Nine year follow-up study of morbidity and mortality in retinal vein occlusion.

PURPOSE: The aim of this study was to conduct a detailed retrospective follow-up of a large cohort of patients with retinal vein occlusion (RVO), examining morbidity and mortality, to investigate a possible relationship between RVO, large vessel disease and stroke, and to determine whether recurrence of RVO was influenced by treatment of associated medical conditions. METHODS: A follow-up study was undertaken in 1994 of all patients (n = 588) who presented to the medical ophthalmology clinics of the Birmingham and Midland Eye Hospital between 1982 and 1989 with a definitive diagnosis of RVO. RESULTS: Follow-up data were obtained on 549 patients (93%). Results showed that recurrence of RVO in the same or fellow eye was decreased by more than half in the follow-up group (3.3%) when compared with the known recurrence rate at initial presentation (8.8%). Comparison of the deceased with the survivors showed that the deceased patients were significantly older (mean age 70.2 vs 63.4 years). The prevalence of rubeosis iridis and smoking were statistically significantly increased when comparing the deceased with the survivors (p < 0.016 and p < 0.008 respectively). The deceased had a higher prevalence of diabetes (15.8% vs 10.1%), and there was a trend towards increased clinically evident macrovascular disease in those patients who had died (23.2% vs 19.5%). Neither hypertension nor hyperlipidaemia predicted death, as the prevalence rates of the two conditions were similar in survivors and those who had died (60.0% vs 60.6% and 48.4% vs 53.3%). The percentage of patients taking antiplatelet drug therapy was not different in the two groups (36.8% vs 38.3%). Analysis of the causes of death of the RVO population (n = 95) compared with the causes of death in the West Midlands population as a whole, showed that the percentage of deaths from myocardial infarction in the RVO population was significantly higher (23.1% vs 14.4%, p < 0.05). There was no statistical difference between the populations for ischaemic heart disease and stroke, although there was a trend for increased mortality from stroke (19% vs 13.5%). CONCLUSION: These data suggest a relationship between RVO, mortality and increased cardiovascular risk factors (smoking, diabetes and macrovascular disease), and support the possibility of an association between RVO and stroke. They also support the potential value of medical treatment of underlying medical conditions in preventing recurrence of RVO.

Sex hormone preparations and retinal vein occlusion.

Retinal vein occlusion (RVO) is most commonly seen in middle-aged or older patients and is associated with underlying cardiovascular risk factors. It is much less common in younger patients. Use of the oral contraceptive pill (OCP) is known to be a risk factor for cardiovascular and cerebrovascular disease. There have previously been a few isolated case reports of patients sustaining an RVO whilst taking the OCP. The aim of this study was to investigate patients sustaining an RVO whilst taking the OCP or hormone replacement therapy (HRT). From a large series of 588 patients, we found 11 with an RVO associated with sex hormone preparations. Of these, 6 had taken the OCP and 5 were HRT users. From this large group there were only 9 female patients aged under 35 years who sustained an RVO. Of these, 6 were associated with use of the OCP. All patients were investigated for recognised medical risk factors for RVO. None of these factors were identified in the patients who had used the OCP. Of the patients taking HRT, 4 of the 5 had other potential risk factors. From our large series, the prevalence of RVO in female patients under 35 years taking the OCP was 66%. There is a 30% uptake of the OCP in the general population. These data support the view that RVO is a contraindication to the use of the OCP. Additionally, it would appear (albeit from limited data) that patients who sustain RVO may continue with their HRT, as HRT is not a major single risk factor for RVO.

Effects of dietary sodium substitution with potassium and magnesium in hypertensive type II diabetics: a randomised blind controlled parallel study.

We have previously demonstrated that modest sodium restriction has a hypotensive effect in hypertensive diabetic subjects. A randomised blind controlled study has therefore been performed to study the effect of replacement of added salt intake using a salt substitute (50% NaCl, 40% KCL, 10% Mg2+, supplied by Cederroth, Sweden), compared to added whole salt intake over a 9 month period of 40 hypertensive Type II diabetic subjects (mean age 62.5 +/- 7.8 years; 24 males and 16 females). After 3 months, there was a significant reduction in systolic blood pressure (SBP) in the salt substitution group (163.2 +/- 24.2 to 153.6 +/- 20.8 mm Hg; P < 0.03) which was maintained at 9 months, when compared to the whole salt group (151.5 +/- 20.6 vs 173 +/- 18.9 mm Hg; P < 0.05). No significant changes were observed in mean weight, fasting lipid or insulin levels or diabetic control (measured by glycosylated haemoglobin). A greater number of patients were withdrawn during the study period owing to consistent BP > 160/95 in the whole salt group (n = 10) compared to salt substitute (n = 4). No significant changes were observed in diastolic pressure, 24-h urine sodium or magnesium excretion, but urine potassium was significantly increased in the salt substitute group (58.8 to 77.3: P < 0.05). The results of this study suggest that substitution of sodium, by potassium and magnesium, produces a clinically significant reduction in SBP in hypertensive Type II diabetic patients, and should be a useful antihypertensive therapy in this patient group.