SIGNS AND SYMPTOMS
The patient typically is in the 50 to 80 age range, and most commonly female. Approximately 50 percent of patients have concurrent systemic arterial hypertension. These patients also have an increased incidence of cardiovascular disease and arteriosclerosis.
Ophthalmoscopy reveals an isolated dilatation of a major arterial (or, rarely, venous) branch, which is unilateral in 90 percent of cases but may be multifocal. Most often, by the time the patient presents, the aneurysm has leaked significantly with exudate and extensive intra-retina and/or subretinal hemorrhage. Occasionally, you may note spontaneous pulsation of the aneurysm.
When there is extensive hemorrhage, you may have difficulty assessing retinal macroaneurysm as the cause; neovascularization is often misdiagnosed as the cause. If the focal dilatation is not apparent on ophthalmoscopy, use fluorescein angiography. With fluorescein angiography, the aneurysm hyperfluoresces early in the angiogram with a characteristic balloon appearance with later-phase leakage.
Frequently, the patient is asymptomatic. However, if the macula is involved, the patient will present with reduced acuity and field. In these cases, permanent vision reduction is possible.
An idiopathic weakening of the vessel wall leads to focal outpouching and aneurysm formation. Leakage occurs in extreme cases. However, there is no microvasculopathy as seen in diabetic retinopathy. Retinal macroaneurysm is strongly associated with hypertension, which may contribute to the vessel wall changes. Retinal macroaneurysm is also strongly associated with arteriosclerosis, retinal emboli and cardiovascular disease. Occasionally, retinal macroaneurysms occur within areas of retinal vein occlusions.
Spontaneous sclerosis and occlusion typically occurs with macroaneurysms, particularly after hemorrhaging. Monitor asymptomatic non-leaking macroaneurysms at four- to six-month intervals. If leakage takes the form of exudation and/or hemorrhage that does not threaten the macula, then monitor every one to three months.
However, if hemorrhage threatens or involves the macula, or if there is persistent macular edema, photocoagulation is indicated. In these cases, moderately intense photocoagulation should be applied directly to the macroaneurysm so as not to produce complete occlusion of the involved artery. Venous macroaneurysms should be treated in the same manner. Also, if you observe a non-hemorrhagic macroaneurysm spontaneously pulsate, then direct photocoagulation should be used since rupture is likely.
In cases of unexplained intra- or subretinal hemorrhage, consider retinal macroaneurysm as the cause. If you don't readily observe the characteristic balloon ophthalmoscopically, use fluorescein angiography to identify the aneurysm.
Due to cardiovascular disease, these patients have a high rate of five-year mortality. Refer these patients to a cardiologist for evaluation. At the very least, order a fasting blood glucose, complete blood count with differential, fasting lipid profile and blood pressure evaluation.