Background: The problem of access to medical information, particularly in low-income countries, has been under discussion for many years. Although a number of developments have occurred in the last decade (e.g., the open access (OA) movement and the website Sci-Hub), everyone agrees that these difficulties still persist very widely, mainly due to the fact that paywalls still limit access to approximately 75% of scholarly documents. In this study, we compare the accessibility of recent full text articles in the field of ophthalmology in 27 established institutions located worldwide. Methods: A total of 200 references from articles were retrieved using the PubMed database. Each article was individually checked for OA. Full texts of non-OA (i.e., “paywalled articles”) were examined to determine whether they were available using institutional and Hinari access in each institution studied, using “alternative ways” (i.e., PubMed Central, ResearchGate, Google Scholar, and Online Reprint Request), and using the website Sci-Hub. Results: The number of full texts of “paywalled articles” available using institutional and Hinari access showed strong heterogeneity, scattered between 0% full texts to 94.8% (mean = 46.8%; SD = 31.5; median = 51.3%). We found that complementary use of “alternative ways” and Sci-Hub leads to 95.5% of full text “paywalled articles,” and also divides by 14 the average extra costs needed to obtain all full texts on publishers’ websites using pay-per-view. Conclusions: The scant number of available full text “paywalled articles” in most institutions studied encourages researchers in the field of ophthalmology to use Sci-Hub to search for scientific information. The scientific community and decision-makers must unite and strengthen their efforts to find solutions to improve access to scientific literature worldwide and avoid an implosion of the scientific publishing model. This study is not an endorsement for using Sci-Hub. The authors, their institutions, and publishers accept no responsibility on behalf of readers.

Purpose: To conduct a morphological study of structural changes in the nasolacrimal duct in secondary acquired nasolacrimal duct obstruction (SALDO) as a result of treatment with radioiodine. Methods: Twenty patients (20 cases) were involved: 10 cases with secondary acquired nasolacrimal duct obstruction at Hasner’s valve level due to the treatment with radioiodine (group 1) and 10 cases with primary acquired nasolacrimal duct obstruction (group 2). During surgery, a biopsy of nasolacrimal duct tissue from Hasner’s valve area was taken. A morphological study was performed using semi-fine sections technique. Results: Patients of group 1 showed the following: desquamation of columnar epithelium, pinpoint ulceration of nasolacrimal duct wall, collapse of a significant part of the capillary bed, and absence of blood cells in their lumen. State of secretory cells of mucous glands varied from necrobiotic to the different stages of dystrophic, decreased lumens of acini with abundant microvesicles in cell cytoplasm were revealed. A specific sign noted in patients of group 2 was mixed inflammatory infiltration of the mucosa of the nasolacrimal duct. The picture corresponds to the exacerbation of a chronic inflammatory process. Conclusions: Changes revealed in patients of group 1 include desquamation of nasolacrimal duct epithelium, mucous gland lesion, and moderate fibrosis that indicate a probable primary character of the lesion. In patients of group 2, fibrotic changes were more significant and were due to a chronic inflammatory process. Thus, secondary acquired nasolacrimal duct obstruction after treatment with radioactive iodine has a specific pathogenesis and should be classified as a separate nosological form.

To study the antifibrotic effectiveness of mitomycin-C in the tissues of the ostium site after it application for endonasal endoscopic dacryocystorhinostomy. The study included 45 patients (48 cases) with primary obstruction of the nasolacrimal duct. All patients underwent endoscopic endonasal dacryocystorhinostomy (EEDCR). At the final stage of the operation, a swab with MMC was placed in the region of the formed ostium at a concentration of 0.2 mg/ml for 3 min. An ostium was not intubated. After that, biopsies of the mucous of the nasal cavity and lacrimal sac were performed to study the morphological changes that occur in the tissues overtime, as well as to calculate the concentration of the drug in the tissues. According to the chemical analysis, the concentration of MMC immediately after application was 0.626 ± 0.176 μg/g; after 30 min the concentration of the drug was reduced to 0.23 ± 0.06 μg/g; a day after the operation the drug was not found in the tissue samples. Morphological study established that the repair processes occurring in the mucosa of the nasal cavity and the lacrimal sac after EEDCR are similar to the reparative processes without the use of MMC. The effectiveness of surgical treatment: "positive results" - 77.1% of cases, "relapses" - 22.9% of cases. Application of MMC for prevention of excessive scarring after EEDCR is impractical as it is not possible to achieve antifibrotic concentration of the drug at dacryocystorhinostomy ostium site using this method.

Background: Radioiodine ablation is a frequent procedure for the management of thyroid cancer. In several cases, this treatment is followed by secondary acquired nasolacrimal duct obstruction (SALDO). Risk factors for the development of SALDO are not defined yet. Aim – to provide clinical and demographic characteristics of tearing in patients after radioiodine treatment. Materials and methods: Material was obtained by a phone survey of 588 patients who underwent radioiodine treatment. Age and gender of the respondent, strength of administered medication, and time since the end of treatment were taken into account. Patients were asked if they had dry mouth and/or tearing at the time of the survey. Differences in values were found using parametric and nonparametric criteria, Pearson’s χ² test. Differences were considered statistically significant at p ≤ 0.05. Results: Severe tearing was reported by 8.8% of patients after single-dose radioiodine treatment and 23.9% of patients after repeated one. The age of patients with severe tearing and without it showed statistically significant difference in patients after single-dose radioiodine treatment and no statistically significant difference in patients after repeated radioiodine treatment. Administration of 4 GBq or more in patients aged 61–71 years results in 4-fold increase of the risk of severe tearing. Dry mouth causes 3.6-fold increase of the risk of developing severe tearing. Conclusion: Finding risk factors for SALDO development after radioiodine therapy in the future will contribute to an individualized approach to the prevention of this complication. Development of preventive measures is one of the tasks facing researchers.

Medical article медицинская статья

To compare the effectiveness of balloon dacryoplasty (DCP) for stenoses at different levels of the vertical portion of lacrimal pathways and to establish the necessity of consequent intubation.