Risk Factors For Progression Following Corneal Collagen Crosslinking In Keratoconus

Purpose: To assess risk factors for progression following corneal collagen crosslinking (CXL) in eyes with keratoconus. Methods: Charts of patients who developed progression following conventional CXL treatment (Dresden protocol) were retrospectively evaluated in two centers (Center 1, and Center 2). 871 eyes of a total of 676 patients were analyzed. Progression was defined as >1 diopter (D) increase in maximum keratometry (Kmax) readings compared to baseline. Results: Progression was noted in 20 eyes of 20 patients (progression rate 3%). The mean age of the patients was 17.65 ± 5.76 (11–34) years and the mean follow-up following CXL was 36.70 ± 25.72 (12–84) months. The gender distribution was 13 (65%) females, and seven (35%) males. Four eyes (20%) had mild, 13 eyes (65%) had moderate, and three eyes (15%) had severe keratoconus at baseline. Fifteen eyes (75%) had allergic conjunctivitis and 20 eyes (100%) reported eye-rubbing. Cone location was central in 17 (85%) eyes and peripheral in 3 (15%) eyes. A mean of 2.21 ± 1.30 D (1.00 – 5.30 D) steepening was determined at Kmax 6 to 82 months following CXL treatment. Conclusions: Progression rate was found to be higher in the patients under the age of 17 years, female gender, allergic conjunctivitis, high preoperative Kmax (>57 D), thin corneas (<430 µm) . The majority of progressive patients were central cone and moderate keratoconus.

Visual function deficits in eyes with resolved endophthalmitis

To evaluate the changes in functional vision in patients with resolved endophthalmitis. This was a cross-sectional study. The study included 20 patients with resolved endophthalmitis and best-corrected visual acuity of 20/100 or better. Visual acuity (VA), contrast threshold (CT), red/green (RG) and yellow/blue (YB) colour vision and 15 Hz flicker modulation threshold (FMT) were assessed using standard psychophysical techniques. The median age was 54 years. The median visual acuity was 0.27 (~ 20/40—Snellen Equivalent) ((interquartile range [IQR]), 0.30) logMAR). The median log contrast threshold (CT) was − 1.13 (IQR, 0.36) log units (normative value for age-matched CT: − 1.61 log units). The median red/green (RG) and yellow/blue (YB) thresholds were 11.52 (IQR, 26.19) and 9.45 (IQR, 16.20) CAD units respectively, which were at least 5 times higher than age-matched normative RG and YB thresholds. The median central cone- mediated FMT was 17.64% (IQR, 23.40%), which was much higher compared to age-matched FMT (5.48% [IQR, 3.47]). Linear regression revealed significant relationship between contrast thresholds and foveal thickness (y = 0.001x−1.47, R2 = 0.20, p = 0.048). Though endophthalmitis may resolve with a good visual acuity, deficits in visual functions like chromatic discrimination, cone-mediated flicker and contrast sensitivity persist.

Genetic and reproductive characterization of distylous Primula reinii in the Hakone volcano, Japan: implications for conservation of the rare and endangered plant

Genetic and ecological evaluation are crucial in effective management of rare and endangered species, including those exhibiting complex breeding systems such as distyly. We studied a threatened distylous herb Primula reinii in the Hakone volcano, central Japan, to obtain baseline information of reproductive and genetic status towards conservation. In two representative populations inhabiting a central cone and somma of the volcano, population size, floral morph ratio, stigmatic pollen deposition, and fruit-set were measured. Using microsatellite markers, we evaluated genetic diversity, structure and differentiation of populations. Population bottlenecks and historical changes in population size were also estimated from genotype data. We found significant deviation from equal morph ratios in the central cone population, which also exhibited skewed mating success together with a high frequency of pollination within the same morph. These trends were not detected in the somma population. From genetic insights, the central cone population showed slightly lower genetic diversity, whereas no significant deviation from Hardy-Weinberg equilibrium was found in either population. The estimated moderate genetic differentiation and admixed genetic structure suggest recent lineage divergence and/or gene flow between populations. While robust evidence for a recent bottleneck was not obtained in our analyses, a clear signature of historical population contraction was detected in the central cone population. Our findings suggest that the skewed morph ratio strongly influenced the reproduction of small and isolated populations in the short-term, highlighting the vulnerability of distylous plant populations under ongoing anthropogenic pressure.

Piton de la Fournaise, elasto-plastic models of stresses and deformation accounting for the topographic load and a magmatic injection

&lt;p&gt;&lt;span&gt;Building on previous work aimed at identifying and characterizing the potential mechanical &lt;/span&gt;&lt;span&gt;trigger&lt;/span&gt;&lt;span&gt; controlling eruptions and destabilization at Piton de la Fournaise, we study the mechanical behavior of the &lt;/span&gt;&lt;span&gt;volcanic edifice&lt;/span&gt;&lt;span&gt; on a crustal scale. Do &lt;/span&gt;&lt;span&gt;the&lt;/span&gt; &lt;span&gt;recurrent &lt;/span&gt;&lt;span&gt;earthquake &lt;/span&gt;&lt;span&gt;pattern&lt;/span&gt;&lt;span&gt; correspond to a destabilization structure, precursor &lt;/span&gt;&lt;span&gt;of&lt;/span&gt;&lt;span&gt; a large-scale flank slid&lt;/span&gt;&lt;span&gt;ing&lt;/span&gt;&lt;span&gt;? &lt;/span&gt;&lt;span&gt;Or instead to a&lt;/span&gt;&lt;span&gt; reactivated &lt;/span&gt;&lt;span&gt;area of &lt;/span&gt;&lt;span&gt;magma storage (partially crystallized &amp;#8220;sill&amp;#8221;)? To answer these questions, we design numerical models which estimate the stress field associated with the volcanic complex. We use the ADELI finite element method in three dimensions, which handles&lt;/span&gt; &lt;span&gt; elasto-visco-plastic rheolog&lt;/span&gt;&lt;span&gt;ies&lt;/span&gt;&lt;span&gt;. In these models, we take into account 1) the topographic &lt;/span&gt;&lt;span&gt;load&lt;/span&gt;&lt;span&gt;, 2) the major density and resistance heterogeneities within the volcano obtained from previous studies, and 3) the &lt;/span&gt;&lt;span&gt;overpressure induced by the &lt;/span&gt;&lt;span&gt;in&lt;/span&gt;&lt;span&gt;tr&lt;/span&gt;&lt;span&gt;usion of a dike of arbitrary geometry.&lt;br&gt;The model&lt;/span&gt;&lt;span&gt;ed dike &lt;/span&gt;&lt;span&gt;injection generates deformation and stress fields such that their &lt;/span&gt;&lt;span&gt;isocontours&lt;/span&gt;&lt;span&gt; highlight an ellipsoidal cup structure &lt;/span&gt;&lt;span&gt;extending &lt;/span&gt;&lt;span&gt;from the central cone to a depth close to 0 and reaching the ends of the eastern flank. This zone could be assimilated to the zone of seismicity observed and described previously. &lt;/span&gt;&lt;span&gt;Toget&lt;/span&gt;&lt;span&gt;h&lt;/span&gt;&lt;span&gt;er with several systematic test cases, w&lt;/span&gt;&lt;span&gt;e will discuss the significance of these results, &lt;/span&gt;&lt;span&gt;such as whether&lt;/span&gt;&lt;span&gt; it &lt;/span&gt;&lt;span&gt;reveals&lt;/span&gt;&lt;span&gt; a rheological delimitation zone of the hydrothermalized &lt;/span&gt;&lt;span&gt;bed&lt;/span&gt;&lt;span&gt;rock, &lt;/span&gt;&lt;span&gt;resulting from&lt;/span&gt;&lt;span&gt; the combin&lt;/span&gt;&lt;span&gt;ed&lt;/span&gt;&lt;span&gt; influence of the topographic load and that of a magmatic injection.&lt;/span&gt;&lt;/p&gt;

Standard and accelerated corneal cross-linking long-term results: A randomized clinical trial

Purpose: To compare long-term results between accelerated and standard corneal cross-linking protocols in the treatment of progressive keratoconus and compare their effectiveness between central (cone in the central 3 mm) and peripheral (cone beyond 3 mm) cases. Methods: In this randomized clinical trial, we compared 31 eyes treated with accelerated corneal cross-linking (18 mW/cm2, 5 min) and 31 eyes treated with standard corneal cross-linking (3 mW/cm2, 30 min), 16 central and 11 peripheral keratoconus in each group. In this report, 4-year changes in vision, refraction, topography, corneal biomechanics, and corneal cell count were evaluated. Results: Uncorrected distance visual acuity improvement was better with standard corneal cross-linking (0.19 ± 0.30 logMAR) than accelerated corneal cross-linking (0.08 ± 0.35 logMAR), but the intergroup difference was not statistically significant (p = 0.283). Cylinder and spherical equivalent significantly increased similarly in both groups. Among topographic indices, anterior Kmax-3 mm showed more reduction in standard corneal cross-linking than accelerated corneal cross-linking (1.35 ± 1.39 vs 0.36 ± 1.10 D, p = 0.011). Anterior Kmax-8 mm reduced by 1.50 ± 1.82 and 0.37 ± 1.58 D in the standard corneal cross-linking and accelerated corneal cross-linking groups, respectively (p = 0.029). Compared to 18-month results, none of the indices at 4 years showed any significant intergroup difference (all p > 0.05). In cases with peripheral keratoconus, changes in anterior Kmax-3 mm (+0.03 ± 0.66 vs −1.17 ± 1.15 D, p = 0.012) and anterior Kmax-8 mm (+0.43 ± 1.09 vs −1.57 ± 1.40 D, p = 0.003) were greater with standard corneal cross-linking. In central cases, no significant intergroup difference was observed. Conclusion: At 4 years after the procedure, standard corneal cross-linking offered better anterior corneal flattening in the center and periphery. These differences concerned cases of peripheral keratoconus, and the two protocols were similarly effective in central cases. Beyond the 18th month, the two protocols appeared to be similarly effective.

Clinical Performance of Toris K Contact Lens in Patients with Moderate to Advanced Keratoconus: A Real Life Retrospective Analysis

Objectives.To evaluate the visual performance of Toris K soft contact lenses in patients with moderate-to-advanced keratoconus and also to compare the results according to cone types, cone location, and severity of keratoconus.Materials and Methods.Sixty eyes of 40 participants were included in this retrospective study. Uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BCVA), best-contact lens corrected visual acuity (BCLCVA), and comfort rating via visual analogue scales (VAS) were measured.Results.The mean age was 27.3 ± 8.6 years (range: 18 to 54). The mean logMAR UCVA, BCVA, and BCLCVA were 0.85 ± 0.38 (range: 0.30–1.30), 0.47 ± 0.27 (range: 0.10–1.30), and 0.16 ± 0.20 (range: 0–1.00). There were significant increases in visual acuities with contact lenses (p<.05). BCLCVA was significantly better in oval type than globus type (p=.022). UCVA and BCLCVA were significantly better in moderate keratoconus group (p=.015,p=.018). The mean line gain in Snellen was 3.6 ± 1.8 lines (range: 0–7 lines). The mean line gain was higher in central cone group than paracentral cone group and oval group than globus group (p=.014,p=.045). The mean VAS score was 8.14 ± 1.88 (range: 6–10).Conclusions.Toris K can improve visual acuity of patients with keratoconus. Toris K is successful even in the moderate and advanced form of the disease.