Florida keratopathy
Encyclopedia
Florida keratopathy is an eye
condition characterized by the presence of multiple spots within both cornea
s. It is most commonly seen in dog
s and cat
s, but is also rarely seen in horse
s and bird
s. 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.
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. 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
.
There is a strong suspicion that it is induced by repeated stings of Wasmannia auropunctata to the eyes, the Little Fire Ant, an invasive
species.
, 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 pathopysiologic model is not already understood, we believe, as many authors previously cited that the most probable etiologic agent of this pathology is Wasmannia auropunctata.
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
condition characterized by the presence of multiple spots within both cornea
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
s. It is most commonly seen in dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s and cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, but is also rarely seen in horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...
s and bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Florida keratopathy is found in animals in the southeastern part of the country. In other parts of the world it is confined to tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
and subtropics
Subtropics
The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
, and it is known as tropical keratopathy.
Florida keratopathy appears as multiple cloudy opacities
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc...
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. There are no other symptoms, and there is no response to treatment with either anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
or antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
drugs. Histological
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
analysis of affected corneas has found acid-fast
Acid-fast
Acid-fastness is a physical property of certain bacteria, specifically their resistance to decolorization by acids during staining procedures.Acid-fast organisms are difficult to characterize using standard microbiological techniques Acid-fastness is a physical property of certain bacteria,...
staining organisms, suggesting Florida keratopathy may be caused by a type of mycobacterium
Mycobacterium
Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. The genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy...
.
There is a strong suspicion that it is induced by repeated stings of Wasmannia auropunctata to the eyes, the Little Fire Ant, an invasive
Invasive
Invasive may refer to:*A military invasion*An invasive species*An invasive medical procedure*The invasively progressive spread of disease from one organ in the body to another, especially in reference to cancer...
species.
French Polynesia example of a Wasmannia auropunctata linked keratopathy (WALK)
Since the early 90’s, the Little Fire Ant, Wasmannia auropunctataElectric ant
The electric ant, also known as the little fire ant, Wasmannia auropunctata, is a tiny , light to golden brown social ant native to Central and South America, now spread to parts of Africa , North America, Puerto Rico, Israel, and six Pacific Island groups The electric ant, also known as the...
, 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 pathopysiologic model is not already understood, we believe, as many authors previously cited that the most probable etiologic agent of this pathology is Wasmannia auropunctata.