Diabetic keratopathy: Insights and challenges

Abstract

Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.

Keywords: corneal diabetes; diabetes review; diabetic complications; diabetic keratopathy; gene therapy; metabolic disease; neurotrophic ulcer.

Figure 1.

The human cornea: Five layers of the human cornea are shown: epithelium, Bowman layer, stroma, Descemet membrane, and endothelium.

Figure 2.

Representative images of common clinical manifestations of diabetic keratopathy. A) Sclerotic scatter illumination slip lamp photograph of the A1) right and A2) left eye highlights areas of central stromal partial light-blocking scarring with adjacent irregular hyperplastic epithelium. Significant superior, nasal and inferior neovascularization is present. B) Sclerotic scatter illumination slit lamp photograph of the B1) right and B2) left eye demonstrates diffuse stromal edema, Descemet folds and microcystic edema following cataract surgery. A vertical corneal epithelial defect is also present. C) Slit lamp photograph of the right eye demonstrates epithelial irregularity and redundant basement membrane in a patient with diabetic keratopathy and epithelial basement membrane disease causing recurrent corneal erosions. D) Slit lamp photograph of the right eye demonstrates florid stromal folds and edema occupying most of the cornea with limbal sparing. Several bullae are seen superiorly. E) Slit lamp photograph of the right eye demonstrates 3+ conjunctival injection with significant epithelial defect occupying approximately 60-70% of the cornea with infiltrate. Prominent corneal neovascularization of 360 degrees of the cornea at multiple levels is also present. A 2mm hypopyon is seen in the anterior chamber.