Corneal endothelial cell dysfunction: etiologies and management

Abstract

A transparent cornea is essential for the formation of a clear image on the retina. The human cornea is arranged into well-organized layers, and each layer plays a significant role in maintaining the transparency and viability of the tissue. The endothelium has both barrier and pump functions, which are important for the maintenance of corneal clarity. Many etiologies, including Fuchs' endothelial corneal dystrophy, surgical trauma, and congenital hereditary endothelial dystrophy, lead to endothelial cell dysfunction. The main treatment for corneal decompensation is replacement of the abnormal corneal layers with normal donor tissue. Nowadays, the trend is to perform selective endothelial keratoplasty, including Descemet stripping automated endothelial keratoplasty and Descemet's membrane endothelial keratoplasty, to manage corneal endothelial dysfunction. This selective approach has several advantages over penetrating keratoplasty, including rapid recovery of visual acuity, less likelihood of graft rejection, and better patient satisfaction. However, the global limitation in the supply of donor corneas is becoming an increasing challenge, necessitating alternatives to reduce this demand. Consequently, in vitro expansion of human corneal endothelial cells is evolving as a sustainable choice. This method is intended to prepare corneal endothelial cells in vitro that can be transferred to the eye. Herein, we describe the etiologies and manifestations of human corneal endothelial cell dysfunction. We also summarize the available options for as well as recent developments in the management of corneal endothelial dysfunction.

Keywords: corneal endothelial dysfunction; etiologies; human corneal endothelium; management.

Figure 1.

The normal cornea consists of five layers, including the epithelium, Bowman’s layer, stroma, Descemet’s membrane, and endothelium. The endothelial cells form a single hexagonal monolayer located in the posterior cornea (arrow; hematoxylin and eosin staining, 10×).

Figure 2.

Long-standing corneal edema. Severe corneal opacity and scarring are evident and prevent the visualization of the details of the iris.

Figure 3.

Fuchs’ endothelial corneal dystrophy. (a) In the slit of light seen passing through the cornea from left (anterior surface) to right (posterior surface), the beaten-metal appearance of guttae is appreciated posteriorly in light reflected from Descemet’s membrane. (b) The anterior segment photograph of cornea with specular reflection illustrates the typical beaten-metal appearance. The dark spots in the photograph demonstrate the areas in which the endothelial cells have been lost.

Figure 4.

Pseudophakic bullous keratopathy. Severe corneal edema in an eye implanted with an angle-supported anterior chamber intraocular lens.

Figure 5.

(a) Clinical photograph of a girl with congenital hereditary endothelial dystrophy type 2 demonstrating bluish-gray ground-glass appearance of the right cornea. The left eye that underwent PK demonstrates a failing graft. (b) The slit beam highlights the uniform thickening of the cornea in the right eye.

Figure 6.

(a) Iridocorneal endothelial syndrome, characterized by atrophy of the iris, multiple atrophic holes, and corectopia. (b) Cogan-Reese syndrome, characterized by iridocorneal adhesion, diffuse nevi, and ectropion uveae.

Figure 7.

A Gundersen conjunctival flap. The cornea is completely covered by an intact layer of bulbar conjunctiva.

Figure 8.

Amniotic membrane transplantation for management of pain and discomfort in a patient with bullous keratopathy.

Figure 9.

Descemet stripping automated endothelial keratoplasty was performed in an eye with pseudophakic bullous keratopathy. The graft and overlying recipient cornea are crystal clear.