Study of the vitreous microbiota in patients with diabetic macular edema (first results)

Purpose. To study the vitreous microbiota in patients with diabetic macular edema (DME) using a bacteriological method. Material and methods. The study included 48 patients (49 eyes) who were treated at the Ufa Research Institute of Eye Diseases, who were divided into 2 groups. The average age of the patients was 62.4±4.5 years. The number of women is 25 (52%), men – 23 (48%). Group 1 of the study included 28 patients (29 eyes) with DME, of which 20 patients (21 eyes) had a non-proliferative stage of diabetic retinopathy, and 8 patients had a proliferative stage. Group 2 (comparison group) consisted of 20 patients with fresh rhegmatogenous retinal detachment and through macular holes. In all patients, vitreous humor was collected in a volume of 400 μl under sterile operating room conditions. To determine the composition of the microbiota of the vitreous body, the classical culture method was used. Results. As a result of inoculating vitreous samples on nutrient media, growth of bacteria of the genus Bacillus (B. megaterium and B. pumilus) was detected in 2 patients from group 1, and growth of Escherichia coli and Staphylococcus hominis was detected in another 1 patient. In patients of group 2 (control group), there was no bacterial growth on nutrient media in all cases. The low frequency of detection (in only 3 patients) of bacterial isolates in clinical material may be due to the peculiarities of cultivation and the need for special conditions for the growth of bacteria from the vitreous body. Conclusion. The identified microbiota in the group of patients with diabetic retinopathy and the presence of DME may indicate the nonsterility of the intraocular media and the presence of a certain composition of the microbiota, which, it is possible, plays a certain pathogenetic role in the development of macular edema. Key words: diabetes mellitus, diabetic macular edema, vitreous body, microbiota, bacteriological method