Corneal collagen crosslinking is one of the most effective methods of prophylactics and treatment of progressive corneal ectasias. In the literature, there are occasional data related to remote results concerning only the most common form of ectasias keratoconus. In published studies, no remote results are met concerning the efficacy of corneal collagen crosslinking in other forms of corneal ectasias, which are now on the rise, including secondary ectasias that became more frequent with refractive surgery. The number of diagnosed cases of pellucid marginal degeneration increased as well. The literature shows no data on comparative analysis of remote results concerning the efficacy of this method in treatment of various forms of corneal ectasias. The aim of the investigation was to evaluate the efficacy of corneal collagen crosslinking based on the analysis of long-term results of this treatment method for various forms of corneal ectasias. Materials and methods. The results of corneal collagen crosslinking in patients with various forms of corneal ectasia 6 years after surgery were analyzed. The nosological structure of the study included patients with keratoconus, pellucid marginal degeneration, and secondary ectasia. The group of patients with keratoconus included 30 patients (30 eyes), that with pellucid marginal degeneration 30 patients (30 eyes), and that with secondary ectasia 30 patients (30 eyes). Corneal collagen crosslinking was performed by the same specialist, during the first or the second year of follow-up. Then changes in the state of the cornea and visual functions were monitored for 6 years. To assess the efficacy, preoperative examination results and interim data were used. Results. In all groups, there was an increase in the best corrected visual acuity, a decrease in the index of asymmetry of the corneal surface and its refractive power in the center of ectasia. However, best corneal collagen crosslinking results were obtained in groups of patients with keratoconus and secondary corneal ectasia.
РЕЗЮМЕ В обзоре представлены данные о так называемых нехирургических методах коррекции кератоконуса (КК). Комплексный подход к корригирующему воздействию на это заболевание роговицы предполагает решение трех основных задач: профилактику прогрессирования, оптическую коррекцию индуцированных рефракционных нарушений и восстановление структурных изменений. Решение первых двух следует расценивать как симптоматическое, а последней-патогенетически ориенти рованное. Кросслинкинг коллагена роговицы и оптическую коррекцию рефракционных нарушений с помощью жестких газопроницаемых склеральных контактных линз следует рассматривать в качестве «нехирургических» методов первого выбора симптоматической коррекции кератоконуса. Ключевые слова: кератоконус, кросслинкинг роговичного коллагена, жесткие газопроницаемые склеральные контактные линзы.
BACKGROUND: One of the purposes of ocular prosthetics is to prevent the progression of pathological processes in the eyelids and conjunctiva of the anophthalmic socket. AIM: The aim of this study is to assess the effectiveness of therapeutic eyelid hygiene products: Blepharowipe, Blepharogel cleansing (Geltek-Medica, Russia), used in the late postoperative and long-term rehabilitation periods, in patients with anophthalmia who lost the eyeball as a result of an injury. MATERIALS AND METHODS: For the study, 3 main (50 patients) and 3 corresponding control groups (50 patients) were created. The examination of patients included: complaints, medical history; biomicroscopy of the eyelids, the conjunctiva of the anophthalmic socket, and the surface of the ocular prosthesis. In the main groups, therapeutic eyelid hygiene products were used for 8 weeks in combination with regular ocular prosthesis care. In the control groups, eyelid hygiene products were not used. Assessment and analysis of the effectiveness of the products was carried out after 1, 2 and 4 weeks in group I and after 4 and 8 weeks in groups II and III based on the dynamics of patient complaints and objective examination indicators. RESULTS: In the main groups I and II, there was a positive dynamics: normalization of the state of the eyelids and the conjunctiva of the anophthalmic socket; increasing comfort of an ocular prosthesis wear. In the main group III and in all control groups, no significant positive dynamics was noted. CONCLUSIONS: The results of using the products included in the course of therapeutic hygiene of the eyelids: Blepharowipe, Blepharogel cleansing showed high efficiency, and give reason to recommend them in late postoperative and long-term rehabilitation periods in patients with anophthalmia.
Being part of a wide variety of soil invertebrates, earthworms play an important role in soil organic matter (SOM) accumulation, mixing and transformation. The goal of this study is to detect organic and mineral particles in the particle-size distributions (PSD) of the casts of Aporrectodea caliginosa and Lumbricus rubellus. The two hypotheses of this study are as follows: (a) earthworms change PSD by grinding organic matter (OM), and (b) PSD without OM does not vary in all the variants. For the first time ever, the authors studied PSD before and after OM oxidation in casts. For the first time ever, they also described the increase in the content of mineral particles in the casts of A. caliginosa and L. rubellus that was not observed in the control samples. The soil did not contain particles of >100 gm (based on the performed particle-size distribution analysis). The experimental site was located 15 km to the north of V. V. Alekhin Central Black Earth State Biosphere Reserve. In 1947, a black earth plot having an area of 0.6 hectares was ploughed under regularly mowed virgin motley grass-meadow vegetation within the Reserve territory (51°34'12.5"N 36°05'22.5" E). In this study, we used a model experiment based on microcosms with earthworms. We took soil from the arable black earth horizon of Kursk Region (51°37'17.1" N; 36°15'42.0" E). This type of soil was Protocalcic Chernozem (Loamic, Pachic). The microcosms belonged to four variants: soil, soil&litter, soil&litter and worms (A. caliginosa), soil&litter and worms (L. rubellus). All the variants had four replications. We took a total of 24 samples (an average sample from 10 different parts of the microcosm) from each variant based on replications and sampling timing (Figure 2). We measured the total content of C after dry combustion in an oxygen stream at 1,000 °C with the AN-7529 carbon analyzer (Gomel Plant of Measuring Devices, Republic of Belarus) using the method of automatic coulometric titration. For our PSD analysis, we used the laser diffractometer Malvern Mastersizer 3000E with a helium-neon red light at a wavelength of 632.8 nm, and the 600ml Hydro LV dispersing device. The measurement ranges of particle sizes were from 0.01 to 2,000 gm (Malvern Panalytical Inc., GB). We determined PSD in soil samples and casts before and after OM oxidation. The laboratory model experiment variants had four replications. We performed a carbon content analysis in three dimensions for each sample. We obtained PSD results in six replications, each of which being an average value of three sample suspension scans. The figures show arithmetic mean values for the replications and the confidence intervals of a standard deviation at the significance level (a = 0.05) calculated using Excel (2010). We made an analysis of variance (ANOVA) and a principal component analysis (PCA) using additive logarithmic ratio transformation for data normalization. The contribution of the earthworm A. caliginosa to SOM accumulation is insignificant. The TOC in the casts of A. caliginosa is 0.32± 0.06% higher vs. the reference variant “soil.” The TOC in the soil with the epigeic soil-litter earthworm L. rubellus (4.99± 0.4%) and its casts (5.03±0.24%) is significantly higher vs. other experiment variants (Figure 3). Earthworms changed the soil PSD, which led to a redistribution of particles (Table 1). Owing to the intake of organic particles, earthworms increased the share of coarse sand in the sand fraction (vs. the particle fraction (PF) of the control sample - soil without litter and earthworms) for A. caliginosa (very fine sand +1.05%, fine sand +1.07%, medium sand +0.4%, coarse sand +0.22%) and L. rubellus (very fine sand +3.36%, fine sand +4.7%, medium sand +2.24%, coarse sand +1.03%) (Figure 4). The earthworms A. caliginosa concentrate mineral particles of fine sand (+0.46%), medium sand (+0.37%), and coarse sand (+0.07%) in their casts, while L. rubellus concentrate silt particles (+3.8%) and fine sand (+0.36%) (Figure 5). The loss of vol.(%) after oxidation in all fractions in all the variants is caused by soil organic matter (Table 2). We used PCA to assess the effect of earthworm species and litter on the size and content of organic particles in casts and soil (Figure 6). The PCA results show important fractions for detection of organic (>100 pm) and mineral (250-500 pm, 500-1,000 pm) particles in the PSD. We assessed the effect of the size and content of organic particles in casts using ANOVA (Table 3). The most important factors are earthworm species and litter (based on the partial n-square). We assume that the source of mineral particles in the casts of A. caliginosa are phytoliths from the litter of Acer platanoides (L). The earthworms L. rubellus have a stronger effect on soil vs. A. caliginosa. The study does not confirm some of our hypotheses. Earthworms change PSD through OM grinding, but the PSD without OM is different in all the variants. We hypothesize in our paper that the reason is the destruction of phytoliths from litter and their accumulation in casts. One may distinguish between organic and mineral components in samples through determination of PSD before and after organic matter removal. We recommend determining a particle-size distribution both before and after organic matter removal from initial samples. The paper contains 5 Figures, 3 Tables, 54 References. The Authors declare no conflict of interest.
BACKGROUND: Recurrent corneal erosion (RCE) is characterized by excacerbation and remission episodes, reduced patients quality of life affecting their daily and professional activities. In case of conservative therapy inefficacy surgical procedures are used (Bowmans membrane polishing with diamond drill, excimer laser phototherapeutic keratectomy, anterior stromal puncture, and amniotic membrane transplantation). All methods have their advantages and weak points, as well as a certain percent of recurrence. In this regard the use of corneal collagen cross-linking is of the interest as an alternative method of the RCE surgical treatment. MATERIALS AND METHODS: 18 patients (20 eyes) with RCE without central corneal stroma scars, aged from 30 to 66 (average 49,5 10,6, all women), after conservative treatment failure (more than 6 months) underwent cross-linking according to the Dresden protocol with the UVX device, version 1000, by IROC INNOCROSS (Switzerland). RESULTS: All patients were asymptomatic and had no recurrence during the observation period (from 1 to 6 years, in average 2,6 1,6). There was a slight but statistically significant BCVA improvement (from 0,93 0,09 at baseline to 0,97 0,07 after intervention). CONCLUSIONS: Crosslinking may be an additional and effective treatment in a number of RCE cases when there is no central corneal stromal scars present. To reduce stromal keratocytes alteration during the procedure modified protocols may be used.
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