Treatment Frequency and Monitoring
The approved posology for ranibizumab and 1-year outcomes in clinical trials were considered in our recommendations: ranibizumab injections should be initiated on a monthly basis, with monthly VA monitoring, until VA stability is achieved for a period of at least two consecutive visits or until normal VA is achieved. Treatment with ranibizumab can be interrupted when VA stability is achieved. This is defined in the approved posology as no further documented VA improvement over three consecutive visits while on treatment. However, monitoring should be continued on a monthly basis and, if VA deteriorates owing to DME, monthly injections should be re-initiated until stability is again achieved.
In clinical practice, decisions on treatment continuation, interruption, and re-initiation are most likely to be based on the combination of OCT and VA. OCT is a useful additional tool for monitoring DME stability and for confirming whether vision loss is due to DME. Fluorescein angiography assessment may be needed in specific situations (eg, development of unexplained visual loss).
On the basis of the above treatment criteria, the frequency of injections in the first year of treatment with ranibizumab can be expected to be similar to that in the RESTORE trial (ie, seven injections (five in the first 6 months and two in the second 6 months)). There may be an opportunity to reduce the frequency of monitoring in the second year of treatment, but no recommendation can yet be made based on the currently available evidence.
Patients with progressive worsening of VA over three consecutive visits in the presence of active DME (ie, when other causes of vision loss have been excluded) can be considered as non-responders to ranibizumab therapy. In these patients, it is recommended to discontinue ranibizumab and consider other treatment options, in particular laser treatment or intravitreal steroids.