Florida keratopathy

Florida keratopathy (Florida spots) is an eye condition characterized by the presence of multiple spots within both corneas. It is most commonly seen in dogs and cats, but is also rarely seen in horses and birds. In the United States, Florida keratopathy is found in animals in the southeastern part of the country. In other parts of the world it is confined to tropics and subtropics, and it is known as tropical keratopathy.^[1]

Florida keratopathy appears as multiple cloudy opacities in the stromal layer of the cornea. The spots appear concentrated at the center and become more diffuse at the periphery. They can range in size from one to eight millimeters.^[2] There are no other symptoms, and there is no response to treatment with either anti-inflammatory or antimicrobial drugs. Histological analysis of affected corneas has found acid-fast staining organisms, suggesting Florida keratopathy may be caused by a type of mycobacterium.^[2]

There is a strong suspicion that it is induced by repeated stings to the eyes by Wasmannia auropunctata the Little Fire Ant, an invasive species.

French Polynesia example of a Wasmannia auropunctata linked keratopathy (WALK) in cats

^[3]

Since the early 90’s, the Little Fire Ant, Wasmannia auropunctata, has been officially established in French Polynesia. The Polynesian government has been actively fighting it since 2005, partially through the mapping of known colonies. This plague is well known in several countries at the equatorial, tropical and subtropical areas, because it is the cause of serious disturbances of ecosystems, agricultural losses and considerable physical threats (due to venom). Those threats and losses were described in countries like New Caledonia (Sadler and Bauer, 2001; Le Breton, 2003), Vanuatu islands (Jourdan et al., 2002), Solomon Islands (Wetterer, 1997), Gabon (Walsh and White 1999; Wetterer et al., 1999; Walker, 2006), Galapagos (Silberglied, 1972; Lubin, 1984), Cuba (Cateineras and Noyra, 1993), Columbia (Armbrecht and Ulloa-Chacon, 2003), and Brazil (Delabie, 1989). One major symptom is referred by several authors as a progressive blindness syndrome on both mammalian and non-mammalian animals. The references to such injuries is documented as “Florida spots”, “Florida keratitis/keratopathy” or “tropical keratopathy” (Roze et al., 2004; Moore, 2005). Though it is clear that literature had reported this observation several times, no scientific work had proven it.

So during the mapping of the colony spreading, we discovered that contaminated areas were also sheltering endemic hearths of Florida keratopathy. We studied 24 cases of keratopathy and 12 control cases within the mega-colony settled in the Mahina commune’s highs (Tahiti). After analysis, we pointed that the threatened animals are those living in contact with the ants (К² >12 within studied Pets cases). Apart from this predisposing factor, we did not find any other characteristic facilitating this pathology outbreak (age, sex, viral status regarding Feline leukosis). We highlighted: 1) symptoms of acute attack such as blepharospasm and whimpering; 2) Topography of injuries shows that the eye median area is the most affected (p<0,05); 3). Though the pathophysiologic model is not already understood, we believe, as many authors previously cited that the most probable etiologic agent of this pathology is Wasmannia auropunctata.

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