Treatment of recurrent myopic macular hole using membrane of plasma rich in growth factors

Plasma rich in growth factors (PRGF) technology as adjuvant to Ab Externo trabeculectomy

PURPOSE

Plasma rich in growth factors (PRGF) technology creates blood-derived products with growth factors that promote wound healing and regeneration. The goal of this study was to assess the potential role of PRGF products as wound modulators in trabeculectomy. Our premise is that due to PRGF's regenerative and antifibrotic properties, its use in trabeculectomy may produce a more physiological bleb, without altering IOP reduction.

METHODS

A retrospective, longitudinal study was conducted in a Hospital in Portugal. Patients with eyes with open angle glaucoma were included. Trabeculectomy was performed on all patients using PRGF membrane (mPRGF) under the conjunctiva, as adjuvant. Data regarding patients' demographics and number of medications used, was collected. Intraocular pressure (IOP) before surgery, 8 days, 1 month, 3 month, 6 month, 9 month and 1 year after surgery was recorded. Bleb morphology was classified according to Moorfields Bleb Grading System 6 months after surgery.

RESULTS

Nine eyes of 9 patients were enrolled. Mean age was 71 ± 5.1 years old. Six were male. Mean IOP decreased from 24.0 ± 8.8 mmHg pre-surgery to 12.9 ± 2.6 mmHg at one year follow-up. The number of hypotensive drugs (mean ± SD) was 4.3 ± 0.9 preoperatively and 0.8 ± 1.1 at 1-year. Complete success was defined as IOP equal to or less than 21 mm Hg without ocular hypotensive medications and qualified success as IOP equal to or less than 21 mm Hg with medications. Complete success was 66.7% and qualified success was 100% at 1 year follow-up.

CONCLUSION

In our study, trabeculectomy with mPRGF demonstrated both safety and efficacy. Low values of bleb height (1.6 ± 0.8) were recorded. mPRGF could improve wound healing and produce a more well-tolerated, favourable bleb, avoiding antimetabolite complications.

PRGF Membrane with Tailored Optical Properties Preserves the Cytoprotective Effect of Plasma Rich in Growth Factors: In Vitro Model of Retinal Pigment Epithelial Cells

The present study evaluates the ability of a novel plasma rich in growth factors (PRGF) membrane with improved optical properties to reduce oxidative stress in retinal pigment epithelial cells (ARPE-19 cells) exposed to blue light. PRGF was obtained from three healthy donors and divided into four main groups: (i) PRGF membrane (M-PRGF), (ii) PRGF supernatant (S-PRGF), (iii) platelet-poor plasma (PPP) membrane diluted 50% with S-PRGF (M-PPP 50%), and (iv) M-PPP 50% supernatant (S-PPP 50%). ARPE-19 cells were exposed to blue light and then incubated with the different PRGF-derived formulations or control for 24 and 48 h under blue light exposure. Mitochondrial and cell viability, reactive oxygen species (ROS) production, and heme oxygenase-1 (HO-1) and ZO-1 expression were evaluated. Mitochondrial viability and cell survival were significantly increased after treatment with the different PRGF-derived formulations. ROS synthesis and HO-1 expression were significantly reduced after cell treatment with any of the PRGF-derived formulations. Furthermore, the different PRGF-derived formulations significantly increased ZO-1 expression in ARPE-19 exposed to blue light. The new PRGF membrane with improved optical properties and its supernatant (M-PPP 50% and S-PPP 50%) protected and reversed blue light-induced oxidative stress in ARPE-19 cells at levels like those of a natural PRGF membrane and its supernatant.

Plasma rich in growth factors membrane as a macular hole treatment in a vitrectomized patient due to rhegmatogenous retinal detachment

The formation of a macular hole after vitrectomy due to rhegmatogenous retinal detachment is a rare complication. Although there are different surgical options in the treatment of these macular holes with favorable outcomes, it has been shown that the history of macula-off retinal detachment is the most important risk factor related to the need for multiple interventions to close these macular holes, therefore special attention should be paid in the management of these patients. We present the case of a patient with macula-off rhegmatogenous retinal detachment who required treatment with cataract surgery with intraocular lens implant and pars plana vitrectomy. Four years after the primary surgery, she presented a large macular hole, and was treated with membrane of plasm rich in growth factors with closure of the macular hole and visual improvement without recurrence 12 months after surgery.

Plasma rich in growth factors as treatment for a full-thickness macular hole due to macular telangiectasia type 2

Full-thickness macular hole is a rare complication of macular telangiectasia type 2, and its treatment is still controversial. A patient with a full-thickness macular hole secondary to macular telangiectasia type 2 underwent vitreoretinal surgery with a plasma rich in growth factors membrane in the macular hole. At the sixth month of follow-up, anatomical and functional improvements were achieved, with no adverse effects. Plasma rich in growth factors is a new option, with advantages due to its biological properties that achieves good results in terms of safety and effectiveness in the surgical treatment of macular hole.

Plasma Rich in Growth Factors in Macular Hole Surgery

The aim of this study was to evaluate the use of PRGF (plasma rich in growth factors) as an adjuvant to PPV (pars plana vitrectomy) in recurrent, persistent, or poor prognosis MH (macular hole). Patients with MH were treated with PPV plus adjuvant therapy (PRGF membrane (mPRGF) and injectable liquid PRGF (iPRGF)). The anatomical closure of MH and postoperative BCVA (best-corrected visual acuity) were evaluated. Eight eyes (eight patients) were evaluated: myopic MH (MMH, n = 4), idiopathic MH (IMH, n = 2), iatrogenic n = 1, traumatic n = 1. The mean age was 53.1 ± 19.3 years. Hence, 66.7% (n = 4) of patients previously had internal limiting membrane peeling. Five patients (62.5%) received mPRGF and iPRGF, and three patients (37.5%) received iPRGF. Gas tamponade (C3F8) was placed in seven cases and one case of silicone oil. Anatomic closure of MH was achieved in seven eyes (87.5%) and BCVA improved in six cases. In the MMH group, visual acuity improved in two lines of vision. Follow-up time was 27.2 ± 9.0 months. No adverse events or MH recurrences were recorded during follow-up. The use of PRGF as an adjuvant therapy to PPV can be useful to improve anatomical closure and visual acuity in MH surgery.

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.

Plasma rich in growth factors as treatment for a full-thickness macular hole due to macular telangiectasia type 2

Full-thickness macular hole is a rare complication of macular telangiectasia type 2, and its treatment is still controversial. A patient with a full-thickness macular hole secondary to macular telangiectasia type 2 underwent vitreoretinal surgery with a plasma rich in growth factors membrane in the macular hole. At the sixth month of follow-up, anatomical and functional improvements were achieved, with no adverse effects. Plasma rich in growth factors is a new option, with advantages due to its biological properties that achieves good results in terms of safety and effectiveness in the surgical treatment of macular hole.

Development and optimization of a personalized fibrin membrane derived from the plasma rich in growth factors technology

PURPOSE

To develop and characterize a new type of plasma rich in growth factors (PRGF) membrane for patients in which immune system is involved in the disease etiology.

METHODS

Blood from three healthy donors was collected to obtain the different fibrin membranes by PRGF technology. PRGF obtained volumes were activated and divided into two groups: PRGF membrane (mPRGF) obtained after incubation at 37 °C for 30 min (control); and is-mPRGF: mPRGF obtained after incubation for 30 min at 56 °C. The concentration of several growth factors, proteins, immunoglobulin E and the complement activity was determined in the different mPRGF. The proliferative potential of heat-inactivated mPRGF were assayed on keratocytes (HK) and conjunctival fibroblasts (HConF). In addition, morphological and physical features of the inactivated mPRGF were evaluated in contrast to the control mPRGF.

RESULTS

Heat-inactivation of the mPRGF preserves the content of most of the growth factors involved in the ocular wound healing while reducing drastically the content of IgE and the complement activity. The heat-inactivated mPRGF conserve the morphological and physical characteristics of the fibrin meshwork in comparison with the control mPRGF. Furthermore, no significant differences were found in the biological activity of the control mPRGF regarding the heat-inactivated mPRGF (is-mPRGF) in any of both ocular cell types evaluated.

CONCLUSIONS

The heat-inactivation of the PRGF membranes (is-mPRGF) reduces drastically the content of IgE and complement activity while preserving the content of most of the proteins and morphogens involved in ocular wound healing. Furthermore, the morphological and physical features of the immunosafe mPRGF were also preserved after heat-inactivation.

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.

Reduced graphene oxide membranes in ocular regenerative medicine

Biological membranes are currently used in Ophthalmology in order to treat different ocular disorders. These membranes have different properties such as cellular biocompatibility and promoting wound healing. Moreover, intrinsic antimicrobial properties could also be desirable because it would allow their use reducing the risk of infections. Graphene and its derivatives are promising biomaterials that already proved their bactericidal effect. However, their clinical use is limited due to the controversial results regarding their toxicity. In this work, we have developed and characterized a reduced graphene oxide membrane (rGOM) for its use in ocular Regenerative Medicine, and studied its in vitro and in vivo biocompatibility and genotoxicity with different types of human ocular cells. We proved that rGOM allowed the growth of different ocular cells without inducing in vitro or in vivo cytotoxicity or genotoxicity in the short-term. These results indicate that rGOM may be a promising candidate in Regenerative Medicine for the treatment of different ocular pathologies.

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.