The use of autologous serum eye drops for the treatment of ocular surface disorders

Abstract

Objectives

To investigate the use of autologous serum (AS) eye drops in patients with ocular surface disorders who were refractory to conventional treatments.

Methods

A retrospective cohort study was conducted at a tertiary care centre. We included patients with a prescription of AS eye drops from December 2006 to January 2016. Electronic prescriptions (Prescriplant) and clinical histories were reviewed. A database with sociodemographic and pharmacotherapheutic variables was created. The efficacy was evaluated subjectively and adverse effects was a measurement of safety. AS eye drops were elaborated, in a laminar flow hood, with the blood samples for a final concentration of 20%.

Results

One hundred and seventy-three patients were considered for the study, 78.03% of them female. Their mean age was 63.87 years (SD 16.69). The use of AS eye drops was indicated for several diseases: corneal diseases (corneal ulcer or corneal persistent epithelial defects) (34.32%); Sjögren syndrome (17.16%); dry eye resulting from autoimmune disease (15.38%); and blepharitis/blepharospasm (12.43%). The regular dosage was every 3 or 4 hours (40.46%). 21.97% patients used the AS in one eye only. The mean length of treatment was 2.71 years. All patients, except one, improved their symptoms with the treatment and no one suffered harmful effects.

Conclusions

Numerous national and international guidelines on dry eye treatment have been published, but they differ in dosing, concentration and indication of AS eye drops. Consequently, there is no consensus about the best therapy with AS. In this article we describe the clinical practice of AS eye drops. In the study, indications for AS therapy were mostly: corneal diseases; Sjögren syndrome; and dry eye resulting from autoimmune disease; and blepharitis or blepharospasm. Patients went to the hospital pharmacy to pick up AS eye drops before 90 days, it ensures the stability of eye drops. AS is an effective, safe and well tolerated treatment.

Introduction

Tears perform a vital role in maintaining the health of the corneal epithelium: they nourish, protect and refresh the eye. They contain fibronectin, growth factors, lysozyme and vitamins that support the migration, proliferation and differentiation of the conjunctival and corneal epithelium. Thus tears have lubricating, mechanical, but also epitheliotrophic and antimicrobial properties. A lack of epitheliotrophic factors or their carrier compromises the integrity of the surface epithelia.¹

Dry eye is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance and tear film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. This definition was adopted by the National Eye Institute and highlights the roles of tear hyperosmolarity and ocular surface inflammation in dry eye, and the effects of dry eye on visual function.² People with dry eyes do not produce enough tears or their tears are of a poor quality. This disease can develop for many reasons: age (50 years or older); sex (females are more likely to develop dry eyes due to hormonal changes); medications (antihistamines, decongestants, blood pressure medications and antidepressants can reduce tear production); medical conditions (autoimmune diseases); environmental conditions (smoke, wind, dry climate or staring at a computer screen); and other factors such as long-term use of contact lenses or refractive eye surgeries, such as laser-assisted in situ keratomileusis (LASIK), contribute to dry eyes.

Dry eye treatment is based on disease severity and it includes: tear supplementation (lubricants); tear retention; tear stimulation; biological tear substitutes; anti-inflammatory therapy; essential fatty acids; or environmental strategies. These recommendations may be modified by practitioners based on individual patient profile and clinical experience.³

Pharmaceutical products are optimised for their biomechanical properties only. None of the commercially available artificial tear preparations include essential tear components such as epidermal growth factor, hepatocyte growth factor, fibronectin, neurotrophic growth factor and vitamin A, all of which have been shown to play an important role in the maintenance of ocular surface epithelial milieu.⁴ Serum and other bodily fluids have been used as natural tear substitutes.^{1 5–8} Serum is the fluid component of blood, devoid of its cellular components and clotting factors.

Autologous serum (AS) eye drops are produced by the hospitals from the patient’s blood. The preparation is done, under good manufacturing practice conditions, in an aseptic environment in hospital pharmacies. The published protocols for the preparation and storage of AS eye drops are incomplete. AS eye drops contain a variety of growth factors, vitamins and immunoglobulins, some of which are in higher concentrations than in natural tears. These epitheliotrophic factors are thought to be responsible for the therapeutic effect of serum observed in ocular surface disorders. The growth- and migration-promoting effects of serum on cell cultures in general and on corneal epithelial cells are well documented.¹

The aim of this study is to review the protocol and the use of autologous serum eye drops in outpatients with ocular surface disorders who were refractory to conventional treatments.

Material and methods

A retrospective cohort study was conducted at a tertiary care centre to review the protocol and the use of AS eye drops. We included all patients with a prescription of AS eye drops and who compounded it at the hospital pharmacy from the period December 2006 to January 2016. A database was created to record variables. It included sociodemographic (age and sex) and pharmacotherapheutic variables (indication, number of dispensing medication, length of treatment, dosage, eyes in treatment and the use of cyclosporine eye drops prepared and dispensed at the hospital pharmacy). We reviewed electronic prescriptions (Prescriplant) and clinical histories of the patients included in the study. The efficacy of the treatment was evaluated subjectively (the doctor interviewed patients about their experience with AS eye drops) and adverse effects was a measurement of their safety.

Data were assessed using conventional statistical methods: mean and SD for normal variables; and median and percentiles for non-normal distribution. Frequency and percentages were used for categorical data.

Preparation of AS eye drops

We conducted a literature review to edit an AS preparation protocol. We reviewed the standard work procedures for other countries and edited our own.¹ We also adapted the blood products' recommendations. Under aseptic conditions, the blood samples by venesection at the antecubital fossa were collected in four sterile tubes without anticoagulants. The containers were left standing for 2 hours at room temperature in an upright position to allow the complete clotting phase. The blood was then centrifuged at 4800 rpm for 8 min. The samples were received at the pharmacy hospital where the pharmacist checked them: if any tube is not correctly clotted, we discard it. Before the preparation, the pharmacist verifies the patient’s serology test (VIH, hepatitis B &C and syphilis). To assure traceability, we developed personal labels with the patient history number and a barcode that identifies the medication as AS eye drops. The supernatant serum was removed under sterile conditions in a laminar airflow hood. One millilitre of serum was taken and filtered with a 0.22 µm filter (Millex-GV ultra-low protein binding) into sterile dropper bottles with a 4 mL physiologic serum for a final concentration of 20%. The bottles were labelled with the patient’s identification and date of production and expiration. The bottles were dispensed to each patient at the outpatients' department with a barcode scanning system to preserve their traceability. Before application, the patients were informed about the use and management of AS eyedrops. They were instructed to keep the current AS bottle under refrigeration (4° C) and to store the extra bottles at −20°C in a freezer for no more than 90 days. Each bottle was discontinued after 5 days of use.

Statistical analysis was carried out with STATA software version 14.1 for Windows (College Station, Texas USA). Mean and SD or median and range were used to describe continuous data. Frequency and percentages were used for categorical data.

Results

AS eye drops were prepared under aseptic conditions at the hospital pharmacy. A total of 173 patients were considered for the study, 78.03% of them females. Their mean age was 63.87 years (SD 16,69). The use of AS eye drops was indicated for several diseases such as corneal diseases (34.32%), Sjögren syndrome (17.16%), dry eye resulting from autoimmune disease (15.38%), and blepharitis or blepharospasm (12.43%) (table 1). The habitual dosage was every 3 or 4 hours (40.46%). Thirty-eight (21.97%) patients used the AS only in one eye. The mean length of treatment was 2.71 years. All patients, except one (this patient experimented a sticky sensation with minimal eye discomfort) improved their symptoms with the treatment and no one suffered harmful effects.

Table 1.

Demographics' variables of patients using AS eye drops

Characteristics	Number (%)
Total patient numbers	173 (100)
Age (years)
Mean±SD	63.87±16,69
Range	21.37–92.69
Sex
Male	38 (22.0)
Female	135 (78.0)
Eyes in treatment
Both eyes	131 (75.7)
Right eye	22 (12.7)
Left eye	16 (9.3)
Duration of the treatment (years)	2.71
Indications
Corneal diseases (corneal ulcer or corneal persistent epithelial defects)	58 (34.3)
Sjögren syndrome	29 (17.2)
Dry eye resulting from autoimmune disease	26 (15.4)
Blepharitis or blepharospasm	21 (12.4)
Palpebral disorder	8 (4.7)
Other syndromes (Cogan syndrome, Fuchs’ dystrophy or Terrien degeneration)	7 (4.1)
Graft-versus-host disease (GVHD)	5 (3.0)
Radiotherapy treatment	5 (3.0)
Conjunctive disorders	4 (2.4)
Laser-assisted in situ keratomileusis (LASIK)	4 (2.4)
Corneal burns	2 (1.2)

Patients went to the hospital pharmacy to pick up AS eye drops every 75.89 days (RIC 60.33;90.88). The dispensed AS eye drops for each patient was 7.00 (min 1; max 46).

We also updated the AS protocol to lastest Spanish quality guarantees for platelet-rich plasma and other blood products. The Pharmacy and Therapeutics Committee approved the use and elaboration of AS eye drops and patients using AS have to meet donation criteria.

Discussion

In this study, we investigated the use of AS eye drops in patients with ocular surface disorders who were refractory to conventional treatments.

A recent study⁹ included 181 patients who received AS 100% for the treatment of corneal epithelial defect following several different types of ocular surgery. The overall success rate of treating persistent postoperative epithelial defect using 100% serum eye drops was 93.92% (95% CI 0.88 to 0.98). Only three patients suffered adverse reactions and no serious complications were reported. This study concluded that the therapy with AS 100% effective, safe and well tolerated. Patients´ demographic data were similar as in our study: mean age (years) was 62.39 (SD 14.28) and range was 34–89. The study included 89 males and 92 females: however in our study were a group predominantly composed of females. Lekhanont et al studied the use of AS eye drops in 85 right eyes and 96 left eyes:⁹ the patients included in our study use AS eye drops mainly in both eyes.

AS eye drops have been used for the treatment of ocular surface disorders, such as Sjögren syndrome; corneal ulcers; persistent epithelial defects resulting from rheumatoid arthritis; systemic lupus erythematosus, Stevens–Johnson syndrome, neurotrophic keratopathy or dry eye; palpebral harm; graft-versus-host disease; after chemotherapy treatment; corneal burns; and conjunctive disorders or another disease (Cogan syndrome, Fuchs’ dystrophy or Terrien degeneration). Young et al¹⁰ carried out a study conducted to review the local spectrum of indications and to examine the outcome of AS 20% tear usage. A total of 10 eyes from 10 patients were identified. No adverse effects were observed with the addition of autoserum tears. AS tears may be considered as a valuable adjunct in the management of recalcitrant cases of PED. Indications were similar to our study in patients without Sjögren syndrome: limbal stem cell disease, neurotrophic ulcer, alkaline burn and patients treated with radiation therapy. The use of AS eye drops in Sjögren syndrome is widely demonstrated as a safe and efficient way to provide essential components to the ocular.^11–13

Hussain et al¹⁴ described the outcomes of 50% AS eye drops after long-term use in a large cohort of patients with dry eyes. The study included 63 patients (123 eyes) who were evaluated with a mean follow-up of 12 months. AS 50% eye drops seems to be a safe and effective long-term treatment for dry eye disease, especially in patients with severe disease who have exhausted all other conventional forms of treatment. Patients included in our study also use AS eye drops as a long-term treatment and the habitual dosage was every 3 to 6 hours. Semeraro et al ¹⁵ studied patients with acute and chronic pathologies treated with AS 50%. The patients received therapy five times a day. The epithelial defects all resolved. Signs and symptoms improved in both groups. AS eye drops effectively stabilise and improve signs and symptoms in eyes previously treated with conventional therapy. Eighteen per cent of patients with chronic eye disease showed recurrences after suspension of AS therapy. To prevent these events we use AS eye drops as chronic therapy.

Previous studies have shown variable effectiveness of AS for the treatment of dry eyes. Tananuvat et al¹⁶ performed a 2-month, prospective, single-masked, placebo-controlled study in 12 patients with bilateral severe dry eye. One eye was randomised to receive the patient’s own serum as a tear substitute, and the fellow eye received unpreserved normal saline solution as a placebo. There was a trend towards improvement in symptoms and signs of dry eye after application of AS 20% in severe dry eye patients, but it was not statistically significant because of the sample size.

Noble et al⁴ reported the beneficial effects of AS in severe ocular surface disorders. AS 50% was superior to conventional treatment and improved impression cytology after 3 months in 16 patients. The ocular surface diseases included Sjögren’s syndrome and keratoconjunctivitis sicca.

Another crossover study¹⁷ comparing a 2-week treatment with 20% AS with conventional artificial tears in 12 patients with severe dry eye syndrome found that the patients treated with AS showed a significant improvement in ocular surface disease index scores. There were no significant changes in Oxford staining scores and tear breakup time between the two groups.

Most recently, 40 patients were included in a prospective, double-blind randomised crossover study¹⁸ to evaluate the efficacy of AS eye drops for severe dry eye syndrome, as compared with conventional preservative-free artificial tears. The study concluded a superior effectiveness of the AS eye drops for improving tear film stability and subjective comfort.

Pan et al¹⁹ reviewed the efficacy and safety of AS given alone or in combination with artificial tears as compared with artificial tears alone, saline, placebo or no treatment for adults with dry eye. They concluded that there might be some benefit in symptoms with AS compared with artificial tears in the short term, but no evidence after 2 weeks of treatment was found.

Watson et al²⁰ studied 10 patients (11 eyes) with persistent epithelial defect. There were no serious or irreversible side effects. AS has the potential to be easily manufactured and widely available. De Pascale et al²¹ reviewed the use of AS eye drops. The study verified the clinical benefits of AS therapy: the treatment improved tear film stability and subjective comfort by determining a faster epithelial healing time and a better corneal transparency without increase of vascularisation or fibrosis. Several data confirmed the safety and the almost absolute absence of toxic and side effects. Our study included only one patient who experimented a sticky sensation with minimal eye discomfort, while the remaining patients improved their symptoms with the treatment and no one suffered harmful effects.

There are a large amount of published studies of AS eye drops therapy, but the treatment considers the variable concentration and diluent of AS, which ranged from 20% to 100%. Cho et al²² compared the effect of AS eye drops with different diluents in 85 patients with dry eyes and persistent epithelial defects. The study included three groups; Sjogren’s syndrome (Group I); non-Sjogren’s syndrome (group II) with dry eye; and persistent epithelial defects (Group III). The eyes of each group were randomly treated with AS eye drops: 100% serum, 50% serum with normal saline, 50% serum with sodium hyaluronate or 50% serum with ceftazidime. In the eyes with Sjogren syndrome and persistent epithelial defects, AS 100% was the most effective in decreasing symptoms, corneal epitheliopathy and promoting the fast closure of wounds. In the eyes with non-Sjogren syndrome, AS 100% and AS 50% (diluted with normal saline) have similar effects in decreasing symptoms and corneal epitheliopathy. AS concentration of 20% is often used to dilute tumour growth factor in the serum to physiologic tear levels, because it is thought to be inhibitory for some epithelial processes.

Limitations

One of the study limitations is that we conducted a unicentre study, consequently there would be differences between other population and the patients included in the study. However, patients' characteristics are very similar to other studies.⁹ Insufficient notification of adverse drug reaction is, probably, another limitation of the study, because this is a retrospective study. We observed, as other studies, that AS is a very safe treatment in clinical practice.^{20 21} Finally, we did not study the effectiveness objectively. It could be interesting to evaluate it with a dry eye test.

Conclusion

Indications for AS therapy were mostly corneal diseases (corneal ulcer or corneal persistent epithelial defects), Sjögren syndrome, dry eye resulting from autoimmune disease, and blepharitis or blepharospasm. Patients went to the hospital pharmacy to pick up AS eye drops before 90 days, which ensures the stability of eye drops. Habitual dosage was every 3 or 4 hours in both eyes.

The efficacy of the treatment was evaluated subjectively, and it is the main limitation of the study. In spite of this, we can consider AS treatment as a chronical therapy. It is an effective safe and well tolerated treatment.

What this paper adds.

What is already known on this subject

• Numerous national and international guidelines on dry eye treatment have been published, and they included the use of AS eye drops.

• The published protocols for the preparation and storage of AS eye drops are incomplete.

What this study adds

• Guidelines and clinical practice with AS eye drops differ in dosing, concentration and indication. Consequently, there is no consensus about the best therapy with AS.