Ciliochoroidal effusion and suprachoroidal (expulsive) hemorrhage both occur in hypotonic eyes and may be serious complications of intraocular surgery or other ocular perforations. Clinical observations have given rise to the suspicion that ciliochoroidal effusion may be a precursor of suprachoroidal hemorrhage, which has resulted in a change of recommended surgical management of the complications. In the present pathologic study, typical ciliochoroidal effusion is demonstrated at the stage at which rupture of stretched posterior ciliary arteries makes suprachoroidal hemorrhage imminent. Our observations morphologically support the clinical conclusions of Maumenee and Schwartz.