Ocular Therapeutics of the Future

Corneal blindness persists as an important cause of blindness throughout the world. Despite significant scientific and engineering advancements, the corneal surgeons regularly encounter difficulties in providing a definitive solution to many patients afflicted with this debilitating condition. This thematic issue on “Ocular Therapeutics of the Future” presents four articles that provide a broad contemporary overview of important areas of corneal research and further our understanding of the future directions of ophthalmic treatments for the management of blinding corneal diseases. Distinguishing features of this issue include limbal stem cell identification, new technologies in the field of nanomedicines and gene therapies, and recent contributions in tissue repair and regeneration. These complementary articles provide a comprehensive foundation for the understanding of relevant research to treat corneal blindness.

Presently, limbal stem cell deficiency is a serious condition that can potentiate corneal blindness. Acquired unilateral limbal stem cell deficiency may benefit from autologous transplant. Unfortunately, severe bilateral process typically necessitates heroic measures. Progress has been made in terms of direct tissue transplant or ex vivo expansion followed by transplantation. However, researchers continue to face the challenge of identifying and isolating limbal stem cells. In their article, “Presentation, Diagnosis and Management of Limbal Stem Cell Deficiency,” Deng et al.¹ reviewed various noninvasive techniques employed for the in vitro and in vivo identification of limbal stem cells. An overview of ocular surface rehabilitation was also summarized.

Heretofore, options for ocular drug delivery have numerous limitations. The emerging field of nanomedicine promises many advantages over traditional medicine. The relevant goal is to provide sustained targeted delivery with reduced adverse systemic effects. Kannan and colleagues in their article, “Nanomedicine-Based Therapeutic Applications for Ocular Diseases” discussed various delivery modalities using nanoparticles, liposomes, dendrimers, and contact lens couriers.² These platforms can be employed to deliver a ranged of bioactive compounds, for example, antiinflammatory, antiviral, ocular hypotensive, and antiangiogenesis agents.

Other alternatives, such as gene therapies in corneal transplantations, are reviewed here as well. The unique properties of the cornea enable scientists to develop many models for gene therapies. Nguyen and Yiu presented a broad-spectrum review of various gene therapeutic options in the article, “Strategies for Local Gene Therapy of Corneal Allograft Rejection,” aimed at potentiating the anterior chamber-associated immune deviation to extend graft survival.³ Successful gene-based prevention and treatment of allograft rejection will improve patient quality of life, reduce health care cost, and alleviate the worldwide corneal shortage.

Keratoprostheses are gaining momentum in its important roles to provide visual rehabilitation for patients, but long-term prognosis remains guarded. Others are investigating alternative tissue engineered or biological corneal substitutes. Elisseeff and colleagues in their article, “Future Perspectives for Regenerative Medicine in Ophthalmology,” summarized the various techniques and bioactive materials to promote tissue repair and regeneration.⁴ Some notable materials, such as collagen hydrogel, decellularized tissue, and ocular adhesive, are being explored for both functional and sacrificial cell growth substrates.

We are grateful to our colleagues and reviewers who contributed to this special issue of MEAJO. This excellent review will provide our valuable readership with current knowledge regarding the rapidly evolving fields of cornea therapy. Indisputably, numerous challenges remain before commercial realization of these treatments. However, given the accelerating rate of knowledge dissemination and scientific progress, we are optimistic that innovations will translate to treatment for corneal blindness in the future.