Proliferative vitreoretinopathy : steps towards prevention

It is still not completely understood why some patients develop proliferative vitreoretinopathy and others do not despite extensive research on cytokine biomarkers, genetic profiles and ocular clinical risk factors. Recently, a new possible treatment target was proposed based on studies on the role of coagulation proteins in the development of PVR. While several pharmaceutical drug therapies have been proposed for PVR – targeting inflammation, proliferation and growth factors – these drugs all have potential side effects. Therefore, to optimise the benefit/risk ratio of drug therapies, it is crucial to select only those patients at high risk of developing PVR.
We tested whether the oral direct thrombin inhibitor dabigatran would be a potential drug candidate for the treatment of PVR. In this respect, we tested whether oral administration would lead to measurable levels in the eye and whether dabigatran was able to oppose the effects of thrombin in an in vitro model. In addition, we tested the amount of endogenous thrombin generation and inhibition in vitreous and subretinal fluid.
Furthermore, we tested the applicability of aqueous humour laser flare measurements in distinguishing between patients at high and low risk of developing PVR. Firstly, we looked at preoperative flare values and secondly at postoperative flare values. We also show that the choice of surgery might also influence postoperative inflammation and thus influences the risk of developing PVR.
An aspect that has gained less attention in research is the possible influence of concomitant systemic drug use. The prevalence of rhegmatogenous retinal detachment (RRD) increases with age with a mean age around 60 years. In this age group, systemic drug use is not uncommon but little is known about the possible impact of these drugs on the eye. Of particular interest would be systemic drugs known to affect inflammation or fibrosis that could potentially have a stimulating or a protective effect on the course and the occurrence of PVR. Lastly, we describe our research into whether medication use around the time of surgery for RRD was of importance for the development of PVR.