To answer the first question there is no fixed number of injections that are required. Each patient responds differently and the number of injections depends on how the eye responds to treatment. The treatment is to be continued till the patient shows visual improvement with reduction in swelling. I generally give an estimate of 3-4 injections as most patients need 3-4 injections to stabilize. However, some patient may need fewer injections and some patients may need more. The injections are usually given on 1 month intervals. The injection is given inside the white part of the eye and is not painful. You can resume your daily activities immediately following the injection with no additional restrictions post injection, no admission required.
To answer the second question, the aim of treatment is to decrease the swelling in the retina. Usually patients show good improvement in vision with treatment with some patients regaining near normal vision back. However, in ischemic CRVO the patient may not have significant improvement in vision with treatment and thus may need treatment to be stopped. Rarely, some patients show improvement in the initial stage of treatment but then do not improve further with treatment due to conversion of non ischemic to ischemic CRVO.
In patients who do not undergo adequate treatment or do not follow up regularly as advised, secondary complications may develop in the form of neovascularization. In such patients laser therapy may be required in addition to intravitreal injection.