In order to investigate the clinical features, pathology and treatment of idiopathic uveal effusion syndrome, ten eyes of seven patients with the syndrome had been studied. In addition to general clinical examinations, indirect opthalmoscopy, fundus fluorescein angiography and (FFA) ultrasonography were used to make definite diagnoses. The findings of these examinations indicate four key features of the idiopathic uveal effusion syndrome. They are: annular cilio-choroidal detachment, shifting non-rhegmatogenous retinal detachment, unremarkable inflammation in the anterior segment, and normal intraocular pressure. The fundus change is characterized by the "leopard-spot". All patients were treated by sclerectomy and sclerotomy, ciliochoroidal detachments disappeared soon after surgery, and retinal detachments resolved later on. Patients' visual acuity recovered well. The histochemical and electron microscopic examinations of excised tissues from five eyes showed thickened sclera, a general increase of the scleral fibril width compared to normal scleral, the disruption of normal lamellar arrangement of the scleral fibers and the deposition of glycosaminoglycans in the interfibrillar spaces. All these indicate that a congenital scleral abnormality seems to be the basic pathophysiology of the idiopathic uveal effusion syndrome.