To study antibiotic resistance patterns and susceptibility to eye antiseptic picloxydine of conjunctival flora in patients undergoing intravitreal injections (IVIs). Conjunctival swabs were taken in 4 groups of patients, 20 patients in each group (n=80): without IVIs and ophthalmic operations in history (group N1; control group); with the first IVI and antibiotic eye drops Tobrex applied 3d before IVI and 5d after it (group N2); with 20 or more IVIs and repeated courses of antibiotic eye drops (group N3); with the first IVI and antiseptic eye drops Vitabact (picloxydine) applied 3d before IVI and 5d after it (group N4). In groups N2 and N4 swabs were taken at baseline and after the treatment. Efficacy of picloxydine in inhibition of growth of conjunctival isolates susceptible and resistant to antibiotic was studied in vitro. Minimal inhibition concentrations (MIC) were determined with microdilution test. Two of the three patients who had to undergo the IVI procedure showed conjunctiva bacterial contamination. Along with few Staphylococcus aureus and Gram-negative isolates susceptible to most antibiotics, the majority (71%-77%) of causative agents were coagulase-negative Staphylococci (CoNS), 40%-50% of which were multidrug resistant (MDR). Eye disinfection in the operating room and peri-injection courses of Tobrex or Vitabact resulted in total elimination of isolates found at baseline. However, in 10% and 20% of patients, respectively, recolonization of the conjunctiva with differing strains occurred. In patients with repeated IVI and Tobrex/Maxitrol treatment, the conjunctival flora showed high resistance rates: 90% of CoNS were MDR. In the in vitro study, picloxydine showed bactericidal effect against Staphylococci isolates both antibiotic resistant and susceptible with MIC≥13.56 µg/mL. Incubation of bacteria for 15min in Vitabact eye drops, commercially available form of picloxydine, 434 µg/mL, showed total loss of colony forming units of all tested isolates including Pseudomonas aeruginosa. The confirmed efficacy of eye antiseptic picloxydine against conjunctival bacterial isolates and the presence of its commercial form, 0.05% eye drops, convenient for use by patients before and after injection, make this eye antiseptic promising for prophylaxis of IVI-associated infectious complications.
Background. Coagulase-negative staphylococci (CNS), primarily Staphylococcus epidermidis, predominate in the normal microflora of the eye. However, due to irrational antibiotic therapy, resistant strains are widely distributed among CNS. Objective. To study the sensitivity of the antibiotic resistant CNS isolates to the antiseptic picloxydine dihydrochloride ("Vitabact"). Methods. Species, sensitivity to antibiotics and antiseptic picloxydine dihydrochloride were determined for 39 isolates of bacteria obtained from the conjunctival swabs. The cells morphology under the influence of antiseptic was studied by electron microscopy. Results. 33 isolates of S. epidermidis (17 sensitive or resistant to drugs of no more than 2 classes of antibiotics and 16 MDR), 2 S. haemolyticus (1 resistant to 2 classes of antibiotics and 1 MDR), 3 S. hominis (1 sensitive and 2 MDR), 1 S. caprae (MDR) were characterized. In vitro tests, the antiseptic picloxydine dihydrochloride showed high efficiency in suppressing the growth of staphylococci regardless of their sensitivity to antibiotics, as well as bactericidal activity at concentration of 31.2 g/ml. In this concentration, the antiseptic had a pronounced destructive effect on the surface structures of bacterial cells. Conclusion. Antiseptic picloxydine dihydrochloride is effective against antibiotic resistant coagulase-negative staphylococci.
Background: Age plays a primary role in the development of age-related macular degeneration (AMD). Telomere length (TL) is one of the most relevant biomarkers of aging. In our study, we aimed to determine the association of TL with T lymphocytes, B lymphocytes, NK cells or monocytes with different forms of AMD. Methods: Our study included 62 patients with AMD: geographic atrophy (GA), neovascular AMD (NVAMD) with and without macular atrophy and 22 healthy controls. Each leukocyte subtype was isolated from peripheral blood by immunomagnetic separation, and the DNA was purified. The TL in the genomic DNA was determined using qPCR by amplifying the telomere region with specific oligonucleotide primers and normalizing to the control gene. Statistical analysis was performed using R version 4.5.1. Results: We observed a statistically significant increase in TL in the T cells between the control and NVAMD groups but not for the GA group. The B cells and monocytes showed a significant decrease in TL in all AMD groups. The TL in the NK cells did not decrease in any of the AMD groups. Conclusions: The TL in the monocytes had the strongest association with AMD. It reflects a person’s “telomeric status” and may become a diagnostic hallmark of these degenerative processes.
Вследствие увеличения продолжительности жизни глобальные темпы старения быстро растут, растет количество возрастных заболеваний, в том числе заболеваний органа зрения. У людей старше 50 лет наиболее распространенными заболеваниями глаз являются возрастная макулярная дегенерация, катаракта, глаукома и диабетическая ретинопатия. Для своевременной и эффективной терапии возрастных заболеваний глаз необходимо более глубокое понимание клеточных механизмов старения.
29 December 2023 in Russian Annals of Ophthalmology
Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus (DM) and considered one of the leading causes of vision loss worldwide. The choroid supplies blood to the retina, photoreceptors and the retinal pigment epithelium, it is essential for metabolic exchange in the retina. Many experimental studies have reported that choroidal pathology in diabetic patients may play a role in the development of DR. Choroidal thickness (CT) can be used to assess the vascularization of the choroid. Choroidal vascularity index (CVI) is also used as a marker in assessment of choroidal vascularization. Many studies have been conducted to evaluate choroidal changes in various eye diseases. However, the data on CT in DM patients, especially in those with DR, are conflicting. Thus, the choroidal status in diabetic patients with or without DR remains controversial. In this systematic review we analyze a number of articles dedicated to the relationship between structural changes in the choroid in patients with diabetes mellitus and diabetic retinopathy of different stages, paying particular attention to choroidal thickness and certain other parameters that allow assessment of choroidal changes.