The Relationship of the Flavobacterium Ophthalmiae to Periodic Ophthalmia in Horses.

The research investigated the role of a specific bacterium, Flavobacterium Ophthalmiae, in causing Periodic Ophthalmia, a recurrent condition causing blindness in horses. The study aimed to confirm whether there was indeed a causal relationship between this bacterium and the disease.

Overview of the Disease

• Periodic Ophthalmia, also known as moon blindness, is essentially a recurrent inflammation of the uvea – the middle layer of the eye that consists of the iris, ciliary body, and choroid. This disease is frequent in horses and less frequent in cattle.
• The disease tends to cause blindness and represents a significant problem in various regions, affecting large populations of horses.

Symptoms and Development of the Disease

• The disease initiates with a slight irritation of the uveal region, minor eye watering (lacrimation), and swelling (edema) of the area surrounding the orbit (peri-orbital fold).
• The cornea becomes mildly hazy and the pattern of the iris gets blurred. The eye’s pupil constricts and adhesions develop between the iris and the lens (posterior synechiae). The clear fluid in the front of the eye (aqueous humor) becomes cloudy and then murky, and there is exudation in the eye’s vitreous humor.
• The inner surface of the eye (the fundus) displays signs of increased blood flow (hyperemia), and while clear exudates are rarely found in the choroid layer and retina, they may form with disease progression.
• The initial attack of the disease lasts for a few days, after which the eye returns to normal with the possible exceptions of signs from the previous inflammation such as the posterior synechiae and vitreous opacities.
• These remissions can last from a few weeks up to several months, after which the disease flares up again. Most commonly, both eyes are affected by this condition.

Role of Flavobacterium Ophthalmiae

• The study highlights the newly discovered organism, Flavobacterium Ophthalmiae, proposed by Dr. E. C. Rosenow, as a potential causal agent for Periodic Ophthalmia.
• The central aim of this study was to validate whether Flavobacterium Ophthalmiae’s etiological relationship to the disease can be confirmed or refuted.