Near-Infrared Light Photobiomodulation Treatment for Retinal Vein Occlusion Macular Oedema

This pilot study aims to establish that treatment with near infrared light (NIR) reduces cystic macular oedema in patients with a retinal vein occlusion.

Intraocular injections of Vascular Endothelial Growth Factor (VEGF) inhibitors have been shown to improve swelling of central retina (macular oedema) and vision in patients with retinal vein occlusions (RVO), however this treatment comes with potentially sight threatening risks. A less invasive treatment might have many advantages. We recently showed that eyes with macular oedema caused by diabetes, the other main cause of macular oedema, who received treatment with near-infrared (NIR) light was not only safe but was also effective in reducing the swelling. The US Diabetic Retinopathy Research Collaboration are currently recruiting for a larger study of NIR light which may or may not confirm our findings. We propose to test the safety and efficacy of the same NIR light in patients with macular oedema from retinal vein occlusions. We anticipate this may reduce the need for injections of VEGF inhibitors in eyes with RVO, in particular eyes with good vision. This pilot study will help determine whether PBM with NIR for RVO warrants further investigation in a larger study.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis macular edema secondary to branch or central vein occlusion (BRVO or CRVO)
* CMT of \>300 µm and less than 550 µm;
* Best corrected visual acuity of 6/6 to 6/24 (letters 87 - 53);
* Intraocular pressure \< 25 mmHg;
* Written informed consent has been obtained.

Exclusion Criteria:

* Loss of vision due to other causes (e.g. age-related macular degeneration, myopic macular degeneration, DME);
* Known allergy to agents used in the study e.g. fluorescein;
* Women who are pregnant, nursing, or planning a pregnancy, or who are of childbearing potential and not using reliable means of contraception;
* Only eye (vision in other eye \<6/60);
* Study eye is an amblyopic eye;
* Macular oedema due to other causes;
* Significant diabetic retinopathy;
* An ocular condition that would prevent visual acuity improvement despite resolution of oedema (such as foveal atrophy or substantial premacular fibrosis;
* Previous treatment with any anti-VEGF therapy or investigational drugs in the study eye at any time prior to baseline.
* Previous use of intraocular or periocular steroids in study eye at any time prior to baseline;
* Cataract surgery within the last 3 months;
* Retinal laser treatment within the last 6 months;
* Media opacity including cataract that already precludes adequate macular photography or cataract that is likely to require surgery within 6 months;
* Intercurrent severe disease such as septicaemia, any condition which would affect follow-up;
* History of chronic renal failure requiring dialysis or renal transplant;
* Blood pressure \>180/120;
* Participant has a condition or is in a situation that in the investigator's opinion may put the participant at significant risk, may confound the study results, or may interfere significantly with the participant's participation in the study