Cardiovascular risk factors in patients with acute, non- arteriitic central retinal occlusion - importance of systematic evaluation and impact on the therapy

Central retinal artery occlusion (CRAO) is an uncommon illness with an acute onset of painless visual loss and a poor prognosis for long-term vision. So far no treatment method has proven to be effective in a prospective and randomized study. The existing data were collected retrospectively and monocentricaly over a very long period of analysis, in which the inclusion criteria often had no uniform quality. However, the evaluation of cardiovascular risk factors in clinical everyday life is of particular significance, as older data suggest a significantly shortened life expectancy for CRAO patients. For the first time the internal medical risk factors were examined in a clearly defined patient population of 77 patients with recent non-arteriitic CRAO in a prospective and standardized study. In 82% of patients we found individual risk factors previously unknown before the occurrence of CRAO. In 29% of all patients no risk factors were previously known; in 53% of study participants there were additional risk factors. In accordance with previous studies, the most common risk factors were hypertension, hypercholesterolemia, cardiac arrhythmias, carotid artery stenosis and stroke. Arrythmias are of particular importance as they lead to a significantly increased risk of a subsequent ischaemic insult. The prevalence of patients with significant carotid artery stenosis (40%) was unexpectedly high. Other significant risk factors in our collective include valvular heart disease, patent foramen ovale, coronary heart disease and the implantation of stents. Changes in the heart valve were slightly less common compared to changes in the carotid artery. However, both changes were a risk factor for retinal artery occlusion. In contradiction to previous studies we did not find a higher prevalence of diabetes mellitus in CROA patients compared to an age adapted general population. Occlusions of the retinal artery have the same systemic risk factors as other cardiovascular diseases including ischemic stroke. Nevertheless, the current assessment of risk factors in patients with acute, non-arteriitic CRAO have to be reconsidered in respect to the diagnostic process. Especially, it requires an interdisciplinary cooperation between ophthalmologists, internists and neurologists. The aim must be to avoid further vascular events, to reduce mortality and prevent the emergence of new thromboembolic events and complications outside of the eye by adequate and timely investigation and treatment. Factors on the functional outcome - In an additional analysis we investigated the effect of certain factors on the functional outcome. It was found that coronary heart disease (CHD) correlates with a poor initial visual acuity and hence is associated with a poorer prognosis for final visual acuity. The poorer initial visual acuity in older patients, can be explained by the fact that the incidence CHD has a direct correlation with age. Since cardiovascular high-risk patients were not included for therapeutic safety within the study, it can be assumed that the incidence of CHD is even higher in the general population at risk. The duration of the time lag between the onset of first symptoms and initiation of therapy also had a relevant prognostic effect on the final visual acuity. We found by a univariate analysis, that a time lag longer than 12 hours was associated with a significantly worse improvement in vision after 30 days compared to those whose initial symptoms to treatment time was less than 12 hours. This verifies a positive relationship between expediency of treatment and functional outcome. However, whether an early fibrinolytic therapy leads to even better results can not be deduced from our data with certainty. In the investigation of the effect of factors influencing the treatment outcome, only the age of the patient had a significantly predictive (therapeutic) effect. This is true in particular for patients ≤ 60 years (difference lysis vs. conservative therapy). Between the ages of 61 - 69 years only marginal effects were found and in patients ≥ 70 years, thrombolytic therapy was associated with a worse visual prognosis. These results point to a treatment difference in respect to the final result. In summary, it can be said that CHD and time delay to treatment of over 12 hours is negative prognostic factor. In addition patients under 60 years of age particularly benefit from the intra-arterial fibrinolysis. However, due to known severe side effects, the intra-arterial fibrinolysis can not be recommended any more.2014-04-1