6.4 Practical Recommendations About the Systemic Workup of Patients with Retinal Vein Occlusion

6.4Practical Recommendations About the Systemic Workup of Patients with Retinal Vein Occlusion

The high PAR% for hypertension, hyperlipidemia, and diabetes mellitus leads to the recommendation that patients with RVO who have not been assessed for these factors should have blood pressure, serum lipid levels, and blood glucose levels checked.190 Although there is no evidence that lowering elevated blood pressure, serum lipids, or blood glucose can favorably inßuence visual acuity outcome or secondary complications in RVO, clinical judgment suggests that these should be gradually normalized under the care of the patientÕs internist or family physician.142 The extent of the workup warranted in patients without known vascular risk factors is controversial. Some have advocated looking for APLAs, AT, the FVLM, prothrombin 20210A, and other possible associations in such patients.106,155,169,183,184,190 Others have argued that the probability of discovering a treatable condition is too low to justify the effort.79,110,183 Some have recommended more indepth testing only if a personal or family history of previous venous thrombosis or spontaneous abortion exists, or if bilateral RVOs are present.179,183,190

Others advocate additional testing for the Òvery youngÓ with RVO, although the deÞnition of Òvery youngÓ is not given.183,190 The thinking behind this recommendation is that the younger the patient, the less likely that the commonly associated vascular risk factors for RVO can be convincingly invoked to explain the presence of the RVO and the more sense it makes to look for underlying thrombophilia.106 The choice of the

age cutpoint, which has typically been somewhere in the range 45Ð55, for when to consider a search for thrombophilia, is arbitrary.107 A more nuanced view would be to favor such an investigation more strongly the younger the patient happened to be.108 There are differences of opinion in the literature on recommendations in the younger patient with RVO. Some authors recommend speciÞc testing, for example, for factor XII deÞciency or FVLM,106,155 whereas others consider the evidence too sparse as yet to recommend such screening based simply on age.104,105,183

A second vexing question is how extensive the studies should be if they are pursued. In addition to the tests already mentioned, the list of possible tests that might be considered includes a complete blood count, erythrocyte sedimentation rate, platelet count, prothrombin time, activated partial thromboplastin time, bleeding time, lipid proÞle, plasma homocysteine, plasma Þbrinogen, D-dimer, Þbrinogen degradation products, protein S, protein C, antinuclear antibodies, antiphospholipid antibodies, anticardiolipin antibodies, lupus anticoagulant, VDRL, factor V, factor V Leiden, factor VII, factor VIII, and factor IX, factor XII, heparin cofactor II, tissue plasminogen activator antigen, plasminogen activator inhibitor activity and antigen, and plasma histidine-rich glycoprotein.70,104,112,183,191 The length of the list suggests that it is impractical to pursue in most cases.

Although there is controversy about when to perform additional testing, there is a consensus about when additional testing can be omitted. Patients who develop RVO who are over the age of 45Ð50 and have cardiovascular risk factors do not need a systemic workup for possible predisposing thrombophilia. The yield relative to the expense of such workups is insufÞcient to justify the effort.156