Fifteen years follow-up of photorefractive keratectomy up to 10 D of myopia: outcomes and analysis of the refractive regression

PURPOSE: To evaluate outcomes of photorefractive keratectomy up to -10.00 D of myopia and -4.50 of astigmatism and to develop a predictive model for the refractive changes in the long term. SETTING: Vissum Corporation and Miguel Hernandez University (Alicante, Spain). DESIGN: Retrospective-prospective observational series of cases. METHODS: This study included 33 eyes of 33 patients aged 46.79±7.04 years (range 40-57) operated with the VISX 20/20 excimer laser with optical zones of 6 mm. No mitomycin C was used in any of these cases. The minimum follow-up was 15 years. The main outcome measures were: uncorrected and corrected distance visual acuity, manifest refraction and corneal topography. Linear regression models were developed from the observed refractive changes over time. RESULTS: Safety and efficacy indexes at 15 years were 1.18 and 0.83, respectively. No statistically significant differences were detected for any keratometric variable during the follow-up (p≥0.103). 15 years after the surgery 54.55% of the eyes were within ±1.00 D of spherical equivalent and 84.85% within ±2.00 D. The uncorrected distance visual acuity at 15 years was 20/25 or better in 60.6% of the eyes and 20/40 or better in 72.73% of the eyes. The correlation between the attempted and the achieved refractions was r=0.948 (p<0.001) at 1 year, and r=0.821 (p<0.001) at 15 years. No corneal ectasia was detected in any case during the follow-up. CONCLUSIONS: Photorefractive keratectomy is a safe refractive procedure in the long term within the range of myopia currently considered suitable for its use, although its efficacy decreases with time, especially, in high myopia. The model developed predicts a myopic regression of 2.00 D at 15 years for an ablation depth of 130 µm

MENINGKATKAN HASILBELAJAR SISWA KELAS XI IPA 2 MAN MODEL GORONTALO PADA MATERI HIDROLISIS GARAM DENGAN MENGGUNAKAN MODEL PEMBELAJARAN KOOPERATIF TIPE GROUP INVESTIGATION (GI)

The research aimed to improve students achievement through Cooperative learning model of GI type in salt Hydrolysis lesson Material. It had done in students of 2008/2009 academic years that consisted of 20 students. Techniques in collecting data wereobservation sheet of teacher and students and test of students achievement. The research had to do second cycle,60% of students reached score less than 6,5. there it had to do second cycle. Second cycle was reparation of step and learning proses from first cycle.The result of second cycle showed that students achievement was improved to 95% and reached score standard more than 6,5. thereby, cooperative learning model of GI type in Salt Hydrolysis leason material can improve students achievement

Refractive surgical correction and treatment of keratoconus

Keratoconus is an ectatic corneal disorder that causes severe vision loss. Surgical options allow us to correct, partially or totally, the induced refractive error. Intracorneal ring segments (ICRS) implantation represents a minimally invasive surgical option that improves visual acuity, with a high success rate and a low overall complication rate. Corneal allogenic ICRS consists of ring segments derived from allogenic eye bank-processed donor corneas. Selective topography-guided transepithelial photorefractive or phototherapeutic keratectomy combined with CXL is another way in selected cases to improve spectacles corrected distance visual acuity. The microphotoablative remodeling of the central corneal profile is generally planned by optimizing the optical zones and minimizing tissue consumption. Phakic intraocular lens (PIOL) implant is considered in patients with stable disease and acceptable anatomical requirements. The two types of pIOLs, depending on their implantation inside the eye, are anterior chamber-pIOLs, which fixate to the anterior surface of the iris by using a polymethomethacrolate claw at the two haptics, and posterior chamber-pIOLs. In patients with both cataracts and keratoconus, the correct IOL power is difficult to obtain due to the irregular corneal shape and K values. Toric IOL is recommended, but carefully judging the topography and the possible need of subsequent keratoplasties

Ground reaction forces, asymmetries and performance of change of direction tasks in youth elite female basketball players

The magnitude and direction of inter-limb asymmetries in a change of direction (COD) have increased interest in scientific research in recent years. This present study aimed to investigate the magnitude of asymmetries in an elite youth female basketball sample (n = 18, age = 17.79 ± 0.67 y) and determine its directionality using force platform technology. Participants performed 70◦ and 180◦ COD tests analyzing the following variables: time, ground contact time (GCT) and ground reaction forces (GRF) along the anterior–posterior, mediolateral, and vertical axes. Inter-limb asymmetries were evident in both COD tests, with substantial differences observed between limbs (p < 0.01). The asymmetry values ranged from 3.02% to 24.31% in COD 180◦ and from 1.99% to 21.70% in COD 70◦, with anterior–posterior GRF consistently exhibiting the highest asymmetry magnitude. Additionally, the directionality exhibited variability between the tests, indicating poor agreement and suggesting the independent directionality of asymmetries across tasks. Moreover, players required more time to complete the COD 180◦, the GCT was noticeably longer for the COD 180◦ than for the COD 70◦, and GRF varied across the axis, suggesting that players adapt uniquely to the specific demands of each task. The utilization of force platforms presents a comprehensive approach to assess asymmetries and COD variables performance variables which are “angle-dependent”, which could have important implications for COD screening and effective training interventions

Pengaruh Model Pembelajaran Pendekatan Saintifik terhadap Hasil Belajar Siswa pada Materi Kelarutan dan Hasil Kali Kelarutan

Tujuan penelitian ini adalah untuk mengetahui pengaruh model pembelajaran pendekatan saintifik terhadap hasil belajar siswa pada materi kelarutan dan hasil kali kelarutan. Sampel berjumlah 61 siswa yang tersebar didua kelas, yaitu kelas eksperimen berjumlah 29 siswa dan kelas kontrol berjumlah 32 siswa. Pengumpulan data menggunakan tes. Analisis data menggunakan uji t. Hasil analisis data menunjukkan bahwa dalam taraf signifikan 0,05 dengan dk = 59 diperoleh nilai thitung &gt; ttabel atau 4,880 &gt; 2,003 maka tolak H0. Kesimpulan terdapat pengaruh model pembelajaran pendekatan saintifik terhadap hasil belajar siswa pada materi kelarutan dan hasil kali kelarutan

Higher vertical jumping asymmetries and lower physical performance are indicators of increased injury incidence in youth team-sport athletes

To date, the literature looking at the association between injury-risk factors and actual injury incidence in young elite team-sports athletes is scarce. The main objective of the present study was to examine how modifiable factors may affect injury incidence. Eighty-one young elite team-sports athletes (age: u-14 to u-18) performed the countermovement jump (CMJ), a single leg CMJ (SLCMJ), the one-legged hop test (OLHT), a 30 m sprint test, the v-cut test, a repeated sprint ability and the 30-15 intermittent fitness test during the pre-season period. Inter-limb asymmetries were calculated for SLCMJ and OLHT. Injuries were recorded prospectively for the entirety of the 2017-2018 season. Comparison of injury and non-injury data was carried out using a two-way analysis of variance (ANOVA). Results of the ANOVA according to injury showed significant differences in CMJ (p = 0.01), SLCMJ on the lowest performing limb (p = 0.03) and SLCMJ asymmetry (< 0.001). Sex*injury interaction was significant from CMJ (p = 0.018) and 30-15 IFT (p = < 0.001). In conclusion, the current study indicated that athletes with greater inter-limb asymmetries, less vertical jump capacity and lower intermittent aerobic fitness had a greater predisposition to injury. Therefore, monitoring CMJ, aerobic performance and inter-limb asymmetries is recommended given their sensitivity to detect significant differences between injured and healthy youth athletes

A community perspective on the role of fathers during pregnancy: a qualitative study

BACKGROUND: Defining male involvement during pregnancy is essential for the development of future research and appropriate interventions to optimize services aiming to improve birth outcomes. Study Aim: To define male involvement during pregnancy and obtain community-based recommendations for interventions to improve male involvement during pregnancy. METHODS: We conducted focus groups with mothers and fathers from the National Healthy Start Association program in order to obtain detailed descriptions of male involvement activities, benefits, barriers, and proposed solutions for increasing male involvement during pregnancy. The majority of participants were African American parents. RESULTS: The involved “male” was identified as either the biological father, or, the current male partner of the pregnant woman. Both men and women described the ideal, involved father or male partner as present, accessible, available, understanding, willing to learn about the pregnancy process and eager to provide emotional, physical and financial support to the woman carrying the child. Women emphasized a sense of “togetherness” during the pregnancy. Suggestions included creating male-targeted prenatal programs, enhancing current interventions targeting females, and increasing healthcare providers’ awareness of the importance of men’s involvement during pregnancy. CONCLUSIONS: Individual, family, community, societal and policy factors play a role in barring or diminishing the involvement of fathers during pregnancy. Future research and interventions should target these factors and their interaction in order to increase fathers’ involvement and thereby improve pregnancy outcomes

Intrastromal corneal ring segments: how successful is the surgical treatment of keratoconus?

This review evaluates the outcomes of intrastromal corneal ring segment (ICRS) implantation for the treatment of keratoconus considering a new grading system based on the preoperative visual impairment of the patient. Additionally, a five-year follow-up analysis of patients with stable and progressive keratoconus is performed in order to assess the long term stability of the surgical procedure. Corrected distance visual acuity decreased statistically significantly in patients with mild keratoconus (P < 0.01) but statistically significantly increased in all other grades (P < 0.05). The improvement in visual acuity and the decrease of keratometric and aberrometric values were stable throughout a long period of time in patients with stable keratoconus. In patients with progressive form keratoconus, a significant improvement was found immediately after the procedure, however clinically relevant regression greater than 3 D was observed at the end of the follow up period

Comparative Analysis of Some Modal Reconstruction Methods of the Shape of the Cornea from Corneal Elevation Data

Purpose: A comparative study of the ability of some modal schemes to reproduce corneal shapes of varying complexity was performed, by using both standard radial polynomials and radial basis functions (RBFs). The hypothesis was that the correct approach in the case of highly irregular corneas should combine several bases. Methods: Standard approaches of reconstruction by Zernike and other types of radial polynomials were compared with the discrete least-squares fit (LSF) by the RBF in three theoretical surfaces, synthetically generated by computer algorithms in the absence of measurement noise. For the reconstruction by polynomials, the maximal radial order 6 was chosen, which corresponds to the first 28 Zernike polynomials or the first 49 Bhatia-Wolf polynomials. The fit with the RBF was performed by using a regular grid of centers. Results: The quality of fit was assessed by computing for each surface the mean square errors (MSEs) of the reconstruction by LSF, measured at the same nodes where the heights were collected. Another criterion of the fit quality used was the accuracy in recovery of the Zernike coefficients, especially in the case of incomplete data. Conclusions: The Zernike (and especially, the Bhatia-Wolf) polynomials constitute a reliable reconstruction method of a nonseverely aberrated surface with a small surface regularity index (SRI). However, they fail to capture small deformations of the anterior surface of a synthetic cornea. The most promising approach is a combined one that balances the robustness of the Zernike fit with the localization of the RBF