Carbon Footprint of Fluorinated Gases Used in Endothelial Keratoplasty.

PURPOSE: The purpose of this study was to examine the direct impact on carbon emissions attributed to the use of fluorinated gases in endothelial keratoplasty (EK) procedures using gas tamponade and to evaluate the respective carbon footprint of different gas delivery systems used in EK procedures. METHODS: In this retrospective, single-center environmental impact study, all corneal procedures using fluorinated gases between January 2021 and January 2024 at the Royal Liverpool University Hospital were reviewed and included. The CO2 equivalent emissions were calculated based on the mass of each fluorinated gas used, following the guidelines of the Intergovernmental Panel on Climate Change. RESULTS: Of 357 total procedures (160 Descemet membrane endothelial keratoplasty [44.8%], 118 Descemet stripping automated endothelial keratoplasty [33.1%], and 79 rebubbling [22.1%]), single-use sulfur hexafluoride (SF6) canisters were used in 278 (77.9%) procedures. SF6 canisters used in corneal transplantation emitted nearly 1.5 tons of CO2 over 3 years. The 30-mL canisters emitted twice the CO2 per GBP compared to SF6 15-mL canisters and 4 times that of C2F6 or C3F8 15-mL canisters. CONCLUSIONS: Fluorinated gas use in corneal transplantation has a significant environmental impact, which can be reduced by the use of smaller single-use canisters with lower carbon footprint, although manufacturing and disposal concerns remain. Our findings advocate for a more environmentally conscious approach to EK, favoring the use of smaller, more cost-efficient canisters and considering air as an alternative tamponade where possible.

Endothelial Migration and Regeneration after Penetrating Trauma Injury in a Deep Anterior Lamellar Keratoplasty Graft: Case Presentation and Literature Overview.

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.

Artificial intelligence in cornea and ocular surface diseases.

In modern ophthalmology, the advent of artificial intelligence (AI) is gradually showing promising results. The application of complex algorithms to machine and deep learning has the potential to improve the diagnosis of various corneal and ocular surface diseases, customize the treatment, and enhance patient outcomes. Moreover, the use of AI can ameliorate the efficiency of the health-care system by providing more accurate results, reducing the workload of ophthalmologists, allowing the analysis of a big amount of data, and reducing the time and resources required for manual image acquisition and analysis. In this article, we reviewed the most important and recently published applications of AI in the field of cornea and ocular surface diseases, with a particular focus on keratoconus, infectious keratitis, corneal transplants, and the use of in vivo confocal microscopy.

ROCK Inhibitors in Corneal Diseases and Glaucoma-A Comprehensive Review of These Emerging Drugs.

Rho kinase (ROCK) inhibitors have gained significant attention as emerging novel treatment options in the field of ophthalmology in recent years. The evidence supporting their efficacy in glaucoma and corneal pathology includes both in vitro and clinical studies. Among the available options, ripasudil and netarsudil have emerged as the leading ROCK inhibitors, and some countries have approved these therapeutic options as treatments for glaucoma. Various dosing regimens have been studied, including monotherapy and combination therapy, especially for patients with secondary glaucoma who are already on multiple medications. Another rising application of ROCK inhibitors includes their use as an adjunct in surgical procedures such as Descemetorhexis Without Endothelial Keratoplasty (DWEK), Descemet Stripping Only (DSO) to accelerate visual recovery, glaucoma surgeries to reduce scarring process and allow better intraocular pressure (IOP) control, or after complicated anterior segment surgery to treat corneal oedema. This article provides a comprehensive overview of the existing literature in the field, offering recommendations for prescribing ROCK inhibitors and also discussing patient selection, drug efficacy, and possible adverse effects.

Ocular-Surface Regeneration Therapies for Eye Disorders: The State of the Art.

The ocular surface is a complex structure that includes cornea, conjunctiva, limbus, and tear film, and is critical for maintaining visual function. When the ocular-surface integrity is altered by a disease, conventional therapies usually rely on topical drops or tissue replacement with more invasive procedures, such as corneal transplants. However, in the last years, regeneration therapies have emerged as a promising approach to repair the damaged ocular surface by stimulating cell proliferation and restoring the eye homeostasis and function. This article reviews the different strategies employed in ocular-surface regeneration, including cell-based therapies, growth-factor-based therapies, and tissue-engineering approaches. Dry eye and neurotrophic keratopathy diseases can be treated with nerve-growth factors to stimulate the limbal stem-cell proliferation and the corneal nerve regeneration, whereas conjunctival autograft or amniotic membrane are used in subjects with corneal limbus dysfunction, such as limbal stem-cell deficiency or pterygium. Further, new therapies are available for patients with corneal endothelium diseases to promote the expansion and migration of cells without the need of corneal keratoplasty. Finally, gene therapy is a promising new frontier of regeneration medicine that can modify the gene expression and, potentially, restore the corneal transparency by reducing fibrosis and neovascularization, as well as by stimulating stem-cell proliferation and tissue regeneration.

Managing Post-Keratoplasty Astigmatism: High-Tech vs. Low-Tech Imaging Techniques for Guiding Suture Manipulation.

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.

Descemet membrane endothelial keratoplasty graft detachments in superior versus temporal approach.

PURPOSE: To evaluate the difference in Descemet Membrane Endothelial Keratoplasty (DMEK) graft detachment rate comparing superior versus temporal main incision approach. METHODS: Retrospective comparative study on patients who underwent DMEK surgery for Fuchs endothelial dystrophy or bullous keratopathy with main wound incision performed at either 90° in the superior approach, or at 180°/0° in the temporal approach. All main incisions were secured with a single 10-0 nylon suture at the end of surgery. Data collected were donor age and gender, endothelial cell counts, graft diameter, recipient age and gender, indication for transplant, surgeon grade, re-bubbling rate, air fill in the anterior chamber (AC) at day one and intra- and early postoperative complications. RESULTS: 187 eyes were included in the study. 99 eyes had DMEK surgery with superior approach, while 88 eyes had temporal approach. The two groups had no differences in donor age and sex, endothelial cell counts, graft diameter, recipient age and sex, indication for transplant, surgeon grade, and air fill in the anterior chamber at day one. Re-bubbling rate was 38.4% for surgeries performed with superior access and 29.5% for those with temporal access(p = 0.186). After exclusion of patients with intraoperative and/or postoperative complication, the difference in re-bubbling rate was higher, although non-significant (37.5% and 25% for superior and temporal approach respectively, p = 0.098). CONCLUSION: The temporal approach in DMEK showed a trend towards a clinically significant lower rate of post-operative re-bubbling compared to the superior approach, however, no statistically significant difference was noted comparing the two approaches, which both remain feasible options in DMEK surgery.

Prophylaxis of Ocular Infection in the Setting of Intraocular Surgery: Implications for Clinical Practice and Risk Management.

In this review we discuss the role of intraocular surgery preoperative prophylaxis. The correct choice of antimicrobial drug is variable in each surgical setting, according to the available strengths of evidence, the anatomical district involved, and the type of procedure. In the ophthalmic surgical field, there has been a progressive shift from antibiotic formulations, which are known to cause antibiotic resistance, to a new class of antiseptic compounds, which proved to be effective not only against bacteria, but also against fungi, protozoa, and viruses. Among these, povidone-iodine (PVI) is a water-soluble polymer that can form a complex with iodine, and the perioperative application of PVI 5-10% eye drop for 3 min is the gold standard for infection prophylaxis. A new formulation of 0.6% PVI eye drop is a new option for infection prophylaxis in the days before surgery. Chlorhexidine is a biguanide compound, which is a valid alternative with a good safety and efficacy profile and is the antiseptic of choice in patients with iodine allergy. New compounds that are currently being studied include polyhexamethylene biguanide (PHMB), picloxydine, ozone, hypochlorous acid (HOCl), and Biosecur. PHMB is a biguanide polymer that was found to be more effective than PVI in in vitro studies for reducing microorganisms and extending the duration of antisepsis, but to date, there are no formulations available on the market for preoperative ocular surgery in which it is present as main ingredient. Ozone is a molecule with oxidizing effect, which showed interesting preliminary results but is not effective against virus, Staphylococcus aureus and Candida albicans. HOCl has a natural bactericidal propriety but its applicability to prophylaxis of ocular infection in the setting of ocular surgery is not established. Biosecur is a non-toxic organic alcohol-free compound that exhibited bactericidal and fungicidal effect versus all common microorganisms and is currently available as an ocular spray.

Carlevale intraocular lens opacification after Descemet stripping automated endothelial keratoplasty.

PURPOSE: To report a case of sutureless scleral-fixated (SSF) Carlevale intraocular lens (IOL) opacification following Descemet stripping automated endothelial keratoplasty (DSAEK) surgery. METHODS: An 82-year-old man underwent combined SSF Carlevale IOL implant and DSAEK surgery for aphakic endothelial decompensation. Surgery was uneventful, while the postoperative period was complicated by multiple graft detachments requiring re-bubbling. After four re-bubbling procedures, the corneal graft attached and cleared over time. RESULTS: 29 months after combined SSF IOL implant and DSAEK surgery, the patient presented with decreased vision due to IOL opacification affecting the visual axis. CONCLUSION: Although combined SSF IOL and DSAEK surgery is an overall safe and effective procedure for aphakic endothelial decompensation, risk of IOL opacification due to anterior chamber air injection is higher when using hydrophilic IOLs and in cases requiring multiple re-bubbling, therefore, intraocular lens material should be chosen after considering the risks and benefits.