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

Long term stability of preservative-free and lyophilized PRGF eye drops stored at different temperature conditions: in vitro comparative study

Long-term stability of blood-derived eye drops is required to adapt the use of this treatment to prolonged clinical treatments and more green pharmacy. This study has been designed to assess the long-term storage life of freeze-dried plasma rich in growth factors (PRGF) eye drops, maintaining their biological content and activity. Thus, blood from five healthy donors was extracted and centrifuged for obtaining PRGF. The obtained PRGF eye-drops after platelet activation were freeze-stored or were lyophilized and then stored for 18 and 24 months at room temperature (RT) or at + 5 °C. Growth factor content and proliferative potential of PRGF eye drops on primary human keratocytes (HK) was evaluated at each storage time and condition. All growth factors maintained their levels at each time and storage condition. No differences were observed on the proliferative activity of keratocytes after treatment with freeze-dried PRGF eye-drops stored at RT or +5 °C for 18 or 24 months in comparison with fresh samples. No microbial contamination was observed in any of the PRGF eye-drops. Accepting the limitations of this study, it is observed that freeze-dried PRGF eye drops retain both key growth factors and biological activity when stored at room temperature or +5 °C for up to 18-24 months.

Autologous blood in the management of ocular surface disorders

Autologous blood therapy has emerged as a promising modality in managing ocular surface disorders. This review provides a comprehensive overview of the current literature regarding the use of autologous blood in ocular surface disorders, encompassing its physiological basis, clinical applications, techniques, challenges, and future perspectives. The ocular surface, comprising the cornea, conjunctiva, and tear film, plays a critical role in maintaining visual function, and its disruption can lead to various pathological conditions. With its rich composition of growth factors, cytokines, and other bioactive molecules, autologous blood offers therapeutic potential in promoting corneal wound healing, reducing inflammation, and improving tear film stability. Clinical studies have demonstrated the efficacy and safety of autologous blood therapy in diverse ocular surface disorders, including persistent epithelial defects, neurotrophic keratopathy, and dry eye disease. However, challenges such as variability in treatment response, adverse effects, and optimal patient selection remain areas of concern. Further research is needed to elucidate the underlying mechanisms of action, refine treatment protocols, and explore synergistic approaches with other therapeutic modalities. Despite these challenges, autologous blood therapy holds promise as a valuable adjunctive treatment option for ocular surface disorders, offering new avenues for improving patient outcomes and quality of life. This review examines the mechanisms underlying ocular surface disorders while discussing existing autologous blood-based therapies for managing these disorders. Current clinical trials are also summarized, and a comparison between autologous blood therapy and conventional eyedrops is attempted. Finally, safe techniques and protocols for autologous blood medicine are elucidated, and adverse effects and future perspectives of this novel therapy are reviewed.

Long-term Results of Topical Insulin Treatment for Persistent Corneal Epithelial Defects

Purpose

To evaluate the effects of topical insulin in patients with persistent corneal epithelial defects that are refractory to the standard treatment.

Methods

A retrospective, hospital-based, clinical study was performed on 17 eyes of 16 patients with different types of refractory persistent epithelial defects who were treated with topical insulin. The treatment was continued until the defect either was resolved or persisted after three months. Patients' demographic information, etiology, comorbidities, and clinical data were reviewed. The rate of epithelial healing was considered as the primary outcome measure.

Results

Neurotrophic keratitis was the most common cause of persistent epithelial defects (58.8%), and within this category, herpetic eye disease was the main comorbidity (44.4%). The mean follow-up time was 17.91 months. Eleven out of fifteen eyes (77.3%) had complete improvement and only one patient did not respond to the treatment. The mean time of reepithelization for the eyes with full recovery was 31.27 days (ranging from 6 to 61 days). The best-corrected visual acuity improved significantly after treatment (P < 0.005), and there were no reports of complications or side effects during the study period.

Conclusion

Our results suggest that topical insulin, due to its good safety profile, availability, and affordability, could be a good therapeutic alternative for persistent epithelial defects.

The role of topical insulin in ocular surface restoration: A review

Corneal epithelial defects are one of the most common ocular disorders. Restoring corneal integrity is crucial to reduce pain and regain function, but in cases of neurotrophic or desensitized corneas, healing can be significantly delayed. Treating neurotrophic corneas is challenging for ophthalmologists, and surgical intervention is often indicated to manage refractory cases that are unresponsive to medical therapy. Over the last decade, as more expensive therapeutics reach the market, topical insulin has returned to the forefront as an affordable option to improve corneal wound healing. There is still a paucity of data on the use and the efficacy of topical insulin, with no consensus regarding its indications, preparation, or posology. Here we review the literature on topical insulin for corneal and ocular surface pathologies, with a focus on the current evidence, its mechanisms of action, and its safety profile. Additionally, we share our experience in the field and provide a potential framework for future research.

Safety of intraoperative autologous plasma incubation of corneal grafts for reducing endothelial cell loss: a pilot study

Background/aims

Corneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL).

Methods

Pilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions.

Results

Thirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p = 0.02, and 44% vs. 33%, p = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points (p = 0.03 and p = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month (p = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group (p < 0.005).

Conclusion

Preoperative incubation with APP is safe and promotes better endothelial cell quality and quantity in the early postoperative period following PK. These findings suggest a potential clinical benefit in enhancing graft outcomes and warrant further investigation.

Topical Insulin for Ocular Surface Disease

Background: Insulin and insulin-like growth factor (IGF)-1 receptors are present in ocular tissues such as corneal epithelium, keratocytes, and conjunctival cells. Insulin plays a crucial role in the growth, differentiation, and proliferation of corneal epithelial cells, as well as in wound healing processes in various tissues. Purpose: This review explores the potential role of topical insulin in the treatment of ocular surface diseases. Specifically, it examines its impact on corneal nerve regeneration, sub-basal plexus corneal nerves, and its application in conditions like corneal epithelial defects, dry eye disease, and diabetic keratopathy. Methods: The review analyzes studies conducted over the past decade that have investigated the use of topical insulin in ocular surface diseases. It focuses on indications, drug preparation methods, side effects, efficacy outcomes, and variations in insulin concentrations and dosages used. Results: While off-label use of topical insulin has shown promising results in refractory corneal epithelial defects, its efficacy in dry eye disease is yet to be demonstrated. Variations in concentrations, dilutions, and dosing guidelines have been reported. However, limited data on ocular penetration, ocular toxicity, and systemic side effects pose challenges to its widespread utility. Conclusion: This review synthesizes findings from ocular investigations on topical insulin to assess its potential applicability in treating ocular surface and corneal diseases. By highlighting indications, preparation methods, side effects, and efficacy outcomes, it aims to provide insights into the current status and future prospects of using topical insulin in ophthalmic practice.

The Role of Insulin-like Growth Factor (IGF) System in the Corneal Epithelium Homeostasis-From Limbal Epithelial Stem Cells to Therapeutic Applications

The corneal epithelium, comprising three layers of cells, represents the outermost portion of the eye and functions as a vital protective barrier while concurrently serving as a critical refractive structure. Maintaining its homeostasis involves a complex regenerative process facilitated by the functions of the lacrimal gland, tear film, and corneal nerves. Crucially, limbal epithelial stem cells located in the limbus (transitional zone between the cornea and the conjunctiva) are instrumental for the corneal epithelium integrity by replenishing and renewing cells. Re-epithelialization failure results in persistent defects, often associated with various ocular conditions including diabetic keratopathy. The insulin-like growth factor (IGF) system is a sophisticated network of insulin and other proteins essential for numerous physiological processes. This review examines its role in maintaining the corneal epithelium homeostasis, with a special focus on the interplay with corneal limbal stem cells and the potential therapeutic applications of the system components.

Effects of injectable platelet-rich fibrin (i-PRF) on pterygium surgery with conjunctival autograft

OBJECTIVES

To investigate the effects of subconjunctival injectable platelet-rich fibrin (i-PRF) injection on healing and complication rates after pterygium surgery with conjunctival autograft.

METHODS

This retrospective and comparative study evaluated 31 eyes that received i-PRF injections under the donor and graft conjunctiva following pterygium surgery, while 34 eyes did not receive i-PRF after the pterygium surgery. The patients' follow-up period was for 12 months. Postoperative recurrence, epithelial healing time, postoperative pain score, graft edema, and sliding of the graft (need for re-suturation) data were evaluated.

RESULTS

For the 12 months after surgery, one eye (3.2%) in the i-PRF group had developed corneal recurrence, and five eyes (14.7%) in the non-i-PRF group had developed recurrence. The mean corneal epithelial healing time was 2.96 ± 0.70 days in the i-PRF group and 3.58 ± 0.70 days in the non-i-PRF group (p = 0.001). The mean healing time of the donor conjunctiva epithelium was 3.84 ± 0.70 days in the i-PRF group, whereas it was 4.44 ± 0.74 days in the non-i-PRF group (p = 0.006). The mean postoperative pain score was 4.45 ± 1.52 in the i-PRF group and 5.08 ± 1.40 in the non-i-PRF group. In the non-i-PRF group, three cases (8.8%) required re-suturation, whereas, in the i-PRF group, no one required re-suturation.

CONCLUSIONS

Thanks to its platelets-derived growth factors, i-PRF can be a safe and effective adjuvant therapy for faster healing of conjunctival autograft and in the prevention of recurrence.