Histomorphological Features of Demodecosis of the Eyes

Abstract

The purpose of the study was to present characteristic histomorphological patterns that indicate demodicosis as the main cause of heterogeneous macroscopic changes in eyelid tissues that do not have clinical specifics and are not associated by ophthalmologists with this parasitic disease. Materials and methods. Clinical and morphological analysis covers 8 cases of demodicosis identified during the histological examination of biopsy and surgical material for the period from 2019 to 2022, carried out on the basis of the laboratory of pathological anatomy of the State Institution “The Filatov Institute of Eye Diseases and Tissue Therapy of the National Academy of Medical Sciences of Ukraine”. The surgical biopsy material was processed according to the generally accepted histological technique. In each case, up to 6 serial histological sections stained with hematoxylin-eosin were examined. Results and discussion. Diagnosis of demodicosis in ophthalmology is based on clinical and laboratory research, directed at the manifestation of the parasite itself. The traces of demodectic invasion in the tissues of the appendages of the eye, which may indicate the nature of granulomatous and tumor-like processes, as a rule, become the object of pathomorphological investigation. Histomorphological diagnosis should be based on the identification of a pathognomonic picture: characteristic cysts at the site of the destroyed sebaceous glands. Against the background of these changes, partially preserved sebaceous glands can be detected, which makes it possible to understand the origin of the patterns, which otherwise can be mistaken for dilated vessels of the sinusoidal or cavernous type, as well as cysts of artificial origin. The presence of foci of dystrophic calcification against the background of cystic ducts can also be considered a pathognomonic picture, but it was found rare. The presence of foci of fibrosis, inflammatory infiltration, including granulomatous, is also characteristic of this pathology, but cannot be the basis for making the correct diagnosis. On the contrary, underestimation of these changes can lead to the omission of the main etiological factor. Understanding the real picture of the prevalence of post-demodectic changes in the eyelids will become possible only with a careful approach to the diagnosis of surgical and biopsy material, taking into account the above histomorphological features. Conclusion. The study showed that post-demodectic changes in the appendages of the eye are quite rare and account for no more than 0.1% of the total volume of biopsy and surgical material, which is tested by a diagnostic study for the above time. However, the real prevalence of this pathology is probably higher, because some patients may not seek medical help without experiencing serious damage to the quality of life or resorting to self-treatment