Impact of Hypothyroidism on Tomography and Biomechanics in Keratoconus – Cross-Sectional and Longitudinal Assessment within the Homburg Keratoconus Center at the Time of Inclusion and after 1 Year

Author(s):  
Sonia Razafimino ◽  
Elias Flockerzi ◽  
Elena Zemova ◽  
Christian Munteanu ◽  
Berthold Seitz

Abstract Background and Purpose The etiology of keratoconus (KC) is probably multifactorial but remains essentially unknown. Previous scientific observations have suggested that hypothyroidism might play a role in the development and progression of KC. The purpose of this study was to analyze the tomographic and biomechanical parameters in KC patients with or without hypothyroidism. Methods Twenty-eight patients with KC and hypothyroidism (HT group) and fifty-six KC patients without thyroid dysfunction (WHT group) with matching gender and age were analyzed. Mean age was 40.3 years (range 14 – 57) in the HT group and 40.3 years (range 14 – 57) in the WHT group. Routine ophthalmic examinations consisted of corneal tomography and biomechanical parameters. We extracted the following KC parameters from the Pentacam (Pentacam HR, Oculus, Wetzlar, Germany): Keratoconus Index (KI), maximum keratometry (Kmax), astigmatism, and thinnest pachymetry (TP). From the ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Depew, NY, USA), we extracted corneal hysteresis (CH), corneal resistance factor (CRF), and KC match index (KMI). Results The comparison of the tomographic and biomechanical values from cross-sectional and longitudinal analyses showed no significant differences between the HT and WHT groups. Conclusion The severity of KC based on tomographical and biomechanical parameters does not seem to depend on the presence of hypothyroidism.

2021 ◽  
pp. 112067212110547
Author(s):  
Francesc Duch ◽  
Ignacio López-Marín ◽  
Federico Alonso-Aliste ◽  
Mariano Hernández-Barahona-Campos ◽  
Santiago C Manito ◽  
...  

Purpose To evaluate the influence of corneal tomographic and biomechanical indexes on the refractive technique indication. Methods A total of 251 eyes from 251 patients interested in refractive surgery were enrolled in this cross-sectional and multicenter study. Previous to the surgeon decision, a preoperative protocol was performed by refractive optometrists, containing four sections: refraction, biometry, corneal tomography and biomechanics. The refractive surgeons made a first decision based only on refraction, biometric and tomographic information. Biomechanical indexes were revealed, and refractive surgeons made a second indication. Additionally, for Laser-Assisted in-situ Keratomileusis cases, the percent tissue altered were calculated. Possible indications were no refractive surgery, photorefractive keratectomy, Laser-Assisted in-situ Keratomileusis or intraocular Collamer lens. Results After the first surgery indication, the distribution was photorefractive keratectomy (47.4%), Laser-Assisted in-situ Keratomileusis (48.2%) while intraocular Collamer lens achieved 2.8%. This proportion changed significantly after the second indication regarding corneal biomechanics and photorefractive keratectomy and Laser-Assisted in-situ Keratomileusis decreased by 24% while intraocular Collamer lens increased 19%. A total of 69 eyes changed the indication (27.5%) and 182 eyes (72.5%) remained unchanged. All indications changes were from photorefractive keratectomy or Laser-Assisted in-situ Keratomileusis to intraocular Collamer lens or no surgery. Indication changes to intraocular Collamer lens were observed in 49 eyes (71%). Tomographic, biomechanical indexes, ablation depth and percent tissue altered achieved statistically significant differences between eyes without and with indication changes (all, P < .01). Conclusion New corneal biomechanical indexes could change the indication decision regarding biometric and tomographic data alone. Intraocular Collamer len was the preferred indication for eyes at risk of ectasia or with subclinical keratoconus due to corneal biomechanical parameters.


2010 ◽  
Vol 26 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Marc Vierhaus ◽  
Arnold Lohaus ◽  
Indra Shah

This investigation focuses on the question whether assessments of the development of internalizing behavior from childhood to adolescence are affected by the kind of research design (longitudinal versus cross-sectional). Two longitudinal samples of 432 second-graders and 366 fourth graders participated in a longitudinal study with subsequent measurements taken 1, 2, and 3 years later. A third sample consisting of 849 children covering the same range of grades participated in a cross-sectional study. The results show that the development of internalizing symptoms in girls – but not in boys – varies systematically with the research design. In girls, there is a decrease of internalizing symptoms (especially between the first two timepoints) in the longitudinal assessment, which may reflect, for example, the influence of strain during the first testing situation. Both longitudinal trajectories converge to a common trajectory from grade 2 to grade 7 when controlling for this “novelty-distress effect.” Moreover, when we control this effect, the slight but significant decrease characterizing the common trajectory becomes similar to the one obtained in the cross-sectional study. Therefore, trajectories based on longitudinal assessments may suggest more changes with regard to internalizing symptoms over time than actually take place, while trajectories based on cross-sectional data may be characterized by an increased level of internalizing symptoms. Theoretical and practical implications of these results are discussed.


Author(s):  
Kashish Narula ◽  
Narendra Kumar Dara ◽  
Shyam Lal Meena

Background: Thyroid hormones influence nearly all major metabolic pathways. Their most obvious and well-known action is the increase in basal energy expenditure obtained by acting on protein, carbohydrate and lipid metabolism. The lipid metabolism is more influenced by the thyroid hormone. Methods: A cross-sectional study was conducted on 100 patients with suspicion of thyroid disorders were taken as cases. One hundred patients with normal thyroid profile and no history of other chronic diseases were taken as control group. Results: The serum TC, TG and LDL levels in hypothyroid individuals (both overt and subclinical) were significantly higher than euthyroid subjects but the levels were comparable between hyperthyroid and euthyroid group. Conclusion: Dyslipidemias are associated with thyroid disorders, so biochemical screening for thyroid dysfunction in all dyslipidemic patients. Therefore, patients presenting with dyslipidemia are recommended for investigation to explore thyroid dysfunction. Keywords: Thyroid profile, Total cholesterol, Triglycerides and LDL


The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 15-19
Author(s):  
Irina Bubnova ◽  
Veronica Averich ◽  
Elena Belousova

Purpose: Evaluation of corneal biomechanical prop¬erties and their influence on IOP indices in patients with keratoconus. Material and methods. The study included 194 eyes with keratoconus (113 patients aged from 23 to 36 years old). Corneal refraction in central zone varied from 48.25 to 56.75 D, values of corneal thickness ranged from 279 to 558 μm. Patients were divided into 4 groups according to Amsler classification: I stage – 40 eyes; II stage – 78 eyes; III stage – 54 eyes and IV stage – 22 eyes. Standard ophthal¬mological examination was carried out including pneumo¬tonometry. IOP indices and values of biomechanical prop¬erties were evaluated by dynamic bidirectional pneumatic applanation and pneumatic impression. Results. Study of corneal biomechanical properties in patients with keratoconus showed a decrease of such biomechanical indices as corneal hysteresis (CH) on aver¬age to 8.42±1.12 mm Hg, corneal resistance factor (CRF) – to 7.45±0.96 mm Hg, coefficient of elasticity (CE) – 5.35± 0.87 mm Hg. Values of these indices strongly depended on the stage of keratoconus. In the whole sample, the aver¬age corneal compensated IOP (IOPcc) amounted to 15.08± 2.43 mm Hg, Goldman IOP (IOPg) was 11.61±2.37 mm Hg and pneumatic tonometry IOP (IOPp) was 10.13±2.94 mm Hg. IOPcc indices didn’t have any statistically significant differ¬ence in dependence on the stage of keratoconus (р>0.473), while in process of disease progression IOPg and IOPp indi¬ces showed statistically significant decrease of mean values. Conclusion. Progression of keratoconus led to a de¬crease in corneal biomechanical properties which deter¬mine reduction of such indices as IOPg and IOPp in contrast to IOPcc.


2021 ◽  
pp. 1-29
Author(s):  
Amy H. Auchincloss ◽  
Jingjing Li ◽  
Kari A. B. Moore ◽  
Manuel Franco ◽  
Mahasin S. Mujahid ◽  
...  

Abstract Objective: To examine whether the density of neighbourhood restaurants affected the frequency of eating restaurant meals and subsequently affected diet quality. Design: Cross-sectional and longitudinal designs. Structural equation models assessed the indirect relationship between restaurant density (≤3 miles (4.8 km) of participant addresses) and dietary quality (Healthy Eating Index 2010 (HEI)) via the frequency of eating restaurant meals, after adjustment for sociodemographics, select health conditions, region, residence duration and area-level income. Setting: Urbanised areas in multiple regions of the USA, years 2000–2002 and 2010–2012. Participants: Participants aged 45–84 years were followed for 10 years (n 3567). Results: Median HEI (out of 100) was 59 at baseline and 62 at follow-up. Cross-sectional analysis found residing in areas with a high density of restaurants (highest ranked quartile) was associated with 52% higher odds of frequently eating restaurant meals (≥3 times/week, odds ratio [OR]:1.52, 95% confidence interval [CI] 1.18-1.98) and 3% higher odds of having lower dietary quality (HEI lowest quartile<54, OR:1.03,CI:1.01-1.06); associations were not sustained in longitudinal analyses. Cross-sectional analysis found 34% higher odds of having lower dietary quality for those who frequently ate at restaurants (OR:1.34,CI:1.12-1.61); and more restaurant meals (over time increase ≥1 times/week) was associated with higher odds of having worse dietary quality at follow-up (OR:1.21,CI:1.00-1.46). Conclusions: Restaurant density was associated with frequently eating out in cross-sectional and longitudinal analyses but was associated with the lower dietary quality only in cross-sectional analyses. Frequent restaurant meals were negatively related to dietary quality. Interventions that encourage less frequent eating out may improve population dietary quality.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Madison E. Andrews ◽  
Anita D. Patrick ◽  
Maura Borrego

Abstract Background Students’ attitudinal beliefs related to how they see themselves in STEM have been a focal point of recent research, given their well-documented links to retention and persistence. These beliefs are most often assessed cross-sectionally, and as such, we lack a thorough understanding of how they may fluctuate over time. Using matched survey responses from undergraduate engineering students (n = 278), we evaluate if, and to what extent, students’ engineering attitudinal beliefs (attainment value, utility value, self-efficacy, interest, and identity) change over a 1-year period. Further, we examine whether there are differences based on gender and student division, and then compare results between cross-sectional and longitudinal analyses to illustrate weaknesses in our current understanding of these constructs. Results Our study revealed inconsistencies between cross-sectional and longitudinal analyses of the same dataset. Cross-sectional analyses indicated a significant difference by student division for engineering utility value and engineering interest, but no significant differences by gender for any variable. However, longitudinal analyses revealed statistically significant decreases in engineering utility value, engineering self-efficacy, and engineering interest for lower division students and significant decreases in engineering attainment value for upper division students over a one-year period. Further, longitudinal analyses revealed a gender gap in engineering self-efficacy for upper division students, where men reported higher means than women. Conclusions Our analyses make several contributions. First, we explore attitudinal differences by student division not previously documented. Second, by comparing across methodologies, we illustrate that different conclusions can be drawn from the same data. Since the literature around these variables is largely cross-sectional, our understanding of students’ engineering attitudes is limited. Our longitudinal analyses show variation in engineering attitudinal beliefs that are obscured when data is only examined cross-sectionally. These analyses revealed an overall downward trend within students for all beliefs that changed significantly—losses which may foreshadow attrition out of engineering. These findings provide an opportunity to introduce targeted interventions to build engineering utility value, engineering self-efficacy, and engineering interest for student groups whose means were lower than average.


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