Reflections on Dry Eye Syndrome Treatment: Therapeutic Role of Blood Products

Autologous serum eye drops for patients with dry eye disease: a systematic review and meta-analysis of randomized controlled trials

Background

Dry eye disease (DED) is highly prevalent worldwide, leading to increased medical costs, economic burdens on families and society, and a diminished quality of life for patients. The utilization of autologous serum eye drops (ASEDs) for the treatment of DED is progressively rising.

Objective

To further evaluate the efficacy and safety of ASEDs in the treatment of DED.

Methods

A thorough search for randomized controlled trials (RCTs) was conducted across eight databases, including PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, SinoMed, and VIP. This search encompassed the inception of each database up to April 1, 2024, with a specific focus on identifying RCTs evaluating the efficacy and safety of ASEDs for the treatment of DED. Data analysis was conducted utilizing Stata 15.0 software and the Cochrane Risk of Bias Assessment Tool was utilized to appraise the literature's quality.

Results

The study encompassed 12 RCTs. In comparison to the use of artificial tears (AT), patients diagnosed with DED who utilized ASEDs displayed elevated the Schirmer test (ST) scores [WMD = 2.35, 95% CI (1.45, 3.24), p < 0.001] and tear-film breakup time (TBUT) scores [WMD = 2.83, 95% CI (2.27, 3.39), p < 0.001], decreased Corneal fluorescence staining (CFS) scores [SMD = -2.11, 95% CI (-3.07, -1.15), p < 0.001] and the Ocular Surface Disease Index (OSDI) scores [WMD = -10.54, 95% CI (-13.31, -7.77), p < 0.001], and experienced a reduced frequency of adverse events [RR = 0.36, 95% CI (0.13, 0.99), p = 0.048].

Conclusion

In this study, ASEDs had been shown to enhance tear secretion, extend tear film break-up time, mitigate corneal epithelial damage, ameliorate OSDI scores, and exhibit greater safety compared to AT.

Bridging the gap in managing dry eye disease: a consensus report by the Taiwan society of cataract and refractive surgeons

BACKGROUND

An impaired ocular surface presents substantial challenges in terms of planning for cataract surgery. As a multifactorial ocular disorder, dry eye disease (DED) is common in the general population and prevalent in patients scheduled for lens replacement surgery. Cataract surgery can exacerbate DED and worsen several ocular parameters. Timely diagnosis and appropriate treatment of DED are vital to ensuring positive ophthalmic surgical outcomes. This consensus report of the Taiwan Society of Cataract and Refractive Surgeons (TSCRS) regarding the management of DED before, during, and after cataract surgery highlights the gaps between clinical guidelines and several aspects of DED, including diagnostic testing, diagnostic criteria, and clinical practice treatment.

METHODS

An expert panel of five specialists in the field of ophthalmology was recruited to develop consensus statements regarding the management of DED in both the general population and in patients undergoing cataract surgery in Taiwan. Two separate meetings of the five specialists, who were endorsed by the TSCRS, were convened for this purpose. A survey questionnaire consisting of binary or multiple-choice questions was developed through a consensus-driven formulation process. A percentage value was calculated for each statement, and a minimum of 60% agreement (equivalent to three out of five members) was required to achieve consensus. The second discussion meeting involved the presentation of the finalized consensus statements and concluded the consensus development process. Lastly, the finalized consensus statements were approved by all the experts, and the formulated recommendations for DED in the general population and prospective cataract surgery patients were accordingly presented.

RESULTS

The optimal algorithm for managing DED in the general population and in patients scheduled for cataract surgery was developed to address the unmet needs of this cohort in Taiwan.

CONCLUSION

This report provides recommendations for managing dry eye disease. It is essential to screen and confirm DED through endorsed questionnaires and tests and then diagnose it. Treatment and management of DED should follow a stepwise approach. Screening and diagnosing DED is also recommended before cataract surgery. After cataract surgery, relatively aggressive treatment strategies are recommended to manage DED effectively.

Fluorescence-based reagent and spectrum-based optical reader for lactoferrin detection in tears: differentiating Sjögren's syndrome from non-Sjögren's dry eye syndrome

Identification of an early biomarker and effective testing device to differentiate dry eye disease secondary to autoimmune disease (Sjögren's syndrome dry eye disease) from non-Sjögren's dry eye disease are prerequisites for appropriate treatment. We aimed to demonstrate the capacity of a new photo-detection device to evaluate tear lactoferrin levels as a tool for differentiating systemic conditions associated with dry eye disease. Patients with non-Sjögren's and Sjögren's syndrome dry eye disease (n = 54 and n = 52, respectively) and controls (n = 11) were enrolled. All participants completed the Ocular Surface Disease Index questionnaire. Tear collection was performed with Schirmer test, and tear break-up time was examined using a slit lamp. Tear lactoferrin was evaluated using our newly developed photo-detection device. The average lactoferrin concentration was significantly lower in samples from patients with non-Sjögren's dry eye disease (0.337 ± 0.227 mg/mL, n = 54) and Sjögren's syndrome dry eye disease (0.087 ± 0.010 mg/mL, n = 52) than in control samples (1.272 ± 0.54 mg/mL, n = 11) (p < 0.0001). Further, lactoferrin levels were lower in patients with Sjögren's syndrome dry eye disease than in those with non-Sjögren's dry eye disease (p < 0.001). Our cost-effective, antibody-free, highly sensitive photo-detection device for evaluating tear lactoferrin levels can assist ophthalmologists in differentiating different types of dry eye diseases.

Blood-Derived Eye Drops for the Treatment of Corneal Neuropathic Pain

Blood-derived preparations, including autologous or allogenic serum, umbilical cord serum/plasma, and platelet-rich plasma eye drops, contain various growth factors, cytokines, and immunoglobulins that resemble natural tears. These components play important roles in corneal cell migration, proliferation, and wound healing. Blood-derived eye drops have demonstrated clinical effectiveness across a spectrum of ocular surface conditions, encompassing dry eye disease, Sjögren's syndrome, graft-versus-host disease, and neuropathic corneal pain (NCP). Currently, management of NCP remains challenging. The emergence of blood-derived eye drops represents a promising therapeutic approach. In this review, we discuss the benefits and limitations of different blood-derived eye drops, their mechanisms of action, and treatment efficacy in patients with NCP. Several studies have demonstrated the clinical efficacy of autologous serum eye drops in relieving pain and pain-like symptoms, such as allodynia and photoallodynia. Corneal nerve parameters were also significantly improved, as evidenced by increased nerve fiber density, length, nerve reflectivity, and tortuosity, as well as a decreased occurrence of beading and neuromas after the treatment. The extent of nerve regeneration correlated with improvement in patient-reported photoallodynia. Cord plasma eye drops also show potential for symptom alleviation and corneal nerve regeneration. Future directions for clinical practice and research involve standardizing preparation protocols, establishing treatment guidelines, elucidating underlying mechanisms, conducting long-term clinical trials, and implementing cost-effective measures such as scaling up manufacturing. With ongoing advancements, blood-derived eye drops hold promise as a valuable therapeutic option for patients suffering from NCP.

Evaluation of curcumin-based ophthalmic nano-emulsion on atropine-induced dry eye in mice

Background

One of the most efficient treatments for dry eye syndrome (DES) is to use nanocarriers as a potential delivery system. We aim to evaluate curcumin in a nano emulsion formulation.

Methods

A new formulation containing 5.5% curcuminoid was used. DLS, Zeta potential, TEM, and HPLC tests were performed to determine the size and morphology. First, 30 mice were selected as atropine-induced dry eye models. Next, 25 mice in 5 groups were treated with the nano emulsion at different doses, and corneal tissues were separated for evaluation.

Results

The DLS test results were indicative of the particles' stability. Nano curcumin appeared to be thoroughly effective in all groups, with the highest dose showing the most similarity to the healthy control group.

Conclusions

Curcumin-based nano emulsion eye drop is a promising candidate for DES management. However, further investigation is required to evaluate the possible risks in humans.

Achieving net-zero in the dry eye disease care pathway

Climate change is a threat to human health and wellbeing across the world. In recent years, there has been a surge in awareness of this crisis, leading to many countries and organisations setting "net-zero" targets. This entails minimising carbon emissions and neutralising remaining emissions by removing carbon from the atmosphere. At the 2022 United Nations Climate Change Conference (COP27), commitments to transition away from fossil fuels and augment climate targets were underwhelming. It is therefore imperative for public and private sector organisations to demonstrate successful implementation of net-zero and set a precedent for the global political consensus. As a top 10 world employer, the United Kingdom National Health Service (NHS) has pledged to reach net-zero by 2045. The NHS has already taken positive steps forward, but its scale and complexity as a health system means stakeholders in each of its services must highlight the specifications for further progress. Dry eye disease is a chronic illness with an estimated global prevalence of 29.5% and an environmentally damaging care pathway. Moreover, environmental damage is a known aggravator of dry eye disease. Worldwide management of this illness generates copious amounts of non-recyclable waste, utilises inefficient supply chains and involves recurrent follow-up appointments and prescriptions. By mapping the dry eye disease care pathway to environmental impact, in this review we will highlight seven key areas in which reduced emissions and pollution could be targeted. Examining these approaches for improved environmental sustainability is critical in driving the transformation needed to preserve our health and wellbeing.

Puerarin alleviates hyperosmotic stress-induced oxidative stress, inflammation, apoptosis and barrier damage of human corneal epithelial cells by targeting SIRT1/NLRP3 signaling

The increase of tear osmolarity caused by excessive evaporation of tear phase is the main pathological mechanism of dry eye disease (DED). Puerarin, the major bioactive ingredient isolated from the root of the Pueraria lobata (Willd.) Ohwi, has been reported to improve ophthalmic diseases in clinic. However, the effect and the potential regulatory mechanism related to silent information regulator sirtuin 1 (SIRT1)/NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling of puerarin in DED has not been evaluated. In this study, we aimed to explore the effect and mechanism of hyperosmotic stress (Hyp)-induced human corneal epithelial cell line (HCE-2). The viability of HCE-2 cells induced by Hyp with or without puerarin treatment was assessed by a CCK-8 assay. Results indicated that puerarin treatment enhanced cell viability, reduced reactive oxygen species (ROS) content, increased CAT and SOD activities, and elevated the ratio of GSH/GSSG in HCE-2 cells exposed to Hyp. Besides, TNF-α, IL-1β and IL-6 contents were decreased by puerarin. Additionally, puerarin inhibited Hyp-induced apoptosis and barrier disruption of HCE-2 cells. Moreover, molecular docking method suggested that puerarin bound to SIRT1, and upregulated SIRT1 and downregulated NLRP3 inflammasome proteins after puerarin treatment was observed. Furthermore, SIRT1 silencing alleviated the protective effects of puerarin on Hyp-induced HCE-2 cell damage. Collectively, puerarin attenuates Hyp-induced injury of HCE-2 cells by targeting regulating SIRT1/NLRP3 signaling.

[Comparison of the Effect of Autologous Serum on Therapy Resistant Corneal Erosions and Ulcers on the Corneal Graft vs. the Patient's Own Cornea]

PURPOSE

The aim of this study is to compare the healing of corneal epithelial defects or ulcers on the corneal graft in comparison with the patient's own cornea after treatment with 100%, undiluted autologous serum eye drops.

METHODS

In a retrospective study over 7 years, we analysed 263 treatments with autologous serum eye drops of persistent corneal epithelial defects (erosions [88%] vs. ulcers [12%]). We compared the epithelial healing tendency of patients with defects on their own cornea (51.9%) vs. patients who had previously undergone penetrating keratoplasty (48.1%). Complete epithelial healing during the 28 days of treatment was considered as therapeutic success. In addition, the recurrence rate of the epithelial defects after finishing the therapy was analysed.

RESULTS

88.2% of the epithelial defects healed during 28 days of therapy. The recurrence rate during follow-up was 5.1%. There was no significant difference with respect to success rate between corneal defects on the patient's own cornea (87.8%) and on the graft (88.6%; p = 0.137). There was a significantly lower success rate for corneal ulcers (74.2%) than for erosions (90.3%; p < 0.001). The recurrence rate of erosions was 4.4%, vs. 4.3% in ulcers during follow-up.

CONCLUSION

The results of our study suggest that autologous serum eye drops are a non-invasive and safe alternative treatment for persistent corneal epithelial defects - with no significant difference in patients with a defect on their own cornea vs. defects on the corneal graft. The success rate, but not the recurrence rate, is significantly worse in ulcers than in erosions.

Meibomian Gland Dysfunction Is Associated with Low Levels of Immunoglobulin Chains and Cystatin-SN

Meibomian gland dysfunction (MGD) is a highly prevalent condition and the most common cause of evaporative dry eye disease. Studying the proteome of MGD can result in important advances in the management of the condition. Here, we collected tear film samples from treatment naïve patients with MGD (n = 10) and age-matched controls (n = 11) with Schirmer filtration paper. The samples were analyzed with label-free quantification nano liquid chromatography-tandem mass spectrometry. The proteins were considered differentially expressed if p < 0.05. A total of 88 proteins were significantly regulated. The largest change was observed in cystatin-SN, which was downregulated in MGD and correlated negatively with tear meniscus height. The downregulation of cystatin-SN was confirmed with targeted mass spectrometry by single reaction monitoring (SRM). Eighteen immunoglobulin components involved in B cell activation, phagocytosis, and complement activation were downregulated in MGD including Ig alpha-1 chain C region, immunoglobulin J chain, immunoglobulin heavy variable 3-15, and Ig mu chain C region. The changes in cystatin-SN and immunoglobulin chains are likely to result from the inflammatory changes related to tear film evaporation, and future studies may assess their association with the meibum quality.

Expanding applications of allogeneic platelets, platelet lysates, and platelet extracellular vesicles in cell therapy, regenerative medicine, and targeted drug delivery

Platelets are small anucleated blood cells primarily known for their vital hemostatic role. Allogeneic platelet concentrates (PCs) collected from healthy donors are an essential cellular product transfused by hospitals to control or prevent bleeding in patients affected by thrombocytopenia or platelet dysfunctions. Platelets fulfill additional essential functions in innate and adaptive immunity and inflammation, as well as in wound-healing and tissue-repair mechanisms. Platelets contain mitochondria, lysosomes, dense granules, and alpha-granules, which collectively are a remarkable reservoir of multiple trophic factors, enzymes, and signaling molecules. In addition, platelets are prone to release in the blood circulation a unique set of extracellular vesicles (p-EVs), which carry a rich biomolecular cargo influential in cell-cell communications. The exceptional functional roles played by platelets and p-EVs explain the recent interest in exploring the use of allogeneic PCs as source material to develop new biotherapies that could address needs in cell therapy, regenerative medicine, and targeted drug delivery. Pooled human platelet lysates (HPLs) can be produced from allogeneic PCs that have reached their expiration date and are no longer suitable for transfusion but remain valuable source materials for other applications. These HPLs can substitute for fetal bovine serum as a clinical grade xeno-free supplement of growth media used in the in vitro expansion of human cells for transplantation purposes. The use of expired allogeneic platelet concentrates has opened the way for small-pool or large-pool allogeneic HPLs and HPL-derived p-EVs as biotherapy for ocular surface disorders, wound care and, potentially, neurodegenerative diseases, osteoarthritis, and others. Additionally, allogeneic platelets are now seen as a readily available source of cells and EVs that can be exploited for targeted drug delivery vehicles. This article aims to offer an in-depth update on emerging translational applications of allogeneic platelet biotherapies while also highlighting their advantages and limitations as a clinical modality in regenerative medicine and cell therapies.

Autologous Serum Eye Drops for Dry Eye: Systematic Review

BACKGROUND

Dry eye is a common condition with serious implications worldwide. The unique composition of autologous serum (AS) eye drops has been hypothesized as a possible treatment.

OBJECTIVES

This study aimed to review the effectiveness and safety of AS.

DATA SOURCES

We searched five databases and three registries up to September 30, 2022.

STUDY ELIGIBILITY

We included randomized controlled trials (RCTs) comparing AS with artificial tears, saline, or placebo for participants with dry eye.

STUDY APPRAISAL AND SYNTHESIS METHODS

We adhered to Cochrane methods for study selection, data extraction, risk-of-bias assessment, and synthesis. We used the Grading of Recommendations Assessment, Development and Evaluation framework to evaluate the certainty of evidence.

RESULTS

We included six RCTs with 116 participants. Four trials compared AS with artificial tears. We found low-certainty evidence that AS may improve symptoms (0- to 100-point pain scale) after 2 weeks of treatment compared with saline (mean difference, -12.00; 95% confidence interval, -20.16 to -3.84; 1 RCT, 20 participants). Ocular surface outcomes (corneal staining, conjunctival staining, tear breakup time, Schirmer test) were inconclusive. Two trials compared AS with saline. Very low-certainty evidence suggested that Rose Bengal staining (0- to 9-point scale) may be slightly improved after 4 weeks of treatment compared with saline (mean difference, -0.60; 95% confidence interval, -1.11 to -0.09; 35 eyes). None of the trials reported outcomes of corneal topography, conjunctival biopsy, quality of life, economic outcomes, or adverse events.

LIMITATIONS

We were unable to use all data because of unclear reporting.

CONCLUSIONS

The effectiveness of AS is uncertain based on current data. Symptoms improved slightly with AS compared with artificial tears for 2 weeks. Staining scores improved slightly with AS compared with saline, with no benefit identified for other measures.

IMPLICATIONS OF KEY FINDINGS

High-quality, large trials enrolling diverse participants with varying severity are needed. A core outcome set would allow for evidence-based treatment decisions consistent with current knowledge and patient values.

TCU-Net: Transformer Embedded in Convolutional U-Shaped Network for Retinal Vessel Segmentation

Optical coherence tomography angiography (OCTA) provides a detailed visualization of the vascular system to aid in the detection and diagnosis of ophthalmic disease. However, accurately extracting microvascular details from OCTA images remains a challenging task due to the limitations of pure convolutional networks. We propose a novel end-to-end transformer-based network architecture called TCU-Net for OCTA retinal vessel segmentation tasks. To address the loss of vascular features of convolutional operations, an efficient cross-fusion transformer module is introduced to replace the original skip connection of U-Net. The transformer module interacts with the encoder's multiscale vascular features to enrich vascular information and achieve linear computational complexity. Additionally, we design an efficient channel-wise cross attention module to fuse the multiscale features and fine-grained details from the decoding stages, resolving the semantic bias between them and enhancing effective vascular information. This model has been evaluated on the dedicated Retinal OCTA Segmentation (ROSE) dataset. The accuracy values of TCU-Net tested on the ROSE-1 dataset with SVC, DVC, and SVC+DVC are 0.9230, 0.9912, and 0.9042, respectively, and the corresponding AUC values are 0.9512, 0.9823, and 0.9170. For the ROSE-2 dataset, the accuracy and AUC are 0.9454 and 0.8623, respectively. The experiments demonstrate that TCU-Net outperforms state-of-the-art approaches regarding vessel segmentation performance and robustness.

The Comparison between the Composition of 100% Autologous Serum and 100% Platelet-Rich Plasma Eye Drops and Their Impact on the Treatment Effectiveness of Dry Eye Disease in Primary Sjogren Syndrome

PURPOSE

The aim of the study was to compare the difference in composition between 100% autologous serum (AS) and 100% platelet-rich plasma (PRP) eye drops and assess their impact on the clinical outcomes after the treatment of severe dry eye (DE) in primary Sjogren Syndrome patients (pSS).

MATERIALS AND METHODS

This is an interventional, non-randomized, comparative, three-month study. 22 patients with severe DE in pSS were treated with 100% AS (22 eyes) and 100% PRP (22 eyes) eye drops 5 times per day in monotherapy mode. The quantifications of growth factors (GFs) such as fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), transforming growth factor (TGF-b), insulin-like growth factor (IGF), fibronectin, and substance p in hemoderivates were done. The main outcome measures were: Ocular Surface Disease Index (OSDI), Best Corrected Visual Acuity (BCVA), the Schirmer test, tear break-up time (TBUT), corneal and conjunctival staining according to the Oxford scale, conjunctival hyperaemia, and Meibomian gland parameters. The results were compared at baseline, 1 month, and 3 months following the treatment. The clinical results were correlated with the concentration of GFs in the biological tear substitutes.

RESULTS

Significant differences were observed in the concentration of FGF (4.42 ± 0.86 vs. 15.96 ± 7.63, p < 0.0001), EGF (4.98 ± 0.97 vs. 39.06 ± 20.18, p < 0.0001), fibronectin (929.6 ± 111.5 vs. 823.64 ± 98.49, p = 0.0005), VEGF (175.45 ± 65.93 vs. 717.35 ± 488.15, p < 0.0001), PDGF AB (619.6 ± 117.30 vs. 349.66 ± 79.82, p < 0.0001), NGF (85.22 ± 23.49 vs. 8.29 ± 9.06, p < 0.0001), PDGF (935.38 ± 434.26 vs. 126.66 ± 54.41, p < 0.0001), substance p (112.58 ± 27.28 vs. 127.51 ± 26.56, p = 0.0125) in PRP compared to AS. The level of TGF-β was undoubtedly higher in AS than in PRP (1031.37 ± 330.23 vs. 726.03 ± 298.95, p = 0.0004). No significant differences between AS and PRP were observed in the concentration of IGF. Therapy with blood products relieved the signs and symptoms in pSS DE patients. There was a statistically significant improvement in BCVA, the Schirmer test, TBUT, Meibomian gland parameters, and the reduction of the OSDI scores, Oxford staining, and conjunctiva hyperaemia in each of the groups. However, the clinical changes were more significant in the PRP group. There were numerous correlations between the level of GFs and the mean change in clinical outcomes. No adverse events were reported.

CONCLUSIONS

Despite the fact that blood derivatives differ in composition, they seem to be effective and safe in the treatment of severe DE in pSS patients. The signs and symptoms of DE were reduced in both groups, but only the mean change in OSDI was statistically significant. A greater reduction in OSDI scores was observed in the PRP group. The obtained results and the composition of haemoderivates may indicate the superiority of PRP in relieving the symptoms of DE in pSS patients compared to AS.

Anti-Inflammatories in the Treatment of Dry Eye Disease: A Review

Inflammation is an important driver of dry eye disease (DED) pathogenesis. An initial insult that results in the loss of tear film homeostasis can initiate a nonspecific innate immune response that leads to a chronic and self-sustaining inflammation of the ocular surface, which results in classic symptoms of dry eye. This initial response is followed by a more prolonged adaptive immune response, which can perpetuate and aggravate inflammation and result in a vicious cycle of chronic inflammatory DED. Effective anti-inflammatory therapies can help patients exit this cycle, and effective diagnosis of inflammatory DED and selection of the most appropriate treatment are therefore key to successful DED management and treatment. This review explores the cellular and molecular mechanisms of the immune and inflammatory components of DED, and examines the evidence base for the use of currently available topical treatment options. These agents include topical steroid therapy, calcineurin inhibitors, T cell integrin antagonists, antibiotics, autologous serum/plasma therapy, and omega-3 fatty acid dietary supplements.

[Neuropathic pain in dry eye syndrome. Part 2. Clinical picture, diagnosis and treatment]

Burning eye syndrome is a chronic neuropathic pain syndrome, which is characterized by dysesthesia, spontaneous pain, allodynia and hyperalgesia. The review describes clinical features and presents available data on possible methods of diagnosis and therapy of this condition.

Effect of Autologous Platelet-Rich Plasma Drops in the Treatment of Ocular Surface Disease

Purpose

Platelet rich plasma (PRP) is an autologous preparation that concentrates platelets in a small volume of plasma. The purpose of this study was to determine if PRP eye drops improved the symptoms and signs of ocular surface disease.

Patients and Methods

A retrospective case series was conducted of patients who were prescribed PRP eye drops. Subjects were excluded if they did not have follow-up, underwent intraocular surgery prior to follow-up, received nerve growth factor treatments, or did not have a baseline examination with photography. Symptoms were assessed using the Ocular Surface Disease Index (OSDI). Patients also underwent a slit lamp exam, ocular surface staining with fluorescein and lissamine green, and Schirmer testing.

Results

The charts of 47 patients treated with PRP drops for ocular surface disease were reviewed. Sixty-four eyes of 32 patients were included in the study who had photographs of lissamine green staining taken at baseline and at follow-up. Thirteen patients (28%) had ocular graft-versus-host disease, 16 patients (34%) had Sjögren's syndrome, and 4 patients (8.5%) had rheumatoid arthritis. There was a statistically significant decrease in OSDI score from baseline to follow-up (39.5 vs 30.8 points, p = 0.02). Among the 64 eyes included, 9 (14%) had an improvement in conjunctival lissamine green staining, while 6 (9%) had an increase in staining at follow-up. Among the 20 eyes with Schirmer testing, there was a borderline significant increase in score from baseline to follow-up (5.9 vs 9.7, p = 0.06). Among the 44 eyes that had corneal fluorescein staining (CFS) reported, 8 (18.2%) had decreased staining and 2 (4.5%) had increased staining at follow-up.

Conclusion

Treatment with PRP drops was associated with a significant improvement in symptoms in patients with ocular surface disease. Future larger prospective studies are needed to further evaluate the efficacy of PRP drops for treating ocular surface disease.

Evaluation of the Regenerative Potential of Platelet-Lysate and Platelet-Poor Plasma Derived from the Cord Blood Units in Corneal Wound Healing Applications: An In Vitro Comparative Study on Corneal Epithelial Cells

Background: Cord blood platelet lysate (CB-PL) and cord blood platelet poor plasma (CB-PPP) have been applied with success in wound healing applications. Pathologies such as Sjogrens’s Syndrome (SS) and chronic graft versus host disease (cGVHD) can lead to severe ophthalmology issues. The application of CB-PL and CB-PPP may be strongly considered for damaged cornea healing. This study aimed to the evaluation of the beneficial properties of CB-PL and CB-PPP in corneal wound healing applications. Methods: Initially, the CB-PL and CB-PPP were produced from donated cord blood units (CBUs), followed by biochemical analysis. Corneal epithelial cells (CECs) were isolated from wistar rats and then cultured with medium containing 20% v/v either of CB-PL or CB-PPP. To define the impact of CB-PL and CB-PPP, biochemical, morphological analysis, scratch-wound assays, and immunoassays in CECs were performed. Results: CB-PL and CB-PPP were characterized by good biochemical parameters, regarding their quality characteristics and biomolecule content. CECs’ morphological features did not change after their cultivation with CB-PL or CB-PPP. A scratch wound assay and molecular analysis of CECs expanded with CB-PL indicated higher migratory capacity compared to those cultured with CB-PPP. Conclusion: CB-PL and CB-PPP exhibited good properties with respect to cell migration and proliferation, and could be considered an alternative source for eye drop production, to possibly be used in cornea wound healing applications.

Short-term Efficacy and Safety of Biological Tear Substitutes and Topical Secretagogues for Dry Eye Disease: A Systematic Review and Network Meta-analysis

PURPOSE

The purpose of this study was to assess short-term efficacy and safety of tear promotion eye drops (biological tear substitutes and topical secretagogues) for treating dry eye disease.

METHODS

Randomized controlled trials comparing short-term effects of biological tear substitutes or topical secretagogues versus placebo or other topical dry eye treatments in adults with dry eye disease were identified from the MEDLINE, Embase, Scopus, ClinicalTrials.gov , and World Health Organization International Clinical Trials Registry Platform databases. Pairwise meta-analysis and network meta-analysis were performed. Outcomes were ocular symptoms, ocular surface staining, tear break-up time, Schirmer test, and adverse events. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach.

RESULTS

Thirty-nine randomized controlled trials (3693 patients) were eligible. Using artificial tears as a reference, autologous platelet lysate was the most effective treatment for lowering ocular surface disease index (unstandardized mean difference [USMD] -31.85; 95% confidence interval [CI]: -43.19 to -20.51) and platelet rich plasma showed the most reduction in corneal fluorescein staining scores (standardized mean difference -2.52; 95% CI: -3.23 to -1.82). Cord blood serum was the most effective treatment for increasing tear break-up time (USMD 2.67; 95% CI: 0.53-4.82), and eledoisin was superior to others in improving Schirmer scores (USMD 2.28; 95% CI: 0.14-4.42). Most interventions did not significantly increase ocular adverse events compared with artificial tears.

CONCLUSIONS

Biological tear substitutes, including autologous serum, autologous platelet lysate, platelet rich plasma, and cord blood serum, might be the most effective treatment among tear promotion eye drops in relieving dry eye symptoms without increasing adverse events. However, there remains uncertainty around these findings because of low/very low certainty of evidence.

In vitro evaluation of platelet extracellular vesicles (PEVs) for corneal endothelial regeneration

Corneal endothelial cells (CECs) slowly decrease in number with increasing age, which is a clinical issue as these cells have very limited regenerative ability. Therapeutic platelet biomaterials are increasingly used in regenerative medicine and cell therapy because of their safety, cost-effective manufacture, and global availability from collected platelet concentrates (PCs). Platelet extracellular vesicles (PEVs) are a complex mixture of potent bioactive vesicles rich in molecules believed to be instrumental in tissue repair and regeneration. In this study we investigated the feasibility of using a PEVs preparation as an innovative regenerative biotherapy for corneal endothelial dysfunction. The PEVs were isolated from clinical-grade human PC supernatants by 20,000 × g ultracentrifugation and resuspension. PEVs exhibited a regular, fairly rounded shape, with an average size of <200 nm and were present at a concentration of approximately 10¹¹ /mL. PEVs expressed cluster of differentiation 41 (CD41) and CD61, characteristic platelets membrane markers, and CD9 and CD63. ELISA and LC-MS/MS proteomic analyses revealed that the PEVs contained mixtures of growth factors and multiple other trophic factors, as well as proteins related to extracellular exosomes with functional activities associated with cell cadherin and adherens pathways. CECs treated with PEVs showed increased viability, an enhanced wound-healing rate, stronger proliferation markers, and an improved adhesion rate. PEVs did not exert cellular toxicity as evidenced by the maintenance of cellular morphology and preservation of corneal endothelial proteins. These findings clearly support further investigations of PEV biomaterials in animal models for translation as a new CEC regeneration biotherapy.

Autologous platelet-rich plasma eye drop versus artificial tear eye drop for symptomatic dry eye disease: A prospective comparative interventional study

Purpose

To evaluate and compare the efficacy of autologous platelet-rich plasma (aPRP) eye drop and artificial tear (AT) eye drop in moderate to severe symptomatic dry eye disease (DED).

Methods

This prospective interventional study included 121 eyes of 61 patients of moderate to severe DED. Patients were divided into aPRP (31 patients) and AT (30 patients) group. Ocular Surface Disease Index (OSDI) score, tear film breakup time (TBUT) (s), corneal fluorescein staining (CFS) score, and Schirmer test score (mm) of both the groups were evaluated and compared pre-treatment and post-treatment at the end of 3 months.

Results

The mean age of the aPRP group and AT group was 52.8 ± 12.8 years and 55.5 ± 13.4 years, respectively. At the end of 3 months, OSDI score reduced more in the aPRP group as compared to AT group, and the mean difference (-22.7) was statistically significant (P < 0.001). There was no significant difference in post-treatment Schirmer test score between the two groups (P = 0.44). Post-treatment improvement in TBUT and CFS score in the aPRP group was significantly higher in the aPRP group as compared to that in the AT group (P < 0.05). Bruising at the site of blood withdrawal was noted in two patients in the aPRP group.

Conclusion

aPRP is safe and more effective than AT in treating patients with moderate to severe symptomatic DED.

Characterization and Chromatographic Isolation of Platelet Extracellular Vesicles from Human Platelet Lysates for Applications in Neuroregenerative Medicine

Human platelet lysates (HPLs) made from clinical-grade platelet concentrates are currently evaluated in the preclinical models of Parkinson's disease, Alzheimer's disease, traumatic brain injury, and others, as a new polyvalent neuroprotective biotherapy of the central nervous system. However, the presence and content of extracellular vesicles (EVs) in HPLs and their potential contribution to the neuroprotective and neurorestorative activities of HPLs are still unknown. We, therefore, characterized the EVs present in four different HPL preparations and after purification by size-exclusion chromatography. We then tested the effect of the isolated EVs on neuronal cell repair. We identified that all four HPLs contained a high and similar amount of EVs (10¹¹ to 10¹²/mL) with a mean size ranging from ca. 50 to 300 nm and a negative zeta potential as determined by nanoparticle tracking analysis and dynamic light scattering. Western blot analysis revealed that the EVs present in HPLs expressed the clusters of differentiation 41 (CD41) and 61 (CD61) characteristic of platelets. These EVs were efficiently isolated from HPL proteins by Sepharose CL-2B size-exclusion column chromatography as confirmed by total protein determination and protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis, with 73-85% recovery and maintenance of their size, negative zeta potential, and CD41 and CD61 expression. Interestingly, the EVs purified from the four HPLs exhibited a differential capacity to promote cell growth and migration in a wound-healing assay using SH-SY5Y neuronal cells, and one EV preparation stimulated network formation in primary neuronal cultures. These data indicated that the EVs present in HPLs have different neuroregenerative capacities and that some EV preparations may have interesting applications as a stand-alone therapy for usage in neuroregenerative medicine.

Emerging therapies for dry eye disease

INTRODUCTION

Dry Eye Disease (DED) is defined as a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and a vicious cycle of inflammation on the ocular surface. Despite its high prevalence and standing as one of the most common eye conditions seen by practitioners, the current treatment options available to patients have not proven adequate.

AREAS COVERED

This review will discuss the burden of DED, its pathophysiology, as well as emerging therapies. These therapies include immunosuppressants, immunomodulators, anti-inflammatory drugs, and corticosteroids. The mechanisms of these drugs will be discussed, as well as their phase of development and results from recent clinical trials. The literature search was performed using PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov, and the Springer AdisInsight database.

EXPERT OPINION

The optimal therapy for DED is associated with improved bioavailability, minimal ocular side effects, and effective dosing. The ideal treatment has not yet been established, but this paper outlines a number of promising therapies. Continued development of therapies targeting the inflammation cascade, as well as the establishment of objective markers to quantify DED severity, are important aspects in the progression of treatment.

Transregional autologous serum eye drop provision by a large German Red Cross Blood Donation Service

BACKGROUND

The Blood Donation Service West serves North Rhine-Westphalia (NRW), Rhineland-Palatinate (RP), and Saarland, an area of 56,500 km². In addition to routine red blood cell concentrates, plasma, and platelets, special products are provided. Since 2014, this has included autologous serum eye drops (ASED) for topical use in patients suffering from different illnesses accompanied by dry eye disease.

METHODS

A volume of 250-525 mL of patient blood was collected into an anticoagulant-free blood bag. Laboratory testing included Hepatitis B/C-, HIV 1/2-, and Lues-serology. Coagulation and centrifugation were followed by leukoreduction. Single-use vials were obtained by filling mini-bag systems using a sterile tube welder. Storage at ≤-20 °C enabled a shelf-life of up to 6 months and 30 days at 4 °C after thawing for shipment.

RESULTS

Contracts were closed with 15 ophthalmology clinics and medical practices in NRW and RP to supply patients with ASED. The patient pool increased from 19 in 2014 to 46 in 2020, with an average age of 43-55 years. Overall, blood collections almost tripled from 31 to 100 per year, increasing the stock of deliverable single-use vials from 3328 to 13,358. Delivery in a liquid state allowed engagement of 44 pharmacies located in the patient neighborhoods for continuous supply.

CONCLUSION

Manufacturing in a closed bag system allowed integration into blood bank operations. However, cost-coverage by health insurance remained a case-by-case decision. Allogeneic application as 'just-another-blood-product' could be an aspiration. Yet, conclusive data from large clinical trials are needed for licensed provision in Germany.

Experimental Models, Induction Protocols, and Measured Parameters in Dry Eye Disease: Focusing on Practical Implications for Experimental Research

Dry eye disease (DED) is one of the major ophthalmological healthcare challenges worldwide. DED is a multifactorial disease characterized by a loss of homeostasis of the tear film, and its main pathogenesis is chronic ocular surface inflammation related with various cellular and molecular signaling cascades. The animal model is a reliable and effective tool for understanding the various pathological mechanisms and molecular cascades in DED. Considerable experimental research has focused on developing new strategies for the prevention and treatment of DED. Several experimental models of DED have been developed, and different animal species such as rats, mice, rabbits, dogs, and primates have been used for these models. Although the basic mechanisms of DED in animals are nearly identical to those in humans, proper knowledge about the induction of animal models is necessary to obtain better and more reliable results. Various experimental models (in vitro and in vivo DED models) were briefly discussed in this review, along with pathologic features, analytical approaches, and common measurements, which will help investigators to use the appropriate cell lines, animal, methods, and evaluation parameters depending on their study design.

Autologous serum eye drops for ocular surface disorders

PURPOSE OF REVIEW

Ocular surface disease is a prevalent, diverse group of conditions that cause patient discomfort and decreased visual acuity and present considerable expense to both patients and healthcare systems. Autologous serum eye drops are a topical treatment modality derived from the patient's own blood. Use of serum eye drops for ocular surface disease has been promising due to biochemical similarities to endogenous tears.

RECENT FINDINGS

Use of serum eye drops for moderate to severe ocular surface diseases such as dry eye, corneal epithelial defects, and inflammatory conditions has become more prevalent. Recent studies have demonstrated that the use of serum eye drops is well-tolerated by patients and associated with improvement in patient-reported outcomes and objective dry eye parameters. Production of serum eye drops may vary, treatment costs can be significant, and the quality of evidence for serum eye drop use published from randomized controlled trials is modest, particularly for long-term treatment. Accessibility remains an area for improvement and may be complemented by allogeneic serum eye drops.

SUMMARY

Serum eye drops are frequently used as a safe, well-tolerated, and effective treatment for ocular surface disease. Further research is needed to assess long-term outcomes and improve accessibility.

A purified human platelet pellet lysate rich in neurotrophic factors and antioxidants repairs and protects corneal endothelial cells from oxidative stress

Human platelet lysate (HPL) is a complex mixture of potent bioactive molecules instrumental in tissue repair and regeneration. Due to their remarkable safety, cost-effective production, and availability at global level from collected platelet concentrates, HPLs can become a powerful biotherapy for various therapeutic applications, if standardized and carefully validated through pre-clinical and clinical studies. In this work, the possibility to use a tailor-made HPL as a corneal transplant alternative to treat the gradual decrease in the number of corneal endothelial cells (CECs) associated with aging, was evaluated. The HPL preparation was thoroughly characterized using various proteomics tools that revealed a remarkable richness in multiple growth factors and antioxidants. Treatment of B4G12 and BCE C/D-1b CECs with the HPL increased their viability, enhanced the wound closure rate, and maintained cell growth and typical hexagonal morphology. Besides, this HPL significantly protected against tert-butyl hydroperoxide (TBHP)-induced oxidative stress as evidenced by increasing CEC viability, decreased cell death and reactive oxygen species formation, and enhanced antioxidant capacity. Proteomics analysis of treated CECs confirmed that HPL treatment triggered the corneal healing pathway and enhanced oxidative stress. These data strongly support further pre-clinical evaluation of this tailor-made HPL as a novel CEC regeneration biotherapy. HPL treatment may eventually represent a pragmatic and cost-effective alternative to corneal transplant to treat damages of the corneal endothelium which is a major cause of blindness worldwide.

Comprehensive Review and Update of Burning Eye Syndrome

Keratoconjunctivitis sicca ("dry eye") is a common (14%-30% of adults over age 48) though difficult to treat condition that causes both discomfort and disability with associated dryness, pain, and visual disturbances. Etiology is not clearly understood but is likely varied, with a subset of patients suffering from chronic neuropathic pain referred to as "burning eye syndrome." This review of existing literature summarizes the clinical presentation, natural history, pathophysiology, and treatment modalities of burning eye syndrome. Chronicity of burning eye syndrome is likely secondary to increased nociception from the cornea, decrease in inhibitory signals, and nerve growth factor expression alterations. Treatment centers around symptomatic alleviation and reduction of inflammation. Conservative treatments focus on well-being and perception and include exercise, acupuncture, and cognitive behavioral therapy. Topical treatment consists of the anti-adhesion T-cell antagonist lifitegrast, corticosteroids, and cyclosporine; all have moderate efficacy and good safety. Autologous serum eye drops are a second-line topical that may promote corneal and neural healing on top of symptomatic relief. When these treatments fail, patients may trial neuromodulation with transcranial magnetic stimulation. Despite general treatment safety, more research is needed to develop novel approaches to this condition, possibly focusing more directly on the neurological component.

Corneal Epithelial Stem Cell Supernatant in the Treatment of Severe Dry Eye Disease: A Pilot Study

PURPOSE

To report the subjective assessment of topical self-administered, cadaver-derived corneal epithelial stem cell supernatant for treatment of severe dry eye disease (DED).

METHODS

Thirty-four eyes of 17 patients with advanced DED as defined by Standardized Patient Evaluation of Eye Dryness (SPEEDTM) questionnaire ≥14, Ocular Surface Disease Index (OSDI©) score ≥40 and documented attempt of at least six conventional dry eye therapies were enrolled into a prospective clinical trial at a single private practice institution. Treatment consisted of patient self-administered topical instillation of the corneal epithelial stem cell-derived product four times daily in both eyes for 12 weeks. Patient-reported outcome measures (PROMs) were taken with the SPEEDTM questionnaire (the main outcome variable), OSDI© score and visual analog score (VAS; UNC Dry Eye Management Scale©), and objective clinical measurements were taken with best-corrected visual acuity (BCVA), corneal topographic index measurements and tear film osmolarity. These measurements were compared at baseline versus the endpoint at completion of the 12-week treatment.

RESULTS

All 34 eyes tolerated the treatment without any adverse events or significant side effects. Compared with baseline, both the SPEEDTM questionnaire and the VAS significantly improved at the conclusion of the 12-week treatment (p = 0.0054 and p = 0.0202, respectively). The OSDI© improved by an average of 10.9 points after the treatment but was not statistically significant (p = 0.1409). There were no significant changes in any of the objective clinical measurements. None of the study subjects failed to complete the treatment course, experienced decrease in any of the PROMs or lost one or more lines of BCVA during the follow-up period.

CONCLUSION

Topical corneal epithelial stem cell-derived supernatant that can be self-administered by the patient shows promise at improving patient symptoms and quality of life in the setting of severe DED that is unresponsive to conventional therapies.

Cord blood and amniotic membrane extract eye drop preparations display immune-suppressive and regenerative properties

Diseases and injuries that compromise the ocular surface cause considerable patient distress and have long term consequences for their quality of life. Treatment modalities that can address the delicate balance of tissue regeneration, inflammation and maintenance of corneal transparency are therefore needed. We have recently formulated two novel eye drops from placental tissues: cord blood platelet lysate (CBED) and amniotic membrane extract eye drops (AMED), which can be used to treat severe ocular disorders. Here we characterise these two preparations by measuring: (a) growth factors (GF) and cytokines composition, (b) promotion of human corneal epithelial cell (HCEC) growth and (c) effects on immune cells in a lymphocyte culture assay. Finally, their bioavailability was assayed in an ex vivo porcine corneal model. We show that both preparations contain GF and cytokines that were able to promote the in vitro growth of HCEC and support repair in an in vitro scratch test. When assessed in a lymphocyte culture, both favoured immune suppression reducing the cellular expression of NKG2D and CD107a as well as the production of interferon gamma (IFN-γ) in natural killer, NKT and T cells. Regarding bioavailability, CBED active molecules were found mainly in the pre-corneal fraction with some penetration into the corneal fraction, in an ex vivo model. In summary, both placental-derived allogeneic preparations, CBED and AMED, display regenerative and immunomodulatory capabilities. These results will help define mechanisms of action and the best indications and doses of each product for use in a particular patient and support the development of off-the-shelf therapies for ocular surface pathologies in which wound healing defects and inflammatory events are contributing factors.

Comparison of treatment efficacy between 100% platelet-rich plasma and 100% serum eye drops in moderate-to-severe dry eye disease: a randomised controlled trial protocol

INTRODUCTION

Dry eye disease (DED) is a common eye problem. Although the disease is not fatal, it substantially reduces quality of life and creates a high economic burden, especially in patients with moderate-to-severe DED. Several biological tear substitutes (eg, autologous serum (AS), autologous platelet-rich plasma (APRP) and autologous platelet lysate) could effectively improve dry eyes. However, evidence on their comparative efficacy is controversial. This study aims to compare the efficacy of 100% APRP with 100% AS eye drops in patients with moderate-to-severe DED.

METHODS AND ANALYSIS

The study is a single-centre, double-blinded randomised, parallel, non-inferiority trial. One hundred and thirty patients with moderate-to-severe DED, aged 18-70 years will be recruited from outpatient clinic, Department of Ophthalmology, Ramathibodi Hospital, Bangkok from February 2021 to January 2023. Patients will be randomised to receive either 100% APRP or 100% AS eye drops (1:1 ratio) for 4 weeks. The primary outcomes are ocular surface disease index (OSDI) and ocular surface staining (OSS) evaluated using the Oxford scale. Secondary outcomes are fluorescein break-up time, Schirmer's I test, meibomian gland parameters and adverse events. Other measured outcomes include best-corrected visual acuity, intraocular pressure and compliance.

ETHICS AND DISSEMINATION

The study protocol and any supplements used in conducting this trial have been approved by the Ethics Committee of Faculty of Medicine, Ramathibodi Hospital, Mahidol University (MURA2020/1930). Informed consent will be obtained from all patients before study entry. Results will be presented in peer-reviewed journals and international conferences.

TRIAL REGISTRATION NUMBER

NCT04683796.

Metabolomics comparison of cord and peripheral blood-derived serum eye drops for the treatment of dry eye disease

Allogeneic peripheral blood-derived (PBS) serum eye drops have been largely used in the treatment of dry eye disease (DED). Recently, cord blood has emerged as an effective alternative serum source (cord blood serum, CBS), containing a higher amount of growth factors than PBS, it holds the promise of a better capability to stimulate corneal healing. However, the lack of a standardized method for preparation, dispensation, storage and a poor biochemical characterization still hamper the establishment of a clinical consensus. Here the metabolomes of the two different serum eye drop preparations were compared using proton nuclear magnetic resonance spectroscopy. We found that both PBS and CBS contained several organic compounds, the majority of them already detected in human tears and may be thereby considered lacrimal substitutes. Metabolites having in the multivariate statistical analysis Partial least squares discriminant analysis (PLS-DA) a VIP scores > 1.0 were considered to be significantly different. All the metabolites identified were found to have a p < 0.05 in the univariate analysis. CBS, in particular, showed the highest amount of choline, myo-inositol, glutamine, creatine and β-hydroxybutyrate. These evidences constitute relevant advances towards serum eye drops characterization and confirm that cord blood is a valid alternative source of serum eye drops.

Inhibition of matrix metalloproteinase-9 for the treatment of dry eye syndrome; a review study

Dry eye syndrome (DES) and tear dysfunction are multifactorial conditions affecting meibomian glands, lacrimal glands, and ocular surface. This ocular disorder can cause eye irritation, irregular cornea, corneal barrier disruption, and blurred vision. Uncontrolled increase in matrix metalloproteinase-9 (MMP-9) level and activity has been detected in the tears and ocular surface in the patients with DES, which has been proved to be related to disruption of tight junctions in apical corneal epithelium associated with severe signs of DES. These uncontrolled activities of MMP-9 lead to desquamation of ocular surface epithelia. Therefore, this review study was conducted to summarize the evidence regarding MMP-9 contribution in DES, and inhibition of MMP-9, as a therapeutic target for treatment of DES. For this purpose, herein, the related studies designed novel pharmaceutical compounds for direct and indirect inhibition of MMP-9 as treatment approaches for DES were reviewed. These compounds were designed to improve corneal barrier function, reduce inflammation on ocular surface, and restore tear production.

A Novel Epidemiological Approach to Geographically Mapping Population Dry Eye Disease in the United States Through Google Trends

PURPOSE

Our study fills the spatiotemporal gaps in dry eye disease (DED) epidemiology by using Google Trends as a novel epidemiological tool for geographically mapping DED in relation to environmental risk factors.

METHODS

We used Google Trends to extract DED-related queries estimating users' intent from 2004 to 2019 in the United States. We incorporated national climate data to generate heat maps comparing geographic, temporal, and environmental relationships of DED. Multivariable regression models were constructed to generate quadratic forecasts predicting DED and control searches.

RESULTS

Our results illustrated the upward trend, seasonal pattern, environmental influence, and spatial relationship of DED search volume across the US geography. Localized patches of DED interest were visualized in urban areas. There was no significant difference in DED queries across the US census regions (P = 0.3543). Regression model 1 predicted DED queries per state (R2 = 0.61), with the significant predictor being urban population [r = 0.56, adjusted (adj.) P < 0.001, n = 50]; model 2 predicted DED searches over time (R2 = 0.97), with significant predictors being control queries (r = 0.85, adj. P = 0.0169, n = 190), time (r = 0.96, adj. P < 0.001, n = 190), time2 (r = 0.97, adj. P < 0.001, n = 190), and seasonality (winter r = -0.04, adj. P = 0.0196, n = 190; spring r = 0.10, adj. P < 0.001, n = 190).

CONCLUSIONS

Our study used Google Trends as a novel epidemiologic approach to geographically mapping the US DED. Importantly, urban population and seasonality were stronger risk factors of DED searches than temperature, humidity, sunshine, pollution, or region. Our work paves the way for future exploration of geographic information systems for locating DED and other diseases through online population metrics.

Detection of systemic immunosuppressants in autologous serum eye drops (ASED) in patients with severe chronic ocular graft versus host disease

PURPOSE

Chronic graft versus host disease is a major consequence after allogeneic stem cell transplantation (allo-SCT) and has great impact on patients' morbidity and mortality. Besides the skin, liver, and intestines, the eyes are most commonly affected, manifesting as severe ocular surface disease. Treatment protocols include topical steroids, cyclosporine, tacrolimus, and ASED. Since these patients often receive systemic immunosuppressant therapy from their oncologists, a topical re-administration of these drugs via ASED with potentially beneficial or harmful effects is possible. The purpose of the study was to determine whether and to which extent systemic immunosuppressants are detectable in ASED.

METHODS

A total of 34 samples of ASED from 16 patients with hemato-oncological malignancies after allo-SCT were collected during the manufacturing process and screened for levels of cyclosporine, mycophenolic acid, everolimus, and tacrolimus via liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The study followed the tenets of the Declaration of Helsinki and informed consent was obtained from the subjects after explanation of the nature and possible consequences of the study.

RESULTS

Cyclosporine was found in 18 ASED samples in concentrations ranging from 6.5-105.0 ng/ml (32.0 ± 22.8 ng/ml, mean ± SD). The concentration range of mycophenolic acid in 19 samples was 0.04-25.0 mg/l (4.0 ± 5.4 mg/l, mean ± SD). Everolimus and tacrolimus concentrations were well below the respective limits of quantification (< 0.6 and < 0.5 ng/ml) of the established LC-MS/MS method in all samples.

CONCLUSIONS

Our study suggests that orally administered cyclosporine and mycophenolic acid for the treatment of systemic GvHD, but not everolimus and tacrolimus, are distinctly detectable in ASED in relevant concentrations. It is highly likely that these agents affect topical therapy of ocular GvHD. However, the extent of this effect needs to be evaluated in further studies.

Human platelet lysates for human cell propagation

A pathogen-free and standardized xeno-free supplement of growth media is required for the ex vivo propagation of human cells used as advanced therapeutic medicinal products and for clinical translation in regenerative medicine and cell therapies. Human platelet lysate (HPL) made from therapeutic-grade platelet concentrate (PC) is increasingly regarded as being an efficient xeno-free alternative growth medium supplement to fetal bovine serum (FBS) for clinical-grade isolation and/or propagation of human cells. Most experimental studies establishing the superiority of HPL over FBS were conducted using mesenchymal stromal cells (MSCs) from bone marrow or adipose tissues. Data almost unanimously concur that MSCs expanded in a media supplemented with HPL have improved proliferation, shorter doubling times, and preserved clonogenicity, immunophenotype, in vitro trilineage differentiation capacity, and T-cell immunosuppressive activity. HPL can also be substituted for FBS when propagating MSCs from various other tissue sources, including Wharton jelly, the umbilical cord, amniotic fluid, dental pulp, periodontal ligaments, and apical papillae. Interestingly, HPL xeno-free supplementation is also proving successful for expanding human-differentiated cells, including chondrocytes, corneal endothelium and corneal epithelium cells, and tenocytes, for transplantation and tissue-engineering applications. In addition, the most recent developments suggest the possibility of successfully expanding immune cells such as macrophages, dendritic cells, and chimeric antigen receptor-T cells in HPL, further broadening its use as a growth medium supplement. Therefore, strong scientific rationale supports the use of HPL as a universal growth medium supplement for isolating and propagating therapeutic human cells for transplantation and tissue engineering. Efforts are underway to ensure optimal standardization and pathogen safety of HPL to secure its reliability for clinical-grade cell-therapy and regenerative medicine products and tissue engineering.

PRP in wound healing applications

Platelets play a crucial role in hemostasis, tissue regeneration and host defense. Based on these settings, platelet-rich plasma (PRP) and its derivatives are therapeutically used to promote wound healing in several scenarios. This review summarizes the biological mechanisms underlying the most traditional as well as innovative applications of PRP in wound healing. These mechanisms involve the combined action of platelet-derived growth factors and cytokines, together with the role of plasma-derived fibrillar, antioxidant and homeostatic factors. In addition, regenerative treatments with PRP consist of personalized and non-standardized methods. Thus, the quality of PRP varies depending on endogenous factors (e.g., age; gender; concomitant medication; disease-associated systemic factors; nutrition) and exogenous factors (anticoagulants and cellular composition). This review also analyses whether these factors affect the biological mechanisms of PRP in wound healing applications.

Extensive characterization of the composition and functional activities of five preparations of human platelet lysates for dedicated clinical uses

Human platelet lysates (HPLs), rich in various growth factors and cell growth-promoting molecules, encompass a new range of blood products that are being used for regenerative medicine, cell therapies, and tissue engineering. Well-characterized dedicated preparations, tailor-made to best fit specific therapeutic applications, are needed for optimal clinical efficacy and safety. Here, five types of HPL were prepared from the same platelet concentrates and extensively characterized to determine and compare their proteins, growth factors, cytokines, biochemical profiles, thrombin-generating capacities, thrombin-associated proteolytic activities, phospholipid-associated procoagulant potential, contents of extracellular vesicles expressing phosphatidylserine and tissue factor, and antioxidative properties. Our results revealed that all five HPL preparations contained detectable supraphysiological levels, in the ca. 0.1 ~ 350-ng/ml range, of all growth factors assessed, except insulin-like growth factor-1 detected only in HPL containing plasma. There were significant differences observed among these HPLs in total protein content, fibrinogen, complement components C3 and C4, albumin, and immunoglobulin G, and, most importantly, in their functional coagulant and procoagulant activities and antioxidative capacities. Our data revealed that the biochemical and functional properties of HPL preparations greatly vary depending upon their mode of production, with potential impacts on the safety and efficacy for certain clinical indications. Modes of preparation of HPLs should be carefully designed, and the product properties carefully evaluated based on the intended therapeutic use to ensure optimal clinical outcomes.

Mucoadhesive Bletilla striata Polysaccharide-Based Artificial Tears to Relieve Symptoms and Inflammation in Rabbit with Dry Eyes Syndrome

Dry eye syndrome (DES) is a multifactorial disorder of the ocular surface affecting many people all over the world. However, there have been many therapeutic advancements for the treatment of DES, substantial long-term treatment remains a challenge. Natural plant-based polysaccharides have gained much importance in the field of tissue engineering for their excellent biocompatibility and unique physical properties. In this study, polysaccharides from a Chinese ground orchid, Bletilla striata, were successfully extracted and incorporated into the artificial tears for DES treatment due to its anti-inflammatory and mucoadhesive properties. The examination for physical properties such as refractive index, pH, viscosity and osmolality of the Bletilla striata polysaccharide (BSP) artificial tears fabricated in this study showed that it was in close association with that of the natural human tears. The reactive oxygen species (ROS) level and inflammatory gene expression tested in human corneal epithelium cells (HCECs) indicated that the low BSP concentrations (0.01–0.1% v/v) could effectively reduce inflammatory cytokines (TNF, IL8) and ROS levels in HCECs, respectively. Longer retention of the BSP-formulated artificial tears on the ocular surface is due to the mucoadhesive nature of BSP allowing lasting lubrication. Additionally, a rabbit’s DES model was created to evaluate the effect of BSP for treating dry eye. Schirmer test results exhibited the effectiveness of 0.1% (v/v) BSP-containing artificial tears in enhancing the tear volume in DES rabbits. This work combines the effectiveness of artificial tears and anti-inflammatory herb extract (BSP) to moisturize ocular surface and to relieve the inflammatory condition in DES rabbit, which further shows great potential of BSP in treating ocular surface diseases like DES in clinics in the future.

Cord Blood Platelet Rich Plasma Derivatives for Clinical Applications in Non-transfusion Medicine

Cord blood platelet rich plasma (CB-PRP) derivatives have been investigated as potential therapeutic agents for the treatment of diverse conditions including ocular surface disease and skin ulcers. We have developed processes for the formulation of several CB-PRP preparations, which have different composition and attributes. Here we describe the molecular characteristics of these preparations and we make recommendations as to their most appropriate clinical application based on functional and immunomodulatory profiles. We show that incubation of adult peripheral blood mononuclear cells (PBMCs) with all three preparations dramatically reduced the production of INFγ and the expression of NKG2D and CD107a in NK, NKT, and T cells thus diminishing their activation, we propose that the likely mechanism is the high levels of soluble NKG2D ligands present in plasma. Of the three preparations we investigated, CB platelet lysate (PL) and platelet releaseate (PR) have higher concentrations of trophic and pro-angiogenic factors, CB platelet poor plasma (PPP) has the lowest concentration of all analytes measured. Based on these finding we propose that CB-PR is the most suitable raw material for skin wound patches, while CB-PL and PPP can be used to prepare eye drops for severe ocular surface pathologies and inflammatory conditions such as corneal ulcers or severe dry eye disease, respectively.

Antioxidant Role of PRGF on RPE Cells after Blue Light Insult as a Therapy for Neurodegenerative Diseases

Oxidative stress has a strong impact on the development of retinal diseases such as age-related macular degeneration (AMD). Plasma rich in growth factors (PRGF) is a novel therapeutic approach in ophthalmological pathologies. The aim of this study was to analyze the antioxidant effect of PRGF in retinal epithelial cells (EPR) in in vitro and ex vivo retinal phototoxicity models. In vitro analyses were performed on ARPE19 human cell line. Viability and mitochondrial status were assessed in order to test the primary effects of PRGF. GSH level, and protein and gene expression of the main antioxidant pathway (Keap1, Nrf2, GCL, HO-1, and NQO1) were also studied. Ex vivo analyses were performed on rat RPE, and HO-1 and Nrf2 gene and protein expression were evaluated. The results show that PRGF reduces light insult by stimulating the cell response against oxidative damage and modulates the antioxidant pathway. We conclude that PRGF’s protective effect could prove useful as a new therapy for treating neurodegenerative disorders such as AMD.

Platelet-derived bio-products: Classification update, applications, concerns and new perspectives

Platelet derived bio-products in the form of platelet rich plasma, plasma rich in growth factors, or plasma-free platelet releasates, are being studied worldwide with the aim of proving their efficacy in tissue regeneration within many different clinical areas, such as traumatology, maxillofacial surgery, ophthalmology, dermatology and otorhinolaryngology, amongst others. The current lack of consensus in the preparation method and application form, or in the quality assessment of each bio-product, precludes adequate interpretation of the relevance of reported clinical outcomes, and, while many in clinicians are very positive about them, many are sceptic. Relevant aspects of these products are considered to propose a classification nomenclature which would aid a comprehensive comparison of clinical outcomes of bio-products of the same characteristics. Finally, the uses of platelet-derived bio-products in in vitro culture (for cell therapy purposes) as a substitute of animal-origin sera, and other future perspectives of applications of platelet-derived bio-products are discussed.

Autologous Serum Eye Drops versus Artificial Tear Drops for Dry Eye Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To compare the efficacy of autologous serum (AS) eye drops and artificial tears (AT) in dry eye disease (DED).

METHODS

Five databases (PubMed, Science Direct, the Cochrane Library, the Chinese National Knowledge Infrastructure, and the Wanfang Database) were searched for randomized controlled trials (RCTs). Efficacy was evaluated in terms of the Ocular Surface Disease Index (OSDI), Schirmer I test, tear break-up time (TBUT), and fluorescein and rose bengal staining of ocular surface. The estimated effects of AS or AT were expressed as a proportion with the 95% confidence interval and plotted on a forest plot.

RESULTS

Seven RCTs with 267 subjects were included in the meta-analysis. For most of the studies, subjects' age was around 50 years old, and the mostly treatment duration was within 8 weeks. The follow-up results showed that the OSDI after AS treatment was lower than that after the AT treatment: the mean difference (MD) was -10.75 (95% CI, -18.12; -3.39) points. There was no difference on the Schirmer I test after treatment between the two groups: the MD was 1.68 (95% CI, -0.65; 4.00) mm. The TBUT of the AS group was longer than that of the AT group, with an MD of 4.53 (95% CI, 2.02; 7.05) s. There was no statistically significant difference on fluorescein staining score of the ocular surface between the AS group and the AT group, the MD was -2.53 (95% CI, -6.08; 1.03) points. The rose bengal staining score of the AS group was slightly lower than that of the AT group after treatment: the MD was -0.78 (95% CI, -1.34; -0.22) points.

CONCLUSION

AS could be an effective treatment for DED, improving OSDI, TBUT, and rose bengal staining score. Further RCTs with large samples and long-term follow-up are still needed to determine the exact role of AS in the management of DED.

Viral safety of human platelet lysate for cell therapy and regenerative medicine: Moving forward, yes, but without forgetting the past

Growth factor-rich pooled human platelet lysate (HPL), made from human platelet concentrates, is one new blood-derived bioproduct that is attracting justified interest as a xeno-free supplement of growth media for human cell propagation for cell therapy. HPL can also find potentially relevant applications in the field of regenerative medicine. Therefore, the therapeutic applications of HPL go far beyond the standard clinical applications of the traditional blood products typically used in patients suffering from life-threatening congenital or acquired deficiencies in cellular components or proteins due to severe genetic diseases or trauma. A wider population of patients, suffering from various pathologies than has traditionally been the case, is thus, now susceptible to receiving a human blood-derived product. These patients would, therefore, be exposed to the possible, but avoidable, side effects of blood products, including transfusion-transmitted infections, most specifically virus transmissions. Unfortunately, not all manufacturers, suppliers, and users of HPL may have a strong background in the blood product industry. As such, they may not be fully aware of the various building blocks that should contribute to the viral safety of HPL as is already the case for any licensed blood products. The purpose of this manuscript is to reemphasize all the measures, including in regulatory aspects, capable of assuring that HPL exhibits a sufficient pathogen safety margin, especially when made from large pools of human platelet concentrates. It is vital to remember the past to avoid that the mistakes, which happened 30 to 40 years ago and led to the contamination of many blood recipients, be repeated due to negligence or ignorance of the facts.

Blood-Based Treatments for Severe Dry Eye Disease: The Need of a Consensus

The use of blood-based eye drops as therapy for various diseases of the ocular surface has become increasingly popular in ophthalmic practice during recent years. The rationale for their use is based on the promotion of cellular proliferation and migration thanks to the supply of metabolically active substances, in particular growth factors. Blood-derived eye drops have been used for the treatment of several ocular surface disorders, such as dry eye disease, corneal ulcer, persistent epithelial defect, neurotrophic keratitis, ocular surface burn, recurrent corneal erosion, and limbal stem-cell deficiency. Both autologous (from patients themselves) and heterologous (from adult donors or from cord blood sampled at birth)-derived products exist, and each source has specific pros and cons. Despite an extensive literature, several issues are still under debate and the aim of this manuscript is to review the indications, preparation methods and storage, characterization of content, rationale for clinical outcomes, patient stratification, length of treatment, and rationale for repeated treatments at disease relapse. A rationale based on a "5 Ws and 2 Hs" protocol is proposed as a way of thinking, with the attempt to clarify Who, Why, When, Where, What, and How to use these treatment options.

Nanoformulation properties, characterization, and behavior in complex biological matrices: Challenges and opportunities for brain-targeted drug delivery applications and enhanced translational potential

Nanocarriers (synthetic/cell-based have attracted enormous interest for various therapeutic indications, including neurodegenerative disorders. A broader understanding of the impact of nanomedicines design is now required to enhance their translational potential. Nanoformulations in vivo journey is significantly affected by their physicochemical properties including the size, shape, hydrophobicity, elasticity, and surface charge/chemistry/morphology, which play a role as an interface with the biological environment. Understanding protein corona formation is crucial in characterizing nanocarriers and evaluating their interactions with biological systems. In this review, the types and properties of the brain-targeted nanocarriers are discussed. The biological factors and nanocarriers properties affecting their in vivo behavior are elaborated. The compositional description of cell culture and biological matrices, including proteins potentially relevant to protein corona built-up on nanoformulation especially for brain administration, is provided. Analytical techniques of characterizing nanocarriers in complex matrices, their advantages, limitations, and implementation challenges in industrial GMP environment are discussed. The uses of orthogonal complementary characterization approaches of nanocarriers are also covered.

Advances in dry eye disease treatment

PURPOSE OF REVIEW

The prevalence and burden of dry eye disease continues to grow at a rapid pace, creating an increased need for new therapies. In a sector once limited to only a handful of treatments, clinicians now have multiple options available for patients who fail traditional therapies. This review summarizes the various treatment options available to clinicians treating complex dry eye disease patients.

RECENT FINDINGS

As we better understand the multifactorial mechanisms leading to dry eye disease, treatments increasingly focus on the amelioration of the underlying deficiencies and inflammation, rather than on transient symptomatic relief alone. Most topical medications seek to replace deficient growth factors and/or decrease inflammation on the ocular surface. The majority of new devices and procedures seek to treat meibomian gland dysfunction, with one new device stimulating tear production through utilizing the nasolacrimal reflex pathway.

SUMMARY

Clinicians have more options at their disposal in the treatment of dry eye disease than ever before, including topical medications and devices.

Novel therapeutic approaches in utilizing platelet lysate in regenerative medicine: Are we ready for clinical use?

Hemoderivative materials are used to treat different diseases. These derivatives include platelet-rich plasma, serum, platelet gel, and platelet lysate (PL). Among them, PL contains more growth factors than the others and its production is inexpensive and easy. PL is one of the proper sources of platelet release factors. It is used in cells growth and proliferation and is a good alternative to fetal bovine serum. In recent years, the clinical use of PL has gained more appeal by scientists. PL is a solution saturated by growth factors, proteins, cytokines, and chemokines and is administered to treat different diseases such as wound healing, bone regeneration, alopecia, oral mucositis, radicular pain, osteoarthritis, and ocular diseases. In addition, it can be used in cell culture for cell therapy and tissue transplantation purposes. Platelet-derived growth factor, fibroblast growth factor, insulin-like growth factor, transforming growth factor β, and vascular endothelial growth factor are key PL growth factors playing a major role in cell proliferation, wound healing, and angiogenesis. In this paper, we scrutinized recent advances in using PL and PL-derived growth factors to treat diseases and in regenerative medicine, and the ability to replace PL with other hemoderivative materials.

Efficacy and safety of treatment of hyposecretory dry eye with platelet-rich plasma

OBJECTIVE

To evaluate and compare the symptomatology and clinical findings in hyposecretory dry eye of the treatment with platelet-rich plasma (PRP) and artificial tears of sodium hyaluronate (SH).

METHODS

Blind single-centre prospective comparative randomized study including 83 patients with hyposecretory dry eye and mean age of 64.0 years. Two groups were differentiated depending on the treatment applied: 44 patients treated with PRP (PRP group), and 39 patients treated with artificial tears of SH (SH group). Changes in Schimer test, tear osmolarity, corneal and conjunctival staining, tear film break-up time (TF-BUT), conjunctival hyperaemia, dry eye-related symptoms with the Ocular Surface Disease Index questionnaire, and caliciform cell density were evaluated during 30 days of treatment.

RESULTS

Significantly larger reduction in symptomatology (p < 0.001), visual improvement (p < 0.001), reduction in hyperaemia (p < 0.001), and corneal and conjunctival staining (p < 0.001), increment of Schirmer test outcome (p ≤ 0.005), and reduction of osmolarity were found in the PRP group in both eyes compared to SH group at 15 and 30 days of treatment. Likewise, a significantly higher increment of caliciform cell density (p < 0.001) was found in the PRP group. Strong and statistically significant correlations were found in the PRP group of the change achieved in visual acuity, hyperaemia, osmolarity, and conjunctival and corneal staining with the baseline values of these variables (p < 0.001).

CONCLUSION

PRP treatment in hyposecretory dry eye induces a more significant positive effect over symptomatology and different dry eye signs than SH, especially in moderate and severe cases.

Aucuba japonica Extract and Aucubin Prevent Desiccating Stress-Induced Corneal Epithelial Cell Injury and Improve Tear Secretion in a Mouse Model of Dry Eye Disease

Dry eye disease is affected by a broad range of causes such as age, lifestyle, environment, medication and autoimmune diseases. These causes induce tear instability that activates immune cells and promotes expression of inflammatory molecules. In this study, we investigated the therapeutic effects of an ethanolic extract of Aucuba japonica (AJE) and its bioactive compound, aucubin, on dry eye disease. The human corneal cells were exposed to desiccation stress induced by exposing cells to air, so that viability was decreased. On the other hand, pre-treatment of AJE and aucubin restored cell survival rate depending on the dose under the dry condition. This result was confirmed again by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The mRNA expression of inflammatory molecules was reduced by the pretreatment of AJE and aucubin under the dry state. The therapeutic effects of AJE and aucubin were examined in the animal model for dry eye induced by unilateral excision of the exorbital lacrimal gland. Declined tear volumes and corneal irregularity in the dry eye group were fully recovered by the administration of AJE and aucubin. The apoptotic cells on the cornea were also decreased by AJE and aucubin. Therefore, this study suggests that administration of AJE can be a novel therapeutic for dry eye disease and that the pharmacological activities of AJE may be in part due to its bioactive compound, aucubin.