Blood-derived topical therapy for ocular surface diseases

Topical blood products modulate the effects of ophthalmic antibiotics against common bacterial pathogens in dogs with infectious keratitis

Bacterial keratitis is a common and serious condition that often leads to vision impairment and potential loss of the eye if not treated promptly and adequately. Topical blood products are often used concurrently with topical antibiotics, helping to mitigate corneal 'melt' from proteases released on the ocular surface. However, blood products are rich in albumin and could affect the efficacy of antibiotics due to drug-protein binding. In this study, serum and plasma samples were harvested from 10 healthy dogs and 10 healthy horses, obtaining fresh and frozen (1 month at -20°C) aliquots for in vitro experiments. Albumin levels were quantified using species-specific ELISA kits. Thirty bacteria (10 Staphylococcus pseudintermedius, 10 Streptococcus canis, 10 Pseudomonas aeruginosa), isolated from canine patients with infectious keratitis, were each tested with blank plates as well as commercial susceptibility plates (Sensititre™ JOEYE2) to assess the minimal inhibitory concentration (MIC) of 17 different antibiotics in the absence (control) or presence of eight test groups: serum or plasma (fresh or frozen) from canines or equines. Albumin concentrations ranged from 13.8-14.6 mg/mL and 25.9-26.5 mg/mL in canine and equine blood products, respectively. A direct antimicrobial effect was observed mostly with equine vs. canine blood products (specifically serum and to a lesser degree plasma), and mostly for Staphylococcus pseudintermedius isolates. MICs generally increased in the presence of blood products (up to 10.8-fold), although MICs also decreased (down to 0.25-fold) for selected antibiotics and ocular pathogens. Median (range) fold changes in MICs were significantly greater (p = 0.004) with the canine blood products [2 (0.67-8.1)] than the equine blood products [2 (0.5-5)]. In practice, clinicians should consider equine over canine blood products (lesser impact on antimicrobial susceptibility), serum over plasma (greater antimicrobial effects), and administering the blood product ≥15 min following the last antibiotic eyedrop to minimize the amount of albumin-antibiotic binding in tear film.

Comparison of autologous serum and platelet-rich plasma in the treatment of severe dry eye and persistent epithelial defects

PURPOSE

To compare the efficacy of topical autologous serum and platelet-rich plasma (PRP) in patients with severe dry eye and persistent epithelial defects.

METHODS

Sixty-seven eyes of 42 patients including 12 Sjogren, 11 meibomian gland dysfunction, 8 post penetrating keratoplasty, 5 acne rosacea, 5 chemical burn and 3 neurotophic keratopathy were analyzed. Best corrected visual acuity, Schirmer, Ocular Surface Disease Index (OSDI), tear break-up time, Oxford staining scores were measured before the treatment and 1 month. One month scores of two groups were compared.

RESULTS

Thirty three eyes received autologous serum and 34 received PRP. There was no statistically significant differences between two groups in ocular surface parameters at baseline. Statistically significant improvements were achieved in both groups in all parameters at 1 month (p < 0.05). Schirmer score improved from 7.9 ± 7.6 to 10.6 ± 8.4 mm in autologous serum (p < 0.001) and from 10.9 ± 9.5 to 13.3 ± 10.1 in PRP (p < 0.001); BUT from 4.3 ± 2.7 to 6.7 ± 3.4 s (p < 0.001) and 4.5 ± 3.0 to 6.0 ± 3.6 (p < 0.001); OSDI from 47.7 ± 14.7 to 25.7 ± 11.0 (p < 0.001) and from 54.1 ± 17.3 to 26.8 ± 11.0 (p < 0.001); Oxford score from 4.0 ± 1.0 to 1.3 ± 1.1 in (p < 0.001) and 3.9 ± 0.9 to 1.6 ± 1.3 (p < 0.001) respectively. Significant visual improvement was achieved with PRP from 0.81 ± 0.73 LogMAR to 0.72 ± 0.63 (p = 0.025), whereas insignificant with serum from 0.60 ± 0.65 to 0.57 ± 0.67 (p = 0.147). Mean epithelial healing time was 6.7 ± 4.7 (2-14) days in serum and 3.6 ± 1.9 (2-7) in PRP (p = 0.195).

CONCLUSIONS

Both treatments are equally effective in severe dry eye and persistent epithelial defects. Although, visual gain is higher in PRP, autologous serum may be preferable due to low cost.

Topical insulin for refractory persistent corneal epithelial defects

The aim was clinical evaluation of the efficacy of topical insulin eye drops in patients with refractory persistent epithelial defects (PEDs). This prospective non-randomized investigation was conducted to examine the efficacy of insulin eye drops in treating patients with PEDs that did not respond to conventional therapy. A total of twenty-three patients were included in the study, and they were administered insulin eye drops formulated as 1 U/mL, four times a day. The rate of epithelial defect resolution and time to complete corneal re-epithelialization were considered primary outcome measures. The relative prognostic impact of initial wound size and other parameters, including age, sex, smoking, diabetes, and hypertension were also analyzed. The results showed that during follow-up (maximum 50 days), a total of 16 patients (69.6%) achieved improvement. Insulin eye drops significantly reduced the corneal wounding area in 75% of patients with small epithelial defects (5.5 mm2 or less) during 20 days. Only 61% of patients with moderate epithelial defects (5.51-16 mm2) showed a significant recovery in 20-30 days. Also, 71% of patients with a defect size greater than 16 mm2, demonstrated a significant improvement in the rate of corneal epithelial wound healing in about 50 days. In conclusion topical insulin reduces the PED area and accelerates the ocular surface epithelium wound healing.

Neurotrophic keratopathy: General features and new therapies

Neurotrophic keratopathy is an uncommon degenerative corneal disorder characterized by compromised corneal sensory innervation resulting in the formation of epithelial defects and nonhealing corneal ulcers. Various treatment modalities are available to stabilize disease progression, improve patient well-being, and prevent vision loss. For eligible patients, medical and surgical reinnervation have emerged as pioneering therapies, holding promise for better management. We present a comprehensive review of the disorder, providing an update relevant to ophthalmologists on pathogenesis, diagnosis, treatment options, and novel therapies targeting pathophysiological pathways.

Efficacy and safety of platelet-rich plasma and autologous-serum eye drops for dry eye in primary Sjögren's syndrome: a randomized trial

We compared the efficacy and safety of autologous-serum (AS) and platelet-rich plasma (PRP) eye drops for dry eye (DE) treatment in primary Sjögren's syndrome (SS). This prospective, randomized, double-blinded clinical study included patients diagnosed with primary SS DE. Thirty-eight participants were randomly assigned to the AS or PRP groups. Corneal and conjunctival staining scores, Schirmer I test, tear film break-up time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at 4 and 12 weeks. Conjunctival impression cytology (CIC) metaplasia grade and goblet cell density grade at 12 weeks were compared with those at baseline. Corneal and conjunctival staining scores and TBUT significantly improved at 4 and 12 weeks in both groups (all p < 0.005). No significant difference between the AS and PRP groups was observed at 4 and 12 weeks. The Schirmer I values, OSDI scores, CIC metaplasia grade, and goblet cell density grade did not significantly change at 4 and 12 weeks in either group. Both AS and PRP eye drops are effective for primary SS DE without a significant difference. Considering that the preparation time of PRP is shorter than that of AS, PRP can be a good alternative treatment for primary SS DE.

Allogeneic Solid Platelet-Rich Plasma for Persistent Epithelial Neurotrophic Defects: A Protocol and Pilot Study

PURPOSE

Here, we present the procedure to obtain allogeneic solid platelet-rich plasma (PRP) and its use in a pilot study of patients with persistent neurotrophic epithelial defects.

METHODS

We included 4 eyes of 4 patients with persistent neurotrophic epithelial defects unresponsive to other therapies from a single institution. PRP and thrombin were produced by the Department of Transfusion Medicine from healthy blood donors. PRP was activated in its solid form in the operating room with addition of thrombin and calcium gluconate 10% and applied on the cornea with fibrin glue and soft contact lens. Corneal healing time, corneal esthesiometry, visual acuity, Oxford staining score, Ocular Surface Disease Index questionnaire, and Schirmer I test were recorded. Anterior segment optical coherence tomography and in vivo confocal microscopy were also evaluated over the 4-month follow-up period.

RESULTS

The persistent epithelial defect healed in all patients in the first 10 days. During the follow-up, there was an absence of recurrences. For all patients, there was a reduction in Ocular Surface Disease Index questionnaire score (case 1: -55 points, -73.3%; case 2: -26.3 points, -58.4%; case 3: -56 points, -69.1%; case 4: -20 points, -26.6%; mean reduction: 39.3 points, 56.85%) and Oxford staining score (case 1, 2, and 3: 3 points decrease; case 4: 2 points decrease; mean reduction: -2.75 points).

CONCLUSIONS

Allogeneic solid PRP in combination with fibrin glue may facilitate wound healing in neurotrophic persistent epithelial defects. Further prospective studies are needed to quantify its efficacy.

[Corneal regeneration: is there a place for tissues of perinatal origin?]

The article reviews the main properties of the cornea and the mechanisms of its physiological regeneration and repair in response to damage and describes the most promising methods of treatment aimed at stimulating limbal stem cells and based on the use of native tissues of perinatal origin, umbilical cord mesenchymal stromal cells, and cell-free therapeutic products.

Effect of Autologous Platelet-Rich Plasma Drops in the Treatment of Ocular Surface Disease

Purpose

Platelet rich plasma (PRP) is an autologous preparation that concentrates platelets in a small volume of plasma. The purpose of this study was to determine if PRP eye drops improved the symptoms and signs of ocular surface disease.

Patients and Methods

A retrospective case series was conducted of patients who were prescribed PRP eye drops. Subjects were excluded if they did not have follow-up, underwent intraocular surgery prior to follow-up, received nerve growth factor treatments, or did not have a baseline examination with photography. Symptoms were assessed using the Ocular Surface Disease Index (OSDI). Patients also underwent a slit lamp exam, ocular surface staining with fluorescein and lissamine green, and Schirmer testing.

Results

The charts of 47 patients treated with PRP drops for ocular surface disease were reviewed. Sixty-four eyes of 32 patients were included in the study who had photographs of lissamine green staining taken at baseline and at follow-up. Thirteen patients (28%) had ocular graft-versus-host disease, 16 patients (34%) had Sjögren's syndrome, and 4 patients (8.5%) had rheumatoid arthritis. There was a statistically significant decrease in OSDI score from baseline to follow-up (39.5 vs 30.8 points, p = 0.02). Among the 64 eyes included, 9 (14%) had an improvement in conjunctival lissamine green staining, while 6 (9%) had an increase in staining at follow-up. Among the 20 eyes with Schirmer testing, there was a borderline significant increase in score from baseline to follow-up (5.9 vs 9.7, p = 0.06). Among the 44 eyes that had corneal fluorescein staining (CFS) reported, 8 (18.2%) had decreased staining and 2 (4.5%) had increased staining at follow-up.

Conclusion

Treatment with PRP drops was associated with a significant improvement in symptoms in patients with ocular surface disease. Future larger prospective studies are needed to further evaluate the efficacy of PRP drops for treating ocular surface disease.

In vitro evaluation of platelet extracellular vesicles (PEVs) for corneal endothelial regeneration

Corneal endothelial cells (CECs) slowly decrease in number with increasing age, which is a clinical issue as these cells have very limited regenerative ability. Therapeutic platelet biomaterials are increasingly used in regenerative medicine and cell therapy because of their safety, cost-effective manufacture, and global availability from collected platelet concentrates (PCs). Platelet extracellular vesicles (PEVs) are a complex mixture of potent bioactive vesicles rich in molecules believed to be instrumental in tissue repair and regeneration. In this study we investigated the feasibility of using a PEVs preparation as an innovative regenerative biotherapy for corneal endothelial dysfunction. The PEVs were isolated from clinical-grade human PC supernatants by 20,000 × g ultracentrifugation and resuspension. PEVs exhibited a regular, fairly rounded shape, with an average size of <200 nm and were present at a concentration of approximately 10¹¹ /mL. PEVs expressed cluster of differentiation 41 (CD41) and CD61, characteristic platelets membrane markers, and CD9 and CD63. ELISA and LC-MS/MS proteomic analyses revealed that the PEVs contained mixtures of growth factors and multiple other trophic factors, as well as proteins related to extracellular exosomes with functional activities associated with cell cadherin and adherens pathways. CECs treated with PEVs showed increased viability, an enhanced wound-healing rate, stronger proliferation markers, and an improved adhesion rate. PEVs did not exert cellular toxicity as evidenced by the maintenance of cellular morphology and preservation of corneal endothelial proteins. These findings clearly support further investigations of PEV biomaterials in animal models for translation as a new CEC regeneration biotherapy.

Equine Umbilical Cord Serum Composition and Its Healing Effects in Equine Corneal Ulceration

Background

Human autologous serum (AS) and umbilical cord serum (UCS) both contain growth and neurotrophic factors that promote corneal healing.

Aim

Our objectives were to compare equine AS and UCS cytokine and growth factor profiles and to assess the safety and clinical feasibility of the therapeutic use of UCS eye drops in cases of spontaneous complex ulcers.

Study Design

Prospective clinical trial.

Methods

Vitamin A insulin growth factor, platelet-derived growth factor-BB, transforming growth factor (TGF)-β1 (enzyme-linked immunosorbent assay), interleukin (IL)-1β, IL-6, interferon-γ, and monocyte chemoattractant protein 1 concentrations were determined in 10 AS collected from different horses and 10 UCS sampled at delivery. Six client-owned horses presenting with complex non-healing corneal defects of >5 mm² were included in a clinical trial and treated with conventional therapy and conditioned UCS drops for 8–15 days. Ulcer surface and time to complete epithelialization were recorded.

Results

Median concentrations of vitamin A, insulin growth factor, and platelet-derived growth factor-BB were not significantly different in AS compared with UCS (respectively, 14.5 vs. 12.05 μg/ml; 107.8 vs. 107.3 pg/ml; and 369.1 vs. 924.2 pg/ml). TGF-β1 median concentration in UCS was significantly higher than in AS (3,245 vs. 2571pg/ml) (p = 0.04). IL-1β, IL-6, interferon-γ, and monocyte chemoattractant protein 1 concentrations were variable in AS and undetectable in UCS. The corneal median ulcerative area was 37.2 mm² (6.28–57.14 mm²) and had a duration of 4–186 days (median 19 days). All lesions healed within 13–42 days (median 17 days). No adverse effects nor recurrences within 1 month were noticed.

Limitations

The sample size was small. Spontaneous corneal epithelial defects presented with variable clinical characteristics. There were no age-matched control horses to assess corneal healing time and rate.

Conclusion and Clinical Significance

Equine UCS may be beneficial, as it contains no pro-inflammatory cytokines and a greater concentration of TGF-β1 compared with AS. Topical UCS appears safe and may potentially be used as adjunctive therapy for equine complex non-healing ulcers.

Exploratory Phase II Multicenter, Open-Label, Clinical Trial of ST266, a Novel Secretome for Treatment of Persistent Corneal Epithelial Defects

Objective

An exploratory phase II, multicenter, open-label, clinical trial (NCT03687632) was conducted to evaluate the safety and effectiveness in treating persistent corneal epithelial defects (PEDs) with ST266, a proprietary novel multi-cytokine platform biologic solution secreted by cultured Amnion-derived Multipotent Progenitor (AMP) cells.

Methods

Subjects with a PED were treated with ST266 eye drops 4 times daily for 28 days, then followed for 1 week. Safety was assessed by monitoring of adverse events (AEs) and serious adverse events (SAEs). Efficacy was assessed by measuring the area of the PED by slit lamp biomicroscopy. Tolerability of ST266, percentage of eyes with complete healing, reduction in area of the epithelial defect, and maintenance of a reduction in the area of the epithelial defect 7 days after treatment were recorded.

Results

Thirteen patients were enrolled into the trial at one of eight sites. The first patient withdrew after 5 days. The remaining 12 patients with PEDs with median duration of 39 days (range = 12 to 393 days) completed treatment. Ten of the 12 eyes had been refractory to treatment with various conventional therapies prior to enrollment. After 28 days of treatment, there was a significant decrease in mean PED area compared with baseline (66.4% ± 35.3%, P = 0.001). At follow-up, 1 week after completion of treatment, on day 35, the PED area was further reduced by 78.8% ± 37.5% (P = 0.01) compared with baseline. During 28 days of treatment, 5 eyes (41.7%) had complete wound closure. There were no AEs of concern thought to be related to the drug, and no SAEs were noted.

Conclusions

In this trial, we found ST266 eye drops might promote corneal epithelization, thereby reducing the PED area, including in refractory cases in a wide range of etiologies. ST266 was well-tolerated by most patients.

Transregional autologous serum eye drop provision by a large German Red Cross Blood Donation Service

BACKGROUND

The Blood Donation Service West serves North Rhine-Westphalia (NRW), Rhineland-Palatinate (RP), and Saarland, an area of 56,500 km². In addition to routine red blood cell concentrates, plasma, and platelets, special products are provided. Since 2014, this has included autologous serum eye drops (ASED) for topical use in patients suffering from different illnesses accompanied by dry eye disease.

METHODS

A volume of 250-525 mL of patient blood was collected into an anticoagulant-free blood bag. Laboratory testing included Hepatitis B/C-, HIV 1/2-, and Lues-serology. Coagulation and centrifugation were followed by leukoreduction. Single-use vials were obtained by filling mini-bag systems using a sterile tube welder. Storage at ≤-20 °C enabled a shelf-life of up to 6 months and 30 days at 4 °C after thawing for shipment.

RESULTS

Contracts were closed with 15 ophthalmology clinics and medical practices in NRW and RP to supply patients with ASED. The patient pool increased from 19 in 2014 to 46 in 2020, with an average age of 43-55 years. Overall, blood collections almost tripled from 31 to 100 per year, increasing the stock of deliverable single-use vials from 3328 to 13,358. Delivery in a liquid state allowed engagement of 44 pharmacies located in the patient neighborhoods for continuous supply.

CONCLUSION

Manufacturing in a closed bag system allowed integration into blood bank operations. However, cost-coverage by health insurance remained a case-by-case decision. Allogeneic application as 'just-another-blood-product' could be an aspiration. Yet, conclusive data from large clinical trials are needed for licensed provision in Germany.

The Limbal Niche and Regenerative Strategies

The protective function and transparency provided by the corneal epithelium are dependent on and maintained by the regenerative capacity of limbal epithelial stem cells (LESCs). These LESCs are supported by the limbal niche, a specialized microenvironment consisting of cellular and non-cellular components. Disruption of the limbal niche, primarily from injuries or inflammatory processes, can negatively impact the regenerative ability of LESCs. Limbal stem cell deficiency (LSCD) directly hampers the regenerative ability of the corneal epithelium and allows the conjunctival epithelium to invade the cornea, which results in severe visual impairment. Treatment involves restoring the LESC population and functionality; however, few clinically practiced therapies currently exist. This review outlines the current understanding of the limbal niche, its pathology and the emerging approaches targeted at restoring the limbal niche. Most emerging approaches are in developmental phases but show promise for treating LSCD and accelerating corneal regeneration. Specifically, we examine cell-based therapies, bio-active extracellular matrices and soluble factor therapies in considerable depth.

Cord blood and amniotic membrane extract eye drop preparations display immune-suppressive and regenerative properties

Diseases and injuries that compromise the ocular surface cause considerable patient distress and have long term consequences for their quality of life. Treatment modalities that can address the delicate balance of tissue regeneration, inflammation and maintenance of corneal transparency are therefore needed. We have recently formulated two novel eye drops from placental tissues: cord blood platelet lysate (CBED) and amniotic membrane extract eye drops (AMED), which can be used to treat severe ocular disorders. Here we characterise these two preparations by measuring: (a) growth factors (GF) and cytokines composition, (b) promotion of human corneal epithelial cell (HCEC) growth and (c) effects on immune cells in a lymphocyte culture assay. Finally, their bioavailability was assayed in an ex vivo porcine corneal model. We show that both preparations contain GF and cytokines that were able to promote the in vitro growth of HCEC and support repair in an in vitro scratch test. When assessed in a lymphocyte culture, both favoured immune suppression reducing the cellular expression of NKG2D and CD107a as well as the production of interferon gamma (IFN-γ) in natural killer, NKT and T cells. Regarding bioavailability, CBED active molecules were found mainly in the pre-corneal fraction with some penetration into the corneal fraction, in an ex vivo model. In summary, both placental-derived allogeneic preparations, CBED and AMED, display regenerative and immunomodulatory capabilities. These results will help define mechanisms of action and the best indications and doses of each product for use in a particular patient and support the development of off-the-shelf therapies for ocular surface pathologies in which wound healing defects and inflammatory events are contributing factors.

Current and future therapies for persistent corneal epithelial defects and neurotrophic keratopathy

PURPOSE OF REVIEW

The corneal epithelium is a crucial barrier against pathogens, and when disrupted in the setting of certain underlying risk factors such as neurotrophic keratopathy (NK), may result in persistent epithelial defects (PEDs) of the cornea. Management is challenging and may require a variety of different approaches ranging from conservative medical therapy to surgical intervention. The purpose of this review is to provide an update on current and potential future therapeutic options for PEDs and NK.

RECENT FINDINGS

Recent research has yielded promising results for numerous novel therapies aimed at treating PEDs. Many of these attempt to stimulate healing at the cellular level, via signaling of corneal epithelial differentiation, migration, and proliferation. Considerable advances have also been made regarding medical and surgical promotion of corneal re-innervation and restoration of corneal sensitivity to directly address the underlying NK condition.

SUMMARY

Together with the current well established therapeutic options available for PEDs and NK, growing research on newer alternatives suggest increasing potential for both more effective and more convenient therapies for these difficult situations.

Amniotic membrane extract eye drops for ocular surface diseases: use and clinical outcome in real-world practice

PURPOSE

To study the indications and clinical outcomes, in a real-word setting, of amniotic membrane extract eye drops (AMEED) use for ocular surface disease (OSD).

METHODS

A retrospective study of patients treated with topical AMEED between January 2018 and January 2020 was conducted. Patients were classified in two groups according to specific OSD-dry eye disease (DED) and wound healing delay (WHD) groups. Demographics, comorbidities, treatment duration and clinical outcomes were analysed.

RESULTS

A total of 50 eyes of 36 patients with or without previous treatments were included. Patients in the DED group presented more systemic comorbidities (83 vs 22%; p < 0.001) and spent more mean time under AMEED treatment (10 vs 7.2 months average) than the WHD group (p = 0.0104). In four patients, long-term treatment (more than 24 months) was reported. Global similar symptomatic improvement was reported for both groups (DED 88.9% vs WHD 100%; p = 0.486), with the WHD group especially consisting in general relief (78%) and the DED group reporting more pain improvement (44%) (p = 0.011). Regarding patients with autologous serum as a previous treatment, no statistical differences were found in subjective or objective improvement. An overall success was achieved in 94.4% of the cases and no adverse events were found.

CONCLUSION

AMEED administration is a promising mean to treat OSD such as dry eye, persistent epithelial defect and corneal ulcers. Although AMEED may be effective in the treatment of severe DED and persistent epithelial defect or corneal ulcers, conclusions are limited owing to the absence of controlled clinical trials.

Corneal neurotization for neurotrophic keratopathy: Review of surgical techniques and outcomes

Neurotrophic keratopathy is a degenerative disease in which damage to the corneal nerves leads to corneal hypoesthesia. Injuries to neurotrophic corneas are notoriously difficult to treat and have traditionally been approached with supportive management. However, recent progress in the field of corneal neurotization has given new direction for addressing nerve loss directly by stimulating new nerve growth onto the cornea from nearby sensory nerves transferred to the perilimbal region. Herein, we review the surgical techniques utilized in corneal neurotization, including direct transfers and the use of nerve grafts. Considerations in surgical approach, as well as factors that influence prognosis and outcomes of the surgical intervention are also discussed.

Experimental Pharmacotherapy for Dry Eye Disease: A Review

Dry eye disease (DED) is a complex multifactorial disease showing heterogenous symptoms, including dryness, photophobia, ocular discomfort, irritation and burning but also pain. These symptoms can affect visual function leading to restrictions in daily life activities and reduction in work productivity with a consequently high impact on quality of life. Several pathological mechanisms contribute to the disease: evaporative water loss leads to impairment and loss of tear homeostasis inducing either directly or indirectly to inflammation, in a self-perpetuating vicious cycle. Dysregulated ocular immune responses result in ocular surface damage, which further contributes to DED pathogenesis. Currently, DED treatment is based on a flexible stepwise approach to identify the most beneficial intervention. Although most of the available treatments may control to a certain extent some signs and symptoms of DED, they show significant limitations and do not completely address the needs of patients suffering from DED. This review provides an overview of the emerging experimental therapies for DED. Several promising therapeutic strategies are under development with the aim of dampening inflammation and restoring the homeostasis of the ocular surface microenvironment. Results from early phase clinical trials, testing the effects of EnaC blockers, TRPM8 agonist or mesenchymal stem cells in DED patients, are especially awaited to demonstrate their therapeutic value for the treatment of DED. Moreover, the most advanced experimental strategies in the pipeline for DED, tivanisiran, IL-1R antagonist EBI-005 and SkQ1, are being tested in Phase III clinical trials, still ongoing. Nevertheless, although promising results, further studies are still needed to confirm efficacy and safety of the new emerging therapies for DED.

Ophthalmologic Manifestations of Primary Sjögren's Syndrome

Sjögren’s syndrome (SS) is a chronic, progressive, inflammatory, autoimmune disease, characterized by the lymphocyte infiltration of exocrine glands, especially the lacrimal and salivary, with their consequent destruction. The onset of primary SS (pSS) may remain misunderstood for several years. It usually presents with different types of severity, e.g., dry eye and dry mouth symptoms, due to early involvement of the lacrimal and salivary glands, which may be associated with parotid enlargement and dry eye; keratoconjunctivitis sicca (KCS) is its most common ocular manifestation. It is still doubtful if the extent ocular surface manifestations are secondary to lacrimal or meibomian gland involvement or to the targeting of corneal and conjunctival autoantigens. SS is the most representative cause of aqueous deficient dry eye, and the primary role of the inflammatory process was evidenced. Recent scientific progress in understanding the numerous factors involved in the pathogenesis of pSS was registered, but the exact mechanisms involved still need to be clarified. The unquestionable role of both the innate and adaptive immune system, participating actively in the induction and evolution of the disease, was recognized. The ocular surface inflammation is a central mechanism in pSS leading to the decrease of lacrimal secretion and keratoconjunctival alterations. However, there are controversies about whether the ocular surface involvement is a direct autoimmune target or secondary to the inflammatory process in the lacrimal gland. In this review, we aimed to present actual knowledge relative to the pathogenesis of the pSS, considering the role of innate immunity, adaptive immunity, and genetics.

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.

Diabetic Corneal Neuropathy

Diabetic keratopathy (DK) is a common, but underdiagnosed, ocular complication of diabetes mellitus (DM) that has a significant economic burden. It is characterised by progressive damage of corneal nerves, due to DM-induced chronic hyperglycaemia and its associated metabolic changes. With advances in corneal nerve imaging and quantitative analytic tools, studies have shown that the severity of diabetic corneal neuropathy correlates with the status of diabetic peripheral neuropathy. The corneal nerve plexus is, therefore, considered as an important surrogate marker of diabetic peripheral neuropathy and helps in the evaluation of interventional efficacy in the management of DM. The clinical manifestations of DK depend on the disease severity and vary from decreased corneal sensitivity to sight-threatening corneal infections and neurotrophic ulcers. The severity of diabetic corneal neuropathy and resultant DK determines its management plan, and a step-wise approach is generally suggested. Future work would focus on the exploration of biomarkers for diabetic corneal neuropathy, the development of new treatment for corneal nerve protection, and the improvement in the clinical assessment, as well as current imaging technique and analysis, to help clinicians detect diabetic corneal neuropathy earlier and monitor the sub-clinical progression more reliably.

Washed Equine Platelet Extract as an Anti-Inflammatory Biologic Pharmaceutical

Mammalian platelets participate in the immediate tissue injury response by initiating coagulation and further promoting tissue injury mitigation and repair. The latter properties are deployed following platelet release of presynthetized morphogens, cytokines, and growth and chemotactic factors, which launch a tissue regenerative, angiogenic, and anti-inflammatory program. Several blood-derived biologic products, like platelet-rich plasma (PRP) and platelet lysate (PL), are currently on the market to allow proper healing and tissue regeneration. However, not all growth factors are released from the platelets and the final products contain plasma proteins such as albumin, fibrinogen, complement, and immunoglobulins, increasing the risks of serum sickness or allergic reaction. To address this problem, we developed a new platelet extract where equine blood platelets are concentrated, washed, and thereafter lysed by detergent Triton X-114. Distinct from PRP, this extract is devoid of albumin, fibrinogen, and immunoglobulins and is 266-fold enriched in platelet-derived growth factor content relative to PRP. Washed equine platelet extract (WEPLEX) is amenable to lyophilization without loss of biological activity. In vitro, WEPLEX significantly inhibits human and equine T cell proliferative response to phytohemagglutinin and also polarizes murine CD45⁺/CD11b⁺ peritoneal macrophages to an IL-10⁺ M2-like phenotype. In vivo, WEPLEX substantially improves clinical outcome of murine experimental dextran sulfate sodium colitis. We propose that equine-sourced, zoonosis-free WEPLEX may serve as an anti-inflammatory biological therapy across mammalian species.

The Role of Multisystem Disease in Composition of Autologous Serum tears and ocular surface symptom improvement

PURPOSE

Autologous serum tears (AST) contain growth factors and vitamins similar to those in healthy tears and are an effective treatment option for ocular surface disease. This study determined the differences in composition of AST in patients with systemic diseases versus patients with localized ocular surface diseases and the effects on ocular surface symptom improvement.

METHOD

An observational study was performed on 53 patients with either systemic diseases (Group I) or localized ocular surface diseases (Group II) who were prescribed AST. Concentrations of epidermal growth factor (EGF), interleukin 8 (IL-8), fibronectin, vitamin A, and tumor necrosis factor-α (TNF-α) were determined through ELISA assays from patients in both groups. The Ocular Surface Disease Index (OSDI) scores were calculated prior to and 6 weeks after initiation of treatment with AST for new patients.

RESULTS

The average concentration of EGF in Group I (29.39 pg/ml ± 52.85 pg/ml) was significantly lower than in Group II (88.04 pg/ml ±113.75 pg/ml) (p < 0.05). Levels of fibronectin, IL-8, and vitamin A were similar in both groups. There was a 24% reduction in OSDI score 6 weeks after initiation in Group I compared to a 36% reduction reported in Group II (p = 0.065). The OSDI score was reduced significantly after the treatment in all subjects (p = 0.002).

CONCLUSION

Serum tears are a promising therapy for management of ocular surface disease and associated symptoms. The differences between levels of EGF in patients with localized ocular surface disease and systemic inflammatory disease may account for differences in therapeutic outcome.

Serum eye drops for the treatment of ocular surface diseases: a systematic review and meta-analysis

BACKGROUND

The use of blood-derived eye drops for topical treatment of ocular surface diseases has progressively increased in recent years.

MATERIALS AND METHODS

To evaluate the use of serum eye drops in ocular surface disorders, we performed a systematic search of the literature.

RESULTS

In this systematic review, we included 19 randomised controlled trials (RCTs) investigating the use of serum eye drops in 729 patients compared to controls. For the quantitative synthesis, we included only 10 RCTs conducted in patients with dry eye syndrome comparing autologous serum to artificial tears. At 2-6 weeks, no clear between-group differences in Schirmer test (MD 1.05; 95% CI: -0.17-2.26) and in fluorescein staining (MD -0.61; 95% CI: -1.50-0.28) were found (very low-quality evidence, down-graded for inconsistency, serious risk of biases, and serious imprecision). Slightly higher increase in tear film break-up time (TBUT) scores in autologous serum compared to control (MD 2.68; 95% CI: 1.33-4.03), and greater decrease in ocular surface disease index (OSDI) in autologous serum compared to control (MD -11.17; 95% CI: -16.58 - -5.77) were found (low quality evidence, down-graded for serious risk of bias, and for inconsistency). For the Schirmer test, fluorescein staining and TBUT, data were also available at additional follow-up timing (2-12 months): no clear between-group differences were found, and the quality of the evidence was graded as low/very-low.

CONCLUSIONS

In patients with dry eye syndrome, it is unclear whether or not the use of autologous serum compared to artificial tears increases Schirmer test and fluorescein staining scores at short-term and medium-/long-term follow up. Some benefit at short-term follow up for the outcome of TBUT and OSDI was observed, but the quality of the evidence was low.

The effect of human platelet lysate on corneal nerve regeneration

AIM

This study aimed to test whether human platelet lysate (HPL) has neurotrophic ability for corneal nerve regeneration.

METHODS

We measured the neurotrophic factors in human peripheral serum (HPS) and two commercially available HPLs, UltraGRO and PLTMax. In vitro, we compared the growth rates, neuronal differentiation and immunostaining of neuron markers in mouse neuroblastoma cell line (Neuro-2a) and primary culture of mouse trigeminal ganglion cells that were cultivated in different concentrations of fetal bovine serum, HPS and HPL. In vivo, we created corneal wounds on Sprague Dawley rats with a rotating burr and evaluated the effects of topical HPL on wound healing and corneal nerve regeneration by in vivo confocal microscopy and corneal aesthesiometry.

RESULTS

HPLs had significantly higher concentrations of various neurotrophic factors compared with HPS (p<0.05). In Neuro-2a cells, 3% HPL was better at promoting neuronal growth and differentiation compared with HPS at the same concentration. HPL was also found to have superior neurotrophic effects compared with HPS in primary cultures of mouse trigeminal ganglion cells. In vivo, HPL-treated eyes had better corneal epithelial wound healing rate, nerve regeneration length and corneal touch threshold compared with eyes treated with artificial tears (p<0.05).

CONCLUSION

HPL has significantly higher concentrations of neurotrophic factors compared with HPS. It showed not only in vitro but also in vivo corneal neurotrophic abilities. Our results suggest that HPL may have a potential role in the treatment of diseases related to corneal nerve damage or degeneration.

Blood-Based Treatments for Severe Dry Eye Disease: The Need of a Consensus

The use of blood-based eye drops as therapy for various diseases of the ocular surface has become increasingly popular in ophthalmic practice during recent years. The rationale for their use is based on the promotion of cellular proliferation and migration thanks to the supply of metabolically active substances, in particular growth factors. Blood-derived eye drops have been used for the treatment of several ocular surface disorders, such as dry eye disease, corneal ulcer, persistent epithelial defect, neurotrophic keratitis, ocular surface burn, recurrent corneal erosion, and limbal stem-cell deficiency. Both autologous (from patients themselves) and heterologous (from adult donors or from cord blood sampled at birth)-derived products exist, and each source has specific pros and cons. Despite an extensive literature, several issues are still under debate and the aim of this manuscript is to review the indications, preparation methods and storage, characterization of content, rationale for clinical outcomes, patient stratification, length of treatment, and rationale for repeated treatments at disease relapse. A rationale based on a "5 Ws and 2 Hs" protocol is proposed as a way of thinking, with the attempt to clarify Who, Why, When, Where, What, and How to use these treatment options.

An update on chemical eye burns

Ocular chemical injuries vary in severity, with the more severe end of the spectrum having profound visual consequences and medicolegal implications. Grading of ocular injuries is critical for determining acute treatment and visual prognosis. Poor immediate management results in more challenging treatment of acute disease. Similarly, poorly controlled acute disease results in more treatment-resistant chronic ocular disease. Despite several decades of research and public health initiatives, simple and effective interventions such as wearing protective eyewear and immediate irrigation of eyes remain as key challenges. Education and prevention are therefore important public health messages. Hurdles in the acute management of disease include poor evidence-base for commonly used treatments (e.g. based on experimental animal studies), reduced treatment adherence rates and high clinic non-attendance rates. The evolution of treatment strategies, particularly limbal stem cell transplantation, has revolutionised the visual and cosmetic outcomes in chronic phases of disease. It is therefore increasingly important to consider tertiary referral for patients with limbal stem cell failure or vision-limiting corneal scarring.

Corneal Neurotization Improves Ocular Surface Health in a Novel Rat Model of Neurotrophic Keratopathy and Corneal Neurotization

Purpose

Corneal neurotization is a novel surgical procedure to reinnervate the cornea in patients with neurotrophic keratopathy (NK). We developed a rat model of NK and corneal neurotization to further investigate corneal neurotization as a treatment to improve maintenance and healing of the corneal epithelium.

Methods

Thy1-GFP+ Sprague Dawley rats were used to develop the model. Corneal denervation was performed via stereotactic electrocautery of the ophthalmomaxillary branch of the trigeminal nerve. Corneal neurotization was performed by guiding donor sensory axons from the contralateral infraorbital nerve into the cornea via two nerve grafts. Corneal imaging, including nerve density measurements and retrograde labeling were performed to validate the model. In vivo assays of corneal maintenance and repair were used to examine whether treatment with corneal neurotization improved healing in rats with NK.

Results

Corneal neurotization significantly increased corneal axon density in rats with NK (P < 0.01). Retrograde labeling of the cornea in rats with corneal neurotization labeled 206 ± 82 neurons in the contralateral trigeminal ganglion, confirming axons reinnervating the cornea derived from the contralateral infraorbital nerve. Corneal reinnervation after corneal neurotization improved corneal epithelial maintenance and corneal healing after injury (P < 0.01).

Conclusions

Donor nerve fibers reinnervate the insensate cornea after corneal neurotization and significantly improve corneal maintenance and repair. This model can be used to further investigate how corneal neurotization influences epithelial maintenance and repair in the context of NK.

Differential profile of protein expression on human keratocytes treated with autologous serum and plasma rich in growth factors (PRGF)

Purpose

The main objective of this study is to compare the protein expression of human keratocytes treated with Plasma rich in growth factors (PRGF) or autologous serum (AS) and previously induced to myofibroblast by TGF-β1 treatment.

Methods

Blood from healthy donor was collected and processed to obtain AS and PRGF eye drops. Blood derivates were aliquoted and stored at -80°C until use. Keratocyte cells were pretreated for 60 minutes with 2.5 ng/ml TGF-β1. After that, cells were treated with PRGF, AS or with TGF-β1 (control). To characterize the proteins deregulated after PRGF and AS treatment, a proteomic approach that combines 1D-SDS–PAGE approach followed by LC–MS/MS was carried out.

Results

Results show a catalogue of key proteins in close contact with a myofibroblastic differentiated phenotype in AS treated-cells, whereas PRGF-treated cells show attenuation on this phenotype. The number of proteins downregulated after PRGF treatment or upregulated in AS-treated cells suggest a close relationship between AS-treated cells and cytoskeletal functions. On the other hand, proteins upregulated after PRGF-treatment or downregulated in AS-treated cells reveal a greater association with processes such as protein synthesis, proliferation and cellular motility.

Conclusion

This proteomic analysis helps to understand the molecular events underlying AS and PRGF-driven tissue regeneration processes, providing new evidence that comes along with the modulation of TGF-β1 activity and the reversion of the myofibroblastic phenotype by PRGF.

Application of Novel Drugs for Corneal Cell Regeneration

Corneal transplantation has been the only treatment method for corneal blindness, which is the major cause of reversible blindness. However, despite the advancement of surgical techniques for corneal transplantation, demand for the surgery can never be met due to a global shortage of donor cornea. The development of bioengineering and pharmaceutical technology provided us with novel drugs and biomaterials that can be used for innovative treatment methods for corneal diseases. In this review, the authors will discuss the efficacy and safety of pharmacologic therapies, such as Rho-kinase (ROCK) inhibitors, blood-derived products, growth factors, and regenerating agent on corneal cell regeneration. The promising results of these agents suggest that these can be viable options for corneal reconstruction and visual rehabilitation.

The corneal epitheliotrophic abilities of lyophilized powder form human platelet lysates

Purpose

To evaluate whether lyophilized human platelet lysate (HPL) powder can preserve the growth factor concentrations and epitheliotrophic properties of liquid HPL, and potentially be used as a clinically-friendly treatment option.

Methods

Two commercialized liquid HPLs, UltraGRO TM (Helios, Atlanta, GA) and PLTMax (Mill Creek, Rochester, MI), were obtained and converted to lyophilized powder. After redissolution, lyophilized powder HPLs were compared with liquid HPLs, as well as human peripheral serum (HPS) and fetal bovine serum (FBS) in liquid or redissolved lyophilized powder forms. Concentrations of epidermal growth factor (EGF), transforming growth factor-β1 (TGF-β1), platelet-derived growth factor-AB (PDGF-AB) and platelet-derived growth factor-BB (PDGF-BB) were evaluated by enzyme-linked immunosorbent assay (ELISA). Human corneal epithelial cell line was incubated with the blood derivatives and evaluated for cell migration with scratch-induced directional wounding and proliferation with MTS assays. Cell differentiation was examined by transepithelial electrical resistance (TEER). Fluorescein staining and in vivo confocal microscopy were used to evaluate in vivo corneal epithelial wound healing in Sprague-Dawley rats that underwent corneal debridement and topical application of liquid and redissolved powder HPLs.

Results

Liquid form and redissolved lyophilized powder form HPLs had similar concentrations of EGF, TGF-β1, PDGF-AB and PDGF-BB. In vitro experiments on cell migration, proliferation and differentiation and rat models on wound healing demonstrated no significant difference between the liquid and redissolved lyophilized powder forms for HPLs, HPS and FBS. In vivo confocal microscopy revealed similar wound healing process at different layers of cornea after corneal epithelial debridement between liquid form and redissolved lyophilized power form of HPLs.

Conclusions

The redissolved lyophilized powder form of both commercialized HPLs showed similar growth factor concentrations and corneal epitheliotrophic abilities compared to the liquid form. Results suggest that the properties of liquid HPLs can be retained despite lyophilization and that lyophilized HPLs can be a treatment option for corneal epithelial disorders.

Wound healing in the eye: Therapeutic prospects

In order to maintain a smooth optical surface the corneal epithelium has to continuously renew itself so as to maintain its function as a barrier to fluctuating external surroundings and various environmental insults. After trauma, the cornea typically re-epithelializes promptly thereby minimizing the risk of infection, opacification or perforation. A persistent epithelial defect (PED) is usually referred to as a non-healing epithelial lesion after approximately two weeks of treatment with standard therapies to no avail. They occur following exposure to toxic agents, mechanical injury, and ocular surface infections and are associated with significant clinical morbidity in patients, resulting in discomfort or visual loss. In the case of deeper corneal injury and corneal pathology the wound healing cascade can also extend to the corneal stroma, the layer below the epithelium. Although significant progress has been made in recent years, pharmaco-therapeutic agents that promote corneal healing remain limited. This article serves as a review of current standard therapies, recently introduced alternative therapies gaining in popularity, and a look into the newest developments into ocular wound healing.

Regenerative Therapies in Dry Eye Disease: From Growth Factors to Cell Therapy

Dry eye syndrome is a complex and insidious pathology with a high level of prevalence among the human population and with a consequently high impact on quality of life and economic cost. Currently, its treatment is symptomatic, mainly based on the control of lubrication and inflammation, with significant limitations. Therefore, the latest research is focused on the development of new biological strategies, with the aim of regenerating affected tissues, or at least restricting the progression of the disease, reducing scar tissue, and maintaining corneal transparency. Therapies range from growth factors and cytokines to the use of different cell sources, in particular mesenchymal stem cells, due to their multipotentiality, trophic, and immunomodulatory properties. We will review the state of the art and the latest advances and results of these promising treatments in this pathology.

Neuropathic Corneal Pain: Approaches for Management

Neuropathic pain is caused by a primary lesion or dysfunction of the nervous system and can occur in the cornea. However, neuropathic corneal pain (NCP) is currently an ill-defined disease. Patients with NCP are extremely challenging to manage, and evidence-based clinical recommendations for the management of patients with NCP are scarce. The objectives of this review are to provide guidelines for diagnosis and treatment of patients with NCP and to summarize current evidence-based literature in this area. We performed a systematic literature search of all relevant publications between 1966 and 2017. Treatment recommendations are, in part, based on methodologically sound randomized controlled trials (RCTs), demonstrating superiority to placebo or relevant control treatments, and on the consistency of evidence, degree of efficacy, and safety. In addition, the recommendations include our own extensive experience in the management of these patients over the past decade. A comprehensive algorithm, based on clinical evaluation and complementary tests, is presented for diagnosis and subcategorization of patients with NCP. Recommended first-line topical treatments include neuroregenerative and anti-inflammatory agents, and first-line systemic pharmacotherapy includes tricyclic antidepressants and an anticonvulsant. Second-line oral treatments recommended include an opioid-antagonist and opiate analgesics. Complementary and alternative treatments, such as cardiovascular exercise, acupuncture, omega-3 fatty acid supplementation, and gluten-free diet, may have additional benefits, as do potential noninvasive and invasive procedures in recalcitrant cases. Medication selection should be tailored on an individual basis, considering side effects, comorbidities, and levels of peripheral and centralized pain. Nevertheless, there is an urgent need for long-term studies and RCTs assessing the efficacy of treatments for NCP.

Use of the Controlled Adverse Environment (CAE) in Clinical Research: A Review

The many internal and external factors that contribute to the pathophysiology of dry eye disease (DED) create a difficult milieu for its study and complicate its clinical diagnosis and treatment. The controlled adverse environment (CAE^®) model has been developed to minimize the variability that arises from exogenous factors and to exacerbate the signs and symptoms of DED by stressing the ocular surface in a safe, standardized, controlled, and reproducible manner. By integrating sensitive, specific, and clinically relevant endpoints, the CAE has proven to be a unique and adaptable model for both identifying study-specific patient populations with modifiable signs and symptoms, and for tailoring the evaluation of interventions in clinical research studies.

Limbal and corneal epithelial homeostasis

PURPOSE OF REVIEW

The aim of this review is to describe the underlying mechanisms of corneal epithelial homeostasis in addition to illustrating the vital role of the limbal epithelial stem cells (LESCs) and the limbal niche in epithelial regeneration and wound healing.

RECENT FINDINGS

The shedded corneal epithelial cells are constantly replenished by the LESCs which give rise to epithelial cells that proliferate, differentiate, and migrate centripetally. While some recent studies have proposed that epithelial stem cells may also be present in the central cornea, the predominant location for the stem cells is the limbus. The limbal niche is the specialized microenvironment consisting of cells, extracellular matrix, and signaling molecules that are essential for the function of LESCs. Disturbances to limbal niche can result in LESC dysfunction; therefore, limbal stem cell deficiency should also be considered a limbal niche deficiency. Current and in-development therapeutic strategies are aimed at restoring the limbal niche, by medical and/or surgical treatments, administration of trophic factors, and cell based therapies.

SUMMARY

The corneal epithelium is constantly replenished by LESCs that are housed within the limbal niche. The limbal niche is the primary determinant of the LESC function and novel therapeutic approaches should be focused on regeneration of this microenvironment.

Comparison of corneal epitheliotrophic capacities among human platelet lysates and other blood derivatives

PURPOSE

To evaluate the corneal epitheliotropic abilities of two commercialized human platelet lysates (HPLs) and to compare the results with other blood derivatives, including human peripheral serum (HPS) and bovine fetal serum (FBS).

METHODS

In vitro, human corneal epithelial cells were incubated in various concentrations (0%, 3%, 5% and 10%) of blood derivatives. Two commercialized HPLs, including UltraGRO TM (Helios, Atlanta, GA) and PLTMax (Mill Creek, Rochester, MI), were tested and compared with HPS and FBS. Scratch-induced directional wounding assay was performed to evaluate cellular migration. MTS assay was used to evaluate cellular proliferation. Cellular differentiation was examined by scanning electron microscopy, inverted microscopy and transepithelial electrical resistance. Sprague-Dawley rats were used to evaluate the effects of the blood derivatives on corneal epithelial wound healing in vivo. Different blood derivatives were applied topically every 2 hours for 2 days after corneal epithelial debridement. The concentrations of epidermal growth factor (EGF), transforming growth factor -β1 (TGF-β1), fibronectin, platelet-derived growth factor-AB (PDGF-AB), PDGF-BB, and hyaluronic acid in different blood derivatives were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

In vitro experiments demonstrated statistically comparable epitheliotropic characteristics in cellular proliferation, migration, and differentiation for the two commercialized HPLs compared to FBS and HPS. Cells cultured without any serum were used as control group. The epitheliotropic capacities were statistically higher in the two commercialized HPLs compared to the control group (p<0.05). Among the different concentrations of blood derivatives, the preparations with 3% yielded better outcomes compared to 5% and 10%. In rats, HPLs also caused improved but not statistically significant wound healing compared to HPS. All the blood derivatives had better wound healing ratios than the control group (p<0.05). In the quantification of epitheliotropic factors, UltraGRO and PLTMax had significantly higher levels of EGF, TGF- β1, fibronectin than human peripheral serum (p<0.05).

CONCLUSIONS

Both commercialized HPLs showed comparable corneal epitheliotropic abilities and wound healing rates compared to HPS and FBS in the in vivo and in vitro studies. Our results suggest that HPLs may have the potential to replace HPS in the treatment of corneal epithelial problems.

Serum components and clinical efficacies of autologous serum eye drops in dry eye patients with active and inactive Sjogren syndrome

PURPOSE:

Autologous serum eye drops are considered safe and efficient for the treatment of various ocular surface disorders, including dry eye diseases (DED) caused by the primary and secondary Sjogren syndrome (SS). However, the serum components in patients of SS may be different from those of normal patients and can thus lead to unpredictable therapeutic effects. This study divided the SS patients into active and inactive types based on the erythrocyte sedimentation rate and the presence or absence of active rheumatoid arthritis.

METHODS:

We compared the serum components of these two groups with standard and multiplex enzyme linked immunosorbent assay arrays and predicted the therapeutic effects of topical autologous serum for the treatment of DED with ocular surface disease index (OSDI) and Oxford Schema scale (OSS).

RESULTS:

Hyaluronic acid and transforming growth factor b1 levels were significantly higher in the active SS group compared to the inactive SS group (P < 0.01), whereas epidermal growth factors, insulin growth factor 1, and fibroblast growth factor b had no significant differences between these two groups. Active SS group had significantly higher expressions of interleukin (IL) 1 beta, IL 6, and tumor necrosis factor alpha compared to inactive SS patients (P < 0.05). There were no statistical differences in therapeutic effects between these two groups, as measured with the OSDI or OSS.

CONCLUSION:

Dividing the Sjogren dry eye patients into active and inactive groups may appear as a reasonable method to predict the quality of autologous serum eye drops, but there seems to be no significant predictability to the therapeutic effects.

Platelet rich plasma in ocular surface

The use of platelet-rich preparations has experienced a significant increase in recent years due to its role in tissue-repair and regeneration. The aim of this study is to examine the available evidence regarding the application of plasma rich in growth factors, and its variations, on the ocular surface. A review is also presented on the effects of platelet-derived growth factors, the implications of the preparation methods, and the existing literature on the safety and efficacy of these therapies in ocular surface diseases. Despite the widespread use of platelet preparations there is no consensus on the most appropriate preparation method, and growth factors concentration vary with different systems. These preparations have been used in the treatment of ocular surface diseases, such as dry eye or persistent epithelial defects, among others, with good safety and efficacy profiles, but further studies are needed to compare to the currently available alternatives.