Shield ulcer in keratoconus in the absence of atopic or vernal kerato-conjunctivitis

Abstract

Corneal shield ulcer is a severe complication of atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC). This condition is caused by the mechanical irritation of the corneal epithelium due to giant papillae and toxic epitheliopathy resulting from inflammatory mediators. To date, there have been no reported cases of corneal shield ulcers in the literature without AKC or VKC. However, the authors have reported a unique case of shield ulcer in a patient with keratoconus but no history of AKC or VKC. The cause is hypothesised to be due to mechanical friction between the corneal steep apex and palpebral conjunctiva. Additionally, a new technique, the use of a dry amniotic membrane, is described to manage the persistent epithelial defect in shield ulcers.

Table 1. The two large retrospective case series on the management and outcome of shield ulcers

Figure 1. Calcified shield ulcer measuring 3 mm by 2.8 mm affecting the paracentral cornea

Figure 2. Lower tarsal conjunctiva, with no evidence of papillary reaction

Figure 3. Upper tarsal conjunctiva with no giant papillae

Figure 4. Partially removed calcific deposit and corresponding corneal epithelial defect

Figure 5. Persistent corneal epithelial defect, two weeks after partial removal of the calcific membrane and starting the medications

Figure 6. Left cornea 2 weeks post-operatively. The amnion has almost absorbed, and the bandage contact lens is in place.

Figure 7. Left cornea 3 weeks post-operatively. The amniotic membrane has fully absorbed, and the bandage contact lens is removed. A faint scar is visible in the paracentral cornea.

Figure 8. Anterior segment OCT of the left cornea 3 weeks post-operatively shows significant posterior elevation, apical stromal thinning (white arrow) (325 µm) and epithelial hypertrophy (yellow arrow) (92 µm) following surface healing.