A 36-year-old man with keratoconus who had a penetrating keratoplasty (PKP) with recent suture removal sneezed and suddenly lost vision in his right eye. His vision was light perception, his PKP was dehisced, and his crystalline lens had been expulsed. B-scan showed large serous choroidal detachment and retinal detachment. A 6-mm trochar was inserted, and infusion pressure was raised to 60 mmHg. After a radial incision on the sclera was made 8mm from the limbus, no egress of choroidal fluid was noted. The superotemporal trochar was inserted and straw-colored choroidal fluid drained from the sclerotomy. Pars plana vitrectomy, drainage of subretinal fluid and endolaser were performed, and 16% C3F8 gas was injected.