Reactions to serum eye drops-New Zealand experience and review of the literature

BACKGROUND

Serum eye drops (SED) are used to treat ocular surface disease. Reactions to SED are poorly documented.

METHODS

We present our experience of self-reported reactions in New Zealand to SED (25%; autologous, allogeneic, or both) between 2003 and 2023, and a focused review of the literature.

RESULTS

In total, 1067 patients received SED treatment (562 autologous, 318 allogeneic, and 187 both). Three (0.5% of those treated with allogeneic SED) reported reactions. All appeared to be allergic. All were associated with allogeneic SED. We have information on two patients: one had an eye reaction; in the other, the gastrointestinal tract was involved. The literature contains few reports of reactions to SED. They have involved both autologous and allogeneic SED, and various SED concentrations. None appears to have been severe. Notably, no eye or systemic infections have been reported.

CONCLUSIONS

Information on the types and frequencies of reactions to SED is poor. This may be due to: serum being less likely to cause reactions; eyes being resistant to reactions; reactions being rare, and insufficient use of SED having occurred; under-reporting related to SED use at home and reactions being mild. More robust monitoring for reactions to SED is needed.

Patient-reported outcomes of serum eye drops manufactured from Australian blood donations and packaged using Meise vials

Introduction

Serum eye drops (SED) are an effective treatment for dry eye syndrome. However, autologous serum collection can have challenges. Patient-tailored (allogeneic) SED (PT-SED) can be made from healthy blood donors. Australian Red Cross Lifeblood has manufactured both autologous SED (Auto-SED) and PT-SED and, in May 2021, introduced Meise vial packaging. This study aimed to explore SED patient-reported outcomes and vial packaging satisfaction.

Methods

A prospective cohort study was conducted with recruitment between 1 November 2021 and 30 June 2022. Participants completed the dry eye questionnaire (DEQ5), health-related quality-of-life (SF-8™), functional assessment of chronic illness therapy-treatment satisfaction-general (FACIT-TS-G), and general wellbeing surveys. Existing patients completed these once, and new patients were surveyed at baseline, 3 months post-treatment, and 6 months post-treatment.

Results

Participants who completed all study requirements were 24 existing and 40 new Auto-SED and 10 existing and 8 new PT-SED patients. Auto-SED patients were younger [56.2 (±14.7) years] than PT-SED patients [71.4 (±10.0) years]. Participants used a mean of 1.8 (±1.1) SED, 5.3 (±2.9) times per day. In new patients, DEQ5 scores improved within 6 months from 14.0 (±2.9) to 10.6 (±3.4) for Auto-SED and from 12.9 (±3.7) to 11.4 (±2.8) for PT-SED. General wellbeing measures improved in the new Auto-SED from 7.0 (±1.9) to 7.8 (±1.7) but were reduced for new PT-SED from 6.7 (±2.9) to 6.1 (±2.9).

Discussion

SED improved dry eye symptoms in most patients, regardless of the serum source. Patients using PT-SED showed decreases in some quality-of-life measures; however, recruitment was reduced due to operational constraints, and concurrent comorbidities were not assessed. General feedback for SED and vial packaging was positive, with some improvements identified.

Closed system production of serum eye drops using dockable saline

BACKGROUND AND OBJECTIVES

A fully closed system solution to manufacture serum eye drops using diluted serum has remained elusive, necessitating production steps to mitigate bacterial contamination risks in a clean suite environment, hampering production efficiency amid growing demand. We describe our recent implementation of a fully closed manufacturing process at New Zealand Blood Service.

MATERIALS AND METHODS

A dockable format for sterile saline manufactured to custom specifications configured with a 15-cm tubing to enable sterile connections was sourced from a local pharmaceutical manufacturer.

RESULTS

From a total of 30,168 eye drop vials manufactured since implementation, the average production time was reduced by up to 45% performed in the general laboratory environment, attributed to eliminating processes performed in a clean suite. No bacterial contamination was observed, demonstrating robust sterile connections.

CONCLUSION

Dockable saline takes serum eye drops manufactured from a functionally closed system to a fully closed system, thereby enhancing patient safety, significantly reducing manufacturing time and cost and transforming production from a highly restrictive process into a portable workflow that is simple, practical and effective.

Eye drops of human origin-Current status and future needs: Report on the workshop organized by the ISBT Working Party for Cellular Therapies

BACKGROUND AND OBJECTIVES

Serum eye drops (SEDs) are used to treat ocular surface disease (OSD) and to promote ocular surface renewal. However, their use and production are not standardized, and several new forms of human eye drops have been developed.

MATERIALS AND METHODS

The International Society for Blood Transfusion Working Party (ISBT WP) for Cellular Therapies held a workshop to review the current types of eye drops of human origin (EDHO) status and provide guidance.

RESULTS

The ISBT WP for Cellular Therapies introduced the new terminology 'EDHO' to emphasize that these products are analogous to 'medical products of human origin'. This concept encompasses their source (serum, platelet lysate, and cord blood) and the increasingly diverse spectrum of clinical usage in ophthalmology and the need for traceability. The workshop identified the wide variability in EDHO manufacturing, lack of harmonized quality and production standards, distribution issues, reimbursement schemes and regulations. EDHO use and efficacy is established for the treatment of OSD, especially for those refractory to conventional treatments.

CONCLUSION

Production and distribution of single-donor donations are cumbersome and complex. The workshop participants agreed that allogeneic EDHO have advantages over autologous EDHO although more data on clinical efficacy and safety are needed. Allogeneic EDHOs enable more efficient production and, when pooled, can provide enhanced standardization for clinical consistency, provided optimal margin of virus safety is ensured. Newer products, including platelet-lysate- and cord-blood-derived EDHO, show promise and benefits over SED, but their safety and efficacy are yet to be fully established. This workshop highlighted the need for harmonization of EDHO standards and guidelines.

Allogeneic and autologous serum eye drops: a pilot double-blind randomized crossover trial

Purpose

Serum eye drops (SEDs) are used to treat a variety of ocular surface defects. Serum eye drops (SEDs) are normally produced from the patient’s blood. However, not all patients can donate sufficient or suitable blood, and logistics can be challenging. Allogeneic blood from voluntary blood donors does not have these disadvantages. Our aim was to evaluate whether autologous and allogeneic SEDs have comparable efficacy and tolerability.

Methods

In a prospective, double‐blind crossover trial, patients with severe dry eyes were randomized to first receive autologous SEDs for one month, followed by one‐month washout, before receiving allogeneic SEDs for 1 month; or receive the SED preparations in reverse order. The Ocular Surface Disease Index (OSDI) was the primary endpoint, and various secondary endpoints were determined. A linear mixed model with random intercept for each patient was applied per treatment group to compare the pre‐ and postoutcome measurements.

Results

Nineteen patients were enrolled, of whom 15 completed the trial. When autologous SEDs were used, the mean ± SD OSDI improved from 62 ± 19 to 57 ± 18. For allogeneic SEDs, the OSDI changed from 59 ± 20 to 56 ± 23. The estimated mean difference (95% confidence interval) was −4.2 (−9.5 to 1.2) for autologous and −4.5 (−9.8 to 0.9) for allogeneic SEDs (both, not significant). Adverse events were mild and resolved completely.

Conclusion

Autologous and allogeneic SEDs have comparable efficacy and tolerability for use in patients with severe dry eyes. Allogeneic SEDs are therefore an attractive alternative for patients who need SEDs but are clinically or logistically unable to donate blood.

Hyaluronic Acid Combined with Serum Rich in Growth Factors in Corneal Epithelial Defects

The aim of this study is to assess if an adhesive biopolymer, sodium hyaluronate (NaHA), has synergistic effects with s-PRGF (a serum derived from plasma rich in growth factors and a blood derivative that has already shown efficacy in corneal epithelial wound healing), to reduce time of healing or posology. In vitro proliferation and migration studies, both in human corneal epithelial (HCE) cells and in rabbit primary corneal epithelial (RPCE) cultures, were carried out. In addition, we performed studies of corneal wound healing in vivo in rabbits treated with s-PRGF, NaHA, or the combination of both. We performed immunohistochemistry techniques (CK3, CK15, Ki67, ß4 integrin, ZO-1, α-SMA) in rabbit corneas 7 and 30 days after a surgically induced epithelial defect. In vitro results show that the combination of NaHA and s-PRGF offers the worst proliferation rates in both HCE and RPCE cells. Addition of NaHA to s-PRGF diminishes the re-epithelializing capability of s-PRGF. In vivo, all treatments, given twice a day, showed equivalent efficacy in corneal epithelial healing. We conclude that the combined use of s-PRGF and HaNA as an adhesive biopolymer does not improve the efficacy of s-PRGF alone in the wound healing of corneal epithelial defects.

[A method of treating purulent corneal ulcer in the eyes with neuroparalytical keratitis and lagophthalmos]

PURPOSE

To develop a method for treatment of advanced purulent corneal ulcers in eyes with neurotrophic keratitis that developed as a complication of intracranial pathological processes or brain surgeries.

MATERIAL AND METHODS

The study involved 13 patients (14 eyes) that underwent combined surgery - keratoplasty, autoconjunctival flap covering, partial tarsorrhaphy performed simultaneously. Before and after the surgery, patients received frequent instillations of antimicrobial agents and autologous serum.

RESULTS

The organ of vision was preserved in all patients, visual function - in 50% of cases, it improved in 35.7% of cases from 0.07±0.05 to 0.26±0.11. Lagophthalmos has decreased from 6.11±0.99 to 2.78±0.62 mm.

CONCLUSION

Patients with intracranial lesions and complicated by neurotrophic keratitis and lagophthalmos often develop advanced severe and progressive corneal purulent ulcers, which seldom respond to the most active conservative therapy. Simultaneous surgery that includes keratoplasty, auto conjunctival flap covering and partial superficial tarsorrhaphy is an effective treatment option that helps preserve visual function in such eyes.

Serum from plasma rich in growth factors regenerates rabbit corneas by promoting cell proliferation, migration, differentiation, adhesion and limbal stemness

PURPOSE

To evaluate the regenerating potential and the mechanisms through which the autologous serum derived from plasma rich in growth factors (s-PRGF) favours corneal wound healing in vitro and in vivo.

METHODS

We compared the effect of various concentrations of s-PRGF versus fetal bovine serum (FBS) and control treatment in rabbit primary corneal epithelial and stromal cells and wounded rabbit corneas. Cell proliferation was measured using an enzymatic colorimetric assay. In vitro and in vivo wound-healing progression was assessed by image-analysis software. Migration and invasion were evaluated using transfilter assays. Histological structure was analysed in stained sections. Protein expression was evaluated by immunohistochemistry.

RESULTS

s-PRGF promoted the robust proliferation of epithelial cultures at any concentration, similar to FBS. Likewise, s-PRGF and FBS produced similar re-epithelialization rates in in vitro wound-healing assays. In vivo, s-PRGF treatment accelerated corneal wound healing in comparison with control treatment. This difference was significant only for 100% s-PRGF treatment in our healthy rabbit model. Histological analysis confirmed normal epithelialization in all cases. Immunohistochemistry showed a higher expression of cytokeratins 3/76 and 15, zonula occludens-1 and alpha-smooth muscle actin proteins as a function of s-PRGF concentration. Notably, keratocyte density in the anterior third of the stroma increased with increase in s-PRGF concentration, suggesting an in vivo chemotactic effect of s-PRGF on keratocytes that was further confirmed in vitro.

CONCLUSION

s-PRGF promotes proliferation and migration and influences limbal stemness, adhesion and fibrosis during corneal healing.

Serum eye drops: a survey of international production methods

BACKGROUND

Serum eye drops (SEDs) are used to treat dry eye syndrome and non-healing corneal lesions when other treatments fail. Despite many clinical studies demonstrating the efficacy of both autologous and allogeneic SEDs, there is no internationally harmonized method for producing SEDs.

MATERIALS AND METHODS

A 40-question survey requesting information regarding donor selection, blood collection and processing, infectious disease screening, shelf life and regulatory requirements for the production of autologous and allogeneic SEDs was developed by the Biomedical Excellence for Safer Transfusion Collaborative. Survey data were collected into a database via a secure web interface and then downloaded into Excel for further analysis.

RESULTS

A total of 55 responses were received, with 21 responses from centres indicating they produce SEDs. Based on the responses, collection and processing practices differ widely, according to the size of the centre making the SEDs, and their ability to collect, process and test the blood.

CONCLUSION

Despite divergences in the methods for producing SEDs, the end result is a small-volume aliquot of serum that can be administered by a patient at home. If more centres move from producing autologous to allogeneic SEDs, this may provide an opportunity for production methods to become more standardized internationally.