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

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

Preparation of human amniotic membrane for transplantation in different application areas

The human amniotic membrane (hAM) is the inner layer of the placenta and plays protective and nutritional roles for the fetus during pregnancy. It contains multiple growth factors and proteins that mediate unique regenerative properties and enhance wound healing in tissue regeneration. Due to these characteristics hAM has been successfully utilized in ophthalmology for many decades. This material has also found application in a variety of additional therapeutic areas. Particularly noteworthy are the extraordinary effects in the healing of chronic wounds and in the treatment of burns. But hAM has also been used successfully in gynecology, oral medicine, and plastic surgery and as a scaffold for in vitro cell culture approaches. This review aims to summarize the different graft preparation, preservation and storage techniques that are used and to present advantages and disadvantages of these methods. It shows the characteristics of the hAM according to the processing and storage methods used. The paper provides an overview of the currently mainly used application areas and raises new application possibilities. In addition, further preparation types like extracts, homogenates, and the resulting treatment alternatives are described.

Pterygium surgery with lyophilized versus cryopreserved amniotic membrane graft

PURPOSE

To evaluate surgical outcomes (recurrence rate, aesthetics and symptoms) of pterygium surgery with two different amniotic membrane preservation approaches - lyophilized (LAM) and cryopreserved (CAM).

METHODS

Primary pterygium patients were randomized to either LAM or CAM surgery. Demographic data, ocular surface disease index (OSDI), aesthetic grading (1 to 4), recurrences and complications were recorded over a 6-month follow-up period.

RESULTS

Twenty-nine patients were recruited. Recurrence at month 6 was detected in 11 cases (37.9%) and was more prevalent with CAM grafts, without reaching statistical significance (P=0.196). Aesthetic outcome grading showed no differences between LAM and CAM at month 6 (P=0.124). Aesthetic results were mostly unsatisfactory (grade 3 and 4) without statistical differences between groups (P=0.514). Baseline OSDI was similar in both groups (P=0.888), and it significantly decreased by the last follow-up visit (P<0.001) for both the LAM and CAM groups. This decrease did not significantly differ between amniotic membrane preservation approach surgery groups (P=0.714).

CONCLUSION

LAM might be considered a legitimate alternative to CAM, showing no inferiority in outcomes, since clinical and aesthetic outcomes were similar for both groups.

Eye drops of human origin-Current status and future needs: Report on the workshop organized by the ISBT Working Party for Cellular Therapies

BACKGROUND AND OBJECTIVES

Serum eye drops (SEDs) are used to treat ocular surface disease (OSD) and to promote ocular surface renewal. However, their use and production are not standardized, and several new forms of human eye drops have been developed.

MATERIALS AND METHODS

The International Society for Blood Transfusion Working Party (ISBT WP) for Cellular Therapies held a workshop to review the current types of eye drops of human origin (EDHO) status and provide guidance.

RESULTS

The ISBT WP for Cellular Therapies introduced the new terminology 'EDHO' to emphasize that these products are analogous to 'medical products of human origin'. This concept encompasses their source (serum, platelet lysate, and cord blood) and the increasingly diverse spectrum of clinical usage in ophthalmology and the need for traceability. The workshop identified the wide variability in EDHO manufacturing, lack of harmonized quality and production standards, distribution issues, reimbursement schemes and regulations. EDHO use and efficacy is established for the treatment of OSD, especially for those refractory to conventional treatments.

CONCLUSION

Production and distribution of single-donor donations are cumbersome and complex. The workshop participants agreed that allogeneic EDHO have advantages over autologous EDHO although more data on clinical efficacy and safety are needed. Allogeneic EDHOs enable more efficient production and, when pooled, can provide enhanced standardization for clinical consistency, provided optimal margin of virus safety is ensured. Newer products, including platelet-lysate- and cord-blood-derived EDHO, show promise and benefits over SED, but their safety and efficacy are yet to be fully established. This workshop highlighted the need for harmonization of EDHO standards and guidelines.

Combined Topography-Guided Trans-Epithelial PRK and PTK for Recalcitrant Recurrent Corneal Erosions in Lattice Corneal Distrophy

Purpose

To report morphologic and functional changes after topography-guided trans-epithelial photorefractive keratectomy (PRK) combined with phototherapeutic keratectomy (PTK) for recalcitrant recurrent corneal erosions in Lattice Corneal Dystrophy (LCD).

Methods

One case report.

Results

A 78-year-old man presented us with decreased visual acuity [20/100 in right eye (RE), and 20/400 in left eye (LE)], and redness with foreign body sensation in both eyes. Clinical examination revealed epithelial erosions, and linear stromal opacities involving the center of the cornea in both eyes, supporting the diagnosis of LCD. Several medical approaches including autologous serum, amniotic membrane extract, and nerve growth factor eye drops allowed a temporary improvement in symptoms. A single-step topography-guided trans-epithelial PRK combined with PTK (CIPTA^®2 software, iVis Technologies) was performed in both eyes. After surface ablation using PRK, PTK was performed using masking agents (1% hydroxy-methylcellulose) to smooth the ablated surface. Subsequently, 0.02% Mitomycin C was applied over the ablated surface. At the 3-month follow-up, a resolution of corneal erosions, and stromal opacities were observed in both eyes, with a visual improvement to 20/25 in the RE and 20/50 in the LE. Furthermore, spherical equivalent, keratometric astigmatism, and corneal morphological irregularity index improved.

Conclusion

Recalcitrant corneal erosions and stromal opacities in LCD may be successfully treated using combined topography-guided trans-epithelial PRK and PTK.

[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.

Effects of commercial amniotic membrane extract on the re-epithelialization time and the early expression of matrix metalloproteinase-9 in cats with experimentally induced corneal ulcers

OBJECTIVES

To investigate whether a commercially available amniotic membrane extract (AME) can accelerate corneal wound healing and suppress the early expression of MMP-9 in the tears of cats with experimentally induced superficial ulcerative keratitis.

PROCEDURES

A total number of 16 cats were included. At the end of keratectomy, cats in the treatment group (TG, n = 8) received 40 μl of AME (EyeQ® Amniotic Eye Drops, Vetrix®) four times daily, while cats in the control group (CG, n = 8) received 40 μl of saline at the same time points. Tears were collected 24 and 48 h after keratectomy, and the total MMP-9 was quantified by ELISA.

RESULTS

The corneal re-epithelialization rate did not differ between groups (p = .26), being 0.48 ± 0.05 mm² /h in the CG and 0.41 ± 0.03 mm² /h in the TG. Similarly, the average time to achieve corneal wound healing did not differ between groups (p = .25) and was 61.50 ± 3.54 h in the CG and 70.50 ± 6.71 h in the TG. The dimensions of the ulcerated areas also did not differ at any time point between the groups (p > .05). In both groups, corneas healed without scarring, pigmentation, or vascularization. The expression of MMP-9 in the tears was similar in both groups at 24 h post-keratectomy, with a slight decrease at 48 h (p > .05).

CONCLUSIONS

The instillation of a commercial AME (EyeQ®) is safe, but it did not decrease the corneal re-epithelialization time or the early expression of MMP-9 in the tears of cats with experimentally induced superficial ulcerative keratitis in this study.

Effects of Amniotic Membrane Extract Eye Drops on Persistent Epithelial Defects of the Cornea

Purpose: To evaluate the clinical efficacy of amniotic membrane extract eye drops (AMEEDs) in patients with persistent epithelial defects (PEDs) of the cornea.Methods: Sixteen patients with PEDs refractory to the conventional treatment were further treated with AMEEDs six times a day. Visual acuity, visual analog scale (VAS), esthesiometer score, and areas of the epithelial defects before and after 1 and 2 months of treatment were evaluated. After 2 months, AMEEDs were considered effective if all epithelial defects were healed, partially effective if the epithelial defects decreased in size compared with the baseline, and ineffective if the epithelial defects increased in size and required additional treatment.Results: After 2 months of treatment with AMEEDs, there was a reduction in the area of epithelial defects (5.2 ± 3.1 mm2 vs. 0.1 ± 0.1 mm2, respectively, p = 0.01), as well as a significant improvement in best-corrected visual acuity (0.8 ± 0.5 logarithm of minimal angle of resolution [LogMAR] vs. 0.6 ± 0.3 LogMAR, respectively, p = 0.03), and VAS scores (4.3 ± 1.0 vs. 2.8 ± 0.7, respectively, p = 0.04) compared with the baseline values. Treatment with AMEEDs was effective in 13 (81.3%) patients and partially effective in three (18.8%) patients.Conclusions: AMEEDs could stimulate epithelial wound healing and improve ocular symptoms in patients with refractory PED. Therefore, AMEEDs could be considered an effective treatment option for refractory PEDs.

Amniotic membrane extract eye drops: a new approach to severe ocular surface pathologies

A protocol for processing amniotic membrane as an extract to be re-hydrated and administered topically as eye drops (amniotic membrane extract eye drops, AMEED) has been developed. Safety and efficacy of AMEED was assessed in patients with severe ocular surface pathologies. prospective clinical follow-up of ocular surface symptoms before and after regular application of the AMEED for at least 4 weeks on patients with severe ocular surface disorders as chronic dry eye disease, limbal stem cell deficiency, neurotrophic ulcer and permanent and disabling symptomatology that were refractory to conventional treatment. Efficacy and tolerability were assessed based on patient-reported symptoms, objective measurements, and reports of adverse events. Thirty-six eyes from 25 patients were included. Although the visual quality function score, by means of a VQF25 questionnaire, was not statistically different after the treatment (p = 0.4657), there was a clear trend, statistically significant, towards the improvement in ocular symptoms like foreign body sensation, itching and stinging (p < 0.05) and clinical presentation of the pathology. All patients with corneal ulcer showed complete epithelization. Topically applied AMEED proved to be safe, well tolerated and effective in reducing the symptoms and clinical signs of severe ocular disease. Further studies are needed to confirm the best indications for AMEED use.