Factors contributing to the occurrence and development of corneal meltdown (keratolysis) in small pets

Abstract

Keratolysis (corneal melting) is an urgent inflammatory-infected condition which is accompanied by the involvement of all layers of the cornea in the pathological process. One of the main complications for the eye is the perforation of the cornea due to the melting of its material (type I and IV collagen). Despite of the available research in the field of diagnosis and treatment of animals with keratolysis, there are no scientifically substantiated data in domestic ophthalmology concerning the occurrence and development of this disease. This paper discusses the risk factors for the occurrence and development of autoimmune keratolysis in small pets, and shows the role of physiological barriers of the eye (precorneal tear film and total tear production indices) in the pathogenesis of the disease and the influence of the location of the ulcerative process in the development of the pathological process. It was revealed that dogs and cats of brachiocephalic breeds older than nine years with a central location of the process (a long-term non-healing ulcer) are most often ill. Based on the use of functional testing and vital dyes, decrease of the function of the physiological barriers of the anterior segment of the eye was revealed expressed in decrease of total tear production and violation of the epithelial barrier which is an indicator of impaired metabolic processes in the cornea and accumulation of under-oxidized products, proteolytic enzymes in the conjunctival cavity and on the surface of the cornea. Despite the acute clinical signs (clouding and violation of the integrity of the cornea), hypofunction of conjunctival goblet cells, decreased tear production, absence of precorneal tear film and destruction of the epithelial-endothelial barrier were revealed.