Atypical hydrops in keratoconus.

To report the clinical presentation, progress and management of atypical acute hydrops. A retrospective case study of three patients with keratoconus, two of whom had previously undergone penetrating keratoplasty. The patients underwent full ophthalmological examination and digital slit-lamp imaging of the cornea throughout the course of the condition. The two patients who had previously undergone keratoplasty had spontaneous hydrops primarily affecting the host bed but in one case extended to the graft inferiorly; however, in the third patient it was traumatic in origin. The Descemet's tear affected the host rim in only one patient, which resolved spontaneously. In another patient, the hydrops was related to an internal dehiscence of the graft-host junction and had to be managed by an endothelial transplant covering the dehisced graft-host junction. In the third patient, hydrops secondary to trauma was also associated with acute haemops. Progression of keratoconus post keratoplasty can occur exclusively in the recipient bed leading to acute hydrops in the host sparing the transplanted cornea. The progressive thinning and ectasia of the recipient bed can also result in internal graft-host dehiscence leading to chronic oedema. Rapid entry of aqueous or blood cells into the corneal stroma following acute rupture of the Descemet's membrane suggests that the abnormal stroma of the eye with keratoconus may have an important role to play in the pathogenesis of acute hydrops/haemops.