Acute corneal hydrops of presumed traumatic origin: An uncontrolled case series (three horses)

Abstract

This case series describes acute corneal hydrops in three young horses. Due to similarities in the clinical appearance and progression of the disease with that which is reported in humans and cats with acute corneal hydrops, traumatic Descemet's membrane rupture was suspected to be the underlying aetiology in these equine cases. The horses presented with acute severe corneal oedema with intrastromal bullae formation and anterior bulging of the corneal contour. Focal posterior corneal changes were also seen in two of three cases. Mild anterior uveitis was also present. Other causes of corneal oedema (e.g. glaucoma) were ruled out based on presentation and clinical examination. Treatment approaches were medical and included various combinations of prophylactic topical antimicrobial therapy in case of secondary corneal ulceration, anti-inflammatory therapy for uveitis, targeted oedema therapy with topical hypertonic saline and corneal cross-linking, and placement of a temporary partial tarsorrhaphy for corneal tamponade. The outcome was excellent in all cases, with rapid resolution of the ocular changes. Acute corneal hydrops of presumed traumatic Descemet's membrane rupture origin should be considered in cases of young horses presenting with acute corneal oedema. However, further studies are warranted to better characterise the disease and to try to confirm the suspected aetiology.

Clinical findings associated with blunt ocular trauma in horses: a retrospective analysis

“…Signs seen with previously reported blunt orbital and ocular trauma in equids include orbital fracture, 7,9–12 eyelid lacerations and swelling 8,11,13 subconjunctival hemorrhage, chemosis, corneal abrasion, hyphema, 3–5,7,8,10,11,13,14 Descemet's membrane separation, 15 uveitis, 5,7,11,14,16 avulsed corpora nigra, 5,16,17 lens subluxation or luxation, 5,7,11,12 phacoceles, 13 cataract development, 7,9,14,18 vitreal hemorrhage, 11 retinal hemorrhage, 11 retinal tears or detachments, 11,19 scleral ruptures, 5,7–9 and secondary glaucoma 14…”

“…No further differentiation was made as to the location or severity of the edema in this study. A recent publication by O’Leary et al (2021) describes acute corneal hydrops secondary to Descemet's membrane rupture following suspected traumatic events, including one case with concurrent iridodialysis 15 22 Descemet's membrane rupture or separation, 15,27 and equine recurrent uveitis.…”

“…Iridodialysis, previously reported anecdotally in the veterinary literature, is defined as separation of the peripheral iris from its insertion at the sclera 2,5,15,35 . Cyclodialysis is an extension of this injury to include separation of the iris and pars plicata portion of the ciliary body from the sclera 2 .…”

Application of a modified nictitating membrane flap in a fledgling feral pigeon (Columba livia domestica) with bullous keratopathy

“…The pathogenesis of BK remains unknown; however, the suggested theories in veterinary patients, including dogs, cats, and horses, are commonly related to the breakdown of the corneal endothelial and epithelial barrier, which control fluid influx into the cornea. [1][2][3][4] Although the cause of BK in this case could not be clearly determined because of the lack of histopathologic examination, the initial development of BK was presumed to be induced by uncontrolled corneal ulcer and uveitis. The primary or secondary corneal infection resulted in a melting keratitis, which exacerbated the corneal edema.…”

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Decompensated corneal endothelium and epithelium against aqueous humor and tears, respectively, caused by numerous factors, such as trauma, uveitis, glaucoma, drug toxicity, infection, and age-related degeneration, lead to bullous keratopathy (BK), which is an excessive accumulation of fluid in the cornea, resulting in severe edema and protrusion. [1][2][3][4] Surgical treatments for BK in dogs, cats, and horses include temporary tarsorrhaphy, nictitating membrane flap (NMF), thermokeratoplasty (TKP), collagen cross-linking, amniotic membrane transplantation, superficial keratectomy and conjunctival advancement hood flap (SKCAHF), and Descemet stripping endothelial keratoplasty (DSEK). Medical treatment for BK includes hyperosmotic sodium chloride therapy, which induces osmotic withdrawal of fluid from the cornea.

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