Comparative cytotoxic and antiproliferative profile of methotrexate and fluorouracil on different ocular cells

Effects of a human amniotic membrane extract on ARPE-19 cells

BACKGROUND

Human Amniotic Membrane (hAM) is endowed with several biological activities and might be considered an optimal tool in surgical treatment for different ophthalmic pathologies. We pioneered the surgical use of hAM to treat retinal pathologies such as macular holes, tears, and retinal detachments, and to overcome photoreceptor damage in age-related macular degeneration. Although hAM contributed to improved outcomes, the mechanisms of its effects are not yet fully understood. The characterization and explanation of the effects of hAM would allow the adoption of this new natural product in different retinal pathologies, operative contexts, and hAM formulations. At this end, we studied the properties of a hAM extract (hAME) on the ARPE-19 cells.

METHODS AND RESULTS

A non-denaturing sonication-based technique was developed to obtain a suitable hAME. Viability, proliferation, apoptosis, oxidative stress, and epithelial-mesenchymal transition (EMT) were studied in hAME-treated ARPE-19 cells. The hAME was able to increase ARPE-19 cell viability even in the presence of oxidative stress (H2O2, TBHP). Moreover, hAME prevented the expression of EMT features, such as EMT-related proteins, fibrotic foci formation, and migration induced by different cytokines.

CONCLUSIONS

Our results demonstrate that the hAME retains most of the properties observed in the whole tissue by others. The hAME, other than providing a manageable research tool, could represent a cost-effective and abundant drug to treat retinal pathologies in the future.

Proliferative vitreoretinopathy: an update on the current and emerging treatment options

Proliferative vitreoretinopathy (PVR) remains the main cause of failure in retinal detachment (RD) surgery and a demanding challenge for vitreoretinal surgeons. Despite the large improvements in surgical techniques and a better understanding of PVR pathogenesis in the last years, satisfactory anatomical and visual outcomes have not been provided yet. For this reason, several different adjunctive pharmacological agents have been investigated in combination with surgery. In this review, we analyze the current and emerging adjunctive treatment options for the management of PVR and we discuss their possible clinical application and beneficial role in this subgroup of patients.

Intraocular Methotrexate for the Treatment and Prevention of Proliferative Vitreoretinopathy: A Review

Purpose:

To review the current literature on the use of intravitreal methotrexate (IVT MTX) for the treatment and prevention of proliferative vitreoretinopathy (PVR).

Methods:

All reports of IVT MTX to treat and prevent PVR published in PubMed, Google Scholar, and EBSCOhost were reviewed. The relevant current studies are included in this report.

Results:

The literature search yielded 32 articles describing the use of MTX in PVR. These included preclinical studies, 1 case report, and several case series. Early studies found that IVT MTX is a promising medication for the treatment and prevention of PVR. MTX works as a potent anti-inflammatory agent through a new mechanism of action different from that of other medications for use in PVR. Few side effects have been reported and were mostly limited to mild reversible corneal keratopathy. There are 2 current ongoing randomized controlled clinical trials to further evaluate the efficacy of MTX for PVR.

Conclusions:

MTX is a safe and potentially efficacious medication for the treatment and prevention of PVR. Additional clinical trials are needed to further establish this effect.

Comparison of clinical outcomes after precut DMEK with or without dextran-containing medium compared to standard DMEK: a prospective pilot study

PURPOSE

To investigate the clinical outcome and complication rate of precut Descemet membrane endothelial keratoplasty (DMEK) in two different culture conditions, dextran-containing and dextran-free medium, and compare the results with the current standard DMEK procedure.

METHODS

A prospective study of 32 eyes suffering from Fuchs endothelial dystrophy were scheduled for DMEK with a follow-up of one year. The eyes were divided into four subgroups. Group + D (n = 7) received a precut DMEK stored in dextran-containing transport medium, and Group - D (n = 9) received a precut DMEK without dextran-containing medium. The respective fellow eyes received a standard DMEK (S) (preparation directly prior to surgery) stored in dextran-containing medium (S-D + ; n = 7) or without (S-D-; n = 9).

RESULTS

Clinical outcome (visual acuity, endothelial cell count, central corneal thickness) and rebubbling rate were comparable for all four groups. None of the patients had a graft failure.

CONCLUSION

The preliminary data of the pilot study show that precut liquid-bubble DMEK leads to comparable clinical results regardless of dextran-containing or dextran-free organ culture medium and is further comparable to the standard DMEK procedure.

Novel vitreous substitutes: the next frontier in vitreoretinal surgery

PURPOSE OF REVIEW

After removing the native vitreous during vitreoretinal surgery, an adequate substitute is required to ensure homeostasis of the eye. Current clinically used endotamponades (silicone oil, gases, semifluorinated alkanes) are effective in promoting retinal reattachment, but lead to complications such as emulsification, prolonged inflammation, blurred vision, raised intraocular pressure, cataract formation or the need for revision surgery. The aim of this review is to provide an update on novel vitreous substitutes with a focus on polymer-based systems.

RECENT FINDINGS

Polymeric hydrogels provide favourable properties such as high water content, optical transparency, suitable refractive indices and densities, adjustable rheological properties, injectability, biocompatibility and their ability to tamponade the retina via viscosity and swelling pressure, comparable to the native human vitreous body. Here, vitreous replacement strategies can be divided into chemically or physically crosslinked hydrogel systems that are applied as preformed or in-situ gelling matrices.

SUMMARY

Several hydrogel-based vitreous substitutes have already been positively evaluated in preclinical tests and have the potential to enter the clinical phase soon.