Purpose: To investigate the risk of stroke development following the occurrence of retinal vein occlusion (RVO) by utilizing a population-based administrative database.
Methods: Data were collected from Taiwan Health Insurance Research Database, which comprises of 1,073,891 random subjects from 23 million Taiwan’s residents. The study cohort comprised all patients with a first-time diagnosis of either central or branch RVO (ICD-9-CM code 362.35 or 362.36) from 1999 to 2001 (n = 350). The comparison cohort was comprised of randomly selected patients (six for every RVO patient, n = 2,100) matched with the study group in terms of age, gender, and the date of ambulatory care visit. Each individual sampled patient was tracked from their index visits for 5 years. Cox proportional hazard regressions were utilized to compute the 5-year stroke-free survival rate after adjusting for possible confounding factors.
Results: Stroke developed in 35.1% of patients with RVO and 19.9% of patients in the comparison cohort during the 5-year follow-up period. After adjusting for patients’ demographic characteristics and selected comorbidities, RVO was not associated with an increased risk of stroke development (adjusted hazard ratio, 1.01; 95% confidence interval [CI] = 0.65~1.57) among subjects of any age. However, RVO patients in the age group of 60~69 years were found to have a 2.34-fold (95% CI, 1.05~5.24) higher risk of suffering a stroke than the matched comparison cohort.
Conclusions: There was no overall association of RVO with stroke except in the 60~69-year subgroup. The possible causes include: an actually increased risk of stroke development in the 60~69-year group, chance finding, the presence of selection biases, small numbers of stroke patients in the <50 and 50~59 age groups, or a lack of power in the ≥ 70-year group.