Topical Ascorbate Administration in Severe Ocular Burns

Background

Euphorbia is a plant family of more than 2000 species growing all around the globe. The sap of many Euphorbia plants is highly toxic and has been reported to cause severe inflammatory reactions on contact with the skin or the ocular surface [1]. Typical findings include pain, photophobia, and diminished visual acuity as well as epithelial defects, stromal edema, Descemetʼs membrane folds, and anterior uveitis. The dimensions of the damage and the clinical course may vary depending on the type of plant and the extent of exposure [1]. While many patients fully recover within 1 – 2 weeks, negligence of proper treatment can lead to severe keratouveitis, corneal scarring, and, subsequently, to permanent blindness [2].

Up to 18% of traumatic injuries to the eye are associated with chemical and thermal burns [3]. According to the clinical signs, ocular burns are graded using the Roper Hall (grade 1 – 4) or Dua (grade 1 – 6) classification system. While some of these injuries are trivial and do not cause any persistent limitations, others are followed by severe and lasting visual restrictions [3].

Immediate eye rinsing is the undisputable primary therapeutic measure after chemical eye burn, as the toxic agent may penetrate the bulb within minutes. Anti-inflammatory treatment and antibiotic prophylaxis later on are also uncontroversial [3]. When conservative measures have failed, surgery has to be considered, including amniotic membrane and limbal stem cell transplantation or even keratoplasty [4]. In some cases, severe ocular surface disease, corneal blindness, and enucleation, unfortunately, cannot be prevented despite all efforts.

Ascorbate is considered to be important with respect to wound healing and prevention of corneal ulceration [5]. After an ocular burn, the disposability of ascorbate in the aqueous humor and the cornea may be reduced for weeks [6]. Topical and systemic administration of ascorbate is hence a supportive conservative treatment option mentioned in the literature [7]. Topical administration has shown favorable results in animal studies [6]. However, there is only a small amount of evidence regarding its use in humans [7], [8]. To the very best of our knowledge, no ascorbate eye drops are commercially available.

• References

• 1 Eke T, Al-Husainy S, Raynor MK. The spectrum of ocular inflammation caused by euphorbia plant sap. Arch Ophthalmol 2000; 118: 13-16
• 2 Sofat BK, Sood GC, Chandel RD. et al. Euphorbia royleana latex keratitis. Am J Ophthalmol 1972; 74: 634-637
• 3 Kuckelkorn R, Schrage N, Keller G. et al. Emergency treatment of chemical and thermal eye burns. Acta Ophthalmol Scand 2002; 80: 4-10
• 4 Wright P. The chemically injured eye. Trans Ophthalmol Soc U K 1982; 102: 85-87
• 5 Chen J, Lan J, Liu D. et al. Ascorbic acid promotes the stemness of corneal epithelial stem/progenitor cells and accelerates epithelial wound healing in the cornea. Stem Cells Transl Med 2017; 6: 1356-1365
• 6 Pfister RR, Paterson CA. Ascorbic acid in the treatment of alkali burns of the eye. Ophthalmology 1980; 87: 1050-1057
• 7 Mackway-Jones K, Marsden J. Ascorbate for alkali burns to the eye. Emerg Med J 2003; 20: 465-466
• 8 Brodovsky SC, McCarty CA, Snibson G. et al. Management of alkali burns: an 11-year retrospective review. Ophthalmology 2000; 107: 1829-1835
• 9 Pfister RR, Paterson CA, Hayes SA. Topical ascorbate decreases the incidence of corneal ulceration after experimental alkali burns. Invest Ophthalmol Vis Sci 1978; 17: 1019-1024
• 10 Petroutsos G, Pouliquen Y. Effect of ascorbic acid on ulceration in alkali-burned corneas. Ophthalmic Res 1984; 16: 185-189