[Autologous serum-eye-drops for ocular surface disorders. A literature review and recommendations for their application]

Recombinant Human Nerve Growth Factor (Cenegermin)–Driven Corneal Wound Healing Process: An Evidence-Based Analysis

Purpose: To evaluate anterior segment optical coherence tomography (AS-OCT) to detect the wound healing process as per monitoring the effectiveness of cenegermin to treat moderate to severe neurotrophic keratoplasty.

Methods: A retrospective chart review was realized to identify patients treated with cenegermin at the Clinica Oculistica, University of Genoa, Italy. All patients underwent careful examinations at baseline and follow-up visits. AS-OCT scans centered on the minimum corneal thickness (CT) area were always performed. We compared findings of AS-OCT with the findings from the slit-lamp examination. A linear regression analysis was used to evaluate factors associated with corneal healing. A further analysis, including a control group treated with 50% autologous serum (AS), was done to investigate and compare the efficacy of cenegermin.

Results: Data from 16 eyes were studied. The average patients' age was 60.9 ± 21.1 years; five (31.2%) eyes experienced persistent epithelial defect and 11 (68.8%) eyes had neurotrophic corneal ulcer. The average reepithelialization time was 3.9 ± 0.5 weeks in the cenegermin group versus 5.9 ± 1.9 weeks in the AS group (p < 0.01). The AS‐OCT scans revealed an average CT at the thinnest point of 276.3 ± 74.1 μm before treatment with an average increase of 176.5 ± 60.3 μm at the end of the cenegermin treatment (B = −0.15; p = 0.035). The AS-OCT percentage increase in corneal thickness between the two groups was statistically significant (p < 0.02).

Conclusion: Understanding the cascade of events involved in the nerve growth factor–driven corneal wound healing process is clinically meaningful for the clinician. AS-OCT is an effective tool for systematic anterior segment imaging, allowing the detailed detection of the front-to-back layered corneal structure for quantitative analysis and monitoring of the healing process.

Therapie des Trockenen Auges

Die Therapie des Trockenen Auges stellt eine schwierige Aufgabe für den behandelnden Augenarzt dar. Fortschritte in unserem Verständnis der Risikofaktoren, der Ätiologie und Pathophysiologie des Trockenen Auges haben zu einer Weiterentwicklung der Behandlungsstrategien geführt. Vor Beginn der Therapie ist die korrekte Zuordnung in eine wässrig-muzinöse Tränenfilmdysfunktion (Mindersekretion), in eine lipidbedingte Tränenfilmdysfunktion (hyperevaporative Form durch eine abnormen Meibom-Drüsen-Physiologie) oder in eine variable Kombination wichtig. Unter Berücksichtigung aktueller Empfehlungen der DOG, des BVA und des TFOS DEWS II Unterausschusses wurde ein Behandlungsalgorithmus abgeleitet, der ein schrittweises Vorgehen je nach Schweregrad der Erkrankung darstellt.

Fingerprick Autologous Blood in the Treatment of Severe Dry Eyes and Ocular Surface Disease

PURPOSE

To evaluate the efficacy of autologous blood eye drops in patients diagnosed with severe ocular surface disease and dry eye who were unresponsive to conventional therapy and who would otherwise be considered for autologous serum eye drops.

METHODS

A total of 38 eyes of 19 patients (15 women and 4 men) with ocular surface disease and severe dry eye refractory to conventional treatment were treated with fingerprick autologous blood 4 times daily for 6 months. Follow-up visits occurred at 1-, 3-, and 6-month intervals. At each visit, visual acuity, Oxford Grading Scheme score, tear film break-up time, Schirmer test, and ocular surface disease index were measured.

RESULTS

There was a significant improvement in the ocular surface staining score at all time gates. The mean score at presentation was 2.13, and this improved to 1.50 at 1 month (P < 0.001), 1.29 at 3 months (P < 0.01), and 1.42 at 6 months (P < 0.01). There was an improvement in tear film break-up time from 4.75 seconds at baseline to 6.79 seconds at 3 months (P < 0.01) and 7.0 seconds at 6 months (P < 0.001). An improvement in the Schirmer test was only found at 6 months with an improvement from 3.67 mm to 13.33 mm (P < 0.05). There was no statistical change in visual acuity at any time gate or ocular surface disease index score, although 83% of patients reported an improvement in their symptoms at 6 months. There were no adverse events reported.

CONCLUSIONS

Fingerprick autologous blood is an effective, readily accessible, and safe therapy for the treatment of recalcitrant cases of severe ocular surface disease and dry eye unresponsive to conventional therapy.

Corneal epithelium tissue engineering: recent advances in regeneration and replacement of corneal surface

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe tissue-engineering and cell-based approaches for corneal regeneration.

[Modern biotechnological treatment methods of persistent corneal epithelial defects]

The article reviews modern methods of treatment of persistent corneal epithelial defects and considers the factors involved in the development of this pathology, including the limbal stem cell deficiency, which is likely to play the main role. The most promising treatment methods are described, particularly the use of blood derivatives and cell therapy.

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

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.

A Case of Neurotrophic Keratopathy Concomitant to Brain Metastasis

We report a case of a 63-year-old Caucasian female referred to the cornea service of Clinica Oculistica with a neurotrophic corneal ulcer, decreased corneal sensitivity, absent corneal reflex, and decreased lacrimation. The medical record review was relevant for mastectomy and adjuvant therapy for breast cancer complicated by pontocerebellar angle metastasis. Eye patching and application of antibiotic and vitamin ointments were prescribed at first, without a significant improvement. Thus, treatment with autologous serum was started. In about two weeks, the cornea recovered and visual acuity improved with a residual corneal scarring. Finally, we should mention that, in our case, the main cause of the neurotrophic corneal ulcer could be identified in the previous trigeminal damage at the pontocerebellar angle and trigeminal ganglion. Sensory nerves play an important regulatory role via neuro-mediators on corneal wound healing, as denervation may interfere with cellular metabolism and inhibit mitosis, leading to an epithelial defect even with no direct damage.

Autologous serum eye drops for dry eye

BACKGROUND

Theoretically, autologous serum eye drops (AS) offer a potential advantage over traditional therapies on the assumption that AS not only serve as a lacrimal substitute to provide lubrication but contain other biochemical components that allow them to mimic natural tears more closely. Application of AS has gained popularity as second-line therapy for patients with dry eye. Published studies on this subject indicate that autologous serum could be an effective treatment for dry eye.

OBJECTIVES

We conducted this review to evaluate 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.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2016), Embase (January 1980 to July 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (December 2016) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 July 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared AS versus artificial tears for treatment of adults with dry eye.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts and assessed full-text reports of potentially eligible trials. Two review authors extracted data and assessed risk of bias and characteristics of included trials. We contacted investigators to ask for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95% confidence intervals (CIs) for continuous outcomes. We did not perform meta-analysis owing to differences in outcome assessments across trials.

MAIN RESULTS

We identified five eligible RCTs (92 participants) that compared AS versus artificial tears or saline in individuals with dry eye of various origins (Sjögren's syndrome-related dry eye, non-Sjögren's syndrome dry eye, and postoperative dry eye induced by laser-assisted in situ keratomileusis (LASIK)). We assessed the certainty of evidence as low or very low because of lack of reporting of quantitative data for most outcomes and unclear or high risk of bias among trials. We judged most risk of bias domains to have unclear risk in two trials owing to insufficient reporting of trial characteristics, and we considered one trial to have high risk of bias for most domains. We judged the remaining two trials to have low risk of bias; however, these trials used a cross-over design and did not report data in a way that could be used to compare outcomes between treatment groups appropriately. Incomplete outcome reporting and heterogeneity among outcomes and follow-up periods prevented inclusion of these trials in a summary meta-analysis.Three trials compared AS with artificial tears; however, only one trial reported quantitative data for analysis. Low-certainty evidence from one trial suggested that AS might provide some improvement in participant-reported symptoms compared with artificial tears after two weeks of treatment; the mean difference in mean change in symptom score measured on a visual analogue scale (range 0 to 100, with higher scores representing worse symptoms) was -12.0 (95% confidence interval (CI) -20.16 to -3.84; 20 participants). This same trial found mixed results with respect to ocular surface outcomes; the mean difference in mean change in scores between AS and artificial tears was -0.9 (95% CI -1.47 to -0.33; 20 participants; low-certainty evidence) for fluorescein staining and -2.2 (95% CI -2.73 to -1.67; 20 participants; low-certainty evidence) for Rose Bengal staining. Both staining scales range from 0 to 9, with higher scores indicating worse results. The mean change in tear film break-up time was 2.00 seconds longer (95% CI 0.99 to 3.01; 20 participants; low-certainty evidence) in the AS group than in the artificial tears group. Investigators reported no clinically meaningful differences in Schirmer's test scores between groups (mean difference -0.40 mm, 95% CI -2.91 to 2.11; 20 participants; low-certainty evidence). None of these three trials reported tear hyperosmolarity and adverse events.Two trials compared AS versus saline; however, only one trial reported quantitative data for analysis of only one outcome (Rose Bengal staining). Trial investigators of the two studies reported no differences in symptom scores, fluorescein staining scores, tear film break-up times, or Schirmer's test scores between groups at two to four weeks' follow-up. Very low-certainty evidence from one trial suggested that AS might provide some improvement in Rose Bengal staining scores compared with saline after four weeks of treatment; the mean difference in Rose Bengal staining score (range from 0 to 9, with higher scores showing worse results) was -0.60 (95% CI -1.11 to -0.09; 35 participants). Neither trial reported tear hyperosmolarity outcomes. One trial reported adverse events; two of 12 participants had signs of conjunctivitis with negative culture that did resolve.

AUTHORS' CONCLUSIONS

Overall, investigators reported inconsistency in possible benefits of AS for improving participant-reported symptoms and other objective clinical measures. There might be some benefit in symptoms with AS compared with artificial tears in the short-term, but we found no evidence of an effect after two weeks of treatment. Well-planned, large, high-quality RCTs are warranted to examine participants with dry eye of different severities by using standardized questionnaires to measure participant-reported outcomes, as well as objective clinical tests and objective biomarkers to assess the benefit of AS therapy for dry eye.

Autologous Serum Eye Drops for Post-Chemical Injuries and Corneal Epithelial Defects

Aim: To evaluate success rate (efficacy, safety) in treatment of post-chemical injuries and corneal defects using autologous serum eye drops.Material and Methods: Authors reviewed 93 patients (116 eyes) hospitalized in Clinic of ophthalmology from 2010 to 2013, who had post-causoma corneal defects that were nonresponsive to conventional treatment and were treated with serum therapy. Authors correlated time of epithelialization of defects with rate of epithelial healing.Results: Authors investigated 93 patients (52 males, 41 females; aged 18 - 74) for treatment of corneal defects. Application of autologous serum therapy 56 (48.28%) of 116 eyes was healed in an average time of 4 weeks. Among 116 eyes, epithelial defects healed in 4 (3.45%) within 1 week, in additional 17 (14.65%) in 1-2 weeks, totalling 31 (26.72%) within 3 weeks. Five eyes (4.31%) completely healed at 5 week; three eyes (2.59%) had subsequent healing of epithelial defect at 6 week; 56 eyes completely healed within one month, and the remaining eight eyes healed within 1.5 month.Conclusion: Using serum therapy, it was managed to reduce time of healing from eleven weeks, which were necessary just couple years ago (before 2010) to four (maximum six) weeks to complete healing which are necessary today.

Autologous serum eye drops for dry eye

BACKGROUND

=Theoretically, autologous serum eye drops (AS) have a potential advantage over traditional therapies based on the assumption that ASserve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AS in dry eye treatment has gained popularity as a second-line therapy in the treatment of dry eye.Published studies on the subject indicate that autologous serum could be an effective treatment for dry eye.

OBJECTIVES

To evaluate the efficacy and safety of AS compared to artificial tears for treating dry eye.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3),Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE,(January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences(LILACS) (January 1982 to April 2013), themetaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov(www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (September 2013) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which AS was compared to artificial tears in the treatment of dry eye in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts and assessed full-text articles of potentially eligible trials. Two review authors extracted data and assessed the methodological quality and characteristics of the included trials.We contacted investigators for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95% confidence intervals(CIs) for continuous outcomes.

MAIN RESULTS

We identified four eligible RCTs in which AS was compared with artificial tear treatment or saline in individuals (n = 72 participants)with dry eye of various etiologies (Sjögren’s syndrome-related dry eye, non-Sjögren’s syndrome dry eye and postoperative dry eye induced by laser-assisted in situ keratomileusis (LASIK)). The quality of the evidence provided by these trials was variable. A majority of the risk of bias domains were judged to have an unclear risk of bias in two trials owing to insufficient reporting of trial characteristics.One trial was considered to have a low risk of bias for most domains while another was considered to have a high risk of bias for most domains. Incomplete outcome reporting and heterogeneity in the participant populations and follow-up periods prevented the inclusion of these trials in a summary meta-analysis. For the primary outcome, improvement in participant-reported symptoms at one month, one trial (12 participants) showed no difference in participant-reported symptoms between 20% AS and artificial tears. Based on the results of two trials in 32 participants, 20% AS may provide some improvement in participant-reported symptoms compared to traditional artificial tears after two weeks of treatment. One trial also showed positive results with a mean difference in tear breakup time (TBUT) of 2.00 seconds (95% CI 0.99 to 3.01 seconds) between 20% AS and artificial tears after two weeks, which were not similar to findings from the other trials. Based on all other objective clinical assessments included in this review, AS was not associated with improvements in aqueous tear production measured by Schirmer's test (two trials, 33 participants), ocular surface condition with fluorescein (four trials, 72 participants) or Rose Bengal staining (three trials, 60 participants), and epithelial metaplasia by impression cytology compared to artificial tears (one trial, 12 participants). Data on adverse effects were not reported by three of the included studies. In one study, there were no serious adverse events reported with the collection of and treatment with AS.

AUTHORS' CONCLUSIONS

Overall there was inconsistency in the possible benefits of AS in improving participant-reported symptoms and TBUT and lack of effect based on other objective clinical measures. Well-planned, large, high-quality RCTs are warranted, in different severities of dry eye and using standardized questionnaires to measure participant-reported outcomes and objective clinical tests as well as objective biomarkers to assess the benefit of AS therapy for dry eye.

Therapeutical approach to dry eye syndrome

Introduction. Dry eye disease or dysfunctional tear syndrome is among the most frequently established diagnoses in ophthalmology. It can be defined as a disorder of the tear film resulting in changes in the ocular surface. Mechanisms in development of dry eye disease. There are many factors causing dry eye and they can be related to deficiency in any of the components of the tear film. It has been suggested that dry eye is an inflammatory disorder that affects the ocular surface and lacrimal gland. Inflammation is the most important mechanism of corneal and conjunctival cell damage, which is responsible for the symptoms and signs of ocular surface pathology. Hormonal imbalance (particularly androgens), neural dysfunction, increased levels of pro-inflammatory cytokines and loss of immune homeostasis of the lacrimal gland and ocular surface could be possible mechanisms in the pathogenesis of dry eye disease. Discussion. The aim of this paper was to review the advances in the pathogenesis and management of the dry eye disease. The appropriate dry eye treatment presupposes knowledge of all existing pharmacologic and non-pharmacologic therapeutic modalities. The mainstay of therapy is still artificial tears, with anti-inflammatory therapy and punctual occlusion therapy as second and third line therapies.

Autologous serum for the treatment of corneal epithelial abrasions in diabetic patients undergoing vitrectomy

PURPOSE

To compare the effect of autologous serum versus hyaluronic acid for the treatment of epithelial corneal lesions in patients such as diabetics with reduced wound healing.

DESIGN

Prospective, randomized, masked clinical trial.

METHODS

Diabetic patients undergoing pars plana vitrectomy mostly combined with cataract extraction and intraocular lens (IOL) implantation who received corneal abrasion for better intraoperative visualization were included in this study. A standardized 8-mm diameter corneal abrasion was performed. Patients were randomized into one group treated with hourly application of autologous serum and another treated with hyaluronic acid drops (Vislube). Besides the time necessary for closure of the corneal epithelium other parameters such as patients' age, gender, duration of surgery, history of diabetes, and current HbA1C were evaluated.

RESULTS

A total of 23 patients were enrolled (15 men, eight women); the autologous serum group consisted of 13 patients, the hyaluronic acid (Vislube) group consisted of 10 patients. Patients' mean age was 64.8 years; mean duration of diabetes was 19.4 years. On average, the operation lasted 145 minutes. Mean epithelialization time was 7.1 days in the hyaluronic acid group. In the autologous serum group, epithelium healed after a mean of 4.3 days. Mann-Whitney U test for statistical analysis showed a significant difference of epithelial closure time between both groups (P < .05); therefore, the study was stopped after treatment of 23 patients.

CONCLUSIONS

It appears that autologous serum leads to a much faster closure of corneal epithelial wounds after abrasion compared with artificial tears.

Amniotic membrane transplantation with cauterization for keratoconus complicated by persistent hydrops in mentally retarded patients

PURPOSE

Vigorous eye rubbing is a cause of extensive hydrops in mentally retarded patients with keratoconus. We describe a new management approach for this condition.

DESIGN

Prospective, noncomparative, consecutive case series.

PARTICIPANTS

Ten eyes of 10 mentally retarded patients aged 18 to 37 years (8 with Down syndrome and 2 with oligophrenia not associated with Down syndrome). All patients had extensive and persistent hydrops in the course of keratoconus that was refractory to traditional therapy.

INTERVENTION

The patients underwent multifocal cauterization of the cornea combined with amniotic membrane transplantation.

MAIN OUTCOME MEASURES

Corneal protuberance, final corneal thickness, time to hydrops resolution, and postoperative complications were assessed.

RESULTS

Hydrops was successfully resolved in all eyes. The mean initial corneal protuberance (7.6+/-4.2 mm) resolved after 21.4+/-9.5 days in all eyes. Mean final central corneal thickness was 0.47+/-0.11 mm. Extent of initial corneal protuberance, final corneal thickness, and time to resolution were positively correlated with each other.

CONCLUSIONS

Amniotic membrane transplantation with cauterization in this series of mentally retarded patients was a highly effective treatment for persistent hydrops related to keratoconus.

Vergleich von Eigenserum und Hyaluronsäure zur Behandlung kornealer Erosiones nach Vitrektomie bei Diabetikern

PURPOSE

The purpose of this study was to evaluate whether treatment with autologous serum exhibits better epitheliotropic properties than hyaluronic acid in patients with reduced wound healing (diabetics).

PATIENTS AND METHOD

This prospective randomized study included all diabetic patients undergoing pars plana vitrectomy with abrasion of the corneal epithelium. In addition to the usual topical therapy one group was treated with hourly application of autologous serum, the other group with hyaluronic acid drops. We evaluated the time needed for closure of the corneal epithelium as well as other parameters such as patient's age, sex, duration of surgery, history of diabetes, and the current HbA1C.

RESULTS

There were 23 patients enrolled in the study. The epithelium healed a mean of 2 days earlier in the autologous serum group. Based on the statistically significant difference in favor of autologous serum, the study was terminated after treatment of 23 patients.

CONCLUSIONS

Autologous serum eye drops lead to earlier closure of the corneal epithelium after intraoperative abrasion in diabetic patients when compared with artificial tears.

Combination of transepithelial phototherapeutic keratectomy and autologous serum eyedrops for treatment of recurrent corneal erosions

PURPOSE

To evaluate the clinical outcomes after transepithelial phototherapeutic keratectomy (t-PTK) using an excimer laser and postoperative administration of autologous serum eyedrops.

SETTING

Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.

METHODS

Twenty-five eyes of 25 patients with 3 to 12 recurrent corneal erosions were treated with t-PTK using the Schwind Keratom broad-beam excimer laser (Schwind). Routine therapy consisted of 2 pulses x 40 pulses (18.82 +/- 2.56 mum ablation). Postoperatively, autologous serum eyedrops were administered 6 times a day for 6 weeks. Postoperative outcomes and rate of recurrent erosions were evaluated.

RESULTS

The median of the follow-up after t-PTK was 15.5 months (range 6 to 20 months), and the mean age of the patients was 40.6 years +/- 12.0 (SD). Twenty of 25 eyes (80%) recovered without further corneal erosion. Five eyes had 1 further erosion, which was treatable in 4 cases with autologous serum eyedrops without additional excimer laser treatment. One patient requested additional t-PTK treatment and recovered without further complications thereafter.

CONCLUSIONS

Transepithelial phototherapeutic keratectomy is a safe and effective therapy for recurrent corneal erosions. Additional treatment with autologous serum eyedrops can support the healing process following corneal erosions and t-PTK and can be given as a long-term artificial tear treatment.

[Epitheliotrophic capacity of serum and plasma eyedrops. Influence of centrifugation]

BACKGROUND

Serum eyedrops are a new modality for the treatment of ocular surface disorders. We examined the influence of the preparation of blood products in a cell culture model and compared it with plasma.

MATERIAL AND METHODS

Serum and plasma were obtained from full blood of ten healthy volunteers and centrifuged at 500 and 3000 G. EGF, PDGF, TGF-beta1, fibronectin, and vitamin A were quantified by means of ELISA and HPLC. Cultures of human corneal epithelial cells were incubated with the four blood products in dose-response experiments and the intracellular ATP quantified.

RESULTS

EGF, PDGF, and vitamin A were present in serum in significantly higher concentrations than in plasma. The concentration of fibronectin was not influenced by the preparation. Support of proliferation was best by 25% platelet-poor serum. Serum supported the differentiation and migration of epithelial cells better than plasma.

CONCLUSION

The biochemical character of serum eyedrops is determined by the parameters chosen to produce the blood product. Plasma does not seem to offer an epitheliotrophic capacity equivalent to serum eyedrops. Their production should be optimized before any meaningful randomized controlled clinical trial can be attempted.

[Sterility of non-preserved autologous serum drops for treatment of persistent corneal epithelial defects]

PURPOSE

To investigate the sterility of non-preserved autologous serum drops in hospitalized patients with persistent corneal epithelial defects.

METHODS

Thirty patients with persistent corneal epithelial defects (aged between 28 and 85, mean 67+/-14 years) were treated with autologous serum drops in five different wards of a university eye hospital between October 2001 and March 2002. After centrifugation of freshly collected autologous blood, the serum was stored in sterile drop bottles at refrigerator temperature (7 degrees C) and applied undiluted every 1 or 2 h up to 7 days. Using blood, chocolate, endo, and Sabouraud agar media, we assessed the sterility of autologous serum drops on the day before application and on the 4th and 7th days. Examinations performed on the 1st and 4th days included 40 autologous serum drops each and on the 7th day 120 samples (40 serum drops, 40 bottle tops, and 40 bottle bottoms). The agar media for bacterial examination were read after 48 h of incubation time, and those for fungal examination were read after 21 days. All patients had received topical autologous serum therapy and prophylactic antibiotic drops for at least 7 days.

RESULTS

The time period of autologous serum treatment ranged from 7 to 28 (10+/-5) days. On the 1st and 4th days autologous serum drops were sterile. On the 7th day, 3 of 40 (7.5%) samples were contaminated with Staphylococcus epidermidis. Two of these contaminations were due to a combined serum drop and bottle top contamination (5%). A third case resulted from additional bottle bottom contamination (2.5%). None of the samples examined showed signs of fungal infection. During application of autologous serum as well as during the follow-up period no patient showed any symptoms of ocular infection.

CONCLUSIONS

The application of autologous serum has proven to be a practicable therapy in patients with persistent corneal epithelial defects. When the drops are applied by trained personnel, the absence of contamination can be ensured up to the 4th day. By additional application of prophylactic antibiotic drops, infections may be avoided even if refrigerated non-preserved autologous serum is used up to 7 days.

Autologous serum eye drops for ocular surface disorders

Tears have antimicrobial, nourishing, mechanical, and optical properties. They contain components such as growth factors, fibronectin, and vitamins to support proliferation, migration, and differentiation of the corneal and conjunctival epithelium. A lack of these epitheliotrophic factors--for example, in dry eye, can result in severe ocular surface disorders such as persistent epithelial defects. Recently, the use of autologous serum in the form of eye drops has been reported as a new treatment for severe ocular surface disorders. Serum eye drops may be produced as an unpreserved blood preparation. They are by nature non-allergenic and their biomechanical and biochemical properties are similar to normal tears. In vitro cell culture experiments showed that corneal epithelial cell morphology and function are better maintained by serum than by pharmaceutical tear substitutes. Clinical cohort studies have reported its successful use for severe dry eyes and persistent epithelial defects. However, the protocols to prepare and use autologous serum eye drops varied considerably between the studies. As this can result in different biochemical properties protocol variations may also influence the epitheliotrophic effect of the product. Before the definitive role of serum eye drops in the management of severe ocular surface disease can be established in a large randomised controlled trial this has to be evaluated in more detail. In view of legislative restrictions and based upon the literature reviewed here a preliminary standard operating procedure for the manufacture of serum eye drops is proposed.