Eye platelet-rich plasma in the treatment of ocular surface disorders

Neurotrophic keratopathy: General features and new therapies

Neurotrophic keratopathy is an uncommon degenerative corneal disorder characterized by compromised corneal sensory innervation resulting in the formation of epithelial defects and nonhealing corneal ulcers. Various treatment modalities are available to stabilize disease progression, improve patient well-being, and prevent vision loss. For eligible patients, medical and surgical reinnervation have emerged as pioneering therapies, holding promise for better management. We present a comprehensive review of the disorder, providing an update relevant to ophthalmologists on pathogenesis, diagnosis, treatment options, and novel therapies targeting pathophysiological pathways.

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.

[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.

Evaluation of the Use of Highly Concentrated Autologous Platelet-Rich Plasma and Platelet-Rich Fibrin Membrane to Improve the Outcome in the Management of Severe Dry Eye Disease, Corneal Neurotrophic Ulcer and Corneal Burn

INTRODUCTION

The aim of this study was to evaluate the use of highly concentrated platelet-rich plasma (PRP) subconjunctival injections, in combination with eye drops (eye PRP, or E-PRP), in treating dry eye disease (DED) and the use of platelet-rich fibrin (PRF) membrane in treating corneal burns and neurotrophic ulcers for the restoration of the homeostasis of the tear film and the morphology and function of the cornea.

METHODS

We studied 16 patients (n=32 eyes) with severe DED. The disease was graded as severe according to the Oxford Grading Scale. There were 12 males (75%) and four females (25%) with a mean age of 56 years; these patients were treated with monotherapy, which involved a single subconjunctival injection of 0.2-0.3 mL of PRP prepared from autologous blood, followed by application of autologous PRP eye drops four times a day for 15 days between September 2019 and December 2020 in the same geographic area. All patients gave written informed consent before undergoing the outlined treatment protocol. We evaluated best corrected visual acuity (BCVA), Schirmer test score, tear film breakup time (TBUT) and corneal staining with fluorescein (Oxford Grading Scale) before and after six to eight weeks of treatment. Subjective normalization was defined by a decrease in the Ocular Surface Disease Index (OSDI) score to 10 or less, an objective normalization of the TBUT to five to six seconds, improvement in the Schirmer test score and Oxford grading and the BCVA gain of at least one line in the vision chart (Snellen chart). Furthermore, we report on the results from different variants of platelet concentrate-based treatments in five cases of corneal diseases: neurotrophic ulcers and corneal burns due to different causes (e.g., chemical burns) using E-PRP and PRF membrane with regard to normalization of morphology and function.

RESULTS

The OSDI score decreased to normalization in 75% of the patients (p=6.545 × 10-15). TBUT was restored significantly in 20 of 32 eyes from 2.78±0.55 to 5.43±0.71 (p=1.612 × 10-24). The Schirmer test score showed an improvement from 4.46±0.67 to 10.28±1.18 (p=3.411 × 10-29), and BCVA improved by 43.75%, from 0.15±0.19 to 0.09±0.16 (logMAR, p=0.2331). Oxford grading changed to Scale I in 75% and Scale 0 in 25% of the patients. No complications or adverse reactions occurred in the five cases of corneal injuries. We observed a restoration of the morphology and function of the cornea with PRP injections or PRF+PRP application in 7-12 days, depending on the severity of the initial finding.

CONCLUSION

 PRP treatment is a new approach in ophthalmology with impressive results. Although patients show good compliance and acceptance of the treatment protocol, studies with larger sample sizes are needed to confirm and optimize its use.

Current Advances in Regenerative Strategies for Dry Eye Diseases: A Comprehensive Review

Dry eye disease (DED) is an emerging health issue affecting millions of individuals annually. Ocular surface disorders, such as DED, are characterized by inflammation triggered by various factors. This condition can lead to tear deficiencies, resulting in the desiccation of the ocular surface, corneal ulceration/perforation, increased susceptibility to infections, and a higher risk of severe visual impairment and blindness. Currently, the clinical management of DED primarily relies on supportive and palliative measures, including the frequent and lifelong use of different lubricating agents. While some advancements like punctal plugs, non-steroidal anti-inflammatory drugs, and salivary gland autografts have been attempted, they have shown limited effectiveness. Recently, there have been promising developments in the treatment of DED, including biomaterials such as nano-systems, hydrogels, and contact lenses for drug delivery, cell-based therapies, biological approaches, and tissue-based regenerative therapy. This article specifically explores the different strategies reported so far for treating DED. The aim is to discuss their potential as long-term cures for DED while also considering the factors that limit their feasibility and effectiveness. These advancements offer hope for more effective and sustainable treatment options in the future.

Developing a Novel Platelet-Rich Plasma-Laden Bioadhesive Hydrogel Contact Lens for the Treatment of Ocular Surface Chemical Injuries

Permanent injury to corneal limbal stem cells after ocular surface chemical and thermal injuries is a major cause of corneal blindness. In this study, a PRP-laden GelMA hydrogel contact lens is manufactured which is aimed to support the limbal niche after ocular surface insults thereby preventing limbal stem cell failure. GelMA with varying platelet-rich plasma (PRP) concentrations (5%, 10%, and 20%) is photopolymerized using a visible light crosslinking system followed by characterizations of mechanical properties, growth factor release, enzymatic degradation, and in vitro cytotoxicity. The addition of 10% PRP into 10% GelMA hydrogel precursor solution results in the highest tensile and compressive modulus (38 and 110 kPa, respectively) and burst pressure (251±37.66 mmHg). Degradation time varies according to the concentration of the collagenase enzyme tested (0, 2.5, 5, and 40 µg/mL) and is most prolonged with 20% PRP. EGF and TGF-β release profiles suggest an initial burst release followed by sustained release, most consistent in the 10% PRP sample. Although cell viability decreases on day 1, rapid recovery is observed and is approximately 120% after day 21. PRP-laden GelMA in the form of a contact lens may be a promising biomaterial-based treatment approach for the maintenance of limbal epithelial stem cells after ocular surface insults.

Efficacy and safety of platelet-rich plasma and autologous-serum eye drops for dry eye in primary Sjögren's syndrome: a randomized trial

We compared the efficacy and safety of autologous-serum (AS) and platelet-rich plasma (PRP) eye drops for dry eye (DE) treatment in primary Sjögren's syndrome (SS). This prospective, randomized, double-blinded clinical study included patients diagnosed with primary SS DE. Thirty-eight participants were randomly assigned to the AS or PRP groups. Corneal and conjunctival staining scores, Schirmer I test, tear film break-up time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at 4 and 12 weeks. Conjunctival impression cytology (CIC) metaplasia grade and goblet cell density grade at 12 weeks were compared with those at baseline. Corneal and conjunctival staining scores and TBUT significantly improved at 4 and 12 weeks in both groups (all p < 0.005). No significant difference between the AS and PRP groups was observed at 4 and 12 weeks. The Schirmer I values, OSDI scores, CIC metaplasia grade, and goblet cell density grade did not significantly change at 4 and 12 weeks in either group. Both AS and PRP eye drops are effective for primary SS DE without a significant difference. Considering that the preparation time of PRP is shorter than that of AS, PRP can be a good alternative treatment for primary SS DE.

In vitro antibacterial efficacy of autologous conditioned plasma and amniotic membrane eye drops

OBJECTIVE

To determine the in vitro antibacterial efficacy of equine and canine autologous conditioned plasma (ACP) and amniotic membrane extract eye drops (AMEED) against aerobic bacteria common to the corneal surface.

PROCEDURES

Canine (n = 4) and equine (n = 4) anticoagulated whole blood samples were sterilely collected, pooled for each species, and processed using the Arthrex ACP® Double-Syringe System. Platelet counts were performed on ACP and pooled blood. AMEED were obtained from a commercial source. An electronic medical records search (2013-2022) identified aerobic bacteria cultured from canine and equine corneal ulcers at Mississippi State University College of Veterinary Medicine (MSU-CVM). Ten commonly isolated bacteria for each species were collected from cultures submitted to the MSU-CVM Microbiology Diagnostic Service and frozen at -80°C. The Kirby-Bauer disk diffusion method was used to determine the sensitivities of these isolates to ACP and AMEED. Bacterial isolates were plated onto Mueller-Hinton +5% sheep blood agar and blank sterile discs saturated with 20 μL of ACP or AMEED were tested in duplicate. Imipenem discs served as positive controls and blank discs as negative controls. Zones of inhibition were measured at 18 h.

RESULTS

ACP platelet counts were 1.06 and 1.65 times higher than blood for equine and canine samples, respectively. Growth of a multi-drug resistant Enterococcus faecalis was partially inhibited by canine and equine ACP. AMEED did not inhibit growth of any examined bacteria.

CONCLUSIONS

Canine and equine ACP partially inhibited E. faecalis growth in vitro. Further studies using varying concentrations of ACP against bacterial isolates from corneal ulcers are warranted.

Advances and prospects of platelet-rich plasma therapy in veterinary ophthalmology

In the recent decades, there has been a significant uptick on the use of platelet-rich plasma (PRP) as a better alternative for ophthalmologic therapies in pathologies, primarily of the ocular surface. PRP is a class of liquid platelet concentrate containing a supra-physiological concentration of platelets in a relatively small amount of plasma. Its potential to heal various tissues has piqued interest in its therapeutic application as a biomaterial in regenerative medicine. It is currently a popular therapeutic agent in plastic surgery, cardiothoracic surgery, reconstructive surgery, and even oral and maxillofacial surgery. Based on the data from in vitro and in vivo studies, it can be concluded that PRP possesses adequate therapeutic potential in ocular pathologies, especially those involving cornea. In addition, the high concentrations of growth factors (TGF-β, VEGF, EGF) present in the PRP accelerate the healing of the corneal epithelium. PRP has great therapeutic prospects in veterinary ophthalmology as a regenerative therapeutic modality. However, several variables are yet to be defined and standardized that can directly affect the efficacy of PRP application in different ophthalmic conditions. There is a shortage of research on the use of PRP in ocular surface defects compared to the number of studies and reports on the use of autologous and allogeneic serum eye drops. Therefore, a data-driven approach is required to generate consensus/guidelines for the preparation, characterization, and therapeutic use of PRP in veterinary ophthalmology. This review aims to inform readers of the latest research on PRP, including its preparation methods, physiological and biochemical properties, clinical applications in veterinary ophthalmology, and their safety and efficacy.

Mustard Gas-Induced Ocular Surface Disorders: An Update on the Pathogenesis, Clinical Manifestations, and Management

PURPOSE

Mustard gas (MG) is a potent blistering and alkylating agent that has been used for military and terrorism purposes. Ocular surface injuries are common after exposure to MG. This review provides an update on the pathophysiology, ocular surface complications, and treatment options for MG-related ocular injuries.

METHODS

Required information was obtained by reviewing various databases such as Cochrane Library, Google Scholar, and PubMed until March 2022. Data were collected by using keywords: "mustard gas" OR "sulfur mustard" AND "eye" OR "cornea" OR "ocular complication" OR "keratitis" OR "keratopathy" OR "limbal stem cell deficiency" OR "dry eye."

RESULTS

Chronic intracellular toxicity, inflammation, and ischemia have been shown to play an essential role in the pathogenesis of MG injury. Ocular surface injuries can have acute, chronic, and most distinctly a delayed-onset presentation leading to various degrees of limbal stem cell deficiency. To date, no treatment has been agreed on as the standard treatment for chronic/delayed-onset MG keratopathy. Based on the authors' experience, we propose a management algorithm for MG-related ocular surface injuries involving optimization of ocular health, anti-inflammatory therapy, and if needed surgical interventions. The management of chronic and delayed-onset presentation remains challenging.

CONCLUSIONS

MG keratopathy is a unique form of chemical injury which can lead to a range of ocular surface pathologies. Long-term anti-inflammatory therapy even in patients with seemingly mild disease may potentially reduce the likelihood of the development of more severe delayed-onset disease.

Mini-Conjunctival Limbal Autograft (Mini-CLAU) Using Platelet-Rich Plasma Eye Drops (E-PRP): A Case Series

PURPOSE

The purpose of this study was to introduce a new method of limbal stem cell transplantation using autologous platelet-rich plasma (E-PRP) eye drops for unilateral total limbal stem cell deficiency.

METHODS

Patients with total unilateral limbal stem cell deficiency due to chemical burn underwent mini-conjunctival limbal autograft using autologous E-PRP drops. One small limbal block, measuring 2 × 2 mm, was harvested from the patients' contralateral healthy eye and transplanted to the diseased eye. All patients received E-PRP drops until achieving complete corneal epithelialization. Subsequent corneal transplantation was performed in eyes with significant stromal opacification. Corneal buttons obtained during corneal transplantation underwent immunohistochemistry for the evaluation of limbal stem cell markers (ABCG2 and P63). Visual acuity, epithelial healing, corneal clarity, and regression of corneal conjunctivalization/vascularization were evaluated after surgery.

RESULTS

Ten patients with acid (n = 7) or alkali (n = 3) burn were included. The mean follow-up period was 21.7 ± 5.8 months (range, 12-32 months). Corneas were completely reepithelialized within 14.9 ± 3.5 days (range, 11-21 days). Corneal conjunctivalization/vascularization dramatically regressed 1 to 2 months after surgery in all cases, and corneal clarity considerably improved in 7 patients. In the 3 eyes with significant stromal opacification, subsequent optical penetrating keratoplasty was performed. The ocular surface was stable throughout the follow-up period in all eyes. BSCVA improved to 0.60 ± 0.0.32 and 0.46 ± 0.0.25 logMAR in eyes with and without corneal transplantation, respectively, at the final follow-up visit. ABCG2 and P63 markers were detected on corneal buttons after keratoplasty.

CONCLUSIONS

Based on our clinical and laboratory findings, mini-conjunctival limbal autograft using E-PRP can be considered as a promising alternative to ocular surface reconstruction.

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.

A Randomized Trial of Topical Fibrinogen-Depleted Human Platelet Lysate Treatment of Dry Eye Secondary to Chronic Graft-versus-Host Disease

Purpose

The purpose of the study was to evaluate, as a pilot trial, safety and tolerability of CAM-101 10% and 30% topical ophthalmic fibrinogen-depleted human platelet lysate (FD hPL) solution in patients with dry eye disease (DED) secondary to graft-versus-host disease (GvHD) after 6 weeks of treatment.

Design

A phase I/II, pilot, prospective, multicenter, randomized, double-masked clinical trial.

Participants

Patients with DED secondary to GvHD.

Methods

Sixty-four adult patients were stratified by “symptom severity” (Ocular Surface Disease Index [OSDI], ocular discomfort Visual Analog Scale (VAS), ocular symptom frequency, and use of artificial tears) and then randomized 1:1:1 to CAM-101 (FD hPL) at 10% or 30% concentration or an electrolyte (Plasma-Lyte A) vehicle control, 1 drop in both eyes, 4 times daily, for 42 days. After 42 days, control patients were offered 42 days of open-label treatment with 30% FD hPL.

Main Outcome Measures

Primary outcome safety measures were ocular and systemic adverse events and the number of patients in each group with clinically significant change from normal to abnormal in any ocular findings. Secondary outcomes were changes from baseline to day 42 in ocular discomfort, OSDI, fluorescein corneal staining, and lissamine green conjunctival staining relative to the vehicle control. The ocular symptom frequency was assessed on a 100-point VAS.

Results

FD hPL 10% and 30% were safe and well tolerated. Relative to the vehicle control, significant decreases from baseline to day 42 were seen in the FD hPL 30% group with regard to ocular discomfort (mean decrease = −18.04; P = 0.018), frequency of burning/stinging (−20.23; P = 0.022), eye discomfort (−32.97; P < 0.001), eye dryness (−21.61; P = 0.020), pain (−15.12; P = 0.044), photophobia (−24.33; P = 0.0125), and grittiness (−20.08; P = 0.0185). Decreases were also seen for itching and foreign body sensation, though not statistically significant. Improvements were seen in tear breakup time (mean increase = 1.30 seconds; P = 0.082) and the investigator’s global evaluation 4-point scale (mean decrease = −0.86; P = 0.026). Corneal fluorescein staining was not improved. The OSDI had a mean decrease of −8.88 compared to the vehicle, although not statistically significant.

Conclusions

Fibrinogen-depleted human platelet lysate appears to be well tolerated, with no significant toxicity at concentrations of 10% and 30%. These initial data suggest some efficacy, especially for subjective outcome measures relative to baseline assessments and treatment with the vehicle, but larger studies are needed to confirm these effects.

Application of platelet-rich fibrin grafts following pterygium excision

PURPOSE

To compare the efficacy, safety and recurrence rate of platelet-rich fibrin (PRF) grafts and limbal conjunctival autografts (LCAs) following pterygium excision.

METHODS

A total of 108 patients (108 eyes) with primary pterygium were included in this study and were divided into group A (56 eyes) and group B (52 eyes). Patients in group A underwent excision of the pterygium followed by LCA while patients in group B underwent PRF grafts following pterygium excision. The PRF was produced using the patient's own whole-blood sample by centrifugation and extrusion. The surgery time, intraoperative complications, postoperative complications, recurrence rate, intraocular pressure (IOP) and follow-up period were recorded and evaluated between the two groups.

RESULTS

The mean surgery time was significantly shorter in group B (25.0 ± 4.2 min) than in group A (36.5 ± 6.3 min) (P < .001). Recurrence was observed in two cases (3.6%) in group A while no recurrence was observed in group B. No graft loss was observed in either group. No other intra/postoperative complications such as a tear in the graft, injury to the medial rectus muscle, excessive bleeding, scleral necrosis, graft oedema, graft necrosis, pannus formation or symblepharon appeared in either group.

CONCLUSIONS

This study presented with a promising outcome of PRF graft applications in primary pterygium surgery. The use of PRF following pterygium excision is a simple, easily applicable, and comfortable method for both patients and surgeons, with less time consumption, recurrence rate and complications, which could be widely used in pterygium management.

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.

Ophthalmologic Manifestations of Primary Sjögren's Syndrome

Sjögren’s syndrome (SS) is a chronic, progressive, inflammatory, autoimmune disease, characterized by the lymphocyte infiltration of exocrine glands, especially the lacrimal and salivary, with their consequent destruction. The onset of primary SS (pSS) may remain misunderstood for several years. It usually presents with different types of severity, e.g., dry eye and dry mouth symptoms, due to early involvement of the lacrimal and salivary glands, which may be associated with parotid enlargement and dry eye; keratoconjunctivitis sicca (KCS) is its most common ocular manifestation. It is still doubtful if the extent ocular surface manifestations are secondary to lacrimal or meibomian gland involvement or to the targeting of corneal and conjunctival autoantigens. SS is the most representative cause of aqueous deficient dry eye, and the primary role of the inflammatory process was evidenced. Recent scientific progress in understanding the numerous factors involved in the pathogenesis of pSS was registered, but the exact mechanisms involved still need to be clarified. The unquestionable role of both the innate and adaptive immune system, participating actively in the induction and evolution of the disease, was recognized. The ocular surface inflammation is a central mechanism in pSS leading to the decrease of lacrimal secretion and keratoconjunctival alterations. However, there are controversies about whether the ocular surface involvement is a direct autoimmune target or secondary to the inflammatory process in the lacrimal gland. In this review, we aimed to present actual knowledge relative to the pathogenesis of the pSS, considering the role of innate immunity, adaptive immunity, and genetics.

Update review on five top clinical applications of human amniotic membrane in regenerative medicine

Due to the increasing number of studies performed in the field of regenerative medicine during the last two decades, more analytic studies are still needed to clarify the future prospect of this area of science. The main aim of this research was to review the clinical applications of human Amniotic membrane in the field of regenerative medicine critically. Furthermore, in the light of increasing numbers of available products derived from amniotic membrane, we aimed look in depth to see whether regenerative medicine research strategies have a place in the clinical setting. More specifically, in the present study, we attempted to provide insight on developing the new indication for more research and in the next step, for market leaders companies to expand cost-effectiveness of new derived AM products. 20 companies or distributers have offered some commercial products in this field. Survey on more than 90 clinical trials in last five years showed dermatology (and more specific wound healing), orthopedic, and ophthalmology are heavily biased toward multibillion dollar industry. Moreover, urology and dentistry with fewer numbers of clinical data in comparison with the above-mentioned areas, currently are in the path of translation (especially dentistry). In addition, otolaryngology and oncology with the lowest number showed more potential of research thorough understanding the properties that will help guiding the use of AM-derived products in these two areas in future. More than 50% of clinical studies were done or are developing in USA, which have the biggest share in market products. Subsequently, China, Egypt, India, Iran, and Germany with the ongoing clinical trials in different phases may have more approved products in near future.

Bioengineering Approaches for Corneal Regenerative Medicine

BACKGROUND

Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments.

METHODS

In this review, we first discussed the anatomy of the cornea and the required properties for reconstructing layers of the cornea. Regenerative approaches are divided into two main categories; using direct cell/growth factor delivery or using scaffold-based cell delivery. It is expected delivered cells migrate and integrate into the host tissue and restore its structure and function to restore vision. Growth factor delivery also has shown promising results for corneal surface regeneration. Scaffold-based approaches are categorized based on the type of scaffold, since it has a significant impact on the efficiency of regeneration, into the hydrogel and non-hydrogel based scaffolds. Various types of cells, biomaterials, and techniques are well covered.

RESULTS

The most important characteristics to be considered for biomaterials in corneal regeneration are suitable mechanical properties, biocompatibility, biodegradability, and transparency. Moreover, a curved shape structure and spatial arrangement of the fibrils have been shown to mimic the corneal extracellular matrix for cells and enhance cell differentiation.

CONCLUSION

Tissue engineering and regenerative medicine approaches showed to have promising outcomes for corneal regeneration. However, besides proper mechanical and optical properties, other factors such as appropriate sterilization method, storage, shelf life and etc. should be taken into account in order to develop an engineered cornea for clinical trials.

Human Platelet Lysate Supports Efficient Expansion and Stability of Wharton's Jelly Mesenchymal Stromal Cells via Active Uptake and Release of Soluble Regenerative Factors

Manufacturing of mesenchymal stromal cell (MSC)-based therapies for regenerative medicine requires the use of suitable supply of growth factors that enhance proliferation, cell stability and potency during cell expansion. Human blood derivatives such as human platelet lysate (hPL) have emerged as a feasible alternative for cell growth supplement. Nevertheless, composition and functional characterization of hPL in the context of cell manufacturing is still under investigation, particularly regarding the content and function of pro-survival and pro-regenerative factors. We performed comparative analyses of hPL, human serum (hS) and fetal bovine serum (FBS) stability and potency to support Wharton’s jelly (WJ) MSC production. We demonstrated that hPL displayed low inter-batch variation and unique secretome profile that was not present in hS and FBS. Importantly, hPL-derived factors including PDGF family, EGF, TGF-alpha, angiogenin and RANTES were actively taken up by WJ-MSC to support efficient expansion. Moreover, hPL but not hS or FBS induced secretion of osteoprotegerin, HGF, IL-6 and GRO-alpha by WJ-MSC during the expansion phase. Thus, hPL is a suitable source of factors supporting viability, stability and potency of WJ-MSC and therefore constitutes an essential raw material that in combination with WJ-MSC introduces a great opportunity for the generation of potent regenerative medicine products.

A humoral solution: Autologous blood products and tissue repair

Autologous blood-derived products (ABP) are the focus of growing scientific interest and are investigated and used for multiple medical indications. ABPs hold promise thanks to their availability, ease of preparation, and low risk of adverse allogenic reaction, hypersensitivity, and contamination. Compositional analysis of ABPs reveals a diverse mixture of cellular components, cytokines and growth factors that play roles in healing processes such as tissue proliferation and angiogenesis, modulation of the local environment through chemotaxis and regulation of inflammation and the extracellular matrix, as well as several immunomodulatory actions. Thus, the administration of ABP induces supraphysiological levels of components necessary for orchestrating reparative efforts in currently difficult-to-treat medical conditions. In this article, we review the variety of autologous blood-derived products, their composition, current clinical uses, regulatory climate, and mechanisms of action.

Platelet-Derived Products in Veterinary Medicine: A New Trend or an Effective Therapy?

Platelet-derived products (PDPs) have gained popularity, mainly due to their high concentrations of bioactive molecules such as growth factors and cytokines, which play important roles in tissue healing and regeneration. PDPs are obtained through minimally invasive procedures and their therapeutic effect has been widely recognized. In veterinary medicine, however, the lack of standard protocols to generate PDPs is a major hurdle for assessing the clinical relevance of PDP-based therapies and for their widespread usage. The aim of this review is to analyze the technical and scientific specificities of PDPs in terms of preparation methodologies, classification categorization, nomenclature, and biological proprieties to advance their future biotechnological potential in veterinary contexts.

Quantification of Growth Factors and Fibronectin in Diverse Preparations of Platelet-Rich Plasma for the Treatment of Ocular Surface Disorders (E-PRP)

Purpose

The purpose of this study was to quantify the presence of growth factors (GFs) and fibronectin in autologous platelet-rich plasma for topical ocular use (E-PRP) comparing their concentration when different preparation and preservation procedures were applied.

Methods

E-PRP was prepared with blood from healthy volunteers. The count of platelets, leukocytes, and red blood cells in the whole blood and E-PRP were performed. The concentration of the GFs platelet-derived growth factor BB (PDGF-BB), transforming growth factor β1 (TGF-β1), epidermal growth factor (EGF), vascular endothelial growth factor A (VEGF-A), and fibronectin was determined in each of the four procedures applied including fresh, frozen at −20°C for 3 months, fresh-spin, and frozen-spin at −20°C E-PRP samples. Posterior statistical analysis was performed to establish significant differences between groups and between GFs in relation to the amounts of platelets.

Results

Platelets in the E-PRP doubled in the number of basal values of whole blood (P ≤ 0.01). The blood cells in the E-PRP decreased drastically in red cells (99%) and also in leukocytes (82%). The concentration of PDGF-BB and EGF was significantly higher (P < 0.01) when the E-PRP samples were frozen at −20°C. However, no significant differences were observed for TGF-β1, VEGF-A, and fibronectin (P > 0.05). The concentration of GFs in the E-PRP did not necessarily correlate with the number of platelets.

Conclusions

Freezing the E-PRP for 3 months at −20°C increased the concentration of important proteins, such as PDGF-BB and EGF, and maintained the levels of others. These findings are essential because treatments, such as E-PRP, used by patients with ocular surface dysfunctions tend to prolong it in time. In addition, subsequent centrifugation of the E-PRP decreased the values of TFG-β1, but not the other GFs, which would allow adjusting the concentration of TFG-β1, as necessary. This procedure guarantees their correct conservation and viability.

Translational Relevance

This work demonstrates how clinical application can be improved by starting from basic research. The quantification of GFs and fibronectin in platelet-rich plasma (PRP) helps to clarify which is the best mode of preparation and preservation of PRP for clinical applications. This allows to optimize the product that is delivered to the patients as a treatment for the dysfunctions of the ocular surface, guaranteeing that the conservation does not affect at all the quality of the PRP that it is going to be used.

Treatment of Severe Keratoconus Hydrops With Intracameral Platelet-Rich Plasma Injection

PURPOSE

To present successful management of severe corneal hydrops by corneal optical coherence tomography (OCT) guidance and intracameral application of eye platelet-rich plasma (E-PRP) in a case with Down syndrome.

METHODS

A 36-year-old woman with Down syndrome presented with acute vision loss, pain, photophobia, and corneal edema in the left eye. Clinical examination revealed keratoconus in the right eye and extreme keratoconus with severe corneal hydrops in the left eye. Anterior segment OCT (MS-39, Costruzione Strumenti Oftalmici, Firenze, Italy) showed intrastromal cystic fluid collection and ruptured and detached Descemet membrane. The OCT-guided management of hydrops is first described in this case report.

RESULTS

Medical treatment and intracameral sulfur hexafluoride injection failed. A sterile 0.3 mL of E-PRP was injected into the anterior chamber. Clinical and anatomical improvement began from the first postoperative day, and corneal edema totally resolved at 1 week. Postoperatively, no significant side effect was noted except an early transient moderate (28 mm Hg) intraocular pressure peak. Anterior segment-OCT demonstrated dramatic normalization in corneal morphology with total disappearance of fluid in the cystic intracorneal space, closure of the DM rupture, and DM reattachment. The patient was stable during the 6-month follow-up.

CONCLUSIONS

In this case, intraocular E-PRP was a promising, apparently safe, and effective treatment option in management of corneal hydrops, in which conventional approaches failed. This is the first case in the literature to describe OCT appearance of corneal hydrops and intracameral use of E-PRP for the resolution of DM rupture in acute corneal hydrops.

TEMPO-Oxidized Sacchachitin Nanofibers (TOSCNFs) Combined with Platelet-Rich Plasma (PRP) for Management of Dry Eye Syndrome

Introduction

In this study, the combination of TEMPO-oxidized sacchachitin nanofibers (TOSCNFs) with chitosan-activated platelet-rich plasma (cPRP) was evaluated for remedying dry eye syndrome (DES).

Methods

TOSCNFs, designated T050SC, were generated. T050SC combined with chitosan-activated (cPRP) was formulated as eye drops for application for severe DES. To evaluate the effects of cPRP and TOSCNFs on the repair of corneal injury, in vitro studies were conducted using Statens Seruminstitut rabbit corneal (SIRC) epithelial cells for cell proliferation and cell migration assays, and a severe DES animal model using rabbits was established with benzalkonium chloride (BAC) treatment for the evaluation.

Results

Results showed that the optimal eye formulation contained PRP activated by 350 μg/mL of the low-molecular-weight chitosan group (L3) combined with 300 μg/mL TO50SC (L3+T050SC). In the WST-1 cell-proliferation assay, L3 and L3+TO50SC significantly increased Statens SIRC cell proliferation after 24 hrs of incubation. In the SIRC cell migration assay, the L3+TO50SC group showed a wound-healing efficiency of 89% after 24-hr treatment. After 5 days of treatment, Schirmer’s test results did not simulate the dry eye animal model. Typical cornea appearance and eye fluorescein staining results showed that the L3 group had the best effect on improving cornea haze and epithelial damage.

Conclusion

This study has determined that TOSCNFs effectively promoted the healing effect on severe cases of corneal damage, and also might enhance the clinical application and medical potential of PRP in ophthalmology.

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.

Cord Blood Platelet Lysate: In Vitro Evaluation to Support the Use in Regenerative Medicine

Platelet-rich plasma (PRP) is an inexpensive and safe substitute of recombinant growth factors in vitro and in vivo. Due to its putative effect on tissue repair, the use of autologous PRP has become largely popular. Recently, a jellified PRP derivative obtained from umbilical cord blood (CB) has been utilized in vivo to treat mucosal and cutaneous lesions. Nevertheless, whether PRP derived from CB and adult blood display different potency in promoting cell growth in vitro has been rarely investigated. In this study, we compared cytokine profile and mesenchymal cell growth supporting the ability of platelet lysate obtained from adult and cord blood. Our in vitro results strongly back the utilization of CB platelet lysate in vivo, as an efficacious, safe and inexpensive alternative to promote damaged tissue healing when the autologous PRP is contraindicated. Moreover, the policy of manufacturing CB platelet lysate can limit the current disposal of many collected CB units not suitable for transplant due to their low nucleated cell count.

Randomised, prospective clinical trial of platelet-rich plasma injection in the management of severe dry eye

BACKGROUND

To evaluate the effectiveness of platelet-rich plasma (PRP) injections in the treatment of severe dry eye.

METHODS

This prospective, intervention study included patients with severe dry eye who had been diagnosed with Sjogren syndrome. Patients were divided into two groups. The intervention group received PRP (n=15) injections on days 0, 30, 60 and 90, as well as hyaluronic acid five times per day. The comparison group received hyaluronic acid (n=15) five times per day. Subjects were measured at baseline and at 30, 60 and 90 days. The primary outcome measures were changes in corneal staining according to the Oxford classification, results of the Schirmer test and tear break-up time (TBUT). The secondary outcome measures were changes in the Ocular Surface Disease Index (OSDI) and treatment compliance.

RESULTS

All subjects completed the study. The intervention group showed improvements in all primary outcome measures when compared with the control group, including a reduction in corneal staining (p<0.001), increase in the mean Schirmer value from 5.6±0.7 to 9.0±1.1 mm, and an increase in TBUT from 4.0±0.4 to 6.4±0.4 s at day 90. An improvement in subjective OSDI values was also found.

CONCLUSION

PRP injection is safe and effective in improving tear parameters as well as subjective parameters, and was found to be superior to hyaluronic acid alone in the management of patients with severe dry eye. This represent a novel alternative treatment for severe dry eye.

TRIAL REGISTRATION NUMBER

NCT02257957.

Cutaneous and Mucosal Manifestations of Sjögren's Syndrome

Sjögren's syndrome is currently considered an "autoimmune epithelitis," as exocrine glands, especially salivary and lacrimal, are progressively destructed by an immune-mediated process associated with specific serum autoantibodies and local lymphocyte infiltrate. Xerostomia remains a key complain in patients with Sjögren's syndrome but should be evaluated also for other causes such as xerogenic medications, followed by radiation and chemotherapy for head and neck cancers, hormone disorders, infections, or other connective tissue diseases. Further, xerophtalmia (also known as dry eye) frequently associated with keratoconjunctivitis sicca cumulatively affects approximately 10-30% of the general population with increasing incidence with age and is more frequently secondary to non-autoimmune diseases. On the other hand, numerous patients with Sjögren's syndrome manifest signs of systemic dryness involving the nose, the trachea, the vagina, and the skin, suggesting that other glands are also affected beyond the exocrine epithelia. Skin involvement in Sjögren's syndrome is relatively common, and various manifestations may be present, in particular xeroderma, eyelid dermatitis, annular erythema, and cutaneous vasculitis. Additional skin non-vasculitic manifestations include livedo reticularis which may occur in the absence of vasculitis, and localized nodular cutaneous amyloidosis possibly representing lymphoproliferative diseases related to Sjögren's syndrome. The treatment of skin and mucosal manifestations in Sjögren's syndrome is similar regardless of the cause, starting from patient education to avoid alcohol and tobacco smoking and to pursue dental hygiene. In conclusion, a strict collaboration between the dermatologist and the rheumatologist is essential in the adequate management of Sjögren's syndrome skin and mucosal manifestations.

Clinical Efficacy of Platelet-Rich Plasma in the Treatment of Neurotrophic Corneal Ulcer

Purpose

Platelet-rich plasma (PRP) is an autologous blood product without preservatives and rich in proteins and growth factors which make it possible for cells to differentiate, proliferate, and migrate, thus stimulating healing and regeneration of tissues. The aim of this study was to evaluate the efficiency of autologous platelet-rich plasma in the treatment of neurotrophic keratopathy.

Methods

The study group consists of 25 patients with nonhealing corneal ulcers due to herpes simplex or herpes zoster infection and facial nerve or trigeminal nerve paralysis as a result of a neurosurgical operation caused by a tumour or stroke. The patients were given autologous platelet-rich plasma drops five times a day and additionally preservative-free artificial tears and a vitamin A ointment at night for maximum 3 months. The following were evaluated: best corrected visual acuity (BCVA), healing of corneal surface, subjective symptoms, and changes in corneal thickness with the use of anterior segment optical coherent tomography (AS-OCT).

Results

BCVA before the treatment was 0.10 ± 0.14, and after the treatment it was –0.3 ± 0.27 (p=0.001). Improved visual acuity and less subjective symptoms were observed in all patients. Complete healing of the ulceration was observed in 20 patients (80%). Four patients (16%) experienced considerable improvement of their clinical condition (reduced size and depth of the ulceration and inflammatory state: smaller conjunctival injection and swelling, improved visual acuity, and less subjective symptoms). In one of the patients, an amniotic membrane was transplanted due to the lack of improvement of his local condition. In all patients, the progression of corneal thinning was stopped. An average corneal thickness in its thinnest point was 322.3 ± 125.8 µm before the treatment, and 404.5 ± 118.7 µm (p < 0.05) after the treatment. None of the patients reported general or local side effects of the treatment.

Conclusions

Autologous platelet-rich plasma is a blood-based product which seems efficient in the treatment of neurotrophic keratopathy.

Amniotic membrane extract and eye drops: a review of literature and clinical application

The amniotic membrane (AM) has a long history of use in the treatment of various diseases of the ocular surface. It contains pluripotent cells, highly organized collagen, anti-fibrotic and anti-inflammatory cytokines, immune-modulators, growth factors, and matrix proteins. It is used to promote corneal healing in severely damaged eyes. Recently, AM extract and AM extract eye drops have been successfully used in clinical applications, including dry eye and chemical burns. We provide an overview on the recent progress in the preparation, mechanisms of action, and use of AM extract/AM extract eye drops for corneal and external eye diseases.

Comparison of growth factor and interleukin content of adult peripheral blood and cord blood serum eye drops for cornea and ocular surface diseases

INTRODUCTION

Various blood-derived products have been proposed for the topical treatment of ocular surface diseases. The aim of the study was to compare the different content of Growth Factors (GFs) and Interleukins (ILs) in peripheral blood (PB-S) and Cord Blood (CB-S) sera.

MATERIALS AND METHODS

Sera were obtained from 105 healthy adult donors (PB-S) and 107 umbilical/placental veins at the time of delivery (CB-S). The levels of epithelial-GF (EGF), fibroblast-GF (FGF), platelet-derived-GF (PDGF), insulin-GF (IGF), transforming-GF alpha (TGF-α,) and beta 1-2-3 (TGF-β1-β2-β3), vascular endothelial-GF (VEGF), nerve-GF (NGF), Interleukin (IL)-1β,IL-4,IL-6,IL-10, and IL-13 were assessed by Bio-Plex Protein Array System (Bio-Rad Laboratories, CA, USA). The Mann-Whitney test for unpaired data was applied to compare GFs and ILs levels in the two sources. The associations among each GF/IL level and the obstetric data for CB-S and hematological characteristics for PB-S were also investigated.

RESULTS

The levels of EGF, TGF-α, TGF-β2, FGF, PDGF, VEGF, NGF, IL-1B, IL-4, IL-6, IL-10, and IL-13 were significantly higher in CB-S compared to PB-S. Conversely, the levels of IGF-1, IGF-2, and TGF-β1 were significantly higher in PB-S. The female sex and the weight of the child showed a significant association in predicting EGF and PDGF levels.

CONCLUSION

A significantly different content in those GFs and ILs was demonstrated in the two blood sources. Since each GF/IL selectively regulates different cellular processes involved in corneal healing, the use of PB-S or CB-S should be chosen on the basis of the cellular mechanism to be promoted in each clinical case.

Treatment with platelet-rich plasma of surgically related dormant corneal ulcers

PURPOSE

To assess the effectiveness of autologous platelet-rich plasma for the treatment of dormant corneal ulcers secondary to corneal surgery and unresponsive to conventional treatment.

SETTING

VISSUM, Ophthalmology Institute of Alicante, Alicante, Spain.

DESIGN

Prospective nonrandomized, observational consecutive study.

METHODS

A total of 44 eyes of 28 patients with dormant corneal ulcers secondary to corneal surgery were included in a prospective study and treated with autologous platelet-rich plasma during 6 weeks. Wilcoxon signed-rank test was used to compare the effect of the treatment.

RESULTS

In all, 28 patients (65.1%) improved their visual acuity at least one line in Snellen chart, 26 (59.09%) had a decrease in the size of the ulcer or even a total closure, and 40 (90.9%) experienced an improvement in their symptoms. The results are also provided for the four groups of patients (keratoplasty, refractive surgery, cross-linking, and chronic postsurgical corneal edema).

CONCLUSION

Platelet-rich plasma eye drops shows to be a good option for the treatment of dormant corneal ulcers secondary to corneal surgery.

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

Dry eye syndrome (DES) is a multifactorial, frequent, pathology characterized by deficient tear production or increased evaporation of tears and associated with ocular surface alteration and inflammation. It mostly affects, but not exclusively, older individuals and leads to varying degrees of discomfort and decreased quality of life. Although the typical treatments of DES rely on using artificial tears, polyunsaturated fatty acids, integrin antagonists, anti-inflammatory agents, or on performing punctal occlusion, recently, standardized blood-derived serum eye drops (SED) are generating much interest as a new physiological treatment option. The scientific rationale in using SED for treating or releasing the symptoms of DES is thought to lie in its composition in multiple factors that resembles that of tears and contributes to the healing and protection of the ocular surface. This manuscript seeks to provide relevant background information on the management of DES, and on the increasing role that various types of SED or platelet lysates, from autologous or allogeneic origins, are playing in the improved therapeutic management of this pathology. The increasing role played by blood establishments in producing better-standardized SED is also addressed.

Autologous Platelet-Rich Plasma Eye Drops for the Treatment of Post-LASIK Chronic Ocular Surface Syndrome

Purpose

To evaluate the efficacy of autologous platelet-rich plasma (E-PRP) eye drops for the treatment of chronic ocular surface syndrome (OSS) following laser in situ keratomileusis (LASIK).

Methods

This prospective interventional consecutive clinical study include 156 eyes of 80 patients affected by post-LASIK chronic OSS who were treated with autologous E-PRP 6 times a day as monotherapy for 6 weeks.

Results

Dry eye symptoms improved in 85% of the cases. A decrease in at least one quadrant to total disappearance on CFS was observed in 89.6% of the patients who had positive CFS before treatment. Three eyes presented severe punctate keratitis (1.9%) at baseline, all of which healed completely. Conjunctival hyperemia improved in 93.3% of the patients with previous signs of ocular surface inflammation. There was a significant improvement in logMAR CDVA from 0.14 ± 0.19 to 0.06 ± 0.12 (p = 0.000), and 74 (71.4%) eyes improved at least 1 line in CDVA.

Conclusion

Monotherapy with autologous E-PRP is a well-tolerated, safe, and effective treatment for the management of post-LASIK ocular surface syndrome.

Precis

Monotherapy with autologous platelet-rich plasma eye drops has been shown to be an adequate option for the treatment of post-LASIK chronic ocular surface syndrome. This trial is registered with NCT03322917.

Regenerative Therapies in Dry Eye Disease: From Growth Factors to Cell Therapy

Dry eye syndrome is a complex and insidious pathology with a high level of prevalence among the human population and with a consequently high impact on quality of life and economic cost. Currently, its treatment is symptomatic, mainly based on the control of lubrication and inflammation, with significant limitations. Therefore, the latest research is focused on the development of new biological strategies, with the aim of regenerating affected tissues, or at least restricting the progression of the disease, reducing scar tissue, and maintaining corneal transparency. Therapies range from growth factors and cytokines to the use of different cell sources, in particular mesenchymal stem cells, due to their multipotentiality, trophic, and immunomodulatory properties. We will review the state of the art and the latest advances and results of these promising treatments in this pathology.

Treatment of Dry Eye Disease with Autologous Platelet-Rich Plasma: A Prospective, Interventional, Non-Randomized Study

Introduction

The objective of this study was to evaluate the use of autologous platelet-rich plasma (PRP) eye drops as monotherapy for the treatment of moderate to severe cases of dry eye disease.

Methods

Three hundred and sixty-eight patients with moderate to severe dry eye disease (DED) were included in this prospective case series. Subjects were classified as evaporative DED (EDED) or aqueous deficient DED (ADDED). Improvement of the DED subjective symptoms, corneal fluorescein staining (CFS), and corrected distance visual acuity (BCVA) were evaluated. We also analysed how many rounds of PRP therapy were used.

Results

Two hundred and ninety-seven (80.7%) patients were women, and 71 (19.3%) were men. Two hundred and thirty-two (63%) patients had EDED, while 136 (37%) had ADDED. After 6 weeks of monotherapy treatment with autologous PRP, dry eye symptoms improved in 322 (87.5%) cases. A decrease of CFS was observed in 280 (76.1%) patients. One hundred and six (28.8%) patients improved at least 1 line of BCVA. The scores in the ocular Surface Disease Index and the Oxford scale of corneal fluorescein staining decreased statistically after the treatment (p < 0.05).

Conclusion

The topical use of autologous platelet-rich plasma as monotherapy is an effective treatment to improve signs and symptoms in patients suffering from moderate to severe chronic DED.

TFOS DEWS II iatrogenic report

Dry eye can be caused by a variety of iatrogenic interventions. The increasing number of patients looking for eye care or cosmetic procedures involving the eyes, together with a better understanding of the pathophysiological mechanisms of dry eye disease (DED), have led to the need for a specific report about iatrogenic dry eye within the TFOS DEWS II. Topical medications can cause DED due to their allergic, toxic and immuno-inflammatory effects on the ocular surface. Preservatives, such as benzalkonium chloride, may further aggravate DED. A variety of systemic drugs can also induce DED secondary to multiple mechanisms. Moreover, the use of contact lens induces or is associated with DED. However, one of the most emblematic situations is DED caused by surgical procedures such as corneal refractive surgery as in laser-assisted in situ keratomileusis (LASIK) and keratoplasty due to mechanisms intrinsic to the procedure (i.e. corneal nerve cutting) or even by the use of postoperative topical drugs. Cataract surgery, lid surgeries, botulinum toxin application and cosmetic procedures are also considered risk factors to iatrogenic DED, which can cause patient dissatisfaction, visual disturbance and poor surgical outcomes. This report also presents future directions to address iatrogenic DED, including the need for more in-depth epidemiological studies about the risk factors, development of less toxic medications and preservatives, as well as new techniques for less invasive eye surgeries. Novel research into detection of early dry eye prior to surgeries, efforts to establish appropriate therapeutics and a greater attempt to regulate and oversee medications, preservatives and procedures should be considered.

Platelet rich plasma in ocular surface

The use of platelet-rich preparations has experienced a significant increase in recent years due to its role in tissue-repair and regeneration. The aim of this study is to examine the available evidence regarding the application of plasma rich in growth factors, and its variations, on the ocular surface. A review is also presented on the effects of platelet-derived growth factors, the implications of the preparation methods, and the existing literature on the safety and efficacy of these therapies in ocular surface diseases. Despite the widespread use of platelet preparations there is no consensus on the most appropriate preparation method, and growth factors concentration vary with different systems. These preparations have been used in the treatment of ocular surface diseases, such as dry eye or persistent epithelial defects, among others, with good safety and efficacy profiles, but further studies are needed to compare to the currently available alternatives.

Ocular Involvement in Systemic Autoimmune Diseases

Eye involvement represents a common finding in patients with systemic autoimmune diseases, particularly rheumatoid arthritis, Sjogren syndrome, seronegative spondyloarthropathy, and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The eye is a privileged immune site but commensal bacteria are found on the ocular surface. The eye injury may be inflammatory, vascular or infectious, as well as iatrogenic, as in the case of hydroxychloroquine, chloroquine, corticosteroids, and bisphosphonates. Manifestations may affect different components of the eye, with episcleritis involving the episclera, a thin layer of tissue covering the sclera; scleritis being an inflammation of the sclera potentially leading to blindness; keratitis, referring to corneal inflammation frequently associated with scleritis; and uveitis as the inflammation of the uvea, including the iris, ciliary body, and choroid, subdivided into anterior, posterior, or panuveitis. As blindness may result from the eye involvement, clinicians should be aware of the possible manifestations and their management also independent of the ophthalmologist opinion as the therapeutic approach generally points to the underlying diseases. In some cases, the eye involvement may have a diagnostic implication, as for episcleritis in rheumatoid arthritis, or acute anterior uveitis in seronegative spondyloarthritis. Nonetheless, some conditions lack specificity, as in the case of dry eye which affects nearly 30 % of the general population. The aim of this review is to elucidate to non-ophthalmologists the major ocular complications of rheumatic diseases and their specific management and treatment options.

Solid Platelet Rich Plasma in Corneal Surgery

Abstract

Solid eye platelet-rich plasma (E-PRP) concentrates platelets in a small volume of plasma which contains a high concentration of important growth factors and cell adhesion molecules. These cell adhesion molecules and growth factors occupy a major role in wound healing and enhance the physiological procedure at the site of the injury or the surgery. There are different materials used to tectonically maintain the solid clot attached at the site where treatment is necessary. Although AM may be used for this purpose, other biomaterials such a bovine pericardium or autologous fibrin membrane are at least as effective with less interdonor variations, no biological hazards, providing a better surgical alternative than the biologically so variable amniotic membrane patch. Solid platelet-rich plasma in the form obtained in ophthalmology, E-PRP, is a reliable and effective surgical coadjuvant to promote corneal wound healing in severe corneal ulcers and corneal perforations, and may be associated with other ocular surface reconstruction procedures.

Funding

Supported in part by a grant from the Spanish Ministry of Science and Innovation, Centro para el Desarrollo Tecnológico Industrial (CDTI), CENIT: “Customized Eye Care”, CeyeC (CEN-20091021).

Solvent/Detergent Virally Inactivated Serum Eye Drops Restore Healthy Ocular Epithelium in a Rabbit Model of Dry-Eye Syndrome

Application of autologous serum eye drops (SEDs) is a recognized means to treat severe dry-eye syndrome (DES). Due to the inconvenience and difficulty of preparing SEDs from some patients, producing SEDs from allogeneic blood donations is gaining popularity. A major safety concern associated with allogeneic blood is virus transmission. We therefore herein evaluated the possibility of applying a solvent/detergent (S/D) treatment to inactivate viruses and studied the impacts of such treatment of SEDs to resolve DES in a rabbit model. Sera prepared from the blood of five rabbits were pooled and divided into two sub-pools. One was untreated (SEDs), while the other was virally-inactivated with 1% Tri-n-butyl phosphate/1% Triton X-45 at 31°C for 1 h (S/D-SEDs). DES was induced in rabbits using 0.1% benzalkonium chloride (BAC). Rabbits were divided into five groups of two rabbits each. One group was untreated (control), three were treated twice daily for 3 weeks using PBS, SEDs, or S/D-SEDs, and the last received an additional 0.1% BAC (as the negative control). The DES condition was determined by measuring aqueous tear secretion (Schirmer’s test), corneal fluorescein staining, a corneal histologic examination, TUNEL stain apoptosis, and corneal inflammatory marker (tumor necrosis factor-α, interleukin (IL)-1β, IL-8, and IL-6) expressions. We first confirmed that SEDs and S/D-SEDs had similar protein profiles and transforming growth factor (TGF)-β contents. Animal experiments showed that tear secretion did not significantly differ between the SED and S/D-SED groups but was significantly higher than in the PBS group. Eye fluorescein staining revealed dramatic improvements in epithelial defects in groups treated with SEDs or S/D-SEDs, and hematoxylin/eosin staining revealed microscopic epithelial layers similar to those of the untreated controls. Inflammatory markers and TUNEL studies showed that healthy epithelium had been restored in groups treated with SEDs or S/D-SEDs. In conclusion, this preclinical study supports the possibility of using S/D virally inactivated SEDs to treat DES and restore a normal epithelium.

The Effect of Autologous Platelet Lysate Eye Drops: An In Vivo Confocal Microscopy Study

Purpose. To determine the effectiveness of autologous platelet lysate (APL) eye drops in patients with primary Sjögren syndrome (SS) dry eye, refractory to standard therapy, in comparison with patients treated with artificial tears. We focused on the effect of APL on cornea morphology with the in vivo confocal microscopy (IVCM). Methods. Patients were assigned to two groups: group A used autologous platelet lysate QID, and group B used preservative-free artificial tears QID, for 90 days. Ophthalmological assessments included ocular surface disease index (OSDI), best corrected visual acuity (BCVA), Schirmer test, fluorescein score, and breakup time (BUT). A subgroup of patients in group A underwent IVCM: corneal basal epithelium, subbasal nerves, Langerhans cells, anterior stroma activated keratocytes, and reflectivity were evaluated. Results. 60 eyes of 30 patients were enrolled; in group A (n = 20 patients) mean OSDI, fluorescein score, and BUT showed significant improvement compared with group B (n = 10 patients). The IVCM showed a significant increase in basal epithelium cells density and subbasal nerve plexus density and number and a decrease in Langerhans cells density (p < 0.05). Conclusion. APL was found effective in the treatment of SS dry eye. IVCM seems to be a useful tool to visualize cornea morphologic modifications.