Topical use of alcohol in ophthalmology - Diagnostic and therapeutic indications

Alcohol delamination and topical mitomycin-C 0.02% for the treatment of corneal intraepithelial neoplasia

PurposeTo report a case of a patient diagnosed with corneal intraepithelial neoplasia (CIN) with ocular discomfort and blurred vision, successfully treated with alcohol delamination (ALD) and topical mitomycin-C.MethodsA 69 year-old man underwent a full slit lamp examination which revealed the presence of a superficial corneal lesion appearing as an opaque intraepithelial plaque extending from the limbus to the visual axis. A manifest refraction with a best corrected visual acuity (BCVA), an anterior segment OCT (AS-OCT) and a corneal topography were performed. In order to remove the lesion an ALD was carried out and the obtained tissue sample was sent for histopathological evaluation confirming the diagnosis of CIN. At the end of the procedure, a bandage contact lens was applied, and the eye was started on a topical treatment with Netilmicin 3% and Dexamethasone 1% 4 times daily for 15 days and mitomycin-C 0.02% drops four times a day, on alternate weeks for 4 weeks.ResultsPatient's symptoms improved and BCVA was restored to 20/20 over 1-month period. The ocular surface showed a significant regularization, clinically and both at the AS-OCT and corneal topography. Three years after the procedure patient's BCVA and refraction were stable without any sign of recurrence.ConclusionsALD is a safe and inexpensive procedure when dealing with CIN allowing both clinical improvements and a definitive histopathological diagnosis.

Enhancing Visual Quality: The Impact of Alcohol-Assisted Delamination on Corneal Aberrations in Patients with Central Epithelial Basement Membrane Dystrophy

Background/Objectives: Epithelial basement membrane dystrophy (EBMD) is a common corneal dystrophy characterized by recurrent corneal erosions and visual impairments due to surface irregularities and opacities. This study aims to evaluate the effectiveness of alcohol-assisted delamination (ALD) of the corneal epithelium in patients with EBMD affecting the visual axis, who experience decreased vision quality due to higher-order aberrations (HOAs) and irregular astigmatism. Methods: Eleven eyes of nine patients (four males and five females) were treated with ALD, with a mean age of 51.3 ± 19.7 years. All patients underwent refraction, best-corrected visual acuity (BCVA) assessment, a comprehensive slit-lamp examination for EBMD pattern identification, anterior segment imaging with and without fluorescein, tear break-up time (BUT) testing, corneal topography, corneal aberrometry (Zernike coefficients (Znm) were calculated for a 5.0 mm simulated pupil), and anterior segment optical coherence tomography preoperatively and at 1-day, 14-day, 1-month, 3-month, 6-month, and 12-month intervals. Results: All patients demonstrated improvements in BCVA and visual quality, ocular comfort, and BUT results. The mean root mean square (RMS) value of total corneal aberrations decreased from 1.72 ± 0.90 μm to 0.90 ± 0.62 μm, while the mean RMS value of HOAs reduced from 0.92 ± 0.48 μm to 0.53 ± 0.28 μm. Astigmatism and trefoil were the aberration components that exhibited the most significant reductions. Conclusions: Alcohol-assisted delamination of the corneal epithelium is a safe and effective treatment for central EBMD patients experiencing visual quality deterioration. Astigmatism and trefoil appear to be the primary aberrations contributing to visual disturbances in this patient population.

A limbal stem cell deficiency murine model with residual limbal stem cells

Bilateral limbal stem cell deficiency (LSCD) is a significant cause of corneal blindness and is more difficult to treat, as compared with unilateral LSCD because no source of autologous limbal stem cells (LSCs) remains in these patients. Thus, bilateral patients could be candidates for treatment with allogeneic LSC transplants that require long-term systemic immunosuppression therapy. Thus, if possible, for the correct candidates, using autologous LSCs could be a preferred treatment. Recent in vivo laser confocal microscopic examination of the ocular surface in situ , combined with impression cytology, has indicated that some patients diagnosed with a complete bilateral LSCD possess residual LSCs. However, it remains unknown whether these residual LSCs still have stem cell potential due to the lack of animal models that mimic this pathology. The goal of the current study is to make a complete LSCD model that possesses evidence of residual LSCs. We induced complete LSCD in mice using two methods: (1) removed the corneal epithelium and the epithelial basement membrane using a rotating burr, and (2) removed the corneal epithelium using 20% ethanol but retained an intact epithelial basement membrane. A complete LSCD was defined by a lack of CK12-positive corneal epithelial cells and the presence of infiltrating CK19-positive conjunctival epithelial cells. Corneas were examined for wound closure, corneal opacity, LSC exhaustion, and inflammation. We observed that complete LSCD mice without an intact epithelial basement membrane resulted in few residual LSCs. By contrast, complete LSCD mice that retained the epithelial basement membrane were accompanied by a reduced inflammatory response plus a significant number of residual LSCs. This model will allow future studies to determine the function of residual LSCs in complete LSCD.

Herpes Simplex Keratitis Following Corneal Crosslinking for Keratoconus: A One-Year Case Series Follow-Up

Corneal crosslinking (CXL) is a medical procedure used to treat keratoconus. CXL works by strengthening the collagen fibers of the cornea through the application of riboflavin (vitamin B2) and ultraviolet (UV) light, which helps to stabilize the cornea and prevent further deterioration. There is a recognized risk that CXL can trigger the reactivation of dormant herpes simplex virus (HSV), leading to herpetic keratitis even in patients with no history of herpetic disease. We examined the medical history of 52 patients who underwent CXL procedures due to previously diagnosed keratoconus. We reviewed the patient's medical histories to assess whether there was a herpes labialis infection and/or herpetic keratitis. Altogether, 52 eyes (from 52 patients) were analyzed. Of those, four (7.69%) patients were diagnosed with epithelial herpetic keratitis on the 5-8th day after surgery. All four patients had a history of herpes labialis and no prior HSV keratitis infection. Two patients developed herpetic keratitis despite prophylactic therapy with acyclovir 5 days before surgery. A positive history of HSV lip infection before CXL was present in 18/52 (34.62%). During a one-year follow-up period, no patient experienced a recurrence. Close follow-up is crucial for diagnosing herpetic keratitis after corneal crosslinking. The use of prophylactic antiviral therapy in patients who are asymptomatic and have a history of recurrent herpes labialis does not guarantee the prevention of infection.

The Role of 20% Ethanol in Enhancing Pterygium Surgery Outcomes: A Clinical Study

Introduction Pterygium is an ocular surface disorder characterized by a hyperplastic growth of conjunctiva encroaching over the cornea. It causes redness, watering, and foreign body sensation. Surgical excision is the preferred mode of treatment when there is encroachment over the visual axis, chronic irritation, restricted ocular motility, and cosmetic concerns. Various surgical methods have been adopted for the treatment and to prevent recurrences. This study assessed the effectiveness and safety of 20% ethanol as an adjuvant in pterygium excision with conjunctival autograft implantation, evaluating surgical outcomes. Methods A prospective hospital-based interventional study was conducted among 30 patients with pterygium from August 2022 to December 2023. Patients were evaluated preoperatively for anterior segment, posterior segment, visual acuity, and corneal astigmatism. Pterygium was excised using 20% ethanol as an adjuvant, and conjunctival autograft was placed over the bare sclera without sutures. Patients were evaluated on postoperative days 1, 8, 30, and 90 for graft condition, visual acuity, corneal astigmatism, and associated complications. Results After three months of follow-up, the mean visual acuity improved to LogMAR 0.46±0.35 (p=0.001), which was statistically significant, and the average corneal astigmatism decreased from 3.36±2.87 to 0.87±0.57 (p=0.0001). No recurrence was noted among the participants. Conclusion This study has shown that using 20% ethanol as an adjuvant for pterygium excision facilitated clean dissection of a pterygium from the underlying cornea and the pterygium-induced corneal astigmatism has significantly decreased, which led to progress in vision.

Microfluidic Fabricated Liposomes for Nutlin-3a Ocular Delivery as Potential Candidate for Proliferative Vitreoretinal Diseases Treatment

Purpose

Proliferative vitreoretinal diseases (PVDs) represent a heterogeneous group of pathologies characterized by the presence of retinal proliferative membranes, in whose development retinal pigment epithelium (RPE) is deeply involved. As the only effective treatment for PVDs at present is surgery, we aimed to investigate the potential therapeutic activity of Nutlin-3a, a small non-genotoxic inhibitor of the MDM2/p53 interaction, on ARPE-19 cell line and on human RPE primary cells, as in vitro models of RPE and, more importantly, to formulate and evaluate Nutlin-3a loaded liposomes designed for ophthalmic administration.

Methods

Liposomes were produced using an innovative approach by a microfluidic device under selection of different conditions. Liposome size distribution was evaluated by photon correlation spectroscopy and centrifugal field flow fractionation, while the liposome structure was studied by transmission electron microscopy and Fourier-transform infrared spectroscopy. The Nutlin-3a entrapment capacity was evaluated by ultrafiltration and HPLC. Nutlin-3a biological effectiveness as a solution or loaded in liposomes was evaluated by viability, proliferation, apoptosis and migration assays and by morphological analysis.

Results

The microfluidic formulative study enabled the selection of liposomes composed of phosphatidylcholine (PC) 5.4 or 8.2 mg/mL and 10% ethanol, characterized by roundish vesicular structures with 150-250 nm mean diameters. Particularly, liposomes based on the lower PC concentration were characterized by higher stability. Nutlin-3a was effectively encapsulated in liposomes and was able to induce a significant reduction of viability and migration in RPE cell models.

Conclusion

Our results lay the basis for a possible use of liposomes for the ocular delivery of Nutlin-3a.

Corneal epithelial and fibrovascular downgrowth postcataract surgery with intrastromal bleed: a rare case study with multimodal imaging

A woman in her 60s presented with diminution of vision and redness in her right eye (OD) 1.5 months duration, 10 months post cataract surgery. The best-corrected visual acuity (BCVA) on the OD was fingers counting at 0.5 m. The anterior section of the OD demonstrated superior pre-Descemet's intrastromal bleeding, superior dense fibrovascular growth in the corneal mid-stroma and superior fibrovascular downgrowth measuring 5×5 mm in the anterior chamber. Along with topical prednisolone acetate (1%) suspension 4 times per day on a tapering dose, antivascular endothelial growth factor therapy was administered intrastromally and subconjunctivally in the superior bulbar conjunctiva near limbus (0.05 mL of 2.5 mg/0.1 mL at each site). Over the course of a week, the intrastromal bleed had completely stopped. Three months later, at the final follow-up, the BCVA had marginally improved to fingers counting 2 m, with a lingering 4×4 mm nebulomacular scar.

Management of keratoconus: an updated review

Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman's layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.

Surgical management of infectious keratitis

The successful management of infectious keratitis is usually achieved with a combination of tools for accurate diagnosis and targeted timely antimicrobial therapy. An armamentarium of surgical interventions is available in the acute stage which can be resorted to in a step wise manner or in combination guided by the response to treatment. Simple surgical modalities can facilitate accurate diagnosis e.g. corneal biopsy and alcohol delamination. Surgery to promote epithelial healing can vary from tarsorrhaphy, amniotic membrane transplantation or conjunctival flaps depending on the extent of infection, visual prognosis, availability of tissue and surgeon's experience. Collagen crosslinking has been increasingly utilized with successful results to strengthen the cornea and reduce the infective load consequently the need for further elaborate surgical interventions. It has shown encouraging results specially in superficial bacterial and fungal keratitis but for deeper infections, viral and acanthamoeba keratitis, its use remains questionable. When globe integrity is compromised, corneal gluing is the most commonly used procedure to seal small perforations. In larger perforations/fulminant infections a tectonic/therapeutic graft is advisable. Partial thickness grafts are increasingly popular to treat superficial infection or internally tamponade perforations. Peripheral therapeutic grafts face challenges with potential requirement for a manually fashioned graft, and increased risk of rejection due to proximity to the limbal vessels. Late stage visual rehabilitation is likely to require further surgical interventions after complete resolution of infection and inflammation. A preliminary assessment of corneal sensation and integrity of the ocular surface are key for any successful surgical intervention to restore vision.

TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface

Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.

Evaluation of the effects of ethanol and mitomycin on survival of rat limbal stem cells: an in vitro study

PURPOSE

Ethanol and mitomycin C (MMC) are clinically used to treat corneal diseases such as LASEK and LASIK surgery. In this study, we investigated the effects of time-dependent alcohol and MMC in cultured rat limbal stem cells (LSCs) to determine the appropriate time for the use of this compound in the clinical setting.

METHODS

LSCs (N = 10 eyes) isolated from male Wistar rats were cultured and characterized; then, isolates were divided into three groups. One group was exposed to a 20% concentration of ethanol for 5, 10, 15, 20, 25, and 30 s, and cell viability was assessed one, three, and five days following ethanol exposure using an MTT assay. To investigate the effect of MMC, cells in the second group were treated with 0.02% MMC in various periods (i.e., 15 s, 30 s, 60 s, 90 s, and 120 s) and time-dependent responses of cultured LSCs were recorded. Cells in the third group were co-treated with ethanol and MMC; then, dose and time dependency was evaluated.

RESULTS

In comparison with the viable cells in the control group, ethanol markedly decreased the viability of cells in a time-dependent manner in days one and three. On day five, the viability of LSCs was improved significantly (p < 0.05) in comparison with day one. The number of viable progenitor cells was significantly decreased after MMC treatment in a time-dependent manner, as determined by the MTT assay (p < 0.001). The use of mitomycin, along with alcohol, decreased cell viability in all groups treated with ethanol + MMC compared to the control on days one, three, and five (p < 0.0001).

CONCLUSIONS

Our findings suggest that ethanol and MMC reduced cell viability in cultured LSCs in a time-dependent manner. In addition, when LSCs were exposed to alcohol alone, they had a better recovery process within 5 days in comparison to when exposed to mitomycin alone or mitomycin + alcohol.

Critical media attributes in E-beam sterilization of corneal tissue

When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea. After irradiation of corneal tissues, mechanical (tensile strength and modulus, elongation at break, and compression modulus), chemical, optical, structural, degradation, and biological properties of the corneal tissues were evaluated. Our study showed that irradiation in lower relative polarity media improved structural properties of the tissues yet reduced optical transmission; higher relative polarity reduced structural and optical properties of the cornea; and intermediate relative polarity (ethanol concentrations = 20-30% (v/v)) improved the structural properties, without compromising optical characteristics. Regardless of media polarity, irradiation did not negatively impact the biocompatibility of the corneal tissue. Our data shows that the absorbed ethanol can be flushed from the irradiated cornea to levels that are nontoxic to corneal and retinal cells. These findings suggest that the relative polarity of the irradiation media can be tuned to generate sterilized tissues, including corneal grafts, with engineered properties that are required for specific biomedical applications. STATEMENT OF SIGNIFICANCE: Extending the shelf-life of corneal tissue can improve general accessibility of cornea grafts for transplantation. Irradiation of donor corneas with E-beam is an emerging technology to sterilize the corneal tissues and enable their long-term storage at room temperature. Despite recent applications in clinical medicine, little is known about the effect of irradiation and preservation media's characteristics, such as polarity on the properties of irradiated corneas. Here, we have showed that the polarity of the media can be a valuable tool to change and control the properties of the irradiated tissue for transplantation.

Epithelial cells removed in advanced surface ablation (ASA) surgery can be used as a source of corneal samples to perform in vitro studies

Human corneal epithelial cells are needed to study corneal pathophysiology in vitro. Due to the limitations of cell lines, the use of primary cells is highly desirable, but the scarcity of human tissues, along with ethical issues, make it difficult to accomplish all required experiments. In advanced surface ablation (ASA), the central corneal epithelium is removed and discarded. We hypothesized that ASA samples could be used to perform in vitro assays. In this study, 29 samples from patients undergoing ASA were recovered in supplemented DMEM/F12 culture medium, RIPA buffer, or RLT lysis buffer. The first aim was to determine whether cells could be maintained in culture. Although with the explant technique, tissue pieces did not attach to the culture surface, after disaggregation, cells showed high viability (90.0 ± 6.0%), attached to plates, and remained viable for up to 14 days. The second aim was to elucidate if ASA samples could be used to study protein or gene expression. Cytokeratin-3, ZO-1, Ki67, and E-cadherin protein expression were confirmed by immunofluorescence. Total protein (485.8 ± 115.8 μg) was isolated from cells in RIPA buffer, and GAPDH was detected by Western blotting, indicating that samples are adequate for protein studies. RNA (9.0 ± 3.6 μg) was isolated from samples in RLT lysis buffer, and GAPDH gene expression was studied by PCR, confirming that samples were also suitable for gene expression studies. These results suggest that samples obtained from corneal surface ablation procedures may constitute a valuable source of human cells to accomplish in vitro studies.

Diagnostic armamentarium of infectious keratitis: A comprehensive review

Infectious keratitis (IK) represents the leading cause of corneal blindness worldwide, particularly in developing countries. A good outcome of IK is contingent upon timely and accurate diagnosis followed by appropriate interventions. Currently, IK is primarily diagnosed on clinical grounds supplemented by microbiological investigations such as microscopic examination with stains, and culture and sensitivity testing. Although this is the most widely accepted practice adopted in most regions, such an approach is challenged by several factors, including indistinguishable clinical features shared among different causative organisms, polymicrobial infection, long diagnostic turnaround time, and variably low culture positivity rate. In this review, we aim to provide a comprehensive overview of the current diagnostic armamentarium of IK, encompassing conventional microbiological investigations, molecular diagnostics (including polymerase chain reaction and mass spectrometry), and imaging modalities (including anterior segment optical coherence tomography and in vivo confocal microscopy). We also highlight the potential roles of emerging technologies such as next-generation sequencing, artificial intelligence-assisted platforms. and tele-medicine in shaping the future diagnostic landscape of IK.