Дистрофия Фукса: симптомы, диагностика и лечение роговичной эндотелиальной дистрофии.

Fuchs dystrophy, also referred to as Fuchs endothelial corneal dystrophy (FECD) and Fuchs endothelial dystrophy (FED), is a slowly progressing corneal dystrophy that usually affects both eyes and is slightly more common in women than in men. Although early signs of Fuchs dystrophy are sometimes seen in people in their 30s and 40s, the disease rarely affects vision until people reach their 50s and 60s.

As a progressive, chronic condition, signs and symptoms of Fuchs dystrophy gradually progress over decades of life, starting in middle age. Early symptoms include blurry vision upon wakening which improves during the morning, as fluid retained in the cornea is unable to evaporate through the surface of the eye when the lids are closed overnight. As the disease worsens, the interval of blurry morning vision extends from minutes to hours. In moderate stages of the disease, an increase in guttae and swelling in the cornea can contribute to changes in vision and decreased sharpness throughout the day. Contrast sensitivity may be affected. The change in the refractive index of the cornea may result in subtle refractive shifts, which affected individuals may experience as a small change in their eyeglass prescription. In the late stages of the disease, the cornea is unable to maintain its fluid content and blisters, known as bullae, form on the surface of the cornea. These cause foreign body sensations and can be painful. The cornea may not heal from such epithelial defects, until corneal transplantation is able to restore the endothelial pump function.

The diagnosis of Fuchs dystrophy is often made with slit lamp biomicroscopy. With direct illumination, the clinician can visualize guttae, the characteristic pathological changes in disease. Scheimpflug imaging, anterior segment optical coherence tomography, confocal microscopy, and specular microscopy are additional imaging techniques that can identify the presence of guttae and quantify the thickness of the cornea. While corneal thickness can be a valuable indicator of how the cornea is changing over time, it is affected by multiple factors and is not adequate itself as a screening tool to diagnose Fuchs dystrophy.

Non surgical treatments of FECD may be used to treat symptoms of early disease. Medical management includes topical hypertonic saline, the use of a hairdryer to dehydrate the precorneal tear film, and therapeutic soft contact lenses. Hypertonic saline draws water out of the cornea through osmosis. When using a hairdryer, the patient is instructed to hold it at an arm's length or directed across the face in a cold setting, to dry out the epithelial blisters. This can be done two or three times a day. Scleral lenses can improve vision when it is affected by irregularities on the surface of the cornea, but may stress the corneal endothelium. Corneal transplantation is the definitive treatment for FECD. The most common types of surgery for FECD are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), which account for over half of corneal transplants in the United States. Injection of cultured endothelial cells is under investigation and in a series of 11 patients in Japan with bullous keratopathy, was able to clear corneal edema.

Few studies have examined the prevalence of FECD on a large scale. First assessed in a clinical setting, Fuchs himself estimated the occurrence of dystrophia epithelialis corneae to be one in every 2000 patients; a rate that is likely reflective of those who progress to advanced disease. Cross sectional studies suggest a relatively higher prevalence of disease in European countries relative to other areas of the world. Fuchs dystrophy rarely affects individuals under 50 years of age. A shift to the understanding of FECD as primarily a disease of the corneal endothelium resulted after a number of observations in the 1920s. Crystal like features of the endothelium were noted by Kraupa in 1920, who suggested that the epithelial changes were dependent on the endothelium. Using a slit lamp, Vogt described the excrescences associated with FCD as drop like in appearance in 1921. In 1924, Graves then provided an extremely detailed explanation of the endothelial elevations visible with slit lamp biomicroscopy. A patient with unilateral epithelial dystrophy and bilateral endothelial changes was described by the Friedenwalds in 1925; subsequent involvement of the second eye led them to emphasize that endothelial changes preceded epithelial changes. As only a subset of patients with endothelial changes proceeded to epithelial involvement, Graves stated on 19 October 1925 to the New York Academy of Medicine that "Fuchs' epithelial dystrophy may be a very late sequel to severer cases of the deeper affection".