What is a retinal vein occlusion?
It is the result of a sudden decline in blood flow in the veins of the retina, which may have an impact on general retinal circulation: stagnation of blood flow results in retinal hypoxia, which can cause more or less severe visual alterations. The occlusion of the central retinal vein has more serious consequences than a branch retinal vein occlusion, which concerns a smaller portion of the retina.
Among the predisposing factors, vascular risk factors (such as hypertension) are the most frequent; increased levels of certain lipids (fats) in the blood system, diabetes mellitus, smoking, but also raised intra ocular pressure (glaucoma) are common underlying causes. Sleep apnea syndrome can be associated with retinal vein occlusion.
Diagnosis and prognosis of retinal vein occlusio
If retinal vein occlusion is suspected upon fundus examination, it is very useful to confirm the diagnosis by fluorescein angiography , which perfectly highlights the blood circulation in the retinal vessels and analyzes the consequences. The optical coherence tomography (OCT) provides useful information to evaluate the macular oedema, which is a very common complication of venous occlusion.
The prognosis of the occlusion of the central retinal vein is highly variable, with possibility of complete or almost complete recovery in about 20% of cases or, in contrast, risk of major visual loss. Worsening of symptoms during the first few weeks is very common, so a regular regular follow up during this period should be done. The duration of evolution from central retinal vein occlusion can range from a few weeks in the most favorable cases, to more than one year in case of slow and gradual deterioration.
What is the initial treatment of the central retinal vein occlusion ?
Several treatments may be proposed. The treatment of risk factors is essential to avoid the risk of relapse or involvement of the other eye (10 – 15% of cases). In the early phase, hemodilution treatment may be offered in the absence of contraindications, in order to reduce blood viscosity and improve blood flow in the retinal vessels. Laser treatment is indicated in some cases, mainly to avoid complications. Anti-oedematous drugs administered by injection into the eye are now prescribed to treat persistent macular oedema, and thus improve vision.
Last page modification: 2 Sep 2013