Evaluating Keratoplasty for Fuchs' Endothelial Corneal Dystrophy: A Literature Review

Abstract

Fuchs' endothelial corneal dystrophy (FECD) is progressive corneal endothelium dysfunction, characterised by corneal oedema, and potential blindness if left untreated. Keratoplasty is the only definitive treatment to restore vision in FECD, with different surgical techniques being described. The corneal transplant has been described as the most commonly performed and most successful allogenic transplant globally; therefore, it is crucial to dissect it further since a large proportion of the population worldwide is likely to be impacted. We feel that an updated literature review is both very relevant and necessary at present and aim to amalgamate more recent data on the topic (including meta-analyses, systematic reviews, and randomised control trials (RCTs), among others). We acknowledge that the paucity of reliable data limits progress for FECD and that there are existing ethical complexities in performing prospective trials on patients. Traditionally, the surgery for FECD was limited to penetrating keratoplasty (PK), yet recent developments have introduced more advanced procedures and adapted the existing ones, to provide treatment specific to the disease-affected corneal layers. The questions we will address encompass: how does the severity of FECD govern the treatment options available, what are the differences between PK and types of endothelial keratoplasty (EK), what are the expected clinical outcomes of each of these operations, what are the potential concerns with the idealistic descemetorhexis surgery, and what do we envisage for times to come? Besides this, novel minimally-invasive pharmacological techniques are now being trialled, such as Rho kinase (ROCK) inhibition and cultured endothelial cells (CECs), which may drastically improve the dependence on corneal donors. We examine and critically appraise the literature to explore the understanding of FECD, and the treatment options that exist: historically, currently, and those anticipated for the future.

Keywords: corneal oedema; cultured endothelial cells; descemet's membrane; descemetorhexis without endothelial keratoplasty; descemet’s membrane endothelial keratoplasty; descemet’s stripping endothelial keratoplasty; deturgescence; fuchs' endothelial corneal dystrophy; penetrating keratoplasty; rho kinase inhibitors.

Figure 1. Diagrammatic representation of anatomical layers of the cornea.

Sourced by open access permissions from Singh et al [5]. Drawn by the authors based on their theoretical knowledge of corneal anatomy.

Figure 2. Flowchart depicting a stepwise approach while planning surgical management in a case of corneal opacity.

Sourced by open access permissions from Singh et al [5]. PK: penetrating keratoplasty, SALK: superficial anterior lamellar keratoplasty, HALK: hemi-automated lamellar keratoplasty; ALTK: automated lamellar therapeutic keratoplasty; DALK: deep anterior lamellar keratoplasty, DSAEK: Descemet’s stripping automated endothelial keratoplasty, DMEK: Descemet's membrane endothelial keratoplasty. PK, DSAEK, and DMEK have already been described. Note that SALK, HALK, ALTK, and DALK are beyond the scope of this literature review.