Retinal vein occlusions are associated with an increase in vascular causes
of
death (both cerebral and cardiac) in large prospective follow up studies.41,42
It is now proven that drug treatment of hypertension reduces the severity of its
complications, and additional therapy of aspirin in well controlled hypertensive
subjects given as a primary prevention reduces cardiovascular event rate.44
Recent trials of cholesterol lowering using statins have confirmed the beneficial
effect of this therapy with reduction of cardiovascular morbidity and mortality.44
Patients with rarer underlying conditions such as myeloma and inflammatory
disorders should be referred and managed by appropriate specialists.
Cardiovascular risk factors identified in patients with retinal vein
occlusion45should be managed according to the joint guidelines of the British
Hypertension Society, British Hyperlipidaemia Association and British Diabetic
Association.44 This approach should ameliorate adverse cardiovascular
outcomes for patients with retinal vein occlusion. Target levels for medical
management recommended by the joint societies and the recent British
Hypertension Society guidelines are shown in Table 3 and, unless a specific
contra-indication, aspirin, 75-150 mg daily is appropriate.
7.1 To prevent the recurrence
of retinal vein occlusion
Several series have demonstrated that recurrence of retinal vein occlusion
may occur in the affected eye or in the fellow eye in up to 15% of patients
over a five year follow up period.40
Rates vary according to studies in differing countries
from 9 to 15%. In view of the poor
potential visual outcome of patients with
recurrent retinal vein occlusion,
this aspect has been studied, but not in controlled trials. Available data
supports the concept that recurrence of retinal
vein occlusion may be reduced by
medical treatments of underlying
cardiovascular risk factors with
the addition of aspirin/persantin.42
7.2 The use of hormone replacement
therapy following retinal vein occlusion
Although estrogen-containing HRT should not be commenced in those women
with retinal vein occlusion, continued
use does not appear to be associated with
a higher rate of recurrence. Historically,
HRT was contraindicated and
discontinued following central vein
thrombosis. Following the work of the Eye
Disease Case-Control Study Group12and
Kirwan and associates16,
medical
practice showed a trend to continue
HRT following retinal vein occlusion due
to the epidemiological evidence
supporting HRT in the prevention of
cardiovascular disease. This policy
has not lead to the potentially disastrous
visual outcome of recurrence of
retinal vein occlusion in the fellow eye.
Currently, the decision about whether
to continue HRT in a woman with retinal
vein occlusion should be made on
a case by case basis. The decision should be
based on the woman’s individual
case history, including the indication for HRT
use. The degree of residual visual
impairment may influence the decision as a
recurrence in the fellow eye may
have a potentially devastating visual outcome.
Further guidance may be obtained
from the results of thrombophilia screening,
as this may provide an indicator
of future risk. The current uncertainty about
the effects of HRT on cardiovascular
risk and recent guidelines for the use of
HRT should also be considered.46
| Introduction | Methods used | Risk factors | CRVO |
| BRVO | Medical treatment | Cardiovascular problems | Young patient |
| References. | Tables | Main index | Main page. |