To describe silicone oil drainage from the vitreous cavity to the subconjunctival space through a Molteno implant. A 52-year-old aphakic man with a Molteno implant inserted after lensectomy, vitrectomy and intravitreal silicone oil injection visited our hospital. The Molteno tube was located in the anterior chamber with two silicone oil drops on it. Corneal dellen, induced by marked bleb-like elevation of the conjunctiva was noted during follow-up and excision biopsy was attempted. The conjunctival elevation consisted of innumerable microdrops of silicone oil enclosed by inflammatory subconjunctival tissue. Silicone oil as well as aqueous humor had drained through the Molteno implant and glaucoma implant surgery may thus not be appropriate for the control of intraocular pressure of aphakia by intravitreal silicone oil before removal of oil.