Corneal Structural Changes in Congenital Glaucoma.

OBJECTIVE: To identify corneal structure differences on quantitative high-frequency ultrasound biomicroscopy (UBM) among subjects with congenital glaucoma compared with controls. METHODS: This prospective case-control study evaluated 180 UBM images from 44 eyes of 30 subjects (18 control and 12 glaucoma, mean age 5.2±8.0 years, range 0.2-25.8 years) enrolled in the Pediatric Anterior Segment Imaging and Innovation Study (PASIIS). ImageJ was used to quantify a comprehensive set of corneal structures according to 21 quantitative parameters. Statistical analysis compared corneal measurements in glaucoma subtypes and age-matched controls with significance testing and mixed effects models. RESULTS: Significant differences between congenital glaucoma cases and controls were identified in 16 of 21 measured parameters including angle-to-angle, central and peripheral corneal thicknesses, scleral integrated pixel density, anterior corneal radius of curvature, and posterior corneal radius of curvature. Eight parameters differed significantly between primary congenital glaucoma and glaucoma following congenital cataract surgery. CONCLUSION: Multiple measurable corneal structural differences exist between congenital glaucoma and control eyes, and between primary and secondary congenital glaucoma, including but not limited to corneal width and thickness. The structural differences can be quantified from UBM image analysis. Further studies are needed to determine whether corneal features associated with glaucoma can be used to diagnose or monitor progression of congenital glaucoma.

Pediatric Corneal Structural Development During Childhood Characterized by Ultrasound Biomicroscopy.

PURPOSE: To quantitatively describe the structural corneal changes from infancy to early adulthood using ultrasound biomicroscopy. METHODS: In this prospective study, 168 ultrasound biomicroscopy images were obtained from 24 healthy eyes of 24 patients who consented and enrolled in the Pediatric Anterior Segment Imaging Innovation Study. Their ages ranged from birth to 26 years. An established ultrasound biomicroscopy imaging protocol including seven views of one eye per patient were obtained and measured using ImageJ software (National Institutes of Health). Twelve corneal structural parameters were measured. Means were compared between younger and older groups. RESULTS: Among the 12 measured structures, 5 demonstrated statistically significant differences (P < .05) between patients younger than 1 year and patients older than 1 year. The mean values for corneal cross-sectional width and length, central corneal thickness, and radii of curvature (anterior and posterior) were significantly different in patients younger than 1 year. Curvature and limbus-to-limbus dimensions changed more dramatically than thickness and tissue density. When comparing the youngest to oldest subgroups, anterior curvature flattened (6.14 to 7.55 radius), posterior curvature flattened (5.53 to 6.72 radius), angle-to-angle distance increased (8.93 to 11.40 mm), and endothelial cross-sectional distance increased (10.63 to 13.61 mm). CONCLUSIONS: Pediatric corneal structures change with age. The most significant changes occur in the first months of life, with additional changes later in childhood. This study further demonstrates the importance of age in pediatric corneal imaging analysis. [J Pediatr Ophthalmol Strabismus. 2020;57(4):238-245.].

Investigation of distribution of radioactivity with effects of heavy metals in toothpastes from Penang markets.

This study was carried out to determine the concentration of 222Rn, 226Ra, and 238U in 25 different toothpastes available in the local market in Penang, Malaysia, using a CR-39 detector. The results showed the maximum concentration of radon/ radium/uranium to be 4197.644 Bq.m-3, 54.369 Bq.Kgm-1, and 0.044 ppm in Colgate4; the annual effective dose was found (0.402 mSvy-1) in S07. The average concentration of radon (42 %, 3.224 KBq.m-3) was higher than the concentration of 214Po, 218Po in POS (32 %, 2.415 KBq.m-3) and POW (26 %, 1.979 KBq.m-3). Also the values of pH of samples ranged from 4.21 (highly acidic) in S04 to 9.97 (highly basic) in S07, with an average of 6.33 which tended towards an acidic behavior; a low or high pH for a long period of time can cause harmful side-effects and enamel erosion. Concentrations of heavy metals varied from the maximum value 56.156 ppm in the Ca elements in the Colgate 4 sample to a minimum value of -0.858 ppm in the Cd elements in Colgate 6 (Ca 56.156 ppm > Cd 51.572 ppm > Zn 41.039 ppm > Mg 11.682 ppm > Pb 11.009 ppm]. Monitoring the accumulation of these metals in toothpaste samples is very important: the average annual effective dose (0.3118 mSvy-1) was below the range (3-10 mSvy-1) reported by ICRP (1993), and therefore there is no evidence of health problems. Significant strong positive correlations were found (r = 1, Pearson correlation, p < 0.000) in concentration of radon, radium, uranium, annual effective dose, pH, and electrical conductivity.

Optical coherence tomography to monitor vigabatrin toxicity in children.

PURPOSE: The antiepileptic drug vigabatrin is known to cause permanent loss of vision. Both visual field testing and electroretinogram are used to detect retinal damage. Adult data on optical coherence tomography (OCT) shows that retinal nerve fiber layer (RNFL) thinning may be an early indicator of vigabatrin-induced retinal toxicity. The purpose of this study was to investigate whether OCT can detect early vigabatrin-induced retinal toxicity in children. METHODS: Pediatric patients (≤18 years of age) requiring vigabatrin for seizure control who were followed at our institution were invited to participate. Patients were examined according to manufacturer guidelines, with most examinations taking place under general anesthesia. RNFL thickness was measured by OCT (Stratus Model 3000, Zeiss) and compared to total cumulative dose of vigabatrin. In most cases, indirect ophthalmoscopy, fundus photography, and electroretinography were also performed. RESULTS: OCT and complete dosing data was available for 19 patients. Patients with tuberous sclerosis (TS, n = 12) received higher cumulative doses (mean, 1463 g) than non-TS patients (mean, 351 g, P = 0.044). RNFL thinning was detected in the nasal (P < 0.01), superior (P < 0.01), and inferior (P < 0.05) quadrants in patients with TS, particularly once cumulative dose exceeded 1500 g. CONCLUSIONS: In our study population of patients with TS, higher cumulative doses of vigabatrin were associated with RNFL thinning in the nasal, superior, and inferior quadrants. These findings were pronounced once cumulative dose exceeded 1500 g. This pattern of RNFL thinning is similar to what has been shown in adult patients taking vigabatrin.

Interaction of low-intensity nuclear radiation dose with the human blood: using the new technique of CR-39NTDs for an in vitro study.

Complete blood counts were analyzed for 30 samples of human blood with radiation dose rate ranging between 10 and 41 µSv/h using a Radium-226 source with different time of exposure. A new technique involving a nuclear track detector type CR-39(CR-39 NTDs) was used to estimate the alpha particle density incident on the blood samples. The results show that the ranges of alpha particle in blood samples and on the surface of CR-39NTDs vary exponentially with energy of alpha particles. This depends on the restricted energy loss and target density. Changes in the blood components due to irradiation occurred for different durations of irradiation, and the duration of irradiation that influenced the blood samples in this study was 6 min. The change in red blood cell (RBC) was negligible, so it is less affected than other blood components. In addition, most changes in the blood contents began at a low radiation dose (10.38-13.41 µSv/h). For the doses 13.41-21.77 µSv/h, platelet (PLT) counts increased rapidly and adversely with the RBC and white blood cell (WBC) due to chromosomal aberration. Besides, rapid PLT count reduction rapidly at high dose (42.1 µSvh) causes thrombocytopenia; in contrast, WBC increased, which is an indication of cancer caused due to increase in alpha particle dose. Generally, our results are in agreement with the essentials of blood content and the principles of biological radiation interaction.

A review of pediatric uveitis: part II. Autoimmune diseases and treatment modalities.

Uveitis is a manifestation of complex processes that can represent an infectious process or a dysfunction of the immune system that may have grave effects on the eye. Although infectious causes, once properly identified, may be successfully treated by addressing the inciting organism with recognized interventions, the immune-modulated chronic forms of uveitis often provide more complex challenges in management. Recent strides in understanding the inflammatory pathway and better bioengineering capabilities have resulted in some new modalities of treatment.

A review of pediatric uveitis: Part I. Infectious causes and the masquerade syndromes.

Uveitis is a manifestation of complex processes that can represent an infectious or a purely immune system modulated condition and may have grave effects on the eye. Much of the morbidity in these conditions is the result of the immune response to these stimuli. These infectious diseases may be successfully treated by addressing the inciting organism with recognized interventions. Treatment of the immune response to the organism often must be pursued simultaneously to minimize long-term complications caused by structural changes within the eye. Assisting the individual's immune response to eliminate the organism while minimizing the immune response's damaging effects remains a unique challenge drawing on both the science and the art of medicine. Several non-infectious conditions that are not autoimmune diseases may commonly masquerade as uveitis, leading to delays in appropriate treatment.

Phenotypic and molecular assessment of seven patients with 6p25 deletion syndrome: relevance to ocular dysgenesis and hearing impairment.

BACKGROUND: Thirty-nine patients have been described with deletions involving chromosome 6p25. However, relatively few of these deletions have had molecular characterization. Common phenotypes of 6p25 deletion syndrome patients include hydrocephalus, hearing loss, and ocular, craniofacial, skeletal, cardiac, and renal malformations. Molecular characterization of deletions can identify genes that are responsible for these phenotypes. METHODS: We report the clinical phenotype of seven patients with terminal deletions of chromosome 6p25 and compare them to previously reported patients. Molecular characterization of the deletions was performed using polymorphic marker analysis to determine the extents of the deletions in these seven 6p25 deletion syndrome patients. RESULTS: Our results, and previous data, show that ocular dysgenesis and hearing impairment are the two most highly penetrant phenotypes of the 6p25 deletion syndrome. While deletion of the forkhead box C1 gene (FOXC1) probably underlies the ocular dysgenesis, no gene in this region is known to be involved in hearing impairment. CONCLUSIONS: Ocular dysgenesis and hearing impairment are the two most common phenotypes of 6p25 deletion syndrome. We conclude that a locus for dominant hearing loss is present at 6p25 and that this locus is restricted to a region distal to D6S1617. Molecular characterization of more 6p25 deletion patients will aid in refinement of this locus and the identification of a gene involved in dominant hearing loss.