Development and Characterization of a Photocrosslinkable, Chitosan-Based, Nerve Growth Factor-Eluting Hydrogel for the Ocular Surface.

Purpose: Recombinant human nerve growth factor (rhNGF; cenegermin-bkbj, OXERVATE) is the first and only U.S. Food and Drug Administration-approved treatment for moderate to severe neurotrophic keratopathy. The aim of this study was to determine the feasibility of incorporating a version of rhNGF in a mucoadhesive hydrogel capable of sustained drug release to the ocular surface. Methods: Hydrogels loaded with rhNGF were synthesized by conjugating chitosan with azidobenzoic acid (Az-Ch), adding rhNGF, and exposing the solution to ultraviolet (UV) radiation to induce photocrosslinking. Az-Ch hydrogels were evaluated for physical properties and rhNGF release profiles. Cytocompatbility of Az-Ch was assessed using immortalized human corneal limbal epithelial (HCLE) cells. TF1 erythroleukemic cell proliferation and HCLE cell proliferation and migration were used to assess the bioactivity of rhNGF released from Az-Ch hydrogels. Results: Az-Ch formed hydrogels in <10 seconds of UV exposure and demonstrated high optical transparency (75-85 T%). Az-Ch hydrogels exhibited good cytocompatibility with no demonstratable effect on HCLE cell morphology or viability. rhNGF was released gradually over 24 hours from Az-Ch hydrogels and retained its ability to induce TF1 cell proliferation. No significant difference was observed between rhNGF released from Az-Ch and freshly prepared rhNGF solutions on HCLE cell proliferation or percent wound closure after 12 hours; however, both were significantly better than control (P < 0.01). Conclusions: rhNGF-loaded Az-Ch hydrogels exhibited favorable physical, optical, and drug-release properties, as well as retained drug bioactivity. This drug delivery system has the potential to be further developed for in vivo and translational clinical applications. Translational Relevance: Az-Ch hydrogels may be used to enhance rhNGF therapy in patients with NK.

Acute Corneal Edema in a Middle-Aged Patient.

A middle-aged patient who had bilateral penetrating keratoplasty 20 years ago for keratoconus presented with pain and blurriness of the right eye for 2 days. Despite prompt corticosteroid therapy, they had no vision improvement and reported occasional pain. What would you do next?

Contact lenses as novel tear fluid sampling vehicles for total RNA isolation, precipitation, and amplification.

The tear fluid is a readily accessible, potential source for biomarkers of disease and could be used to monitor the ocular response to contact lens (CL) wear or ophthalmic pathologies treated by therapeutic CLs. However, the tear fluid remains largely unexplored as a biomarker source for RNA-based molecular analyses. Using a rabbit model, this study sought to determine whether RNA could be collected from commercial CLs and whether the duration of CL wear would impact RNA recovery. The results were referenced to standardized strips of filtered paper (e.g., Shirmer Strips) placed in the inferior fornix. By performing total RNA isolation, precipitation, and amplification with commercial kits and RT-PCR methods, CLs were found to have no significant differences in RNA concentration and purity compared to Schirmer Strips. The study also identified genes that could be used to normalize RNA levels between tear samples. Of the potential control genes or housekeeping genes, GAPDH was the most stable. This study, which to our knowledge has never been done before, provides a methodology for the detection of RNA and gene expression changes from tear fluid that could be used to monitor or study eye diseases.

Relaxing descemetotomy: microscope-integrated OCT-guided technique for acute corneal hydrops.

Introduction: 3 cases are used to illustrate the technique of Descemet membrane (DM) relaxing incisions followed by air descemetopexy for the management of patients with acute corneal hydrops. Patients and Clinical Findings: In each case, anterior-segment optical coherence tomography (OCT) demonstrated taut DM detachments and hydrops was refractory to conservative medical management and intracameral air injection. Diagnosis Intervention and Outcomes: To facilitate the reapproximation of DM and potentiate corneal deturgescence, intraoperative OCT-guided descemetotomy was performed with bent surgical scissors and a bent 30-gauge needle. Subsequent air descemetopexy was successful, and DM reattachment was maintained postoperatively. Corneal edema improved in all patients relatively rapidly postoperatively. Conclusions: Relaxing descemetotomy with air descemetopexy may be useful in cases of acute corneal hydrops with taut DM detachments that are unresponsive to air tamponade alone.

Suppression of Neovascularization by Topical and Subconjunctival Bevacizumab After High-Risk Corneal Transplantation.

Purpose: To assess the effectiveness of topical and subconjunctival bevacizumab in suppressing vascularization in graft and host bed after high-risk corneal transplantation. Design: Secondary analysis of prospective, randomized, double-blind, placebo-controlled multicentric clinical trial. Participants: The study includes patients aged > 18 years who underwent high-risk penetrating keratoplasty, which was defined as corneal vascularization in ≥ 1 quadrants of the corneal graft and host bed, excluding the limbus. Methods: Patients were randomized to treatment and control groups. The patients in the treatment group received subconjunctival injection of bevacizumab (2.5 mg/0.1 ml) on the day of the procedure, followed by topical bevacizumab (10 mg/ml) 4 times per day for 4 weeks. The patients in control group received injection of vehicle (0.9% sodium chloride) on the day of procedure, followed by topical vehicle (carboxymethylcellulose sodium 1%) 4 times a day for 4 weeks. Main Outcome Measures: Vessel and invasion area of vessels in the corneal graft and host beds. Results: This study included 56 eyes of 56 patients who underwent high-risk corneal transplantation, with equal numbers in the bevacizumab and vehicle (control) treatment groups. The mean age of patients who received bevacizumab was 61.2 ± 15.9 years, and the mean age of those treated with vehicle was 60.0 ± 16.1 years. The vessel area at baseline was comparable in the bevacizumab (16.72% ± 3.19%) and control groups (15.48% ± 3.12%; P = 0.72). Similarly, the invasion areas were also similar in the treatment (35.60% ± 2.47%) and control (34.23% ± 2.64%; P = 0.9) groups at baseline. The reduction in vessel area was significantly higher in the bevacizumab-treated group (83.7%) over a period of 52 weeks compared with the control group (61.5%; P < 0.0001). In the bevacizumab-treated group, invasion area was reduced by 75.8% as compared with 46.5% in the control group. The vessel area was similar at 52 weeks postprocedure in cases of first (3.54% ± 1.21%) and repeat (3.80% ± 0.40%) corneal transplantation in patients who received bevacizumab treatment. In the vehicle-treated patients, the vessel area was significantly higher in repeat (9.76% ± 0.32%) compared with first (8.06% ± 1.02%; P < 0.0001) penetrating keratoplasty. In the bevacizumab treatment group, invasion areas at week 52 were comparable in first (11.70% ± 3.38%) and repeat (11.64% ± 1.74%) procedures, whereas invasion area was significantly higher in repeat (27.87% ± 2.57%) as compared with first (24.11% ± 2.17%) penetrating keratoplasty in vehicle-treated patients. Conclusions: In patients undergoing vascularized high-risk corneal transplantation, bevacizumab is efficacious in reducing vascularization of corneal graft and host bed, thereby reducing the risk of corneal graft rejection in vascularized host beds. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Long-Term Outcomes of 6-Week Treatment of Lotilaner Ophthalmic Solution, 0.25%, for Demodex Blepharitis: A Noninterventional Extension Study.

PURPOSE: The aim of this study was to evaluate the long-term outcomes of lotilaner ophthalmic solution, 0.25%, in the treatment of Demodex blepharitis. METHODS: This observational, extension study included patients with Demodex blepharitis (N = 239) who completed the Saturn-1 study and presented for the day 180 visit. All participants were assessed at days 180 and 365 after the initiation of 6-week treatment with the study drug or its vehicle. RESULTS: The proportion of patients with 0 to 2 collarettes (grade 0) was significantly higher in the study group (N = 128 patients) than in the control group (N = 111 patients) (39.8% vs. 2.7% at day 180 and 23.5% vs. 2.9% at day 365; P < 0.0001). Similarly, the proportion of patients with ≤10 collarettes (collarette grade 0-1) in the study group was significantly higher than in the control group (70.3% vs. 18.0% at day 180 and 62.6% vs. 21.9% at day 365; P < 0.0001). In the study group, erythema continued to improve even after completion of the 6-week lotilaner treatment. No serious ocular adverse events were observed in the study group, and there was 1 treatment-related ocular adverse event in the study group, which was considered mild. CONCLUSIONS: After 6-week treatment with lotilaner ophthalmic solution, 0.25%, for Demodex blepharitis, no long-term concerns were observed during 1 year of follow-up. A high proportion of patients with 0 to 2 collarettes (grade 0) or ≤10 collarettes (collarette grade of 0 or 1) was observed throughout 1 year of follow-up, indicating that the efficacy of lotilaner ophthalmic solution, 0.25%, against Demodex blepharitis may last well after completion of therapy.

Lotilaner Ophthalmic Solution 0.25% for Demodex Blepharitis: Randomized, Vehicle-Controlled, Multicenter, Phase 3 Trial (Saturn-2).

PURPOSE: To evaluate the safety and efficacy of lotilaner ophthalmic solution 0.25% compared with vehicle for the treatment of Demodex blepharitis. DESIGN: Prospective, randomized, double-masked, vehicle-controlled, multicenter, phase 3 clinical trial. PARTICIPANTS: Four hundred twelve patients with Demodex blepharitis were assigned randomly in a 1:1 ratio to receive either lotilaner ophthalmic solution 0.25% (study group) or vehicle without lotilaner (control group). METHODS: Patients with Demodex blepharitis treated at 21 United States clinical sites were assigned either to the study group (n = 203) to receive lotilaner ophthalmic solution 0.25% or to the control group (n = 209) to receive vehicle without lotilaner bilaterally twice daily for 6 weeks. Collarettes and erythema were graded for each eyelid at screening and at all visits after baseline. At screening and on days 15, 22, and 43, 4 or more eyelashes were epilated from each eye, and the number of Demodex mites present on the lashes was counted with a microscope. Mite density was calculated as the number of mites per lash. MAIN OUTCOME MEASURES: Outcome measures included collarette cure (collarette grade 0), clinically meaningful collarette reduction to 10 collarettes or fewer (grade 0 or 1), mite eradication (0 mites/lash), erythema cure (grade 0), composite cure (grade 0 for collarettes as well as erythema), compliance with the drop regimen, drop comfort, and adverse events. RESULTS: At day 43, the study group achieved a statistically significant (P < 0.0001) higher proportion of patients with collarette cure (56.0% vs. 12.5%), clinically meaningful collarette reduction to 10 collarettes or fewer (89.1% vs. 33.0%), mite eradication (51.8% vs. 14.6%), erythema cure (31.1% vs. 9.0%), and composite cure (19.2% vs. 4.0%) than the control group. High compliance with the drop regimen (mean ± standard deviation, 98.7 ± 5.3%) in the study group was observed, and 90.7% of patients found the drops to be neutral to very comfortable. CONCLUSIONS: Twice-daily treatment with lotilaner ophthalmic solution 0.25% for 6 weeks generally was safe and well tolerated and met the primary end point and all secondary end points for the treatment of Demodex blepharitis compared with vehicle control. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Recurrent keratoconus: an analysis of breaks in Bowman's layer in corneal grafts.

OBJECTIVE: To study in a masked fashion whether an objective histological feature associated with keratoconus (KCN) occurs in donor corneas in eyes originally receiving a corneal graft for KCN. METHODS: Two ocular pathologists performed a retrospective masked histological analysis of slides from donor buttons recovered from 21 eyes with a history of KCN undergoing repeat penetrating keratoplasty (failed-PK-KCN), 11 eyes that underwent their first PK due to KCN (primary KCN), and 11 eyes without history of KCN which underwent PK for other conditions (failed-PK-non-KCN). Breaks/gaps in Bowman's layer served as the pathological feature indicative of recurrent KCN. RESULTS: Breaks in Bowman's layer were present in 18/21 (86%) of the failed-PK-KCN group, 10/11 (91%) of the primary KCN group, and in 3/11 (27%) of the failed-PK-non-KCN group. Pathological evidence suggests that the prevalence of breaks is significantly higher in grafted patients with a history of KCN than non-KCN controls (OR: 16.0, 95% CI 2.63 to 97.2, Fisher's exact test p=0.0018) with a conservative Bonferroni criterion of p <0.017 to account for multiple group comparisons. There was no statistically significant difference found between the failed-PK-KCN and primary KCN groups. CONCLUSIONS: This study provides histological evidence that breaks and gaps in Bowman's layer, consistent with those found in primary KCN, may develop within the donor tissue in eyes with a history of KCN.

Efficacy and Safety of a Water-Free Topical Cyclosporine, 0.1%, Solution for the Treatment of Moderate to Severe Dry Eye Disease: The ESSENCE-2 Randomized Clinical Trial.

Importance: Dry eye disease (DED) is a common public health problem with significant impact on vision-related quality of life and well-being of patients. Medications with rapid onset of action and a good tolerability profile remain an unmet need. Objective: To assess efficacy, safety, and tolerability of a water-free cyclosporine ophthalmic solution, 0.1% (CyclASol [Novaliq GmbH]), applied twice daily in DED compared with vehicle. Design, Setting, and Participants: CyclASol for the Treatment of Signs and Symptoms of Dry Eye Disease (ESSENCE-2) was a phase 3, multicenter, randomized, double-masked, vehicle-controlled clinical study conducted from December 5, 2020, to October 8, 2021. Following a 14-day run-in period with an artificial tear administered 2 times per day, eligible participants were randomly assigned 1:1 to the treatment groups. Patients with moderate to severe DED were included in the study. Interventions: Cyclosporine solution vs vehicle administered 2 times per day for 29 days. Main Outcomes and Measures: The primary end points were changes from baseline in total corneal fluorescein staining (tCFS; 0-15 National Eye Institute scale) and in dryness score (0-100 visual analog scale) at day 29. Conjunctival staining, central corneal fluorescein staining, and tCFS responders were also assessed. Results: A total of 834 study participants were randomly assigned to cyclosporine (423 [50.7%]) or vehicle (411 [49.3%]) groups at 27 sites. Participants had a mean (SD) age of 57.1 (15.8) years, and 609 (73.0%) were female individuals. The majority of participants self-identified in the following race categories: 79 Asian (9.5 %), 108 Black (12.9%), and 635 White (76.1%). Participants treated with cyclosporine solution had greater improvement in tCFS (-4.0 grades) than the vehicle group (-3.6 grades) at day 29 (change [∆] = -0.4; 95% CI, -0.8 to 0; P = .03). The dryness score showed treatment benefits from baseline in both groups: -12.2 points for cyclosporine and -13.6 points for vehicle (∆ = 1.4; 95% CI, -1.8 to 4.6; P = .38). In the cyclosporine group, 293 participants (71.6%) achieved clinically meaningful reductions of 3 grades or higher in tCFS vs 236 (59.7%) in the vehicle group (∆ = 12.6%; 95% CI, 6.0%-19.3%; P < .001). These responders showed greater improvement in symptoms at day 29 including dryness (∆ = -4.6; 95% CI, -8.0 to -1.2; P = .007) and blurred vision (Δ = -3.5; 95% CI, -6.6 to -4.0; P = .03) compared with nonresponders. Conclusions and Relevance: The ESSENCE-2 trial confirmed that treatment with a water-free cyclosporine solution, 0.1%, results in early therapeutic effects on the ocular surface compared with vehicle. The responder analyses suggest that the effect is clinically meaningful in 71.6% of participants in the cyclosporine group. Trial Registration: ClinicalTrials.gov Identifier: NCT04523129.

Recurrent Keratoconus: Corneal Transplants for Keratoconus Develop Tomographic Ectatic Changes.

PURPOSE: The purpose of this study was to evaluate postoperative Scheimpflug imaging changes during the first 5 years after penetrating keratoplasty (PK) in patients with keratoconus (KC). METHODS: This retrospective, interventional case series includes 31 eyes of 31 patients who underwent their first PK with a history of KC. Postoperative Scheimpflug imaging was performed 3 months after the removal of the last suture (baseline) and then repeated 3 and 5 years after the PK. Demographic data, donor and host trephination diameter, and Scheimpflug imaging (Pentacam HR, Oculus, Germany) parameters indicative of ectasia were analyzed to evaluate postoperative graft changes that occur after PK. RESULTS: The maximal keratometry (Kmax) progressed significantly between baseline (53.5 ± 6.1 D) and postoperative year 3 and year 5 [56.5 ± 6.1 diopter (D) and 58.8 ± 7.9 D, P < 0.001]. Significant changes were also observed for the anterior best fit sphere and posterior best fit sphere ( P < 0.001 for 3 and 5 years compared with baseline). Kmax increased by at least 2 Ds for 74.2% of patients and up to 7 Ds or more for 25.8% of the patients. A significant inverse correlation was observed for host trephine size and progression of Kmax (r = -0.52, P = 0.01), which indicated that larger host trephination size was associated with a smaller increase in postoperative Kmax. CONCLUSIONS: Tomographic graft changes indicative of ectasia were observed within 3 to 5 years after PK in patients with KC. These changes were observed more frequently and sooner after corneal transplants than previously reported.

2021 Survey of Keratoplasty Postoperative Steroid Management.

PURPOSE: The aim of the study is to investigate US-based ophthalmologists' preferred corneal transplant techniques and postoperative steroid regimen. METHODS: Ophthalmologists attending the 2021 Cornea and Eye Banking Forum and/or Cornea Subspecialty Day were surveyed in person. RESULTS: Ninety-two ophthalmologists with a median of 13 years (range of 1-35; mean of 14.5; ±9.05 mean ± SD) of experience as attending clinicians were surveyed. One hundred percent of the surgeons performed penetrating keratoplasty, which was followed by 96.7% for Descemet stripping endothelial keratoplasty, 90.2% for Descemet membrane endothelial keratoplasty, and 72.8% for deep anterior lamellar keratoplasty. Prednisolone 1% for postoperative care was the preferred choice across all surveyed keratoplasty techniques and postsurgery time intervals. All surgeons reported steroid administration frequency of 4 times a day in the first month and once a day after 12 months postkeratoplasty. To manage ocular hypertension after corneal transplantation, the leading approach was adding a glaucoma medication (44.6%), and beta-adrenergic antagonists were ranked as the most preferred choice by 59 (66.3%) of the respondents. For graft rejection after corneal transplantation, topical steroids (79.8%) were the initial treatment of choice with hourly administration being the most common frequency prescribed (87.4%). Most surgeons either agreed or strongly agreed (78.4%) that a randomized clinical trial evaluating the safety and efficacy of different steroid regimens after corneal transplantation would influence their clinical decision making. CONCLUSIONS: Prednisolone remains the predominantly used steroid across different keratoplasties. Steroid regimens are similar for non-high-risk penetrating keratoplasty, Descemet membrane endothelial keratoplasty, Descemet stripping endothelial keratoplasty, and deep anterior lamellar keratoplasty. To treat graft rejection, surgeons tend to initially add a glaucoma medication than to reduce the potency or frequency of the steroid.

Prospective, Randomized, Multicenter, Double-Masked, Clinical Trial of Corneal Cross-Linking for Boston Keratoprosthesis Carrier Tissue.

PURPOSE: To assess whether cross-linking the carrier donor cornea of the Boston Keratoprosthesis (BKPro) improves retention of the device in participants at high risk for keratolysis. DESIGN: Prospective, double-masked, randomized clinical trial. METHODS: In this multicenter study, 68 adult participants who were scheduled for BKPro implantation were enrolled. Masked participants were randomized to receive either a cross-linked (CXL) or non-cross-linked (non-CXL) donor corneal carrier. The Kaplan-Meier event-free survival was determined by the product-limit method and compared by the log-rank test to examine whether survival curves were different between the CXL and non-CXL groups. The primary outcome of the study was time from surgery to BKPro removal. The secondary endpoint was 12-month retention rate. RESULTS: A total of 68 participants were enrolled and randomized 1:1 to each group. The average age at the time of surgery was 62 (range = 24-89) years, and 42 participants (62%) were male. The overall BKPro retention rate was 70% during a mean follow-up time of 93 (range = 6-201) weeks. Twenty BKPros were removed, 10 in the CXL group and 10 in the non-CXL group, with 18 requiring removal because of sterile keratolysis. There was no difference in the time to removal between the groups during the study (P = .910). At 12 months, there was no significant difference in the retention rate in the CXL group (94%) vs the non-CXL group (82%, P = .150). CONCLUSIONS: In this prospective study, cross-linking of the carrier cornea prior to BKPro implantation did not reduce the incidence of sterile keratolysis or increase device retention among participants at high risk for retention failure.

Incidence and risk factors for glaucoma development and progression after corneal transplantation.

OBJECTIVE: To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery. DESIGN: Retrospective cohort study. METHODS: Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed. RESULTS: Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all). CONCLUSIONS: A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

Topical Sustained Delivery of Miltefosine Via Drug-Eluting Contact Lenses to Treat Acanthamoeba Keratitis.

This study aimed to develop a miltefosine-eluting contact lens (MLF-CL) device that would allow sustained and localized miltefosine release for the treatment of Acanthamoeba keratitis. MLF-CLs were produced in three different miltefosine doses by solvent-casting a thin miltefosine-polymer film around the periphery of a methafilcon hydrogel, which was then lathed into a contact lens. During seven days of in vitro testing, all three formulations demonstrated sustained release from the lens at theoretically therapeutic levels. Based on the physicochemical characterization of MLF-CLs, MLF-CL's physical properties are not significantly different from commercial contact lenses in terms of light transmittance, water content and wettability. MLF-CLs possessed a slight reduction in compression modulus that was attributed to the inclusion of polymer-drug films but still remain within the optimal range of soft contact lenses. In cytotoxicity studies, MLF-CL indicated up to 91% viability, which decreased proportionally as miltefosine loading increased. A three-day biocompatibility test on New Zealand White rabbits revealed no impact of MLF-CLs on the corneal tissue. The MLF-CLs provided sustained in vitro release of miltefosine for a week while maintaining comparable physical features to a commercial contact lens. MLF-CL has a promising potential to be used as a successful treatment method for Acanthamoeba keratitis.

Doxorubicin-Loaded Extracellular Vesicles Enhance Tumor Cell Death in Retinoblastoma.

Chemotherapy is often used to treat retinoblastoma; however, this treatment method has severe systemic adverse effects and inadequate therapeutic effectiveness. Extracellular vesicles (EVs) are important biological information carriers that mediate local and systemic cell-to-cell communication under healthy and pathological settings. These endogenous vesicles have been identified as important drug delivery vehicles for a variety of therapeutic payloads, including doxorubicin (Dox), with significant benefits over traditional techniques. In this work, EVs were employed as natural drug delivery nanoparticles to load Dox for targeted delivery to retinoblastoma human cell lines (Y-79). Two sub-types of EVs were produced from distinct breast cancer cell lines (4T1 and SKBR3) that express a marker that selectively interacts with retinoblastoma cells and were loaded with Dox, utilizing the cells' endogenous loading machinery. In vitro, we observed that delivering Dox with both EVs increased cytotoxicity while dramatically lowering the dosage of the drug. Dox-loaded EVs, on the other hand, inhibited cancer cell growth by activating caspase-3/7. Direct interaction of EV membrane moieties with retinoblastoma cell surface receptors resulted in an effective drug delivery to cancer cells. Our findings emphasize the intriguing potential of EVs as optimum methods for delivering Dox to retinoblastoma.

Advances in biomaterials for the treatment of retinoblastoma.

Retinoblastoma is the most common primary intraocular malignancy in children. Although traditional chemotherapy has shown some success in retinoblastoma management, there are several shortcomings to this approach, including inadequate pharmacokinetic parameters, multidrug resistance, low therapeutic efficiency, nonspecific targeting, and the need for adjuvant therapy, among others. The revolutionary developments in biomaterials for drug delivery have enabled breakthroughs in cancer management. Today, biomaterials are playing a crucial role in developing more efficacious retinoblastoma treatments. The key goal in the evolution of drug delivery biomaterials for retinoblastoma therapy is to resolve delivery-associated obstacles and lower nonlocal exposure while ameliorating certain adverse effects. In this review, we will first delve into the historical perspective of retinoblastoma with a focus on the classical treatments currently used in clinics to enhance patients' quality of life and survival rate. As we move along, we will discuss biomaterials for drug delivery applications. Various aspects of biomaterials for drug delivery will be dissected, including their features and recent advances. In accordance with the current advances in biomaterials, we will deliver a synopsis on the novel chemotherapeutic drug delivery strategies and evaluate these approaches to gain new insights into retinoblastoma treatment.

Extracellular Vesicles in Corneal Fibrosis/Scarring.

Communication between cells and the microenvironment is a complex, yet crucial, element in the development and progression of varied physiological and pathological processes. Accumulating evidence in different disease models highlights roles of extracellular vesicles (EVs), either in modulating cell signaling paracrine mechanism(s) or harnessing their therapeutic moiety. Of interest, the human cornea functions as a refractive and transparent barrier that protects the intraocular elements from the external environment. Corneal trauma at the ocular surface may lead to diminished corneal clarity and detrimental effects on visual acuity. The aberrant activation of corneal stromal cells, which leads to myofibroblast differentiation and a disorganized extracellular matrix is a central biological process that may result in corneal fibrosis/scarring. In recent years, understanding the pathological and therapeutic EV mechanism(s) of action in the context of corneal biology has been a topic of increasing interest. In this review, we describe the clinical relevance of corneal fibrosis/scarring and how corneal stromal cells contribute to wound repair and their generation of the stromal haze. Furthermore, we will delve into EV characterization, their subtypes, and the pathological and therapeutic roles they play in corneal scarring/fibrosis.

Extracellular Vesicles Secreted by Corneal Myofibroblasts Promote Corneal Epithelial Cell Migration.

Corneal epithelial wound healing is a multifaceted process that encompasses cell proliferation, migration, and communication from the corneal stroma. Upon corneal injury, bidirectional crosstalk between the epithelium and stroma via extracellular vesicles (EVs) has been reported. However, the mechanisms by which the EVs from human corneal keratocytes (HCKs), fibroblasts (HCFs), and/or myofibroblasts (HCMs) exert their effects on the corneal epithelium remain unclear. In this study, HCK-, HCF-, and HCM-EVs were isolated and characterized, and human corneal epithelial (HCE) cell migration was assessed in a scratch assay following PKH26-labeled HCK-, HCF-, or HCM-EV treatment. HCE cells proliferative and apoptotic activity following EV treatment was assessed. HCF-/HCM-EVs were enriched for CD63, CD81, ITGAV, and THBS1 compared to HCK-EV. All EVs were negative for GM130 and showed minimal differences in biophysical properties. At the proteomic level, we showed HCM-EV with a log >two-fold change in CXCL6, CXCL12, MMP1, and MMP2 expression compared to HCK-/HCF-EVs; these proteins are associated with cellular movement pathways. Upon HCM-EV treatment, HCE cell migration, velocity, and proliferation were significantly increased compared to HCK-/HCF-EVs. This study concludes that the HCM-EV protein cargo influences HCE cell migration and proliferation, and understanding these elements may provide a novel therapeutic avenue for corneal wound healing.

Bevacizumab in High-Risk Corneal Transplantation: A Pilot Multicenter Prospective Randomized Control Trial.

PURPOSE: To determine the efficacy of local (subconjunctival and topical) bevacizumab (Avastin) treatment in patients undergoing vascularized high-risk corneal transplantation. DESIGN: Pilot, prospective, randomized, double-blind, placebo-controlled clinical trial conducted at 5 clinical centers in the United States, India, and Brazil. PARTICIPANTS: Patients aged > 18 years undergoing high-risk penetrating keratoplasty, defined as corneal neovascularization (NV) in 1 or more quadrants ≥2 mm from the limbus or extension of corneal NV to the graft-host junction in a previously failed graft. METHODS: Patients were randomized to receive subconjunctival bevacizumab (2.5 mg/0.1 ml) or placebo at the time of surgery, followed by topical bevacizumab (10 mg/ml) or topical placebo, administered 4 times per day for 4 weeks. MAIN OUTCOME MEASURE: The 52-week endothelial immune rejection rate. RESULTS: Ninety-two patients were randomized to receive bevacizumab (n = 48) or control (n = 44). The 52-week endothelial rejection rate was 10% in the bevacizumab group and 19% in the control group (P = 0.20). Post hoc, extended follow-up at the lead study site showed an endothelial rejection rate of 3% in the bevacizumab group and 38% in the control group (P = 0.003). Treatment with bevacizumab was found to have a hazard ratio of 0.15 (95% confidence interval, 0.03-0.65, P = 0.01) in a post hoc Cox regression analysis. CONCLUSIONS: In patients undergoing vascularized high-risk corneal transplantation, there was no statistically significant difference in the rate of endothelial rejection at 1 year in the bevacizumab treatment group compared with the control group. This study may have been underpowered to detect a difference between treatment groups, and taken together, our data suggest that, in the current trial design, bevacizumab has a positive but not (yet) significant effect on endothelial rejection.