Extreme Descemet's membrane rupture with hydrops in keratoconus: Clinical and histological manifestations

Abstract

PurposeTo study the clinical and histological manifestations of an extreme Descemet's membrane rupture as a result of keratoconus.ObservationsUsing Periodic acid-Schiff assay to study a keratoconic cornea with an extreme rupture showed that the ruptured Descemet's membrane had retracted and folded into scrolls and ridges. The dimensions of the rupture were estimated to be 3.7mm2, and the central cornea was extremely thinned with a thickness of only 260μm. Stromal scarring and loosely packed lamellae were present anterior to the scrolls and ridges. Antibodies targetting the major components of Descemet's membrane, Laminin and type IV collagen, displayed intense labelling adjacent to the scrolls where the stroma was denuded and differential expression patterns lined the ridges. Environmental scanning electron microscopy showed possible collagen deposition at the site of rupture.Conclusions and importanceThe specific staining patterns of laminin and type IV collagen suggest these components have an important role in re-endothelisation of the cornea. This is the first known report of spatial resolution of the topography of the Descemet's membrane rupture established by environmental scanning electron microscopic image montage.

Regression of Corneal Vascularization Occurring after Corneal Suturing in a Case of Acute Hydrops Managed with a Combination Therapy of Argon Laser Photocoagulation and Intrastromal Ranibizumab Injection: A Case Report

“…Spontaneous resolution usually occurs by endothelial sliding over a period of 2-4 months. 5 It has been reported in previous case reports that resolution of acute hydrops in its natural course results in extreme thinning and flattening of the cornea, 6 which can in turn compromise the tectonic integrity of the globe and adversely affect the subsequently planned elective procedures for tectonic and/or optical rehabilitation.…”

“…In some cases, the presence of large stromal clefts delays resolution and the persistent edema can incite inflammation and vascularization that may adversely affect the chances of graft survival later. 6 Intracameral injection of air or presence of deep neovascularization was noticed at the 2-month review and the corneal sutures were removed, considering them to be the continuing risk factor to incite vascularization and inflammation as the hydrops had resolved. In spite of removing all the sutures at 5 months postoperatively, he presented with recurrence of inflammation and edema and persistence of deep corneal vascularization.…”

Management of acute corneal hydrops – Current perspectives

“…On immunohistochemistry, laminin and type IV collagen were localized adjacent to the scrolled DM, with lesser staining in the nonscarred areas, suggesting that both these components had an important role to play in re-endothelization of the cornea. [ 17 ] Laminin and collagen type IV labeling were found immediately adjacent to the scroll and less along the denuded stroma where DM had ruptured. Almost no type IV collagen labeling was found in the scroll of retracted DM, whereas it was found in the central and posterior stroma above the retracted DM where the thickness of the cornea increased.…”

Hydrops after corneal perforation during manual deep anterior lamellar keratoplasty for keratoconus

“…I n our recently published article 'Are Descemet membrane ruptures the root cause of corneal hydrops in keratoconic eyes?' (Parker et al 2019), we described how hydrops formation in keratoconus (KC) may be subjected to a more complex mechanism than currently hypothesized, that is, a hydrops would result from a break in Descemet membrane (DM) in the background of abnormal collagen of the corneal stroma in KC (Dua et al 2015;White et al 2017;Loh et al 2018;Parker et al 2019). In eyes with Fuchs endothelial corneal dystrophy and coexisting KC, removal of DM during descemetorhexis never resulted in any sign of hydrops formation, while a stromal perforation into the anterior chamber during Bowman layer transplantation consistently produced a significant hydrops (Parker et al 2019).…”