The investigators believe that oxygen saturation measurements in the retina may provide more information on how well the retina is working and may detect problems in the retina earlier than the fundus fluorescein angiography (FFA). This may be useful to an ophthalmologist so that they may identify abnormal areas of the retina and commence or change the treatment so that they may prevent irreversible blindness.
Most patients with clinically significant macular oedema and/or ischaemic diabetic retinopathy could have either laser or Intravitreal Anti-VEGF injection treatment provided they are counseled about the risks. It is known the Anti-VEGF injections reduce oedema and it is believed that laser treatment of the retina in this condition improves the oxygen supply to the retina and sometimes reverses the damage. It will be useful to take pictures of these treated eyes using the Oxymap spectral retinal camera(s) to see whether the investigators can detect a change in the oxygen saturation in the retina before and after treatment using our oxygen saturation methods.