In a study supported by the Swedish-Norwegian Foundation for Equine Research, Anna Hellander-Edman, et. al, addressed corneal cross-linking in 9 horses with ulcerative keratitis to see if corneal cross-linking could be performed in sedated, standing horses with ulcerative keratitis with or without stromal melting.
Treating eye diseases in horses
A recent study addressed corneal cross-linking in 9 horses with ulcerative keratitis to see if corneal cross-linking could be performed in sedated, standing horses with ulcerative keratitis.
Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers.
Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients.
Therefore we decided to study if CXL can be performed in sedated, standing horses with ulcerative keratitis with or without stromal melting.
Results of study of ulcerative keratitis in horses
Nine horses, aged 1 month to 16 years (median 5 years) were treated with a combination of CXL and medical therapy. Two horses were diagnosed with mycotic, 5 with bacterial and 2 with aseptic ulcerative keratitis. A modified Dresden-protocol for CXL could readily be performed in all 9 horses after sedation.
Stromal melting, diagnosed in 4 horses, stopped within 24 h. Eight of nine eyes became fluorescein negative in 13.5 days (median time; range 4–26 days) days after CXL. One horse developed a bacterial conjunctivitis the day after CXL, which was successfully treated with topical antibiotics. One horse with fungal ulcerative keratitis and severe uveitis was enucleated 4 days after treatment due to panophthalmitis.
Conclusions
CXL can be performed in standing, sedated horses. We did not observe any deleterious effects attributed to riboflavin or UVA irradiation per se during the follow-up, neither in horses with infectious nor aseptic ulcerative keratitis.
These data support that CXL can be performed in the standing horse, but further studies are required to compare CXL to conventional medical treatment in equine keratitis and to optimize the CXL protocol in this species.
Authors’ contributions
AHE conceived the study, performed ophthalmic examinations and CXL treatments, analysed the data and helped to draft the manuscript. KM provided advice regarding the CXL protocol and helped to draft manuscript. JM proposed the CXL protocol and assisted when CXL was performed. BE helped with the study design, analysis of results and to draft the manuscript. All authors read and approved the final manuscript.
Acknowledgments
The study was supported by the Swedish-Norwegian Foundation for Equine Research. Peschke Meditrade GmbH is acknowledged for generously providing a CCL-365 UVA-light source during the study.
© 2013 Hellander-Edman et al.; licensee BioMed Central Ltd.
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