Anit-VEGF treat and extend
The drugs are given by injection into the vitreous cavity of the eyeball see. The drugs last 4-8 weeks. There are different protocols, but the most recent is 'treat and extend'. BJO 14 diagram on this site Retina 14 Eye 15
All injectons now are offered as treat and extend
- For an average case type 1 'occult' or type 1 with ped or type 2 cnv, 3 injections with 4 week gap to start with.
- For a type 3 case (a 'RAP' type), or polypoidal 5 injections with 4 week gap.
- If at the last of the injections there is no fluid/leakage, the interval before the next injection can be extended by two weeks to make it 6 weeks.
- After 6 weeks there is another injection and OCT: once again, if at this time there is no fluid/leakage, the interval before the next injection can be extended by two weeks to make it 8 weeks, then to 10 weeks, with a maximum interval of 12 weeks.
- If at the time of an injection there is fluid/leakage present, the interval to the next injection is reduced by two weeks (to make the minimum interval 4 weeks).
- After a number of injections with a 12 week interval, usually about 3, injections may be stopped but OCT monitoring continued for about 6 months.
- But some CNV respond exceptionally well, such as those in myopes (1-3 injections in most cases), peripapillary CNV, (3 injections 80%). After the (1-3) injections, monthly OCTs are needed to confirm the condition stays dry.
- Even after one year of a 'dry' appearance, 25% of patients will notice a recurrence in the next 12 months. BJO 16
- At a recent meeting: discharge after 12 months (with injetions during this period) of being 'dry', that is no leakage or activity, treatment can be stopped. Another year of observation will be needed to check the condition remains dry. Reuccrence after this is 10% /year
- Polypoidal CNV and PEDs are more likely to need ongoing treatment in the second and subsequent years Retina 17.
- A very slightly longer interval between injections may be possible with Eylea.
- Fixed interval may help classic rather than occult BJO 20