The final step for many people with eye disease to regain good vision could involve a corneal transplant. Over 184,000 corneal transplant procedures are carried out annually worldwide, with over 80,000 taking place in the United States.
Qingguo Xu, D.Phil., associate professor of pharmaceutics and ophthalmology at VCU School of Pharmacy, (right) in the lab with Tuo Meng, Ph.D., (left) and Vineet Kulkarni. (School of Pharmacy). Image Credit: Virginia Commonwealth University
The corneal graft rejection rates, however, might reach 10%. This is mostly because patients do not adhere to their prescribed treatment plans, which call for repeated applications of topical eyedrops over an extended period of time.
When patients exhibit early symptoms of transplanted corneal rejection, this situation becomes very serious. Patients must use topical eyedrops hourly to prevent the corneal grafts from failing when this happens.
Patients bear a heavy burden because of the arduous eyedrop dosage technique. Even higher rates of graft rejection could result from the consequent noncompliance with drug therapy.
Using nanoparticles to encapsulate the medication in corneal grafts could improve their effectiveness, according to research led by a team at Virginia Commonwealth University.
According to a report recently published in Science Advances titled “Six-Month Effective Treatment of Corneal Graft Rejection,” the unique strategy could significantly boost patient compliance.
Dexamethasone sodium phosphate, one of the most used corticosteroids for treating numerous ocular diseases such as ocular inflammation, noninfectious uveitis, macular edema, and corneal neovascularization, is included within each nanoparticle.
Patients would need one injection following corneal transplant surgery and would not need to use regular eye drops because of the use of nanoparticles to regulate the drug’s release over time.
Studies conducted by the study team have demonstrated that when employing this strategy, medication retains its potency on a model of corneal grant rejection for six months.
In addition, the method requires far smaller dosages than current routine eyedrop treatment while offering improved effectiveness and safety profiles since the medication is given gradually and exactly where it is most required.
Justin Hanes, Ph.D., the Lewis J. Ort professor of ophthalmology at Johns Hopkins University, worked with Qingguo Xu, D.Phil., the project’s principal investigator and an associate professor of pharmaceutics and ophthalmology at the VCU School of Pharmacy.
To improve patient compliance and treatment efficacy, we developed a tiny nanoparticle (around 200 nanometers) that in animal studies enables the release of the drug up to six months after a single subconjunctival injection along the eyeball.
Qingguo Xu, Study Principal Investigator and Associate Professor, Pharmaceutics and Ophthalmology, Virginia Commonwealth University
The study’s first author, Tuo Meng, Ph.D., a doctoral student at VCU, stated, “In our preclinical corneal graft rejection model, the single dosing of the nanoparticle successfully prevented corneal graft rejection for six months.”
More significantly, the nanoparticle strategy reversed early rejection symptoms and kept corneal grafts functioning properly for six months without rejection.
Through the R01 grant R01EY027827, the National Eye Institute, National Institutes of Health provided funding for this study.
The ultimate objective of Xu’s laboratory is to create safer and more effective nanotherapeutics for the treatment of various eye diseases.
Journal Reference:
Meng, T., et al. (2023) Six-month effective treatment of corneal graft rejection. Science Advances. doi:10.1126/sciadv.adf4608