We present four cases of Terrien's marginal degeneration that developed spontaneous ruptures in Descemet's membrane resulting in corneal hydrops. In all cases, the hydrops was characterized by a clear intracorneal pocket of aqueous humor rather than by stromal clouding. In two cases, the pocket extended peripherally to form a conjunctival filtering bleb. Although a lamellar corneal patch graft was used in one case for severe astigmatism, hypotony, and impending perforation, most cases were merely observed without treatment.