The ocular surface is a morphofunctional unit that owes its action to the perfect cooperation of all its structures (i.e., conjunctival and corneal epithelium, lacrimal apparatus, and eyelids) [
The rationale for the use of AS arises from its strong similarity to tears, which contains growth factors, cytokines, vitamins, and bactericidal components that provide the necessary nutritional factors to maintain cellular tropism and reduce the risk of contamination and infection during epithelial repair processes [
This single-center prospective study was conducted from January 2008 to January 2013. We enrolled patients who came to our department because of ocular surface dysfunction related to trophic deficiency (e.g., recurrent corneal erosion, neurotrophic keratitis, and keratoconjunctivitis sicca [Sjögren and non-Sjögren-related]) and chemical burns. Table
Inclusion and exclusion criteria of the study.
Criteria | Inclusion criteria | Exclusion criteria |
---|---|---|
General | Inability of venous blood sampling because of | |
|
||
Chemical eye burn |
(i) Persistent epithelial defect |
(i) Corneal perforation/melting |
Severe dry eye syndrome | (i) Symptoms of dry eye with daily activity limitation | |
Neurotrophic keratitis | (i) Patients with persistent epithelial defects |
HBV = hepatitis B virus; HCV = hepatitis C virus; HIV = human immunodeficiency virus.
Written informed consent was obtained from all subjects before their enrollment after they received an explanation of the nature and possible consequences of the study. The institutional review board of the Spedali Civili Hospital (Brescia, Italy) ethics committee approved the study. The Declaration of Helsinki was followed. All patients had a screening visit. The best corrected visual acuity (BCVA) was measured using a Snellen-type acuity in all patients.
Specialized ophthalmologists collected clinical data by slit-lamp examination (using corneal fluorescein staining to study epithelial defects) and evaluated epithelial defects, inflammation, corneal opacity, and corneal neovascularization. A grading scale of 1 to 3 was used to identify the severity of these signs in which grade 1 was “absence of signs”; grade 2 was “slight”; and grade 3 was “severe.”
A similar scale was used for subjective symptoms. We recorded data on tearing, burning, sense of foreign body or sand, photophobia, blurred vision, and difficulty in opening the eyelids on a scale graded from 1 to 4 in which grade 1 was “no symptom,” grade 2 was “slight,” grade 3 was “moderate,” and grade 4 was “severe.” When possible, a picture of the anterior segment of the eye was obtained.
Patients were divided into 2 groups: (1) patients with an acute illness (e.g., chemical burns) and (2) patients with chronic disease (e.g., recurrent corneal erosion, neurotropic keratitis, and keratoconjunctivitis sicca (non-Sjögren and Sjögren-related)).
Group 1 eyes had chemical burns [grades II and III chemical injuries (based on the Dua classification [
Group 2 included patients with chronic diseases that were unresponsive to conventional therapy (e.g., lubricating drops and ointments, punctal plug, bandage contact lenses, tarsorrhaphy, and gold eyelid weight). The treatment in this group was 5 times a day for 3 months and then was reduced progressively to 3 times a day for 3 months until the absence of symptoms. An antibiotic (moxifloxacin/netilmicin/tobramycin) was administered 4 times a day until the closing of the epithelial defect. No other supportive therapies were used during the treatment period. For each patient, the specialist could modify the therapy whenever necessary. The change was registered and justified.
Autologous serum drops were produced in the following manner. A total of 200 mL of blood was procured by venipuncture and collected in a sterile container. The blood was allowed to stand for 24–48 h at 4°C to allow clotting. The blood was centrifuged at 4000 rpm for 10 min. The serum was separated from the blood and diluted with saline to 50% in a laminar flow cabinet. At this point, the product was quarantined until the outcome of the sterility test performed by the Laboratory of Microbiology of the AO Civil Hospital of Brescia (Brescia, Italy). The final product was formed from an average of 288 single-dose eye drops for venipuncture. Single-application packs were packed in bags of 20 and marked with a label plate.
At −30°C, the product is preserved for 6 months from the date of withdrawal. From the time of delivery, the product is stored at a destination (e.g., home freezer) at −20°C for a period not exceeding 3 months from the date of delivery and no later than the expiration date stated on the label. If the entire production process is successful, the eye drops are validated, which takes into account negative serology examinations, group control transmitted and validated by the Emonet management system (i.e., computer system with records of the personal data of patients and the procedure to be performed), and negative results of sterility control.
In this study 28 eyes of 28 patients were enrolled. Two patients dropped out of the study because of the impossibility of obtaining blood samples: the first patient was seropositive for the human immunodeficiency virus and the second patient did not have venous access.
Of the 26 eyes of the 26 patients treated with AS, 18 patients were men and 8 were women. The mean age was
Summary of the 26 eyes treated with autologous serum eye drops.
Eye | Sex | Age (y) | Etiology | Weeks of serum therapy | Comorbidity |
---|---|---|---|---|---|
1 | M | 41 | CB | 24 | None |
2 | M | 22 | CB | 24 | None |
3 | M | 59 | CB | 12 | None |
4 | F | 81 | CB | 12 | Diabetes mellitus |
5 | M | 29 | CB | 24 | None |
6 | M | 41 | CB | 12 | None |
7 | M | 30 | CB | 48 | None |
8 | M | 32 | CB | 12 | None |
9 | M | 38 | CB | 12 | None |
10 | M | 55 | CB | 12 | None |
11 | M | 31 | CB | 12 | None |
12 | M | 50 | CB | 24 | None |
13 | M | 19 | CB | 24 | None |
14 | M | 23 | CB | 12 | None |
15 | M | 43 | CB | 12 | None |
16 | F | 71 | SS | 24 | None |
17 | F | 37 | NK | 24 | s/p PK |
18 | F | 64 | NK | 12 | s/p trabeculectomy |
19 | M | 71 | DE | 12 | None |
20 | M | 80 | DE | 24 | None |
21 | M | 60 | NK | 12 | Trigeminal neuralgia |
22 | F | 79 | SS | 48 | None |
23 | F | 44 | NK | 48 | s/p trabeculectomy |
24 | M | 37 | NK | 72 | Acoustic neuroma |
25 | F | 40 | NK | 12 | None |
26 | F | 51 | NK | 48 | Lagophthalmos |
CB = chemical burn; DE = dry eye syndrome; NK = neurotrophic keratopathy; s/p PK = status postpenetrating keratoplasty; s/p trabeculectomy = status posttrabeculectomy; SS = Sjogren’s syndrome.
Group 1 consisted of 15 eyes (58% of all patients in the study) injured by chemical agents of different natures. Group 2 (i.e., patients with chronic eye diseases) consisted of 11 eyes as follows: 6 eyes with neurotrophic keratopathy, 3 eyes with keratoconjunctivitis sicca not Sjögren, and 2 eyes with keratoconjunctivitis sicca, Sjögren-related.
The average therapy period was
The
In group 1 before treatment, 100% of patients had inflammation (it extended to the entire eye in 73% of patients and was grade 2 in 27% of patients); 100% of patients had corneal opacity (grade 3 in 93% of patients and grade 2 in 7% of patients); and 60% of patients had neovascularization (grade 3 in 33% of patients and grade 2 in 27% of patients).
In group 2 before treatment, 100% of patients had corneal inflammation (grade 3 in 64% of patients and grade 2 in 36% of patients); 82% of patients had corneal opacity (grade 3 in 60% of patients and grade 2 in 40% of patients); and 55% of patients had corneal neovascularization (grade 3 in 36% of patients, grade 2 in 27% of patients, and grade 1 in 37% of patients) (Table
Summary of the distribution and evolution of the clinical signs in the 2 groups of patients.
Signs | Presence of sign PRE-AS gr 1 | Presence of sign POST-AS gr 1 | Distribution of grades | Distribution of grades |
Average of the |
Average of the |
|
---|---|---|---|---|---|---|---|
Epithelial defect | 100% | 0% | GRADE 3: 73% | GRADE 3: 0% |
|
1 | <0.01 |
GRADE 2: 27% | GRADE 2: 0% | ||||||
GRADE 1: 0% | GRADE 1: 100% | ||||||
|
|||||||
Inflammation | 100% | 14% | GRADE 3: 73% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 27% | GRADE 2: 13% | ||||||
GRADE 1: 0% | GRADE 1: 87% | ||||||
|
|||||||
Corneal opacity | 100% | 27% | GRADE 3: 84% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 6% | GRADE 2: 40% | ||||||
GRADE 1: 0% | GRADE 1: 60% | ||||||
|
|||||||
Neovascularization | 60% | 40% | GRADE 3: 33% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 27% | GRADE 2: 27% | ||||||
GRADE 1: 40% | GRADE 1: 73% | ||||||
Epithelial defect | 100% | 0% | GRADE 3: 73% | GRADE 3: 0% |
|
1 | <0.01 |
GRADE 2: 27% | GRADE 2: 0% | ||||||
GRADE 1: 0% | GRADE 1: 100% | ||||||
|
|||||||
Inflammation | 100% | 10% | GRADE 3: 64% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 36% | GRADE 2: 19% | ||||||
GRADE 1: 0% | GRADE 1: 81% | ||||||
|
|||||||
Corneal opacity | 88% | 28% | GRADE 3: 45% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 36% | GRADE 2: 45% | ||||||
GRADE 1: 19% | GRADE 1: 55% | ||||||
|
|||||||
Neovascularization | 55% | 45% | GRADE 3: 36% | GRADE 3: 0% |
|
|
<0.01 |
GRADE 2: 18% | GRADE 2: 27% | ||||||
GRADE 1: 46% | GRADE 1: 73% |
Post-AS = postautologous serum treatment; pre-AS = preautologous serum treatment.
The average improvement was 1.53 degrees ±0.52 in group 1 (
The symptoms reported in group 1 were (in decreasing frequency) burning, feeling a foreign body/sand in the eyes, tearing, photophobia, and blurred vision.
Tearing was present in 42% of patients at the first visit: 73% of patients had grade 4 and 27% of patients had grade 3.
Burning was present in 73% of patients at first visit: 79% of patients had grade 4, 11% of patients had grade 3, and 10% of patients had grade 2.
The sense of sand in the eyes was present in 78% of patients at the first visit: 55% of patients had grade 4 and 45% of patients had grade 3.
Photophobia was present in 65% of patients at the first visit: 53% of patients had grade 4, 37% of patients had grade 3, and 10% of patients had grade 2.
Difficulty opening
The most severe symptom was eye burning. The symptoms reported in group 2 (in decreasing frequency) were a sense of a foreign body in the eyes, blurred vision, burning, and photophobia. The feeling of sand in the eyes and blurred vision were the most severe symptoms (Table
Burning at the end of followup was grade 1 in 74% of patients, grade 2 in 21% of patients, and grade 3 in 5% of patients. There was an improvement of 3 degrees in 53% of patients, 2 degrees in 32% of patients, and 1 degree in 15% of patients (i.e., 100% of patients improved). The average improvement was
The sense of sand in the eyes at the end of followup was grade 1 in 75% of patients, grade 2 in 15% of patients, and grade 3 in 10% of patients. There was an improvement of 3 degrees in 40% of patients, 2 degrees in 45% of patients, and 1 degree in 10% of patients; however, 1 (5%) patient with neurotrophic keratopathy showed no improvement. The average improvement was
Photophobia at the end of followup was grade 1 in 71% of patients and grade 1 in 29% of patients.
There was an improvement of 3 degrees in 35% of patients, 2 degrees in 47% of patients, and 1 degree in 18% of patients (i.e., 100% of patients improved). The average improvement was
Blurred vision at the end of followup was grade 1 in 63% of patients, grade 2 in 21% of patients, and grade 3 in 16% of patients. There was an improvement of 3 degrees in 32% of patients, 2 degrees in 37% of patients, 1 degree in 21% of patients, and no improvement in only 2 (10%) patients (the first patient had a chemical eye injury with a slight degree of injury and the second patient had Sjögren syndrome eye with a mild degree of injury). The average improvement was
Difficulty opening
Autologous serum eye drops are actually used in the treatment of many ocular diseases, and many studies have demonstrated the effectiveness of AS eye drops in treating different conditions such as superior limbic keratoconjunctivitis [
Despite clinical evidence of the efficacy of AS, a shared protocol for the preparation and the administration of this therapy is lacking because of the bureaucratic and technical difficulties of handling biological materials. The European Union (European Parliament and Council) has issued several directives concerning AS eye drops (1965/65, 1975/139, and 1975/318). However, in the European Union, individual countries regulate the manufacture and distribution of pharmaceuticals, and the use of serum eye drops remains an experimental approach [
In addition, there have been few reports that show the efficacy of some blood products such as platelet-rich plasma (PRP) in treating chemical burns [
We chose to use 50% AS eye drops instead of other concentrations (e.g., 20% or 100%) used in some works in the literature [
The main focus of the study was to show the clinical success of AS eye drops in the treatment of different ocular surface diseases. All collected data were analyzed complexly and subsequently in 2 distinct groups of pathologies—acute eye pathology (i.e., group 1) and chronic eye pathology (i.e., group 2)—with the aim of understanding the potential and the efficacy of this therapy.
The data analysis showed that all patients achieved a significant improvement in symptoms and all patients had excellent compliance with the treatment. No patient in the current study has reported any adverse effects to date; however, some studies have reported adverse effects [
Best corrected visual acuity improved in all patients, which was in contrast to the study of Ziakas et al. [
In primary or secondary tear deficiency, the AS supplies the lacking factors and reestablishes a correct ocular surface balance. This is the situation with dry eyes, Sjögren and non-Sjögren-related. For mild dry eyes, artificial tears, when frequently applied, are usually effective since they are able to reduce symptoms and prevent complications and the progression of damage [
In our study, the patients with dry eye syndrome started therapy with AS eye drops because the symptom had not resolved with conventional therapy and they had a long history of chronic inflammation and recurrent epithelial defects leading to infection, opacity, and visual capacity damage [
In neurotropic keratopathy, a different mechanism occurs [
Clinical evolution of a patient with neurotrophic keratitis due to trigeminal nerve injury that occurred during acoustic neuroma excision.
Evolution of clinical signs in group 1 and group 2. All data significantly improved.
Evolution of visual acuity in the patients in the 2 groups. AS = autologous serum; p1–p15 = patient 1–patient 15.
The patients with ocular burn represent a different framework in which a single traumatic event, the acid burn, leads to an ocular surface injury with an action at term, but persistent damage. Few studies are available in the literature on chemical burns, and used as a treatment PRP [
The rationale of using AS in chemical burns derives from the fact that it contains antiproteases such as alpha 2 macroglobulin (which reduces collagenase) and vitamin A (which modulates the normal growth and differentiation of the epithelium) [
In our casuistry, 5–7 days after injury, all patients had evident signs of corneal suffering with epithelial instability and inflammation that was caused by trophic damage on the cornea and conjunctiva, despite limited limbal deficiency. The study of clinical signs showed that in each patient we attained the primary objective, which was the stabilization of the condition in the absence of inflammation, and a complete restitution of epithelial integrity. The regression of neovascularization in most patients may be because of an increase in trophic factors and a decrease in inflammatory factors. In fact, neovascularization that is formed to provide nourishment disappears quickly if the stimulus ceases. Opacity declined because of the reduction of inflammation and because of stromal remodeling supported by serum factors such as EGF, fibronectin, TGF-
All our patients obtained these results, although with different timings between acute and chronic diseases. Chemical burns had a shorter average treatment time. This suggests that chemical injury is reversible and the ocular surface stability can be self-maintained if inflammation is properly reduced and growth factors are rebalanced. We suggest that our patients had a limited limbal ischemia with a largely preserved limbus. None of the chemically burned patients remain in therapy and all patients have a healthy ocular surface.
A limitation of our study is the lack of a control arm for the acute group patients. A future goal will be to followup with a control arm treated with anti-inflammatory drugs and artificial tears to make direct comparisons between both therapies in chemical injury.
In our casuistry, AS eye drops have been effective in improving and stabilizing signs and symptoms in patients who do not improve with conventional therapy. We believe that a reconfirmation of our findings will be desirable in a larger group of patients in a prospective controlled trial setting. Studies aimed at clarifying the beneficial effects and risks of prolonged application of AS drops at different AS concentrations should also be the subject of future investigations.
In addition, a future goal will be to conduct examinations, especially in the composition of tears. This can help scientists understand what factors are decreased in the tears of these patients and how they are decreased and how long AS components can effectively remain in tears after therapy.
The authors declare that there is no conflict of interests regarding the publication of this paper.