Plasma Rich in Growth Factors for the Treatment of Cicatrizing Conjunctivitis

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

PURPOSE

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

BASIC PROCEDURES

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

MAIN FINDINGS

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

PRINCIPAL CONCLUSIONS

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

A multicenter report of the use of plasma rich in growth factors (PRGF) for the treatment of patients with ocular surface diseases in North America

PURPOSE

To investigate the efficacy and safety of plasma rich in growth factors (PRGF) eyedrops in the management of patients with ocular surface diseases in North America.

METHODS

Multicenter interventional case series of patients using PRGF eyedrops for the first time. A cohort of patients was analyzed for corneal staining score at initial visit and at 3 months of therapy with PRGF. Another cohort responded to a 10-item questionnaire that evaluated patients' satisfaction and safety, which included the symptom assessment questionnaire in dry eye (SANDE) score, after 6 months of PRGF treatment.

RESULTS

A total of 153 patients were analyzed. Of these, 102 were reviewed for corneal epitheliopathy and 99 patients responded to the questionnaire. The mean (±SD) age of the population was 63.7 ± 17 years and 72.5% were female. The clinical indications for PRGF usage were dry eye (60%), neurotrophic keratopathy (15%), dormant corneal ulcers (12%), limbal stem cell deficiency (10%), and cicatrizing conjunctivitis (4%). At the final visit, 74.3% of patients showed an improvement of their corneal staining. Those who had punctate epithelial erosions or epithelial defects were reduced from 76.5% to 47% and 23.5%-7.8% respectively (p < 0.0001). Symptoms, measured via SANDE score, significantly decreased from a median of 90 to 34.6 out of 100 points on follow-up (p < 0.0001). Only one patient (0.98%) complained of ocular burning sensation as a side effect.

CONCLUSIONS

This multicentric study demonstrates the safety and efficacy of the use of PRGF for treating signs and symptoms in patients with significant ocular surface diseases.

Combined therapy of ocular surface disease with plasma rich in growth factors and scleral contact lenses

PURPOSE

To review safety and efficacy of combined plasma rich in growth factors (PRGF) eye drops and scleral contact lens (SCL) therapy in patients with ocular surface disease.

METHODS

Patients with ocular surface disease of various etiologies were screened for at least 3 months of concurrent treatment with PRGF and SCL. Retrospective pre- and post-treatment measurements were collected, including patient satisfaction, severity and frequency of dry eye symptoms measured by a modified Symptom Assessment in Dry Eye (SANDE) questionnaire, visual acuity, and number of concurrent treatments.

RESULTS

26 patients with ocular surface disease were included in the study with 20 patients answering the questionnaire (77% response rate). There were no adverse events reported. Most patients thought the combined therapy was better than previous treatments and would recommend to others (80%, 90% respectively). SANDE scores significantly decreased after use of concurrent therapy. There was a small but significant decrease in the number of other concurrent treatments. Visual acuity was unchanged.

CONCLUSIONS

This retrospective cohort study found PRGF used in combination with SCL is safe and significantly decreases symptoms in patients with recalcitrant ocular surface disease.

Progress in the use of plasma rich in growth factors in ophthalmology: from ocular surface to ocular fundus

Introduction: The use of blood derivatives and especially Plasma rich in growth factors (PRGF), for regenerative purposes has been a common trend along the last decades in the field of oral surgery, dermatology, orthopedics, and more recently in ophthalmology.Areas covered: PRGF is a type of platelet-rich plasma that is being explored for the treatment of ocular injuries. The present review article highlights 50 ophthalmology-related publications about the application of PRGF in the treatment of acute and chronic pathologies in ophthalmology as well as most relevant challenges and future prospects.Expert opinion: PRGF technology provides a wide range of formulations that can be used therapeutically in many different acute and chronic ocular pathologies. In addition to eye drops enriched with autologous growth factors, PRGF enables the preparation of both immunologically safe and fibrin-based formulations. Recent advances in the field have promoted PRGF storage for 12 months under freezing conditions, its daily use for 7 days at room temperature and the freeze-dried formulation. The thermally treated immunosafe formulation has shown promising clinical results for the treatment of several diseases such as Sjögren syndrome, graft versus host disease or cicatrizing conjunctivitis. In addition, several fibrin formulations have been preclinically evaluated and clinically incorporated as an adjuvant to ocular surface or glaucoma surgeries, dermal fat graft procedures, limbal stem cell expansion and retinal surgeries. The present review explores the latest scientific and clinical data, current challenges, and main prospects of this technology for the treatment of several ocular injuries.

Plasma Rich in Growth Factors Promotes Autophagy in ARPE19 Cells in Response to Oxidative Stress Induced by Blue Light

Age-related macular degeneration (AMD) causes the degeneration of photoreceptors and retinal cells leading to vision loss in older subjects. Among possible exogenous risk factors, it has been recently proposed that long-term exposure to blue light could aggravate the course of AMD. In the search for therapeutic options, plasma rich in growth factors (PRGF) has been shown to enhance cell antioxidant pathways and protect photoreceptors against the harm produced by blue light, although its mechanism of action remains unknown. One possible mechanism, autophagy, is one of the most conservative cell renewal systems used in eukaryotes to destroy cellular components that have been damaged by some kind of insult. The oxidative stress of exposure to blue light is known to induce cell autophagy. In this study, we examined the combined effects on autophagy of blue light and PRGF in a retinal cell line, ARPE19. In response to treatment with both PRGF and blue light, we detected the modulated expression of autophagy markers such as NF-kB, p62/sqstm1, Atg5, LC3 and Beclin1, and inflammatory markers such as IL1B and IL18. Our findings suggest that PRGF promotes cell autophagy in response to exposure to blue light.

Fibrin-Plasma Rich in Growth Factors Membrane for the Treatment of a Rabbit Alkali-Burn Lesion

The purpose of this work is to describe the use of Fibrin-Plasma Rich in Growth Factors (PRGF) membranes for the treatment of a rabbit alkali-burn lesion. For this purpose, an alkali-burn lesion was induced in 15 rabbits. A week later, clinical events were evaluated and rabbits were divided into five treatment groups: rabbits treated with medical treatment, with a fibrin-PRGF membrane cultured with autologous or heterologous rabbit Limbal Epithelial Progenitor Cells (LEPCs), with a fibrin-PRGF membrane in a Simple Limbal Epithelial Transplantation and with a fibrin-PRGF membrane without cultured LEPCs. After 40 days of follow-up, corneas were subjected to histochemical examination and immunostaining against corneal or conjunctival markers. Seven days after alkali-burn lesion, it was observed that rabbits showed opaque cornea, new blood vessels across the limbus penetrating the cornea and epithelial defects. At the end of the follow-up period, an improvement of the clinical parameters analyzed was observed in transplanted rabbits. However, only rabbits transplanted with cultured LEPCs were positive for corneal markers. Otherwise, rabbits in the other three groups showed positive staining against conjunctival markers. In conclusion, fibrin-PRGF membrane improved the chemically induced lesions. Nonetheless, only fibrin-PRGF membranes cultured with rabbit LEPCs were able to restore the corneal surface.

Plasma Rich in Growth Factors Enhances Cell Survival after in Situ Retinal Degeneration

PURPOSE

The purpose of this study was to examine the effect of plasma rich in growth factors (PRGFs) under blue light conditions in an in vivo model of retinal degeneration.

METHODS

Male Wistar rats were exposed to dark/blue light conditions for 9 days. On day 7, right eyes were injected with saline and left eyes with PRGF. Electroretinography (ERG) and intraocular pressure (IoP) measurements were performed before and after the experiment. After sacrifice, retinal samples were collected. Hematoxylin and eosin staining was performed to analyze the structure of retinal sections. Immunofluorescence for brain-specific homeobox/POU domain protein 3A (Brn3a), choline acetyltransferase (ChAT), rhodopsin, heme oxygenase-1 (HO-1), and glial fibrillary acidic protein (GFAP) was performed to study the retinal conditions.

RESULTS

Retinal signaling measured by ERG was reduced by blue light and recovered with PRGF; however, IoP measurements did not show significant differences among treatments. Blue light reduced the expression for Brn3a, ChAT, and rhodopsin. Treatment with PRGF showed a recovery in their expressions. HO-1 and GFAP results showed that blue light increased their expression but the use of PRGF reduced the effect of light.

CONCLUSIONS

Blue light causes retinal degeneration. PRGF mitigated the injury, restoring the functionality of these cells and maintaining the tissue integrity.