Birth weight and refractive state measured by Spot Vision Screener in children aged 40 months

ObjectivesChildren with retinopathy of prematurity (ROP) often have myopia. Even without ROP, birth weight and refractive state are related immediately after birth, but this relationship is reduced with increasing age. Here, we examined whether refractive state and birth weight were associated in 40-month-old children.Methods and analysisOf 541 children aged 40 months in Tsubame City, Japan, who underwent a medical examination between April 2018 and March 2019, this cross-sectional study enrolled 411 whose birth weights were available (76% of all).We measured the non-cycloplegic refraction using a Spot Vision Screener and correlated this with birth weight. Children were divided into three groups according to normal (2500–3500 g), high (>3500 g) or low (<2500 g) birth weights, and mean differences in spherical equivalent (SE) between the groups were analysed.ResultsThe average SE for the right eye was 0.34 D (95% CI 0.28 to 0.40). Average birth weight was 3032.1 g (95% CI 2990.2 to 3073.9). Birth weight did not correlate with SE for the right eye (Pearson’s correlation, r=−0.015, p=0.765) or with the degree of anisometropia (Pearson’s correlation, r=−0.05, p=0.355). Furthermore, the mean SE showed no significant difference across the three groups of children with different birth weights (one-way analysis of variance, p=0.939).ConclusionData on refractive states and birth weight for 411 children of similar age in one Japanese city were analysed, showing that birth weight did not influence SE, J0, J45 and the absolute degree of anisometropia at about 40 months of age.

Ablation of mpeg+ macrophages exacerbates mfrp-related hyperopia

PURPOSE: Proper refractive development of the eye, termed emmetropization, is critical for focused vision and impacted by both genetic determinants and several visual environment factors. Improper emmetropization caused by genetic variants can lead to congenital hyperopia, which is characterized by small eyes and relatively short ocular axial length. To date variants in only four genes have been firmly associated with human hyperopia, one of which is MFRP. Zebrafish mfrp mutants also have hyperopia and similar to reports in mice, exhibit increased macrophage recruitment to the retina. The goal of this research was to examine the effects of macrophage ablation on emmetropization and mfrp-related hyperopia. METHODS: We utilized a chemically inducible, cell-specific ablation system to deplete macrophages in both wild-type and mfrp mutant zebrafish. Spectral-domain optical coherence tomography (SD-OCT) was used to measure components of the eye and determine relative refractive state. Histology, immunohistochemistry, and transmission electron microscopy was used to further study the eyes. RESULTS: While macrophage ablation does not cause significant changes to the relative refractive state of wild-type zebrafish, macrophage ablation in mfrp mutants significantly exacerbates their hyperopic phenotype. CONCLUSIONS: Genetic inactivation of mfrp leads to hyperopia as well as abnormal accumulation of macrophages in the retina. Ablation of the mpeg1-positive macrophage population exacerbates the hyperopia, suggesting that macrophages are recruited in an effort help preserve emmetropization and ameliorate hyperopia.

Refraction in Preschool Children in Kazanlak, Bulgaria

Introduction: The refractive state of the eye changes as the eye&rsquo;s axial length increases and the cornea and lens flatten. In general, eyes are hyperopic at birth, become slightly more hyperopic until the age of 7, which at this point we see a myopic shift toward plano until the eyes reach their adult dimensions, usually by about the age 16. Aim: To determine the prevalence of refractive error in preschool children aged 3 - 6 in the city of Kazanlak, Bulgaria. Materials and methods: A cross-sectional study was conducted in a kindergarten based school within the city of Kazanlak, Bul&shy;garia. Out of 15 kindergarten schools, 10 chose to participate in the study. The children underwent non-mydriatic refraction screening using a Plus-Optix S12&#1089; mobile camera. Myopia, hyperopia and astigmatism were defined as being a spherical equivalent (SE) &le; &minus;0.50 D, SE &ge; +2.00 D and cylindrical diopters &le; &minus;1.00 D. Results: A total of 596 children were screened. Out of these 596 children; 526 were with ametropia (470 hypermetropia, 46 myopia) and 50 had astigmatism. Strabismus was found in 12 children, with a further 8 children suffering from amblyopia and finally 8 children were also found to be diagnosed with anisometropia. In 8 cases there were no results due to opacities or due to the small size of the pupil. Conclusion: The prevalence of refractive error in preschool children is similar to that found in other research in the field. While most cases fall into the category of emmetropia or mild hypermetropia, most of the children had never been to an ophthalmologist. A manda&shy;tory checkup should be issued for all children below the age of seven.

Correlation between refractive state, corneal thickness, and keratometry in ametropic patients

Purpose: To analyze the correlation between age, gender, refractive error, keratometry, and corneal thickness in a large group of subjects. Methods: This study is a retrospective analysis of patients who underwent refractive surgery between January 2000 and February 2015 at Care Vision Refractive Clinic, Tel Aviv, Israel. Patient demographics, subjective refraction, pachymetry, and average keratometry were collected. Results: Overall, 51,113 eyes of patients averaging 28.8 ± 9.3 years of which 53.9% were males were included. Average keratometry, spherical equivalent and cylindrical error differed significantly between male and female subjects (p < 0.001), while pachymetry did not (p = 0.332). In myopic eyes, correlations between age, pachymetry, average keratometry, spherical equivalent, and cylindrical error were all statistically significant except for the correlation between age and either pachymetry (p = 0.462) or spherical equivalent (p = 0.016). All correlations found were negligible or small (|r|= 0.003 to 0.141). In hyperopic eyes, correlations between age, pachymetry, average keratometry, spherical equivalent, and cylindrical error were all statistically significant except for the correlation between average keratometry and either pachymetry or cylindrical error (p = 0.344 or p = 0.274, respectively). All correlations found were negligible or small, except for a moderate correlation found between age and cylindrical error (r = 0.365). Conclusion: Refractive state, pachymetry, and keratometry of refractive surgery candidates are mostly weakly correlated.