Autologous serum eye drops for ocular surface disorders

Experimental interventions attenuate a conjunctival epidermal metaplasia model

The conjunctiva is a non-keratinized, stratified columnar epithelium with characteristics different from the cornea and eyelid epidermis. From development to adulthood, a distinguishing feature of ocular versus epidermal epithelia is the expression of the master regulator PAX6. A conditionally immortalized conjunctival epithelial cell line (iHCjEC) devoid of stromal or immune cells established in our laboratory spontaneously manifested epidermal metaplasia and upregulated expression of the keratinization-related genes SPRR1A/B and the epidermal cytokeratins KRT1 and KRT10 at the expense of the conjunctival trait. In addition, iHCjEC indicated a significant decrease in PAX6 expression. Dry eye syndrome (DES) and severe ocular surface diseases, such as Sjögren's syndrome and Stevens-Johnson syndrome, cause the keratinization of the entire ocular surface epithelia. We used iHCjECs as a conjunctiva epidermal metaplasia model to test PAX6, serum, and glucocorticoid interventions. Reintroducing PAX6 to iHCjECs resulted in upregulating genes related to cell adhesion and tight junctions, including MIR200CHG and CLDN1. The administration of glucocorticoids or serum resulted in the downregulation of epidermal genes (DSG1, SPRR1A/B, and KRT1) and partially corrected epidermal metaplasia. Our results using an isolated conjunctival epidermal metaplasia model point toward the possibility of rationally "repurposing" clinical interventions, such as glucocorticoid, serum, or PAX6 administration, for treating epidermal metaplasia of the conjunctiva.

Novel treatments for dry eye syndrome

Dry eye syndrome (DES) is a prevalent and multifactorial disease that leads to a self-perpetuating cycle of inflammation and damage to the ocular surface. This results in symptoms such as redness, burning, and blurred vision, which can negatively affect a patient's quality of life. While treatments are available to manage DES, they only temporarily relieve symptoms. Furthermore, long-term use of certain medications can cause harm to the ocular surface. Therefore, there is a need for safer and effective treatments for DES. This review highlights the latest advancements in DES therapy, providing valuable insights into ongoing efforts to improve patient outcomes.

Effects of Autologous Serum and Platelet-Rich Plasma on Human Corneal Endothelial Cell Regeneration: A Comparative Study

OBJECTIVES

To investigate the effects of autologous serum (AS) and platelet-rich plasma (PRP) on human corneal endothelial cell (HCEC) proliferation and apoptosis in comparison to Y-27632 as the commonly studied Rho-associated kinase (ROCK) inhibitor.

METHODS

The human corneal endothelial primary cell line was used for this study. As the treatment groups, HCECs were incubated with AS, PRP, and Y-27632, whereas the control group received no treatment. Cell proliferation (measured by 5-bromo-2'-deoxyuridine [BrdU] incorporation) and apoptosis (based on the caspase-3 level) were compared between the control, Y-27632, AS, and PRP groups.

RESULTS

In the Y-27632, AS, and PRP groups, the ratios of BrdU-incorporated cells were significantly higher (115±0.2%, 125±0.2%, 122±0.4% at 24 hr, and 138±2.4%, 160±0.2%, 142±0.2% at 48 hr, respectively) than in the control group (100±18.4% at 24 hr, 100±1.1% at 48 hr) ( P <0.05 for all). Furthermore, AS provided a higher HCEC proliferation ratio compared with the Y-27632 group at 24 and 48 hr ( P <0.05 for all). Caspase-3 was significantly lower in the AS group (60.3±3.3%) than in the control (100±2.3%), Y-27632 (101.9±5.2%), and PRP (101±6.8%) groups ( P <0.05 for all).

CONCLUSIONS

The results of this study demonstrated for the first time that AS and PRP promoted HCEC proliferation and AS significantly decreased apoptosis in HCECs. A superior effect on HCEC proliferation was also observed with AS compared with Y-27632. Future "autologous" regenerative therapeutic options for corneal endothelial failure may involve the utilization of AS and PRP owing to their accessibility, simplicity in preparation, immunologic compatibility, and donor-free nature.

Multi-Frequency RF Combined with Intense Pulsed Light Improves Signs and Symptoms of Dry Eye Disease Due to Meibomian Gland Dysfunction

Purpose

To evaluate the efficacy of multi-frequency RF and IPL + MGX combination for treatment of Meibomian Gland Dysfunction (MGD).

Patients and Methods

Eligible subjects had signs and moderate-to-severe symptoms of DED (Dry Eye Disease) due to MGD. Subjects underwent 4 treatments at 2-week intervals. Each treatment consisted of intense pulsed light (IPL) followed by radiofrequency (RF) on the periocular skin, followed by meibomian gland expression (MGX). The main outcome measure was the quality of meibum in 15 meibomian glands along the lower eyelid, using the modified Meibomian Gland Score (mMGS). The main hypothesis was a reduction of mMGS between the baseline (BL) and the follow-up (FU). Other outcome measures, such as symptoms measured with the OSDI (Ocular Surface Disease Index) questionnaire, meibography, non-invasive tear break-up time (NIBUT), and matrix metallopeptidase 9 (MMP-9) levels in tear samples were evaluated as well.

Results

31 subjects completed the FU. Between BL and FU, mMGS decreased from 30.4 (8.5) to 9.3 (9.5) (-69.3%, 95% CI: -55.6% to -82.9%, p<0.0001); OSDI decreased from 63.6 (17.2) to 25.0 (20.6) (-60.7%, 95% CI: -47.8% to -73.5%, p<0.0001); NIBUT did not change (p=0.92). An adjusted model with a historical control was constructed to allow the comparison of these subjects with those treated similarly with IPL+MGX (but without RF) in a different study. This analysis identified that the change in mMGS was larger when RF was included (-20.9 vs -18.3, adjusted p-value (p_adjusted) <0.05). The difference in OSDI change was not significant (-38.1 vs -25.5, p_adjusted = 0.196).

Conclusion

Combination of multi-frequency RF and IPL+MGX improves signs and symptoms of MGD. In comparison to a historical control, improvements were generally larger. A randomized controlled study comparing the combination of RF and IPL+MGX with IPL+MGX alone is required to further elaborate the relative contribution of RF.

Corneal neuroepithelial compartmentalized microfluidic chip model for evaluation of toxicity-induced dry eye

Part of the lacrimal functional unit, the cornea protects the ocular surface from numerous environmental aggressions and xenobiotics. Toxicological evaluation of compounds remains a challenge due to complex interactions between corneal nerve endings and epithelial cells. To this day, models do not integrate the physiological specificity of corneal nerve endings and are insufficient for the detection of low toxic effects essential to anticipate Toxicity-Induced Dry Eye (TIDE). Using high-content imaging tool, we here characterize toxicity-induced cellular alterations using primary cultures of mouse trigeminal sensory neurons and corneal epithelial cells in a compartmentalized microfluidic chip. We validate this model through the analysis of benzalkonium chloride (BAC) toxicity, a well-known preservative in eyedrops, after a single (6h) or repeated (twice a day for 15 min over 5 days) topical 5.10-4% BAC applications on the corneal epithelial cells and nerve terminals. In combination with high-content image analysis, this advanced microfluidic protocol reveal specific and tiny changes in the epithelial cells and axonal network as well as in trigeminal cells, not directly exposed to BAC, with ATF3/6 stress markers and phospho-p44/42 cell activation marker. Altogether, this corneal neuroepithelial chip enables the evaluation of toxic effects of ocular xenobiotics, distinguishing the impact on corneal sensory innervation and epithelial cells. The combination of compartmentalized co-culture/high-content imaging/multiparameter analysis opens the way for the systematic analysis of toxicants but also neuroprotective compounds.

Patient-reported outcomes of serum eye drops manufactured from Australian blood donations and packaged using Meise vials

Introduction

Serum eye drops (SED) are an effective treatment for dry eye syndrome. However, autologous serum collection can have challenges. Patient-tailored (allogeneic) SED (PT-SED) can be made from healthy blood donors. Australian Red Cross Lifeblood has manufactured both autologous SED (Auto-SED) and PT-SED and, in May 2021, introduced Meise vial packaging. This study aimed to explore SED patient-reported outcomes and vial packaging satisfaction.

Methods

A prospective cohort study was conducted with recruitment between 1 November 2021 and 30 June 2022. Participants completed the dry eye questionnaire (DEQ5), health-related quality-of-life (SF-8™), functional assessment of chronic illness therapy-treatment satisfaction-general (FACIT-TS-G), and general wellbeing surveys. Existing patients completed these once, and new patients were surveyed at baseline, 3 months post-treatment, and 6 months post-treatment.

Results

Participants who completed all study requirements were 24 existing and 40 new Auto-SED and 10 existing and 8 new PT-SED patients. Auto-SED patients were younger [56.2 (±14.7) years] than PT-SED patients [71.4 (±10.0) years]. Participants used a mean of 1.8 (±1.1) SED, 5.3 (±2.9) times per day. In new patients, DEQ5 scores improved within 6 months from 14.0 (±2.9) to 10.6 (±3.4) for Auto-SED and from 12.9 (±3.7) to 11.4 (±2.8) for PT-SED. General wellbeing measures improved in the new Auto-SED from 7.0 (±1.9) to 7.8 (±1.7) but were reduced for new PT-SED from 6.7 (±2.9) to 6.1 (±2.9).

Discussion

SED improved dry eye symptoms in most patients, regardless of the serum source. Patients using PT-SED showed decreases in some quality-of-life measures; however, recruitment was reduced due to operational constraints, and concurrent comorbidities were not assessed. General feedback for SED and vial packaging was positive, with some improvements identified.

A Biomimetic Peptide-drug Supramolecular Hydrogel as Eyedrops Enables Controlled Release of Ophthalmic Drugs

The rapid clearance of instilled drugs from the ocular surface due to tear flushing and excretion results in low drug bioavailability, necessitating the development of new drug delivery routes. Here, we generated an antibiotic hydrogel eye drop that can extend the pre-corneal retention of a drug after topical instillation to address the risk of side effects (e.g., irritation and inhibition of enzymes), resulting from frequent and high-dosage administrations of antibiotics used to obtain the desired therapeutic drug concentration. The covalent conjugation of small peptides to antibiotics (e.g., chloramphenicol) first endows the self-assembly ability of peptide-drug conjugate to generate supramolecular hydrogels. Moreover, the further addition of calcium ions, which are also widely present in endogenous tears, tunes the elasticity of supramolecular hydrogels, making them ideal for ocular drug delivery. The in vitro assay revealed that the supramolecular hydrogels exhibited potent inhibitory activities against both gram-negative (e.g., Escherichia coli) and gram-positive (e.g., Staphylococcus aureus) bacteria, whereas they were innocuous toward human corneal epithelial cells. Moreover, the in vivo experiment showed that the supramolecular hydrogels remarkably increased pre-corneal retention without ocular irritation, thereby showing appreciable therapeutic efficacy for treating bacterial keratitis. This work, as a biomimetic design of antibiotic eye drops in the ocular microenvironment, addresses the current issues of ocular drug delivery in the clinic and further provides approaches to improve the bioavailability of drugs, which may eventually open new directions to resolve the difficulty of ocular drug delivery. STATEMENT OF SIGNIFICANCE: Herein, we present a biomimetic design for antibiotic hydrogel eye drops mediated by calcium ions (Ca²⁺) in the ocular microenvironment, which can extend the pre-corneal retention of antibiotics after topical instillation. The mediation of Ca²⁺ which is widely present in endogenous tears, tunes the elasticity of hydrogels, making them ideal for ocular drug delivery. Since increasing the ocular retention of antibiotic eye drops enhances its action and reduces its adverse effects, this work may lead to an approach of peptide-drug-based supramolecular hydrogel for ocular drug delivery in clinics to combat ocular bacterial infections.

Highly stable fibronectin-mimetic-peptide-based supramolecular hydrogel to accelerate corneal wound healing

Without timely treatment, poor wound healing in corneal injuries can seriously impair vision and lead to blindness. Thus, it is vital to develop a therapeutic strategy to accelerate corneal re-epithelialization. The conjugation of self-assembled motifs with a fibronectin-mimetic peptide sequence (PHSRN) drastically improves the chemical stability of PHSRN against protease hydrolysis and minimally affects its biological activity to promote the migration of corneal epithelial cells. The optimized Nap-FFPHSRN self-assembled into bioactive supramolecular hydrogels increases cell motility by remolding F-actin and boosts the tight junction of the corneal epithelium by increasing the expression of zonula occludens-1 (ZO-1). An in vivo experiment showed that a Nap-FFPHSRN hydrogel provided extended precorneal retention with good ocular tolerance after topical instillation. An animal model of corneal scrape showed that a single daily dose of Nap-FFPHSRN hydrogel had a superior therapeutic effect in facilitating corneal re-epithelialization with complete morphological and architectural recovery. With a rational approach to mimic bioactive proteins, this study presents a new strategy to demonstrate the potential of peptide-based supramolecular hydrogels for use in clinical treatment of corneal injury. STATEMENT OF SIGNIFICANCE: Here we systematically investigate the self-assembly behavior and chemical stability of designed peptide amphiphiles (Nap-FPHRSN, Nap-FFPHSRN and Nap-FFFPHSRN). The introduction of self-assembled motifs (Nap-F, Nap-FF and Nap-FFF) drastically enhances the chemical stability of fibronectin-mimetic peptide (PHSRN). Moreover, topical instillation of Nap-FFPHSRN hydrogel once daily, exhibits a better in vivo effect than PHSRN and the same in vivo effect as fibronectin, both of which are instilled three times daily, for promoting full morphological and architectural recovery after corneal re-epithelialization. As a rational design of conjugating bioactive peptides with self-assembled motifs to mimic bioactive proteins, this work may lead to a new approach that improves the in vivo therapeutic effect for treating corneal injury in clinic settings.

Development of a new plasma rich in growth factors membrane with improved optical properties

PURPOSE

The aim of the present work was to develop a fibrin membrane using plasma rich in growth factors (PRGF) technology with improved optical properties to be used for the treatment of ocular surface diseases.

BASIC PROCEDURES

Blood was drawn from three healthy donors, and the volume of PRGF obtained from each donor was divided into two main groups: i) PRGF or ii) platelet-poor plasma (PPP). Each membrane was then used pure or diluted to 90 %, 80 %, 70 %, 60 % and 50 %. The transparency of each of the different membranes was evaluated. The degradation and morphological characterization of each membrane was also performed. Finally, a stability study of the different fibrin membranes was performed.

MAIN FINDINGS

The transmittance test showed that the fibrin membrane with the best optical characteristics was obtained after removal of platelets and dilution of fibrin to 50 % (50 % PPP). No significant differences (p > 0.05) were observed between the different membranes in the fibrin degradation test. The stability test showed that the membrane at 50 % PPP retains its optical and physical characteristics after storage at - 20 °C for 1 month compared to storage at 4 °C.

PRINCIPAL CONCLUSIONS

The present study describes the development and characterization of a new fibrin membrane with improved optical characteristics while maintaining mechanical and biological characteristics. The physical and mechanical properties of the newly developed membrane are preserved after storage for at least 1 month at - 20 °C.

Beneficial Effects of Plasma Rich in Growth Factors (PRGF) Versus Autologous Serum and Topical Insulin in Ocular Surface Cells

PURPOSE

In the last few decades, several blood derived products such as platelet-rich plasma (PRP), plasma rich in growth factors (PRGF) and autologous serum (AS) have been used for the treatment of ocular surface disorders. Recently, insulin has been proposed to be used as an alternative for the treatment of ocular surface diseases. The aim of this study was to evaluate the biological potential of PRGF eye drops in comparison with AS and insulin on ocular surface cells.

METHODS

Blood from three healthy young donors was collected to obtain autologous serum (AS) eye drops and plasma rich in growth factors (PRGF) eye drops. Insulin (Actrapid^®) was diluted at 1 and 0.2 IU/mL. The biological potential of PRGF, AS and insulin was assessed by proliferation in HCE, HK and HConF cells. Wound healing assay was performed in HCE cells after incubation with the different treatments. HConF and HK cells were differentiated to myofibroblast after treatment with 2.5 ng/mL of TGF-β1 and then incubated with all treatments.

RESULTS

PRGF eye drops induced significantly higher proliferation rate compared to AS or insulin in HConF and HK cells, but not in HCE cells. In addition, the percentage of wound healing area was significantly reduced after PRGF treatment in comparison with AS or insulin treatment. Furthermore, PRGF significantly reduced the number of myodifferentiated cells compared to AS and insulin at both concentrations analyzed.

CONCLUSION

The results obtained in the present study show that PRGF increases the biological activity of the ocular surface cells and reduces the expression of fibrosis marker compared to insulin or AS.

TRANSLATIONAL RELEVANCE

The present study suggests that plasma rich in growth factors eye drops are a more effective therapy than insulin and autologous serum eye drops for the treatment of ocular surface diseases.

Immune-related keratitis is a rare complication associated with nivolumab treatment in a patient with advanced colorectal cancer: A case report

Background

Immunotherapy has been widely used to treat Colorectal cancer but has also observe some immune-related adverse effects. With proper treatment, most irAE can be solved and the effect of immunotherapy will not be affected by temporary immunosuppression. However, there are few reports about corneal irAE, and the current understanding of irAE is incomplete. Here we report a metastatic colorectal cancer case of immune-related keratitis caused by nivolumab and to explore the occurrence of immune-related keratitis.

Case description

Here we report the case of a 49-year-old man with mCRC who had no previous ocular disease but developed immune-related ulcerative keratitis after treatment with nivolumab. We summarize a large amount of literature to discuss the mechanism of immune-related keratitis. In addition, we conclude a method that may be used to detect the occurrence of immune keratitis, by monitoring MMPs and maspin in patients treated with nivolumab. We believe immune-related keratitis may be a rare complication of nivolumab in the treatment of mCRC. The effect of simple anti-infective therapy and repair-promoting drugs was not obvious, but the effect of glucocorticoid combined with autologous serum was significant.

Conclusion

The mechanism of immune-related keratitis is that nivolumab destroys the immune microenvironment and ACAID, and affects corneal healing. Patients who use nivolumab can prevent immune keratitis by testing MMPs and maspin. The occurrence of immune keratitis may be a good indicator of the efficacy of ICI, and further study can be done in the follow-up.

Intense pulsed light improves signs and symptoms of dry eye disease due to meibomian gland dysfunction: A randomized controlled study

Purpose

To compare the safety and efficacy of intense pulsed light (IPL) followed by meibomian gland expression (MGX), against monotherapy of MGX.

Methods

Patients with moderate to severe meibomian gland dysfunction (MGD) were 1:1 randomized to 4 sessions of intense pulse light + MGX at 2-week intervals, or 4 sessions of Sham + MGX at 2-week intervals. Both patients and examiners were blinded to the allocation. Outcome measures, evaluated at the baseline (BL) and at a follow-up (FU) conducted 4 weeks after the last IPL session, included fluorescein tear breakup time (TBUT) as the primary outcome measure, OSDI (Ocular Surface Disease Index) questionnaire, Eye Dryness Score (EDS, a visual analog scale (VAS)-based questionnaire), Meibomian gland score (MGS, a score of meibum expressibility and quality in 15 glands on the lower eyelid), daily use of artificial tears, and daily use of warm compresses. In addition, during each treatment session, the number of expressible glands was counted in both eyelids, the predominant quality of meibum was estimated in both eyelids, and the level of pain/discomfort due to MGX and IPL was recorded.

Results

TBUT increased from 3.8±0.2 (μ±standard error of mean (SEM)) to 4.5±0.3 seconds in the control arm, and from 4.0±0.2 to 6.0±0.3 in the study arm. The difference between arms was statistically significant (P < .01). Other signs/symptoms which improved in both arms but were greater in the study arm included MGS (P < .001), EDS (P < .01), the number of expressible glands in the lower eyelids (P < .0001) and upper eyelid (P < .0001), the predominant meibum quality in the lower eyelid (P < .0001) and upper eyelid (P < .0001), and the level of pain due to MGX (P < .0001). Outcome measures which improved in both arms with no significant differences between the two were OSDI (P = .9984), and the daily use of artificial tears (P = .8216). Meibography, daily use of warm compresses, and severity of skin rosacea did not show statistically significant changes in either arm. No serious adverse events were observed. There was a slight tendency for more adverse events in the control group (P = 0.06).

Conclusions

The results of this study suggest that, in patients with moderate to severe symptoms, combination therapy of intense pulse light (IPL) and meibomian gland expression (MGX) could be a safe and useful approach for improving signs of dry eye disease (DED) due to meibomian gland dysfunction (MGD). Future studies are needed to elucidate if and how such improvements can be generalized to different severity levels of MGD.