[Switching the Treatment Regime from PRN (pro re nata, as needed) to T&E (Treat and Extend) for Intravitreal Therapy with Anti-VEGF Agents in Private Practice or Small Institutions]

Abstract

In everyday practice, intravitreal therapy in an "as needed" regimen (pro re nata, PRN) is less predictable and requires more visits (monitoring and injections taken together) with poorer functional results than with the treat and extend (T&E) regimen. Current literature supports the benefit of a switch. However, practical advice is still missing. This article provides "best practice" recommendations for private practice or smaller institutions for the change from PRN to T&E. The requirements are organisational adjustments, staff training, definition of the scenario triggering the switch (A - functional or anatomical deterioration; B - general switch at a predefined date), counselling of the patients, defining benchmarks for the follow-up of the switch and preparing for higher capacity utilisation during the transition (shorter treatment intervals during the switching phase). Guidance is provided for each phase (a, preparation; b, transition; and c, follow-up).