Features of the hypoperfusion retinopathy:
(1) progressive visual loss in the affected eye(s)
(2) Often there is a history of one or more diseases associated with atherosclerosis such as hypertension, hyperlipidemia, diabetes, peripheral vascular disease, ischemic heart disease, and/or cerebrovascular disease.
(3) One or both carotid arteries show severe stenosis or complete occlusion.
(4) Involvement is usually unilateral and ipsilateral to a severely affected carotid artery.
(5) dilatation and tortuosity of the retinal veins
(6) breakdown of the capillary walls with superficial (flame-shaped) and deep (dot-blot) retinal hemorrhages. In the early stages these tend to affect the retinal midperiphery rather than the posterior pole
(7) macular edema
(8) neovascular proliferations in the retina and iris (late)
(9) absence of optical disc swelling
The Ocular Ischemic Syndrome occurs when severe hypoperfusion retinopathy is associated with anterior segment ischemia, with:
(1) corneal edema
(2) ischemic uveitis
(3) neovascularization of the iris
(4) raised intraocular pressure which may progress to glaucoma
Differential diagnosis:
(1) polycythemia
(2) Waldenstrom's macroglobulinemia
(3) diabetic retinopathy (usually bilateral and affects the posterior pole)
(4) hemoglobinopathy
(5) myeloma
(6) malignant lymphoma
(7) central retinal vein occlusion (associated with optical disc swelling)
Therapy:
(1) panretinal photocoagulation
(2) reduction of a raised intra-ocular pressure with topical and/or systemic agents
(3) management of the carotid occlusion by endarterectomy or vascular bypass from the superficial temporal artery to the middle cerebral artery
