CANINE AND FELINE KERATOMALACIA TREATED WITH CO2 LASER Ana Calado Lopes 1, Luís Filipe Carvalho 2 1 – Escola Universitária Vasco da Gama, Av. José R. Sousa Fernandes 197, Lordemão, 3020-210 Coimbra. 2 – Hospital Veterinário da Marinha Grande, R. Dom João Pereira Venâncio 7, 2430-291 Marinha Grande. Introduction - Canine and feline keratomalacia is a painful Objective - This study aims to evaluate the treatment outcome of and rapidly progressive corneal disease of infectious or CO2 laser in 25 animals, 19 dogs (mean age of 6,2 years +/- 5,1 non-infectious origin (Ion, Lonascu, & Birtoiu, 2015) whose years) and 6 cats (mean age of 6,5 years +/- 6,1 years) with medical and surgical management have unreliable keratomalacia of unknown etiology and variable severity, size, outcomes (Kokuti, 2019, Ion et al., 2015). Highly precision duration and deepness. CO2 laser surgery in keratomalacia patients is an innovative Materials and Methods - Laser surgery consisted of CO2 laser and poorly documented method, not fully consensual, that excimer 2 W (power range), repeat pulse mode of 10Hz, 5 msec, enables damaged cells vaporization with minor 5%, size tip of 0,4 mm, focused at 1 to 3 mm from the selected inflammatory onset (Gilmour, 2003). tissue, until its vaporization. A third eyelid-scleral pexia was placed over two weeks. Support treatment with topical Protease tobramycin, artificial tears QID and pain relief (cats - meloxicam Bacteria Neutrophils inhibitors 0,1mg/Kg SID; dogs carprofen 4mg/Kg SID, PO) were administered for three days. After suture removal cornea was clinically controlled. Results - All animals recovered from keratomalacia after third Proteolytic enzymes eyelid suture removal. Corneal regeneration and transparency was almost completely achieved in dogs (Figure 1) over Keratomalacia 20,37 days +/-8,7 days and in cats over 24,0 days +/-6,1 days. Both keratomalacia and mild associated edema (Figure 2) and chronic keratitis with collagenolysis (Figure 3) fully recovered. A A A B B B Figure 1 – Canine right keratomalacia. Figure 2 – Canine left keratomalacia. Figure 3 – A) Canine left eye chronic keratitis A) Fluorescein positive area is identified (red A) Fluorescein positive area is identified (red with axial granulation tissue surrounded by line) before CO2 laser surgery and associated line) before CO2 laser surgery with mild collagenolytic tissue. B) Post-surgical healthy and corneal edema is noticed. B) Two-week post- associated corneal edema. B) Two-week post- regular transparent cornea, two weeks after CO2 surgical control exhibits transparent cornea with surgical control exhibits healthy and regular laser treatment. mild scar tissue. transparent cornea. Discussion – CO2 laser surgery is able to promote Conclusion – CO2 laser surgery is a highly satisfactory safe and keratomalacia fully recovery, preserving healthy tissues, consistent method to treat keratomalacia of unknown origin in due to damaged cells ablation by vaporization, minimizing canine and feline patients of all ages. inflammatory response. This outcome is independent on ulcer etiology and severity, patient age and preexistent Acknowledgments - We thank to Dr. Pedro Tralhão for his underlying diseases. contribution to this work. Bibliography Gilmour, M. A. (2003). Laser applications for corneal disease. Clin Tech Small Anim Pract, 18(3), 199-202. doi:10.1016/s1096-2867(03)90017-x Ion, L., Lonascu, L., & Birtoiu, A. (2015). Melting keratitis in dogs and cats. Agriculture and Agricultural Science Procedia, 6, 342 – 349 Kokuti, R. (2019). Medical treatment of keratomalacia in a cat. Veterinary Record Case Reports, 7: e000820. doi:doi: 10.1136/vetreccr-2019-000820 McGavin, M. D. Z., J. F. (2017). The eye. In Elsevier (Ed.), Pathologic Basis of Veterinary Disease (6 ed., pp. 1265). St. Louis.