Evaluation of the efficacy of 50% autologous serum eye drops in different ocular surface pathologies

Persistent Corneal Epithelial Defect Following Pars Plana Vitrectomy: A Narrative Review

PURPOSE

Persistent corneal epithelial defects (PCEDs) following pars plana vitrectomy (PPV) represent a significant clinical challenge, potentially leading to corneal scarring, vision loss, and other severe complications. This review aims to summarize the prevalence, associated risk factors, and management strategies for PCEDs in the context of PPV, providing evidence-based guidance for clinicians.

METHODS

A comprehensive systematic review was conducted using PubMed and Embase databases, identifying English-language studies addressing PCEDs after PPV.

RESULTS

The prevalence of PCEDs post-PPV varied widely, from 0% to 78.37%, influenced by intrinsic factors such as diabetes mellitus, which impairs corneal nerve function and healing, and extrinsic factors like intraoperative tamponade with C3F8. Management strategies ranged from conservative options like bandage contact lenses to advanced treatments like topical insulin.

CONCLUSION

PCEDs after PPV are multifactorial and demand individualized management. Advanced therapies, particularly serum-based treatments, and topical insulin, show promising outcomes. Further prospective research is warranted to refine these treatments.

Autologous Serum Eye Drops Diluted with Cyclosporine A 0.05% and Sodium Hyaluronate 0.1%: An Experimental Comparative Study

PURPOSE

The purpose of this study was to assess in-vitro efficacy of a suffusion of autologous serum withcyclosporine 0.05% (CsA) and sodium hyaluronate 0.1% (SH).

METHODS

The expression of proinflammatory markers interleukin 6 (IL-6) and TNF-Alpha (TNF-α) in limbal epithelial cells was evaluated. Also, assessment of the stability of epithelial growth factor and transforming growth factor-beta (EGF, TGF-β) in the 50% combinations with autologous serum (AS) was done. The characteristics (pH, density, osmolality) of the two combinations were also evaluated. Additionally, cytotoxicity effect of given test compounds was evaluated on human limbal epithelial cells (LEpiC).

RESULTS

The percentage of cells expressing IL-6 subjected to AS + SH and AS + CsA were 6.23% and 5.69% respectively. There was no significant difference in percentage of cells expressing TNF-α between the formulations (5.87%, 5.83% respectively). The growth factors; EGF and TGF-β remained stable forone month duration (on 2 and 4 weeks) at 4 °C without significant difference between the time intervals tested. The results of MTT assay suggested that limbal epithelial cells treated with AS + CsA and AS + SH combinations showed minimal toxicity however it was not significant statistically (p ≤ 0.05).

CONCLUSION

Two test combinations (AS + CsA, AS + SH) showed stable growth factors (EGF, TGF-β) and good anti-inflammatory property against pro-inflammatory markers. Also, the 2 combinations were found safe on cultured limbal epithelial cells. The novel combination of autologous serum in CsA may provide added benefit in dry eye disease (DED) through their combined anti-inflammatory and epitheliotropic effects.

Autologous blood in the management of ocular surface disorders

Autologous blood therapy has emerged as a promising modality in managing ocular surface disorders. This review provides a comprehensive overview of the current literature regarding the use of autologous blood in ocular surface disorders, encompassing its physiological basis, clinical applications, techniques, challenges, and future perspectives. The ocular surface, comprising the cornea, conjunctiva, and tear film, plays a critical role in maintaining visual function, and its disruption can lead to various pathological conditions. With its rich composition of growth factors, cytokines, and other bioactive molecules, autologous blood offers therapeutic potential in promoting corneal wound healing, reducing inflammation, and improving tear film stability. Clinical studies have demonstrated the efficacy and safety of autologous blood therapy in diverse ocular surface disorders, including persistent epithelial defects, neurotrophic keratopathy, and dry eye disease. However, challenges such as variability in treatment response, adverse effects, and optimal patient selection remain areas of concern. Further research is needed to elucidate the underlying mechanisms of action, refine treatment protocols, and explore synergistic approaches with other therapeutic modalities. Despite these challenges, autologous blood therapy holds promise as a valuable adjunctive treatment option for ocular surface disorders, offering new avenues for improving patient outcomes and quality of life. This review examines the mechanisms underlying ocular surface disorders while discussing existing autologous blood-based therapies for managing these disorders. Current clinical trials are also summarized, and a comparison between autologous blood therapy and conventional eyedrops is attempted. Finally, safe techniques and protocols for autologous blood medicine are elucidated, and adverse effects and future perspectives of this novel therapy are reviewed.

The effect of platelet-rich plasma and sodium alginate hydrogel on corneal wound healing after corneal alkali burns in rats with computer-assisted anterior segment optical coherence tomography image analysis

Our objective was to determine the effect of a semi-synthetic sodium alginate hydrogel and its combination with platelet-rich plasma (PRP) on histopathological, biochemical, clinical, and anterior segment optical coherence tomography (AS-OCT) data. Alkali chemical burn of the cornea was induced. Injured rats were randomly divided into five equal groups and topically treated with phosphate-buffered saline (sham), platelet-rich plasma (PRP), 0.5% sodium citrate, a semi-synthetic sodium alginate hydrogel, or a combination of PRP and hydrogel (combined group) three times daily. The degree of corneal opacity (CO), corneal epithelial staining (CES), percentage of corneal epithelial defects (CEDP), degree of ciliary hyperemia (CH), neovascularization size (NVS), and extent of neovascularization (NVE) were evaluated. AS-OCT was performed at nine days, and then rats were sacrificed. Histological examination and enzyme-linked immunosorbent assays were performed to detect the concentrations of IL-1β and MMP-9 in the cornea. There were no significant differences between the groups regarding CEDP, CO, CES, CH, NVS, or NVE on the first day after corneal alkali burn injury (p > 0,05). At the last examination, CO was significantly lower in the PRP group than in the sham group (p = 0,044), while the CO concentrations were similar in terms of NVS (p > 0,05). Similarly, in terms of tissue MMP-9 levels, there were no significant differences between groups (p > 0,05). However, there was a significant difference in tissue IL-1β levels between the groups (p < 0,001). In the PRP and combined groups, the level of IL-1β was significantly lower than that in the sham group (p = 0,043 and p = 0,036, respectively). There was a significant difference in epithelial necrosis between the PRP, and it was the lowest in the combined group (p = 0,003). Epithelial thickness was highest in the combined group (p = 0,002). CEDP was significantly different at the last visit between the groups (p = 0.042). The fastest epithelial closing rate was observed for the combined group (p = 0,026). There was a significant negative correlation between tissue MMP-9 levels and corneal solidity and between tissue MMP-9 levels and the corneal area according to the AS-OCT measurements (p = 0,012 and p = 0,027, respectively). When used alone, topical hydrogel application did not significantly enhance the healing of corneal wounds. However, when combined with PRP, it leads to an increased rate of epithelial closure and neovascularization. This combination did not exacerbate inflammation or corneal opacity compared to PRP alone. The anticoagulant citrate solution in the PRP tube did not prove effective. The synergistic use of PRP and hydrogel could enhance epithelial thickness and reduce epithelial necrosis. The use of new parameters for corneal wound healing assessment was facilitated through AS-OCT image processing.

Understanding Ocular Graft-versus-Host Disease to Facilitate an Integrated Multidisciplinary Approach

Ocular graft-versus-host disease (oGVHD) remains a challenging and potentially devastating complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although oGVHD significantly impacts the quality of life of affected survivors, it often goes unrecognized, particularly in the early stages. Targeting all providers in the HSCT community who see patients regularly and frequently for their post-allo-HSCT care, this review and opinion piece introduces the basic concepts of ocular surface pathophysiology, dissects the different stages of clinical presentation of oGVHD, explains why the current diagnostic criteria tend to capture the late disease stages, and highlights the warning signs of early disease development to facilitate prompt referral of oGVHD suspects for ocular specialist care. Along with introducing a comprehensive list of treatment options, this review emphasizes basic therapeutic strategy and options that can be safely and effectively initiated by any care provider. We believe in empowering patients as well as care providers beyond disciplinary boundaries to provide the most cohesive and integrated care in a multidisciplinary approach.

Ocular Lichen Planus: A clinicopathologic review

Lichen planus is a chronic inflammatory dermatosis that can affect the skin, mucous membranes and nails. Cutaneous lichen planus lesions are best described by the "six Ps" - purple pruritic polygonal planar papules and plaques. Mucous membrane lesions are commonly associated with cutaneous lichen planus. Ocular involvement with lichen planus is rare and conjunctival involvement usually predominates, it can however be visually devastating. Ocular lichen planus often progresses to extensive conjunctival scarring which can be impossible to distinguish clinically from other cicatrising conjunctivitis, requiring histopathological confirmation. Here we review the ocular pathology of this condition.

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.

Recent United States Developments in the Pharmacological Treatment of Dry Eye Disease

Dry eye disease (DED) can arise from a variety of factors, including inflammation, meibomian gland dysfunction (MGD), and neurosensory abnormalities. Individuals with DED may exhibit a range of clinical signs, including tear instability, reduced tear production, and epithelial disruption, that are driven by different pathophysiological contributors. Those affected often report a spectrum of pain and visual symptoms that can impact physical and mental aspects of health, placing an overall burden on an individual's well-being. This cumulative impact of DED on an individual's activities and on society underscores the importance of finding diverse and effective management strategies. Such management strategies necessitate an understanding of the underlying pathophysiological mechanisms that contribute to DED in the individual patient. Presently, the majority of approved therapies for DED address T cell-mediated inflammation, with their tolerability and effectiveness varying across different studies. However, there is an emergence of treatments that target additional aspects of the disease, including novel inflammatory pathways, abnormalities of the eyelid margin, and neuronal function. These developments may allow for a more nuanced and precise management strategy for DED. This review highlights the recent pharmacological advancements in DED therapy in the United States. It discusses the mechanisms of action of these new treatments, presents key findings from clinical trials, discusses their current stage of development, and explores their potential applicability to different sub-types of DED. By providing a comprehensive overview of products in development, this review aims to contribute valuable insights to the ongoing efforts in enhancing the therapeutic options available to individuals suffering from DED.

An adaptive drug-releasing contact lens for personalized treatment of ocular infections and injuries

This research introduces an innovative solution to address the challenges of bacterial keratitis and alkali burns. Current treatments for bacterial keratitis and alkali burns rely on the frequent use of antibiotics and anti-inflammatory eye drops. However, these approaches suffer from poor bioavailability and fluctuating concentrations, leading to limited efficacy and potential drug resistance. Our approach presents an adaptive drug-releasing contact lens responsive to reactive oxygen species (ROS) at ocular inflammation sites, synchronously releasing Levofloxacin and Diclofenac. During storage, minimal drug release occurred, but over 7 days of wear, the lens maintained a continuous, customizable drug release rate based on disease severity. This contact lens had strong antibacterial activity and biofilm prevention, effectively treating bacterial keratitis. When combined with autologous serum, this hydrophilic, flexible lens aids corneal epithelial regeneration, reducing irritation and promoting healing. In summary, this ROS-responsive drug-releasing contact lens combines antibacterial and anti-inflammatory effects, offering a promising solution for bacterial keratitis and alkali burns.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Comparison of the Effect of Autologous Serum on Therapy Resistant Corneal Erosions and Ulcers on the Corneal Graft vs. the Patient's Own Cornea]

PURPOSE

The aim of this study is to compare the healing of corneal epithelial defects or ulcers on the corneal graft in comparison with the patient's own cornea after treatment with 100%, undiluted autologous serum eye drops.

METHODS

In a retrospective study over 7 years, we analysed 263 treatments with autologous serum eye drops of persistent corneal epithelial defects (erosions [88%] vs. ulcers [12%]). We compared the epithelial healing tendency of patients with defects on their own cornea (51.9%) vs. patients who had previously undergone penetrating keratoplasty (48.1%). Complete epithelial healing during the 28 days of treatment was considered as therapeutic success. In addition, the recurrence rate of the epithelial defects after finishing the therapy was analysed.

RESULTS

88.2% of the epithelial defects healed during 28 days of therapy. The recurrence rate during follow-up was 5.1%. There was no significant difference with respect to success rate between corneal defects on the patient's own cornea (87.8%) and on the graft (88.6%; p = 0.137). There was a significantly lower success rate for corneal ulcers (74.2%) than for erosions (90.3%; p < 0.001). The recurrence rate of erosions was 4.4%, vs. 4.3% in ulcers during follow-up.

CONCLUSION

The results of our study suggest that autologous serum eye drops are a non-invasive and safe alternative treatment for persistent corneal epithelial defects - with no significant difference in patients with a defect on their own cornea vs. defects on the corneal graft. The success rate, but not the recurrence rate, is significantly worse in ulcers than in erosions.

Current Advances in Regenerative Strategies for Dry Eye Diseases: A Comprehensive Review

Dry eye disease (DED) is an emerging health issue affecting millions of individuals annually. Ocular surface disorders, such as DED, are characterized by inflammation triggered by various factors. This condition can lead to tear deficiencies, resulting in the desiccation of the ocular surface, corneal ulceration/perforation, increased susceptibility to infections, and a higher risk of severe visual impairment and blindness. Currently, the clinical management of DED primarily relies on supportive and palliative measures, including the frequent and lifelong use of different lubricating agents. While some advancements like punctal plugs, non-steroidal anti-inflammatory drugs, and salivary gland autografts have been attempted, they have shown limited effectiveness. Recently, there have been promising developments in the treatment of DED, including biomaterials such as nano-systems, hydrogels, and contact lenses for drug delivery, cell-based therapies, biological approaches, and tissue-based regenerative therapy. This article specifically explores the different strategies reported so far for treating DED. The aim is to discuss their potential as long-term cures for DED while also considering the factors that limit their feasibility and effectiveness. These advancements offer hope for more effective and sustainable treatment options in the future.

Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

BACKGROUND/AIMS

This study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.

METHODS

At our single institution, PRP and AS eye-drops were prepared using peripheral blood obtained from six healthy volunteers and stored at 4°C. Platelet and leucocyte counts and transforming growth factor (TGF)-β1, epidermal growth factor (EGF), and fibronectin levels were assessed during storage for up to 4 weeks. Sterility was assessed by culturing 4-week poststorage samples. PRP, AS, and phosphate-buffered saline (PBS) eye-drop efficacies were compared using corneal epithelial wound healing assays in vitro and in vivo and monitoring wound areas under a microscope every 3 hours.

RESULTS

Higher platelet and lower leucocyte counts were seen in PRP than in whole blood on the day of preparation. After storage, TGF-β1, EGF, and fibronectin levels were significantly higher in PRP than in AS eye-drops. In vitro and in vivo, PRP eye-drops used on the day of preparation significantly promoted corneal epithelial wound healing compared with PBS. Moreover, PRP eye-drops stored for 4 weeks significantly promoted corneal wound healing compared with PBS and AS eye-drops.

CONCLUSION

PRP eye-drops stored at 4°C for 4 weeks promoted corneal epithelial wound healing with higher levels of growth factors than those observed in AS eye-drops, while maintaining sterility, suggesting that this preparation satisfies the unmet medical needs in the treatment of refractory keratoconjunctival epithelial disorders.

Topical analgesics for acute corneal pain: current options and emerging therapeutics

Acute corneal pain is a common complaint that causes significant distress to patients and continues to challenge therapeutic avenues for pain management. Current topical treatment options have marked limitations in terms of both efficacy and safety, thus often prompting the adjunctive use of systemic analgesics, including opioids. In general, there have not been extensive advancements in pharmacologic options for the management of corneal pain over the past several decades. Despite this, multiple promising therapeutic avenues exist which hold the potential to transform the ocular pain landscape, including druggable targets within the endocannabinoid system. This review will summarize the current evidence base for topical nonsteroidal anti-inflammatory drugs, anticholinergic agents, and anesthetics before focusing on several potential avenues in the setting of acute corneal pain management, including autologous tear serum, topical opioids and endocannabinoid system modulators.

Long-Term Comprehensive Management of Bilateral Limbal Stem Cell Deficiency Secondary to Severe Chemical Burn: 10 Years of Follow-Up

PURPOSE

To describe the long-term management of bilateral limbal stem cell deficiency secondary to a severe chemical burn.

METHODS

Descriptive case report.

IMPORTANCE

This case highlights the importance of early intervention in ocular chemical burns for the preservation of tissue integrity and avoidance of perforation. We also review the use of proper ocular surface reconstructive techniques to restore the function of the limbal area, as well as the immunomodulatory strategies and follow-up needed for these interventions.

Combination of Bandage Contact Lens and Autologous Serum Eye Drop for the Treatment of Superior Limbic Keratoconjunctivitis

PURPOSE

To report clinical improvement after combined treatment of bandage contact lens and autologous serum eye drop in a patient with superior limbic keratoconjunctivitis (SLK) complicated with dry eye disease (DED) and meibomian gland dysfunction (MGD).

PATIENTS AND METHODS

Case report.

RESULTS

A 60-year-old woman was referred for unilateral chronic recurrent redness of the left eye not responding to topical steroids and cyclosporine 0.1% eye drop. She was diagnosed with SLK, which was complicated by the presence of DED and MGD. The patient was then commenced with autologous serum eye drop and fitted with silicone hydrogel contact lens in her left eye, and treated with intense pulsed light therapy for MGD in both eyes. Remission was seen Information Classification: General serum eye drop and bandage contact lens wear.

CONCLUSION

Long-term application of autologous serum eye drop combined with bandage contact lens can be used as an alternative treatment approach in SLK.

Comparative evaluation of effectiveness of twenty versus fifty percent autologous serum eye drops in treatment of dry eye

Purpose

The objective of the study was to compare the efficacy and safety of two concentration of autologous serum (AS) 20% vs 50% in recalcitrant moderate-to-severe dry eye patients.

Methods

A double-blind prospective, interventional, and randomized study was done on 44 patients (80 eyes) clinically diagnosed with moderate-to-severe dry eye disease (DED) that was refractory to conventional treatment, and all patients were treated with AS20% or AS50% for 12 weeks. We documented Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), OXFORD corneal staining score (OSS), and Schirmer test (ST) at baseline, 2,4,8, and 12 weeks. These parameters were compared in both groups and between the groups by using Student's t-test. The study included 11 males and 33 females.

Results

Out of 80 eyes, 33 eyes had moderate and 47 had severe DED. The age of patients in AS20% was 44.73 ± 14.37 years, and in AS50% was 46.41 ± 14.47 years. The most common etiology associated with DED was secondary Sjogren syndrome. In moderate DED, both the groups showed significant improvement in both subjective and objective parameters. But in severe DED, the AS20% group failed to show any significant improvement objectively, though subjective improvement was present.

Conclusion

In refractory severe DED patients, AS50% is better option for treatment and in moderate DED both concentrations of autologous serum are effective.

Immunomodulatory Role of Neuropeptides in the Cornea

The transparency of the cornea along with its dense sensory innervation and resident leukocyte populations make it an ideal tissue to study interactions between the nervous and immune systems. The cornea is the most densely innervated tissue of the body and possesses both immune and vascular privilege, in part due to its unique repertoire of resident immune cells. Corneal nerves produce various neuropeptides that have a wide range of functions on immune cells. As research in this area expands, further insights are made into the role of neuropeptides and their immunomodulatory functions in the healthy and diseased cornea. Much remains to be known regarding the details of neuropeptide signaling and how it contributes to pathophysiology, which is likely due to complex interactions among neuropeptides, receptor isoform-specific signaling events, and the inflammatory microenvironment in disease. However, progress in this area has led to an increase in studies that have begun modulating neuropeptide activity for the treatment of corneal diseases with promising results, necessitating the need for a comprehensive review of the literature. This review focuses on the role of neuropeptides in maintaining the homeostasis of the ocular surface, alterations in disease settings, and the possible therapeutic potential of targeting these systems.

The impact of sensory neuropathy and inflammation on epithelial wound healing in diabetic corneas

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes, with several underlying pathophysiological mechanisms, some of which are still uncertain. The cornea is an avascular tissue and sensitive to hyperglycemia, resulting in several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity, and tear film changes. The manifestation of DPN in the cornea is referred to as diabetic neurotrophic keratopathy (DNK). Recent studies have revealed that disturbed epithelial-neural-immune cell interactions are a major cause of DNK. The epithelium is supplied by a dense network of sensory nerve endings and dendritic cell processes, and it secretes growth/neurotrophic factors and cytokines to nourish these neighboring cells. In turn, sensory nerve endings release neuropeptides to suppress inflammation and promote epithelial wound healing, while resident immune cells provide neurotrophic and growth factors to support neuronal and epithelial cells, respectively. Diabetes greatly perturbs these interdependencies, resulting in suppressed epithelial proliferation, sensory neuropathy, and a decreased density of dendritic cells. Clinically, this results in a markedly delayed wound healing and impaired sensory nerve regeneration in response to insult and injury. Current treatments for DPN and DNK largely focus on managing the severe complications of the disease. Cell-based therapies hold promise for providing more effective treatment for diabetic keratopathy and corneal ulcers.

Comparison of the efficacy of topical insulin with autologous serum eye drops in persistent epithelial defects of the cornea

PURPOSE

To investigate the effect of topical insulin on epithelization in persistent epithelial defects (PED) refractory to usual treatment compared to autologous serum.

DESIGN

Retrospective, consecutive case-control series.

METHODS

The charts of 61 consecutive patients with PED treated with topical insulin (case group) and 23 treated with autologous serum (control group) were reviewed. Primary efficacy end points were the percentage of patients in which epithelization was achieved, as well as the rate and time until epithelization. Secondary efficacy point was need for amniotic membrane transplantation (AMT) or other surgeries.

RESULTS

Mean time between PED diagnosis and start of topical insulin was 22.7 ± 18.5 days (range 13-115) and the mean area was 14.8 ± 16.2 mm² (range 1.1-70.6). In the control group, mean time was 27.9 ± 16.8 days, mean epithelial defect area being 18.6 ± 15.0 mm² (range 1.7-52.9). No differences in baseline characteristics were found between groups (p > 0.05). Epithelization was achieved in 51 patients (84%) on insulin and 11 patients (48%) on autologous serum (p = 0.002). In those patients, mean time until reepithelization was 32.6 ± 28.3 days (range 4-124) in the insulin group and 82.6 ± 82.4 days (range 13-231) in the autologous serum group (p = 0.011). The need for AMT was significantly lower in the insulin group (p = 0.005). PED recurrence was higher in patients treated on autologous serum (43%) compared with insulin (11%) (p = 0.002).

CONCLUSIONS

Topical insulin is an effective treatment and safely promotes healing of PED. In our series, topical insulin presented better epithelization outcomes than autologous serum and could thus be considered as a first-line treatment.

Clinical and instrumental assessment of the corneal healing in moderate and severe neurotrophic keratopathy treated with rh-NGF (Cenegermin)

PURPOSE

To evaluate corneal healing in patients with moderate and severe neurotrophic keratitis (NK) treated with topical rh-NFG (Cenegermin).

METHODS

Twenty-one patients (12F and 9M) aged from 21 to 93 years (62.5 ± 19.4) with moderate and severe NK were enrolled in the study. The patients were divided into 2 groups accordingly to the severity of the disease. The underlying causes of NK were determined. The VAS questionnaire was dispensed. The ocular examination comprised slit lamp evaluation, ocular surface assessment with Keratograph 5M (Oculus, Germany), corneal sensitivity with Cochet-Bonnet esthesiometer (Lunneaux, France) and corneal thickness measurement with AC-OCT (DRI, Triton, Topcon, Japan). The drops of Cenegermin 0.002% were administrated 6 times daily for 8 weeks. All participants were evaluated at baseline, after 4 and 8 weeks of the treatment. The area of corneal defect with maximum diameter less than 0.5 mm was considered as healed. The main outcome measures were corneal healing, corneal sensitivity recovery and corneal thickness in the ulcer group.

RESULTS

The herpetic keratitis was the most common cause of NK. Thirteen eyes were affected by severe grade of NK with corneal ulcer and 8 eyes presented a moderate grade. After 8 weeks a complete healing of the corneal defects was registered both in moderate and severe NK. Significant increase of the corneal sensitivity and thickness were registered.

CONCLUSIONS

The rh-NGF (Cenegermin) resulted effective in the treatment of the severe and moderate NK with significant recovery of the corneal sensitivity and healing of the corneal defects in both groups.

New Pharmacological Approaches for the Treatment of Neurotrophic Keratitis

Neurotrophic keratitis (NK) is a rare degenerative condition that is caused by damage to the trigeminal nerve, with partial or complete loss of corneal sensory innervation. The loss of innervation leads to impaired healing of corneal epithelium, which subsequently results in punctate epithelial erosions, persistent epithelial defects, corneal ulcers and corneal perforation. Management of NK is often supportive and aims to promote epithelial healing and prevent progression of disease. Multiple novel pharmacological approaches have been proposed to address the underlying pathophysiology of NK, which are discussed in this paper.

Modified Gundersen Flap Using Inferior Palpebral-Bulbar Conjunctiva

PURPOSE

The purpose of this article was to describe a modification to the traditional Gundersen flap technique that expands eligible eyes to include those with severe conjunctival scarring and to report results from a clinical case.

METHODS

A 68-year-old woman with a history of herpes simplex keratitis, multiple failed penetrating keratoplasties, lagophthalmos, persistent epithelial defect, and low visual potential in the left eye presented for the evaluation of a Gundersen flap. Severe superior bulbar conjunctival scarring precluded a traditional approach. A modified Gundersen flap technique using a contiguous flap of inferior palpebral-bulbar conjunctiva extending from the inferior tarsal border to the limbus was devised and performed.

RESULTS

The modified Gundersen flap technique successfully stabilized the ocular surface, obviating the need for a cosmetically disfiguring permanent tarsorrhaphy or an evisceration.

CONCLUSIONS

This modified Gundersen flap technique expands the indications to eyes with severe conjunctival scarring and can be offered in eyes with previous trabeculectomies, glaucoma drainage implants, and scleral buckles, which were previously excluded from the globe-preserving option.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Treatment of persistent epithelial defects with single-dose autologous serum eye drops

PURPOSE

We aimed to investigate the efficacy and safety of single-dose autologous serum eye drops (ASEDs) for treatment of persistent corneal epithelial defects (PEDs).

METHODS

About 34 eyes of 26 patients treated from March 2016 to May 2020 with a single dose of ASEDs for PEDs that did not respond to conventional treatment were retrospectively evaluated. Patient demographics, predisposing factors, size, and duration of the PED, duration of treatment, and dosage of ASEDs, PED healing time, success rate of the ASED treatment, and follow-up time after the onset of ASED treatment were recorded. Autologous serum eye drops (20%) were prepared by diluting the serum with preservative-free artificial tears in single-dose vials. Vials were stored at -20°C and used daily after dissolving.

RESULTS

The mean patient age was 47.0 ± 18.5 years, and 13 (50%) of the patients were male. The most common indication for ASEDs was PED after keratoplasty. The mean duration of ASED treatment was 8.5 ± 6.3 months, and mean follow-up time was 22.8 ± 12.2 months. Autologous serum eye drop treatment was effective in 25 (73.5%) eyes and partially effective in 5 (14.7%) eyes. None of the eyes displayed complications related to the treatment.

CONCLUSION

In patients with PED for whom conservative treatment is insufficient, ASEDs prepared by dilution with preservative-free artificial tears in single-dose vials and administered based on the daily use principle appear to be effective and safe.

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.

Metabolomics comparison of cord and peripheral blood-derived serum eye drops for the treatment of dry eye disease

Allogeneic peripheral blood-derived (PBS) serum eye drops have been largely used in the treatment of dry eye disease (DED). Recently, cord blood has emerged as an effective alternative serum source (cord blood serum, CBS), containing a higher amount of growth factors than PBS, it holds the promise of a better capability to stimulate corneal healing. However, the lack of a standardized method for preparation, dispensation, storage and a poor biochemical characterization still hamper the establishment of a clinical consensus. Here the metabolomes of the two different serum eye drop preparations were compared using proton nuclear magnetic resonance spectroscopy. We found that both PBS and CBS contained several organic compounds, the majority of them already detected in human tears and may be thereby considered lacrimal substitutes. Metabolites having in the multivariate statistical analysis Partial least squares discriminant analysis (PLS-DA) a VIP scores > 1.0 were considered to be significantly different. All the metabolites identified were found to have a p < 0.05 in the univariate analysis. CBS, in particular, showed the highest amount of choline, myo-inositol, glutamine, creatine and β-hydroxybutyrate. These evidences constitute relevant advances towards serum eye drops characterization and confirm that cord blood is a valid alternative source of serum eye drops.

Stabilization of eye drops containing autologous serum and recombinant human epidermal growth factor for dry eye syndrome

Human epidermal growth factor (hEGF) and autologous serum are considered safer and more effective in treating dry eye syndrome. However, suitable formulas and preparation methods are needed to obtain eye drop containing autologous serum and hEGF, which are stable during storage and use. Therefore, this study aimed to develop a stable and effective eye drops containing autologous serum and hEGF. Stabilization of autologous serum and hEGF was done by adding lyoprotectant and antioxidant agents, and then prepared using the freeze-drying method. The clarity, pH, sterility, and endotoxin content of the preparation were evaluated. The effectiveness of the preparation was assessed by a cell viability test using a WST-8 reagent. Based on the results, all formulas produce preparations that are isotonic, clear, sterile, stable, and free from endotoxins. Cell viability test shows the addition of 25 μg/mL hEGF increased epithelial cell proliferation by up to 197%. It can be concluded that eye drops containing autologous serum and 25 μg/mL hEGF can be a promising therapy for dry eye syndrome.

Management Strategies of Ocular Chemical Burns: Current Perspectives

Ocular chemical burns are absolute ophthalmic emergencies and require immediate management to minimize devastating sequelae. Management of alkali and acid burns is started at the scene of the accident by copious irrigation. Treatment is directed at improving epithelial integrity and stromal stability, reduction of undue inflammation, and prevention or timely management of complications. To ascertain the best possible outcome, numerous biological medications and surgical interventions have been merged into conventional therapeutic regimens. These include autologous and umbilical cord serum preparations, platelet-rich plasma, amniotic membrane transplantation, limbal stem-cell transplantation, and anti-angiogenic agents.

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.

Recent innovations with drugs in clinical trials for neurotrophic keratitis and refractory corneal ulcers

Introduction: Corneal ulcers normally resolve spontaneously because of the proliferative ability of the corneal epithelium; however, sometimes, epithelial healing is diminished, even when standard treatments are administered. Hence, the treatment of refractory corneal ulcers is challenging and is the subject of ongoing efforts in preclinical and clinical development. Emerging treatment approaches include thymosine β4, CODA001, and topical insulin. Cenegermin eye drops, containing recombinant human nerve growth factor and ReGenerating Agent, a matrix therapy agent, have recently been commercialized for the treatment of moderate to severe neurotrophic keratitis in adults.Areas covered: We describe emerging therapeutic approaches for the management of refractory corneal ulcers and treatments recently introduced to the market. Pubmed and Clinicaltrial.gov databases were first searched including the terms: "corneal ulcer" or "neurotrophic keratopathy" and "treatment." Each treatment was searched in the same databases separately.Expert opinion: Affections of the sensory corneal nerves are the main factor contributing to the pathophysiology of neurotrophic keratopathy; this explains the healing difficulties of this form of ulcer. Cenegermin is a promising therapy acting as a neurotrophic agent for corneal healing. ReGenerating Agent has led to rapid pain relief and corneal healing, but randomized clinical trials are still necessary for further assessment.

Autologous Serum-Based Eye Drops for Treatment of Ocular Surface Disease: A Report by the American Academy of Ophthalmology

PURPOSE

To describe the safety and effectiveness of using autologous serum-based eye drops for the treatment of severe dry eye and persistent corneal epithelial defect.

METHODS

Literature searches of the PubMed and Cochrane Library databases were conducted most recently in March 2019. The searches identified 281 citations, which were reviewed in abstract form. Of these, 48 were selected for a full-text review, and 13 met the inclusion criteria and were assigned a quality-of-evidence rating by the panel methodologist. Eight of these studies were rated level II and 5 were rated level III; there were no level I studies.

RESULTS

This analysis included 10 studies of the use of autologous serum-based eye drops for severe dry eye disease and 4 studies of persistent epithelial defect. Several studies showed good effectiveness, with some improvement in symptoms, signs, or both. Eight of the studies reported improved symptoms for severe dry eye disease, and all noted improvement in at least 1 clinical sign. For persistent epithelial defects, all of the studies showed improvement, with 3 of the 4 demonstrating an improvement rate of more than 90%. Adverse events were rare.

CONCLUSIONS

Although autologous serum-based tears may be effective in the treatment of severe dry eye and persistent epithelial defect, conclusions are limited owing to the absence of controlled trials.

Phototherapeutic keratectomy

Phototherapeutic keratectomy is an excimer laser-based surgical procedure widely performed by corneal surgeons for treating anterior corneal stromal pathologies. Phototherapeutic keratectomy helps by ablating the corneal stroma, thereby improving corneal clarity and smoothening the surface. Transient discomfort and induced hyperopia from corneal flattening are the immediate postoperative concerns. The long-term course is often marked by the recurrence of original corneal pathology and corneal haze formation. Phototherapeutic keratectomy, however, allows for repeat stromal ablation for managing recurrences, as the corneal thickness permits, without affecting the outcome of future keratoplasty. Adjunctive methods such as topical mitomycin-C may be additionally used to reduce recurrence rates. Also, various masking agents such as carboxymethyl cellulose, sodium hyaluronate, and dextran are used in eyes with irregular corneal surface to allow for uniform stromal ablation. Overall, phototherapeutic keratectomy has provided corneal surgeons an additional surgical tool, particularly those residing in developing nations where the availability of donor corneal tissue is an important limiting factor.

Emerging Approaches for Ocular Surface Regeneration

Purpose of review

In this manuscript, the recent advancements and novel approaches for regeneration of the ocular surface are summarized.

Recent findings

Following severe injuries, persistent inflammation can alter the rehabilitative capability of the ocular surface environment. Limbal stem cell deficiency (LSCD) is one of the most characterized ocular surface disorders mediated by deficiency and/or dysfunction of the limbal epithelial stem cells (LESCs) located in the limbal niche. Currently, the most advanced approach for revitalizing the ocular surface and limbal niche is based on transplantation of limbal tissues harboring LESCs. Emerging approaches have focused on restoring the ocular surface microenvironment using (1) cell-based therapies including cells with capabilities to support the LESCs and modulate the inflammation, e.g., mesenchymal stem cells (MSCs), (2) bio-active extracellular matrices from decellularized tissues, and/or purified/synthetic molecules to regenerate the microenvironment structure, and (3) soluble cytokine/growth factor cocktails to revive the signaling pathways.

Summary

Ocular surface/limbal environment revitalization provide promising approaches for regeneration of the ocular surface.

Strategies for reconstructing the limbal stem cell niche

The epithelial cell layer that covers the surface of the cornea provides a protective barrier while maintaining corneal transparency. The rapid and effective turnover of these epithelial cells depends, in part, on the limbal epithelial stem cells (LESCs) located in a specialized microenvironment known as the limbal niche. Many disorders affecting the regeneration of the corneal epithelium are related to deficiency and/or dysfunction of LESCs and the limbal niche. Current approaches for regenerating the corneal epithelium following significant injuries such as burns and inflammatory attacks are primarily aimed at repopulating the LESCs. This review summarizes and assesses the clinical feasibility and efficacy of current and emerging approaches for reconstruction of the limbal niche. In particular, the application of mesenchymal stem cells along with appropriate biological scaffolds appear to be promising strategies for long-term revitalization of the limbal niche.

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.

Improvement of chronic corneal opacity in ocular surface disease with prosthetic replacement of the ocular surface ecosystem (PROSE) treatment

Purpose

To demonstrate clearing of chronic corneal opacities and improvement of visual acuity with the use of BostonSight prosthetic replacement of the ocular surface ecosystem (PROSE) treatment in ocular surface disease.

Observations

We undertook retrospective analysis of the medical records of a series of patients who underwent PROSE treatment from August 2006 to December 2014. Patients were referred for ocular surface disease of various etiologies. Primary inclusion criterion was corneal opacity that improved with PROSE treatment. Patients were excluded if topical steroids or adjuvant therapy used once PROSE treatment was initiated. Underlying disease, prior treatment, clinical presentation, and clinical course were extracted from the medical record. Four patients are included in this series. There were three females and one male; median age at time of treatment initiation was 30 years (range = 0.5–58 years). Median duration of PROSE treatment at time of retrospective analysis was 3.5 years (range = 1–8 years). Two cases had corneal opacification in the context of neurotrophic keratopathy: a unilateral case due to presumed herpes simplex keratitis and a bilateral case due to congenital corneal anesthesia associated with familial dysautonomia. One case had corneal opacity from exposure related to seventh nerve palsy, and one had corneal opacification associated with recurrent surface breakdown, neurotrophic keratopathy, and limbal stem deficiency of uncertain etiology. After consistent wear of prosthetic devices used in PROSE treatment for support of the ocular surface, visual acuity improved and clearing of the opacities was observed, without use of topical steroids or adjuvant therapy.

Conclusions and importance

These cases demonstrate clearing of chronic corneal opacity with PROSE treatment for ocular surface disease. This clearing can occur with no adjuvant therapy, suggesting that restoration of ocular surface function and integrity allows for corneal remodeling.

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.

Treatment of acute ocular chemical burns

Ocular chemical burns are an ophthalmic emergency and are responsible for 11.5%-22.1% of ocular injuries. Immediate copious irrigation is universally recommended in acute ocular burns to remove the offending agent and minimize damage. Conventional medical therapy consists of the use of agents that promote epithelialization, minimize inflammation, and prevent cicatricial complications. Biological fluids such as autologous serum, umbilical cord blood serum, platelet-rich plasma, and amniotic membrane suspension are a rich source of growth factors and promote healing when used as adjuncts to conventional therapy. Surgical treatment of acute ocular burns includes the debridement of the necrotic tissue, application of tissue adhesives, tenoplasty, and tectonic keratoplasty. Amniotic membrane transplantation is a novel surgical treatment that is increasingly being used as an adjunct to conventional treatment to promote epithelial healing, minimize pain, and restore visual acuity. Various experimental treatments that aim to promote wound healing and minimize inflammation are being evaluated such as human mesenchymal and adipose stem cells, beta-1,3 glucan, angiotensin-converting enzyme inhibitors, cultivated fibroblasts, zinc desferrioxamine, antifibrinolytic agents, antioxidants, collagen cross-linking, and inhibitors of corneal neovascularization.

Effect of human autologous serum and fetal bovine serum on human corneal epithelial cell viability, migration and proliferation in vitro

AIM

To analyze the concentration-dependent effects of autologous serum (AS) and fetal bovine serum (FBS) on human corneal epithelial cell (HCEC) viability, migration and proliferation.

METHODS

AS was prepared from 13 patients with non-healing epithelial defects Dulbecco's modified eagle medium/Ham's F12 (DMEM/F12) with 5% FBS, 0.5% dimethyl sulphoxide (DMSO), 10 ng/mL human epidermal growth factor, 1% insulin-transferrin-selenium, then were incubated in serum media: DMEM/F12 supplemented by 5%, 10%, 15% or 30% AS or FBS. HCEC viability was analyzed using cell proliferation kit XTT, migration using a wound healing assay, proliferation by the cell proliferation enzyme-linked immunosorbent assay (ELISA) BrdU kit. Statistical analysis was performed using the generalized linear model, the values at 30% AS or 30% FBS were used as the baselines.

RESULTS

HCEC viability was the highest at 30% AS or 15% FBS and the lowest at 10% AS or 30% FBS application. HCEC migration was the quickest through 30% AS or 30% FBS and the slowest through 5% AS or 5% FBS concentrations. Proliferation was the most increased through 15% AS or 5% FBS and the least increased through 30% AS or 30% FBS concentrations. HCEC viability at 10% and 15% AS was significantly worse (P=0.001, P=0.023) compared to baseline and significantly better at 15% FBS (P=0.003) concentrations. HCEC migration was significantly worse (P≤0.007) and HCEC proliferation significantly better (P<0.001) in all concentration groups compared to baseline.

CONCLUSION

For the best viability of HCEC 30% AS or 15% FBS, for HCEC migration 30% AS or 30% FBS, for proliferation 15% AS or 5% FBS should be used. Therefore, we suggest the use of 30% AS in clinical practice.

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.

Comparison of Autologous Serum Versus Preservative Free Artificial Tear in Patients with Dry Eyes Due to Systemic Isotretinoin Therapy

PURPOSE

To investigate dry eye development in the patients receiving systemic retinoic acid therapy and to compare effectiveness of Autologous Serum (AS) and preservative free artificial tear (PFAT) in the patients with dry eye disease.

METHOD

This prospective, crossover, double blind study was conducted on patients who have dry eyes due to systemic isotretinoin treatment for different indications. Patients detected as having dry eye during systemic isotretinoin treatment were included to our study. At baseline, 1 and 2 month of study, detailed ocular examination, best corrected visual acuity measurement, intraocular pressure measurement, and Tear Break-up Time (TBUT) and Schirmer Test (ST) without topical anesthesia were performed. We compared the efficacy of AS and PFAT. To accomplish crossover after the first month, treatment given to each patient was switched to the other treatment. Statistical analysis was measured using SPSS version 20.0. p values of < 0.05 were considered as statistically significant.

RESULT

At the end of the first month, there was a significant improvement for the TBUT test in both AS and PFAT groups compared to baseline (respectively p < 0.001, p < 0.001). TBUT was found to be significantly higher in the AS group compared to the PFAT group at the end of the first month (p < 0.001). At the end of the second month, TBUT was found to be significantly higher in the AS group compared to the PFAT group at the posttreatment time (p < 0.001). There was a significant OSDI score decreasing in both groups compared to that reported previously at the end of the first and second months (respectively p < 0.001, p < 0.001). OSDI score decreasing was more significant in the AS group compared to the PFAT group at both time points (respectively p < 0.001, p < 0.001).

CONCLUSION

AS may be an effective alternative to PFAT in the treatment of dry eye developed during isotretinoin use.

Human Serum Eye Drops in Eye Alterations: An Insight and a Critical Analysis

Human serum contains a physiological plethora of bioactive elements naturally released by activated platelets which might have a significant effect on the regeneration of corneal layers by stimulating the cell growth. This mechanism supported the use of human serum eye drops in some ocular diseases associated with dystrophic changes and alterations of the tear film, such as persistent corneal epithelial defects and dry eye syndrome. We focused our effort on potential benefits and limitations of the use of human serum eye drops when conventional therapies failed. We reviewed the recent literature by reporting published studies from 2010 to 2014. Despite the limited evaluated study populations, most of the clinical studies have confirmed that serum eye drop therapy is effective in corneal healing by reducing ocular symptom, particularly during the short-term follow-up. In addition, three recent published studies have shown the efficacy of the serum eye drop therapy in comparison to traditional ones in intractable patients. Besides, reported ongoing clinical studies confirmed the open debate regarding the use of biologic tools for cornea regeneration. Results from these studies might open novel challenges and perspectives in the therapy of such refractory patients.

Autologous serum therapy in recalcitrant laser-assisted in situ keratomileusis-induced neurotrophic epitheliopathy

Background/Purpose:

To evaluate the efficacy of autologous serum eye drops for patients with recalcitrant laser-assisted in situ keratomileusis (LASIK)-induced neurotrophic epitheliopathy (LINE) unresponsive to conventional treatment, and to determine the possible predisposing risk factors of these patients.

Methods:

We enrolled 10 consecutive patients (20 eyes) undergoing femtosecond-assisted myopic LASIK surgery presenting with recalcitrant LINE for > 1 year. Another 340 patients (713 eyes) receiving femtosecond-assisted myopic LASIK without recalcitrant LINE were set as controls. Possible risk factors associated with recalcitrant LINE were investigated. Twenty percent autologous serum treatment was prescribed to 20 eyes. The efficacy of autologous serum was assessed with ocular surface conditions, tear function, and the change of best-corrected visual acuity.

Results:

Age older than 30 years [odds ratio (OR) = 7.74; 95% confidence interval (CI), 1.74–34.50], flap thickness < 110 μm (OR = 3.47; 95% CI, 1.22–9.73), and a flap diameter < 8.5 mm (OR = 5.38; 95% CI, 1.95–14.85) pose higher risks in femtosecond laser-assisted myopic LASIK. All eyes (100%) achieved remission after autologous serum treatment. The visual acuity before treatment was 0.49 ± 0.41 in LogMAR, and the visual acuity after treatment was 0.14 ± 0.22 in LogMAR. Time to achieve remission was 8.26 ± 11.87 weeks. Mean relapse-free survival after discontinuing autologous serum was 47 weeks.

Conclusion:

Risk factors of recalcitrant LINE in femtosecond laser-assisted myopic LASIK were identified as older age, a thinner flap (<110 μm), and a small flap diameter (<8.5 mm). Autologous serum eye drops can effectively improve corneal surface conditions and postoperative visual acuity.