PURPOSE: We studied the incidence of vitreous hemorrhage in a well-defined population to determine the underlying causes of such hemorrhages. METHODS: We prospectively studied all eyes with dense spontaneous first-time vitreous hemorrhage during a 2 1/2-year period in the greater Göteborg area (542,000 inhabitants). Follow-up time was one year. RESULTS: Ninety-four patients (95 eyes) were included, corresponding to a yearly incidence of seven cases per 100,000 inhabitants. Because of demographic factors and the organization of Swedish ophthalmologic care, we believe that this is close to the true incidence. The cause of vitreous hemorrhage could be verified in all but four eyes but frequently not until late in the follow-up period. The most common underlying cause was vitreous detachment and traction to a retinal vessel (39 eyes). In 28 of these eyes a retinal tear was also present. Five of these eyes developed a retinal detachment. In 19 eyes, bleeding was caused by proliferative diabetic retinopathy. This figure was relatively smaller than in previous studies. Retinal vein occlusion was the cause of hemorrhage in 15 eyes. Retinal macroaneurysm (seven eyes) was an easily overlooked cause, often diagnosed late in the follow-up period. CONCLUSIONS: Because of the common diagnostic difficulties and the frequent need for laser treatment, vitrectomy, or both, it is recommended that eyes with vitreous hemorrhage be followed up in centers with ultrasonographic and surgical expertise.
PURPOSE: We studied the incidence of vitreous hemorrhage in a well-defined population to determine the underlying causes of such hemorrhages. METHODS: We prospectively studied all eyes with dense spontaneous first-time vitreous hemorrhage during a 2 1/2-year period in the greater Göteborg area (542,000 inhabitants). Follow-up time was one year. RESULTS: Ninety-four patients (95 eyes) were included, corresponding to a yearly incidence of seven cases per 100,000 inhabitants. Because of demographic factors and the organization of Swedish ophthalmologic care, we believe that this is close to the true incidence. The cause of vitreous hemorrhage could be verified in all but four eyes but frequently not until late in the follow-up period. The most common underlying cause was vitreous detachment and traction to a retinal vessel (39 eyes). In 28 of these eyes a retinal tear was also present. Five of these eyes developed a retinal detachment. In 19 eyes, bleeding was caused by proliferative diabetic retinopathy. This figure was relatively smaller than in previous studies. Retinal vein occlusion was the cause of hemorrhage in 15 eyes. Retinal macroaneurysm (seven eyes) was an easily overlooked cause, often diagnosed late in the follow-up period. CONCLUSIONS: Because of the common diagnostic difficulties and the frequent need for laser treatment, vitrectomy, or both, it is recommended that eyes with vitreous hemorrhage be followed up in centers with ultrasonographic and surgical expertise.