need for additional gas injections (rebubbling) was analyzed. RESULTS: Octafluoropropane (C3F8) 12% was used in nine patients and sulfur hexafluoride (SF6) 20% in three patients as anterior chamber tamponade to ensure adhesion of the EndoArt®. At least one rebubbling was necessary in four eyes. The preoperative BSCVA was 1.6 (±â€¯0.5) logMAR and significantly improved to 1.1 (±â€¯0.6) logMAR after 12 weeks (p = 0.028). The preoperative CCT was 719 µm ± 145.7, which significantly decreased to 622.4 µm ± 174.9 after six weeks (p = 0.004) and to 591.7 µm ± 190.8 after 12 weeks (p = 0.096). In one eye, the prosthesis was explanted due to a suspected fibrotic remodelling of the cornea following multiple previous DMEKs. DISCUSSION: EndoArt® led to a significant improvement in BSCVA and reduction in CCT; however, there was a high rebubbling rate in patients with GDD. In high-risk patients, the use of EndoArt® may be advantageous in avoiding graft failure after EK.

Clinical Outcomes of Stage 2 (Pivotal) Use of a Modified Keratoprosthesis Device (ORC-KPro) in Patients with End-stage Corneal Blindness.

Purpose: To investigate the short-term results and performance of a modified Boston keratoprosthesis device manufactured by the Ophthalmic Research Center (ORC-KPro) in patients with end-stage corneal blindness. Methods: This prospective interventional case series was conducted on patients with corneal blindness who were candidates for KPro. The inclusion criterion comprised patients with a best-corrected visual acuity (BCVA) of less than 20/200 in both eyes, in whom the main reason for vision loss was corneal pathology. The ORC-KPro was implanted using the method previously described for Boston KPro. Results: This study focused on 12 eyes of 12 patients with an average age of 45.9 ± 16.8 (range, 19 to 70) years. Eleven patients were male. The KPro indication was corneal blindness due to chemical burns in nine patients (75%) and failure of multiple previous corneal grafts in three patients (25%). Anatomical success was achieved in all patients. The preoperative BCVA was light perception (LP) in 10 eyes and hand motion in 1 eye. Except for one patient who was diagnosed with grade C proliferative vitreoretinopathy during the surgery, the vision of all other patients (91.6%) improved after surgery. The retroprosthetic membrane (RPM) was formed in two eyes (18.1%) after six months. Of the 12 patients, 10 (83.3%) were under treatment with two antiglaucoma medications before surgery. The intraocular pressure of three eyes (25%) was estimated to be high by tactile palpation; however, it decreased in two eyes to the acceptable range. One patient underwent retinal surgery due to total retinal detachment, and two patients (16.7%) underwent vitrectomy due to endophthalmitis. Conclusion: The current study showed that, in the short term, the use of ORC-KPro achieved favorable anatomical success in patients with corneal blindness. However, the functional success rate was limited by the low visual potential due to advanced glaucoma in most patients.

Treatment of Corneal Dermoid with Fibrin Glue Boned Multi-Layer Lenticules from Small Incision Lenticules Extraction Surgery: A Preliminary Study of Five Patients.

PURPOSE: Dermoid excision combined with lamellar keratoplasty was one of the most common surgical techniques for corneal dermoid. Due to the huge shortage of corneal donors, small incision lenticule extraction (SMILE) derived lenticules might be the novel and feasible corneal grafts instead of traditional corneal donors. Therefore, we tried to use FG boned multi-layer lenticules as grafts in the treatment of corneal dermoid. METHODS: Five patients (the oldest patient was 54 years old and the youngest case was 5 years old) were diagnosed with corneal dermoid and complaining of blurred vision or unsatisfied cosmetic appearance. All patients underwent corneal dermoid excision combined with FG boned multi-layer corneal lenticules transplantation. Slit-lamp microscopy and anterior-segmental optical coherence tomography(AS-OCT)were used to observe ocular appearance, corneal grafts survival, epithelialization, transparency, interlamellar fluid accumulation and the degradation of FG. The preoperative and postoperative change of best-corrected visual acuity (BCVA) and astigmatism were respectively recorded. RESULTS: All patients were satisfied with the postoperative cosmetic results. BCVA had been increased and astigmatism had been decreased in all cases. We observed that the FG boned multi-layer corneal lenticules were covered with smooth corneal epithelium in one week after transplantation and successfully adhered to the corneal beds, without any dislocation or interlayer separation. FG was gradually degraded and absorbed within 1 month after surgery. The lenticule grafts grew well without rejection and kept transparency during the follow-up period. CONCLUSIONS: FG boned multi-layer lenticules would be the novel and feasible substitute for lamellar keratoplasty in the treatment of corneal dermoid. FG could not be only used as binder adhering multi-layer lenticules, closing the interlayer space of multi-layer lenticules, preventing the formation of interlayer fluid, but also increasing the thickness and toughness of lenticules, and therefore which is more facilitate to intraoperative suture.

Long-Term Evaluation of Patients with Neurotrophic Keratopathy Undergoing Staged Keratoplasty After Corneal Neurotization.

PURPOSE: Corneal neurotization (CN) is a novel, potentially curative surgical procedure for the treatment of neurothophic keratopathy (NK). Patients with severe NK can present with corneal opacification requiring optical keratoplasty, which would likely fail without a proper trophic support of corneal nerves in the recipient cornea. METHODS: This is a pilot study on 4 patients undergoing keratoplasty after CN. Pre- and postoperative data at 12, 24 months and at the last follow-up were collected for the examination of (i) best corrected visual acuity (BCVA), (ii) slit lamp examination and photograph acquisition with and without fluorescein staining, (iii) corneal aesthesiometry, (iv) in vivo confocal microscopy of the central cornea. Neurophysiological study of the corneal reflex before corneal graft and at last follow up was performed. RESULTS: Four female patients (47.25 ± 5.06 y.o.) underwent keratoplasty after CN (3 penetrating keratoplasty, 1 deep anterior lamellar keratoplasty). The mean interval between CN and keratoplasty was 22 (± 12) months. The mean graft survival time was 42 (± 25) months. Graft follow-up ranged from 72 to 132 months. At the final follow-up, BCVA was improved in 2 out of 4 patients. The mean corneal sensitivity was 11.9 ± 8.3 mm at last follow-up. In vivo confocal microscopy confirmed the presence of functioning nerves at the last follow-up in all patients. NK-related complications occurred in 3 eyes (2 persistent epithelial defect, 1 corneal melting). The former complication was successfully treated by autologous serum eye drops while the latter required repeated keratoplasty. CONCLUSIONS: Keratoplasty is a viable strategy to improve visual acuity in patients with corneal opacity who underwent CN for the treatment of NK. Even in the presence of functioning corneal nerves before keratoplasty, surgeons should be aware of the increased rate of NK-related complications that could require the need for repeated procedure.

Results of Lucia Keratoprosthesis Implantation in Severe Corneal Disease.: Results of Lucia KPro.

PURPOSE: Describe complications, functional success, and retention of the Lucia Keratoprosthesis (KPro). DESIGN: Retrospective interventional case series METHODS: The demographic data, baseline characteristics, complications, functional success, and retention were analyzed for Lucia KPro at Instituto de Oftalmologia Conde de Valenciana in Mexico City from 2021-2023. Multivariate regression analysis and Kaplan-Meier plots were performed to identify associations with functional failure. The main outcome measures were postoperative complications; functional success defined as best-corrected visual acuity (BCVA) ≥ 20/200 (LogMAR 1.0); and device retention rate. RESULTS: Forty-eight eyes of 48 patients (56.88% male) were studied. The mean age at implantation was 57.29 ± 15.63 years (range 27-91) with a mean follow-up of 20.5 ± 8.83 months (range: 3-40). Diagnostic indications for implantation included recurrent graft rejection (54.17%), autoimmune disease (20.83%), chemical injury (12.5%), and other (12.5%). At least one postoperative complication occurred in 75% of patients leading to 65 additional interventions (mean number of subsequent procedures: 1.35 ± 1.3, range 0-5). The preoperative BCVA was 2.40 ± 0.36 LogMAR. At the final follow-up, 62.5% had achieved functional success and 22.92% had a BCVA of 20/40 (LogMAR 0.3) or better. Glaucoma (adjusted OR: 469.74, 95% CI 5.02 - 43939.14, p=0.007) and retinal pathology before KPro (adjusted OR: 372.38, 95% CI 4.18 - 33162.11, p=0.009) were associated with functional failure. The device remained in place in 95.83% of recipients over the follow-up period. CONCLUSION: The Lucia KPro offers functional success in severe corneal diseases and excellent retention in the short to intermediate term.

Evaluation of Sociomedical Factors on Corneal Donor Recovery Using Machine Learning.

PURPOSE: To evaluate co-morbid sociomedical conditions affecting corneal donor endothelial cell density and transplant suitability. METHOD(S): Corneal donor transplant information was collected from the CorneaGen eye bank between June 1, 2012 and June 30, 2016. A natural language processing algorithm was applied to generate co-morbid sociomedical conditions for each donor. Variables of importance were identified using four machine learning models (random forest, Glmnet, Earth, nnet), for the outcomes of transplant suitability and endothelial cell density. SHAP (SHapley Additive exPlanations) values were generated, with beeswarm and box plots to visualize the contribution of each feature to the models. RESULTS: With a total of 23,522 unique donors, natural language processing generated 30,573 indices, which were reduced to 41 most common co-morbid sociomedical conditions. For transplant suitability, hypertension ranked the top overall variable of importance in two models. Hypertension, chronic obstructive pulmonary disease, history of smoking, and alcohol use appeared consistently in the top variables of importance. By SHAP feature importance, hypertension (0.042), alcohol use (0.017), ventilation of donor (0.011), and history of smoking (0.010) contributed the most to the transplant suitability model. For endothelial cell density, hypertension was the sociomedical condition of highest importance in three models. SHAP scores were highest among the sociomedical conditions of hypertension (0.037), alcohol use (0.013), myocardial infarction (0.012), and history of smoking (0.011). CONCLUSION: In a large cohort of corneal donor eyes, hypertension was identified as the most common contributor to machine learning models examining sociomedical conditions for corneal donor transplant suitability and endothelial cell density.

Long-term prognosis of penetrating keratoplasty in a patient with limited form of Scleroderma- a case report.

PURPOSE: To explore the challenges of managing recurrent graft rejections in patients with Macular Corneal Dystrophy (MCD) undergoing Penetrating Keratoplasty (PKP) who also have an underlying diagnosis of Systemic Sclerosis, specifically the limited form known as CREST syndrome. METHODS: The case of a 47-year-old female diagnosed with MCD who underwent multiple PKPs over a 13 year period was reviewed. The patients treatment included extensive surgical interventions (PKPs, amniotic membrane transplatation, tarsorrhaphy) and medical management involving systemic and topical steroids and immunosuppressive therapy (Tacrolimus ointment). RESULTS: Initial PKP surgeries improved the patients vision, but subsequently graft rejections,both acute and chronic, required further surgical and medical interventions. Despite aggressive management, the patient experienced multiple graft failures, with the final visual outcome being significantly compromised (vision 6/60). the presence of CREST syndrome complicated the management and prognosis of graft survival. CONCLUSION: This case illustrates the significant impact of systemic autoimmune disorders like CREST syndrome on the prognosis of PKP in patients with MCD. It highlights the necessity for diligent systemic evaluation and possibly more aggressive immunosuppresive strategies to manage graft rejections and prolong graft survival in such complex clinical scenarios.

Clinical characteristics and viral colonization of corneal donors with coronavirus disease 2019: a comprehensive analysis before and after corneal transplantation.

PURPOSE: To evaluate the clinical characteristics and viral Colonization of corneas donated by volunteers with coronavirus disease 2019 (COVID-19) before and after corneal transplantation. METHODS: We retrospectively compared the characteristics and clinical outcomes of patients who received corneas from donors with and without a history of COVID-19 after corneal transplantation. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate the expression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA on ocular surfaces in corneal preservation solutions as well as the recipients' tears. Immunofluorescence was also performed to evaluate the expression of viral spike proteins in the corneas. Intraocular pressure (IOP) measurement, optical coherence tomography (OCT), and slit-lamp inspection at each follow-up examination were performed to assess the surgical efficacy. RESULTS: The RT-PCR results of eye surface swabs before corneal extraction, the corneal preservation solutions before transplantation as well as the recipients' tears were negative, thereby indicating the suitability for transplantation. No significant differences in IOP measurements, OCT findings, or in the incidence of post transplantation complications were observed between donors with and without COVID-19. CONCLUSIONS: Corneal transplantation using corneas from COVID-19 infected donors does not alter clinical outcomes when compared to controls receiving corneas from non-infected donors.

[How to talk to relatives about corneal donation]. / Wie spreche ich mit Angehörigen über die Hornhautspende?

Corneal donation counselling is an important part of the process to inform and support potential donors and their relatives. In this article various aspects of the conversation techniques on corneal donation are discussed, including raising awareness of the importance of donation, clarifying questions and concerns, emphasizing the potential of donation and considering the emotional burden on the relatives of potential donors. Also emphasized is the role of the counsellor as a trustworthy and empathetic contact who can help family members of potential donors make an informed and positive decision. It is pointed out that a professional and empathetic approach to corneal donation can help to increase the willingness to donate and ultimately that a donation can help visually impaired or blind people regain their sight and quality of life through donation.

Multimodal imaging and histopathological evaluation in silicone oil keratopathy.

PURPOSE: To describe features in silicone oil keratopathy using multimodal imaging and histopathological examination. METHODS: Case report. RESULT: A 21-year-old male developed right corneal decompensation in the heavy SO (HSO)-filled eye. The patient underwent an initial lensectomy, pars plana vitrectomy (PPV) and HSO tamponade due open-globe injury with corneal wound, lens damage and in two retained intravitreal glass foreign bodies, followed by a revisional PPV with HSO tamponade due to tractional detachment associated with proliferative vitreoretinopathy and epiretinal membrane. One month after the removal of HSO, ophthalmic examination of the right eye showed corneal decompensation. The AS-OCT showed corneal thickening, intrastromal scattered hyperreflective dots and large rounded/oval hyporeflective space; the latter were suggestive of emulsified HSO microbubbles and larger bubbles, respectively. In vivo confocal microscopy showed multiple presumed SO-related corneal changes, including hyper-reflective fibrotic changes in the basal epithelium, reduced density ans altered morphology of keratocytes cell population, increased pleomorphism and polymegathism of the endothelium with reduced endothelial cell, and presence of inflammatory cells. The patient underwent a penetrating keratoplasty, pupilloplasty and retropupillary iris-claw IOL implantation. The histopathological examination of the host corneal button showed Descemet's membrane irregularity and thickened corneal stroma with focal intrastromal silicone oil vacuoles, surrounded by macrophages. CONCLUSION: We described for the first time intrastromal hyperreflective dots as a sign associated with SO-related keratopathy. Moreover, this case report supports the ability of emulsified SO to penetrate the cornea inducing a local low-grade chronic inflammation.

Standardizing Corneal Transplantation Records Using openEHR: Case Study.

BACKGROUND: Corneal transplantation, also known as keratoplasty, is a widely performed surgical procedure that aims to restore vision in patients with corneal damage. The success of corneal transplantation relies on the accurate and timely management of patient information, which can be enhanced using electronic health records (EHRs). However, conventional EHRs are often fragmented and lack standardization, leading to difficulties in information access and sharing, increased medical errors, and decreased patient safety. In the wake of these problems, there is a growing demand for standardized EHRs that can ensure the accuracy and consistency of patient data across health care organizations. OBJECTIVE: This paper proposes the use of openEHR structures for standardizing corneal transplantation records. The main objective of this research was to improve the quality and interoperability of EHRs in corneal transplantation, making it easier for health care providers to capture, share, and analyze clinical information. METHODS: A series of sequential steps were carried out in this study to implement standardized clinical records using openEHR specifications. These specifications furnish a methodical approach that ascertains the development of high-quality clinical records. In broad terms, the methodology followed encompasses the conduction of meetings with health care professionals and the modeling of archetypes, templates, forms, decision rules, and work plans. RESULTS: This research resulted in a tailored solution that streamlines health care delivery and meets the needs of medical professionals involved in the corneal transplantation process while seamlessly aligning with contemporary clinical practices. The proposed solution culminated in the successful integration within a Portuguese hospital of 3 key components of openEHR specifications: forms, Decision Logic Modules, and Work Plans. A statistical analysis of data collected from May 1, 2022, to March 31, 2023, allowed for the perception of the use of the new technologies within the corneal transplantation workflow. Despite the completion rate being only 63.9% (530/830), which can be explained by external factors such as patient health and availability of donor organs, there was an overall improvement in terms of task control and follow-up of the patients' clinical process. CONCLUSIONS: This study shows that the adoption of openEHR structures represents a significant step forward in the standardization and optimization of corneal transplantation records. It offers a detailed demonstration of how to implement openEHR specifications and highlights the different advantages of standardizing EHRs in the field of corneal transplantation. Furthermore, it serves as a valuable reference for researchers and practitioners who are interested in advancing and improving the exploitation of EHRs in health care.

Examining Medical Students' and Professionals' Perspectives on Eye Donation and Corneal Transplantation.

Background Corneal blindness affects millions across India. Corneal transplantation is the primary treatment; however, there is a severe shortage of donor corneas. This study aimed to assess awareness, knowledge, and attitudes towards corneal donation among medical students and professionals, identify barriers to donation, and explore popular information sources for promoting awareness about corneal transplants and eye donation. Methods Using a validated, self-administered questionnaire, this cross-sectional study surveyed 350 medical undergraduates, postgraduates, and doctors. Data collection occurred over a period of three months via Google Forms (Mountain View, CA: Google LLC). The questionnaire assessed knowledge about corneal donation criteria, willingness to donate corneas, factors influencing donation decisions, and sources of awareness about corneal transplants. Ethical clearance was obtained, and data was analyzed using SPSS version 20.0 (Armonk, NY: IBM Corp.). Results Regarding donor eligibility, 269 (76.9%) knew that anyone regardless of age can donate, 270 (77.1%) knew that donation occurs postmortem, 269 (68.3%) knew the time limit for cornea collection, only 133 (38%) knew medical conditions impacting donor eligibility, and 250 (71.4%) knew only corneal tissue is retrieved. A large number, 333 (95.1%), are aware of the functions of eye banks. Of the participants, 228 (65.1%) were willing to donate their corneas. Popular reasons for donations included helping blind people improve their quality of life and the nobility of the act. The main barriers include a lack of awareness, a desire to preserve the body, health issues, and ethical concerns during extraction. The most preferred sources of information are social media, health workers/eye camps, TV advertisements, and celebrity endorsements. Overall, doctors and postgraduates demonstrated superior knowledge in most areas compared to undergraduates, and ophthalmologists showed higher knowledge in specific domains (like age limits, factors affecting the eligibility of eye donors, time frame for cornea harvesting, and the identification of certain diseases and conditions barring donation) than non-ophthalmologists. Conclusion Our research uncovered knowledge deficits regarding corneal donation criteria and procedures mainly among undergraduate students. The findings highlight the importance of impactful educational initiatives that utilize preferred communication channels. These efforts should address myths and misconceptions, analyze vital motivating factors, overcome barriers, and understand cultural perspectives influencing the overall attitude towards corneal donation.

Emerging Applications of Intraoperative Optical Coherence Tomography in Corneal Surgery: A Narrative Review.

Intraoperative OCT (iOCT) is an innovative imaging modality that provides ophthalmic surgeons with real-time cross-sectional views of the surgical field. Recent advances in OCT technology, such as higher acquisition scanning rates, enable real-time video visualization. iOCT systems are widely used in both vitreoretinal and anterior segment surgeries. In corneal surgeries, iOCT imaging aims to optimize efficacy and safety by improving depth perception and enhancing visualization in cases of opaque optical media. iOCT is a valuable tool not only for experienced corneal surgeons, but also for training novice surgeons. This review summarizes the emerging applications of iOCT in corneal surgery, particularly in technically demanding lamellar keratoplasty procedures, as well as in various other corneal diseases and complications that require surgical intervention.

Evolving indications and surgical techniques for corneal transplantation at a tertiary eye care center in southern China.

BACKGROUND: This retrospective study aimed to analyze the evolution of primary indications and surgical techniques for corneal transplantation in Southern China from 2012 to 2021. METHODS: The medical charts of all patients who underwent keratoplasty between January 2012 and December 2021 at Zhongshan Ophthalmic Centre, Sun Yat-Sen University, Guangzhou, Southern China were reviewed. We collected and analyzed the primary indications for corneal transplantation and the surgical methods used in each keratoplasty. RESULTS: The total number of corneal transplantations was 7,286 during this decade, increasing from 210 cases in 2012 to 1054 cases in 2021. The primary indications for keratoplasty included acquired nontraumatic corneal diseases (56.2%), congenital corneal abnormalities (16.4%), acquired traumatic corneal diseases (14.0%), and regraft (13.4%). Infectious keratitis was the leading indication among all keratoplasties (18.5%), followed by regraft (13.4%). Over the decade, the proportion of infectious keratitis gradually decreased (P = 0.013), while the proportion of regraft increased (P = 0.019). The predominant surgical technique was penetrating keratoplasty (PKP), accounting for 56.7%. However, the number of deep anterior lamellar keratoplasty (DALK) and endothelial keratoplasty (EK) significantly increased from 2012 to 2021 (P = 0.007 and P = 0.002). CONCLUSIONS: The annual number of corneal transplants significantly increased from 2012 to 2021. In the past decade, infectious keratitis and regraft have become the leading primary indications for corneal transplantation. Although the use of customized lamellar techniques has dramatically increased, PKP remains the predominant surgical technique for keratoplasty.

A review of Bowman's layer structure, function, and transplantation.

Bowman's layer is an acellular corneal structure, which is considered to be a specially modified anterior stroma. It is presumed, that it forms as a result of ongoing epithelial-stromal interactions and no clear physiological purpose has been proven. Despite this fact, Bowman's layer has found its place in corneal transplantation. It has been performed for over a decade, mainly in treatment of advanced keratoconus with multiple modifications. Transplantation of Bowman's layer can be expected to become a widely used surgical procedure in the treatment of many corneal pathologies involving fragmentation and destruction of Bowman's layer. This article aims to summarize information available on its structure, possible function, and transplantation. A thorough literature search was performed in the PubMed database and Google Scholar using keywords: Bowman's layer, structure, function, preparation and corneal transplantation. All the relevant sources were used, which represent 77 peer-reviewed articles with information corcerning the topic of this article.

Bubble-graft coverage after Descemet Membrane Endothelial Keratoplasty depending on gaze angle.

PURPOSE: In Descemet Membrane Endothelial Keratoplasty (DMEK) a gas bubble is usually used to attach the graft to the host cornea. In this study, we observed the bubble size and bubble-graft coverage at different gaze angles following DMEK. METHODS: This observational prospective study analyzed 465 images of patients who underwent an uneventful DMEK. Intraoperatively, the anterior chamber was filled up to 90% of its volume with a 20% Sulfur Hexafluoride (SF6) gas-air mixture. Postoperatively, the bubble was photographed daily in different gaze angles ranging from a supine position (0°) to an upright position (90°) and a slightly inclined position (105°). The primary outcomes were bubble-graft coverage and bubble diameters depending on the gaze angle and time after DMEK. RESULTS: The highest bubble-graft coverage was achieved at a 0° gaze angle at all times of measurement. In the first 48 h after DMEK, the mean bubble-graft coverage was over 85% at a gaze angle between 0° and 45°. Starting 72 h after DMEK, the graft coverage declined at all gaze angles. The graft coverage at a 0° gaze angle was 88.61 ± 10.90% after 96 postoperative hours, while the graft coverage was below 85% at all other gaze angles. CONCLUSION: Our clinical results provide novel insight into variation in bubble-graft coverage as a function of gaze angle and may be used to aid in patient counselling for appropriate body positioning following DMEK to prevent early graft detachment. Maintaining supine positioning seems to be most advantageous starting 48 h after DMEK.

Enhancing Visual Acuity through Combined Intraocular Lens Fixation, Penetrating Keratoplasty, and Vitrectomy: The Role of Temporary Landers Wide-Field Keratoprosthesis.

Introduction: Complex corneal conditions present surgical challenges and necessitate innovation. Here, we present two cases where we performed intraocular lens trans-scleral fixation using the double-needle Yamane technique, followed by penetrating keratoplasty and vitrectomy using a temporary Landers wide-field keratoprosthesis. Case Presentation: Case 1 involved a 70-year-old man with an aphakic eye of bullous keratopathy and corneal opacity owing to multiple penetrating and endothelial keratoplasty, endophthalmitis, and herpetic keratitis. His visual acuity was counting fingers at 20 cm before surgery. Penetrating keratoplasty with vitrectomy and intraocular lens scleral fixation was performed using the double-needle Yamane technique, and 10 months postoperatively, his best-corrected visual acuity improved to 0.6, presenting a clear cornea. Case 2 involved a 62-year-old man who underwent penetrating keratoplasty twice for corneal perforation and therapeutic penetrating keratoplasty with vitrectomy for traumatic globe rupture, resulting in the loss of the intraocular lens. The patient exhibited graft failure, and his best-corrected visual acuity was 0.03. Utilizing a temporary Landers wide-field keratoprosthesis, we performed penetrating keratoplasty and intraocular lens trans-scleral fixation without complications. His final best-corrected visual acuity improved to 0.15 with a clear cornea. Conclusions: Trans-scleral fixation of intraocular lens with penetrating keratoplasty, using temporary Landers wide-field keratoprosthesis, yielded positive clinical outcomes without serious complications.

A sustainable approach to derive sheep corneal scaffolds from stored slaughterhouse waste.

Aim: The escalating demand for corneal transplants significantly surpasses the available supply. To bridge this gap, we concentrated on ethical and sustainable corneal grafting sources. Our objective was to create viable corneal scaffolds from preserved slaughterhouse waste.Materials & methods: Corneas were extracted and decellularized from eyeballs that had been refrigerated for several days. These scaffolds underwent evaluation through DNA quantification, histological analysis, surface tension measurement, light propagation testing, and tensile strength assessment.Results: Both the native and acellular corneas (with ~90% DNA removed using a cost-effective and environmentally friendly surfactant) maintained essential optical and biomechanical properties for potential clinical use.Conclusion: Our method of repurposing slaughterhouse waste, stored at 4°C for several days, to develop corneal scaffolds offers a sustainable and economical alternative xenograft model.

[Box: see text].

Mechanism and treatment of secondary glaucoma after corneal transplantation: a review.

Corneal transplantation is a common treatment for corneal diseases. Secondary glaucoma after corneal transplantation is the second leading cause of failure of keratoplasty. This article reviews the mechanism and treatment of secondary glaucoma after corneal transplantation.