Purpose: To investigate four cases of acute hydrops caused by recurrent keratoconus following penetrating keratoplasty (PKP).
Methods: We retrospectively investigated four eyes in four patients with acute hydrops due to recurrent keratoconus following PKP in terms of the clinical course, data obtained using anterior segment optical coherence tomography and corneal topography, and histopathological images of the cornea obtained during repeat surgery.
Results: The four patients were males, and mean age at the onset of acute hydrops was 54.8±5.7 years. Mean duration until acute hydrops onset after PKP was 22.3±4.0 years. Descemet's membrane tearing was observed in the inferior graft-host junction in all cases, whereas Descemet's membrane was found to be detached in three. Anterior air injection was unsuccessful, and repeat corneal grafting was required. The pathological specimens exhibited Bowman's layer breaks in both the host and graft sides. In the patient without Descemet's membrane detachment, the corneal edema improved with conservative treatment; however, thinning of the thinnest corneal point continued thereafter.
Conclusions: Acute hydrops mainly occurred around the graft-host junctions in the present four cases in contrast to normal keratoconus, suggesting that acute hydrops was caused by Descemet's membrane tearing due to the progression of host side thinning and graft-host junction structural frailty in those areas rather than changes within the graft. Even relatively elderly patients who have undergone PKP for keratoconus need to be observed over time with the possibility of keratoconus progression kept in mind. In such cases, evaluation of graft-host junction corneal thickness using anterior segment optical coherence tomography is of particular importance.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 122: 758-765, 2018.