One of the most frequent causes of vision loss in the elderly patient is the occlusion of the retinal veins.
Can we use DOACs in these patients?
A vein branch or the central retinal vein can be occluded.
If the occlusion is not very extensive, the prognosis is good and there may be a recovery of vision in half of the cases. In 30% of cases, thrombosis involves a very large area and retinal ischemia appears, with a much more unfavorable prognosis for the recovery of visual acuity.
The main causes are arterial hypertension, glaucoma, diabetes mellitus and hyperlipidemia.
Thrombophilia, hyperviscosity syndromes and vasculitis (from drugs or parainfectives) are minor causes.
The main factor causing the slowing of venous flow is the compression of the retinal vein by the central retinal artery, on an atherosclerotic basis. In fact, the vein and artery have a single adventitia.
Prevalence ranges from 1 to 5 in 1000 adults, and the typical clinical picture is characterized by painless loss of vision without other neurological signs.
In the patient over 50 years of age, we will evaluate the cardiovascular risk to correct hypertension, dyslipidemia or diabetes according to international guidelines. Thrombophilia (especially in the case of bilateral occlusion or personal or family history of VTE) and secondary forms of vasculitis (sarcoidosis, syphilis, tuberculosis) will be excluded in the patient under the age of 50.
There is no fully effective drug available for either prevention or treatment or central retinal vein occlusion.
In patients with retinal vein occlusion, vascular endothelial growth factor (VEGF) increases resulting in edema and development of new vessels (neo-vascularization) that are prone to bleeding.
Treatment in these cases involves intravitreal injections of an anti-VEGF drug to prevent local complications, and some surgical options also exist. Anticoagulant and antiplatelet therapy has been proposed in some trials. From the meta-analysis of the relevant studies, it seems to emerge that, despite limited evidence, the use of LMWH in selected patients with recent onset of symptoms (i.e. less than 15 days), as well as the use of aspirin for the long-term treatment of patients with retinal vein occlusion and concomitant cardiovascular risk factors.
A systematic review and meta-analysis of three randomized controlled trials comparing LMWH with aspirin in a total of 229 patients with acute retinal vein occlusion showed that patients treated with heparin had significantly improved visual acuity and a significantly higher risk. low to develop any adverse ocular outcome.
There is also some evidence to suggest a possible role for anti-platelet agents in preventing recurrence of retinal vein occlusion.
No studies have explored the use of DOACs for the treatment of retinal vein occlusion.
Blair K, Czyz CN. Central Retinal Vein Occlusion. [Updated 2022 Jan 31]. https://www.ncbi.nlm.nih.gov/books/NBK525985/