Purpose. To evaluate the refractive status and optical components in school age children born prematurely and to examine the risk factors associated with refractive errors. Methods. The participants were a cohort of children aged 7 to 9 years with gestational age less than 35 weeks or birth weight less than 1500 g. The participants' neonatal histories were reviewed; their refractive status and optical components were measured. The study results were compared with the results of age-matched children from a national survey. Results. Of the 108 children studied, 48 (44%) had retinopathy of prematurity (ROP); 29 (27%) had ROP ≥ stage 3. Compared with the control subjects, the study cases showed higher prevalence of myopia (48% vs. 29%), hyperopia (23% vs. 15%), and astigmatism (73% vs. 41%). Common ocular features included shallow anterior chamber depth (ACD), thick lenses, and steep corneal curvature. The hyperopic cases had the shortest axial length (AL), whereas the myopia cases had significantly shallower ACD and greater LT. Those with a history of ROP had more prominent changes in the anterior segment. Generalized estimating equations showed that refractive errors could be predicted by a combination of optical components. Conclusions. In children born prematurely, the development of myopia is mainly influenced by anterior segment components, whereas hyperopia is mainly attributable to short AL. Astigmatism is primarily cornea-related. A combination of various optical components results in complicated refractive outcomes. The presence of ROP may be associated with significantly shorter ACD, thicker lens, and higher myopia and astigmatism. (ClinicalTrials.gov number, NCT01045616.)
We evaluated whether orally administered astaxanthin (AST) protects against oxidative damage in the ocular tissues of streptozotocin (STZ)-induced diabetic rats. Fifty 6-week-old female Wistar rats were randomly assigned to receive an injection of STZ to induce diabetes (n = 40) or to remain uninduced (n = 10). The diabetic rats were randomly selected into four groups and they were separately administered normal saline, 0.6 mg/kg AST, 3 mg/kg AST, or 0.5 mg/kg lutein daily for eight weeks. Retinal functions of each group were evaluated by electroretinography. The expression of oxidative stress and inflammatory mediators in the ocular tissues was then assessed by immunohistochemistry, western blot analysis, ELISA, RT-PCR, and electrophoretic mobility shift assay (EMSA). Retinal functions were preserved by AST and lutein in different levels. Ocular tissues from AST- and lutein-treated rats had significantly reduced levels of oxidative stress mediators (8-hydroxy-2'-deoxyguanosine, nitrotyrosine, and acrolein) and inflammatory mediators (intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and fractalkine), increased levels of antioxidant enzymes (heme oxygenase-1 and peroxiredoxin), and reduced activity of the transcription factor nuclear factor-kappaB (NF-κB). The xanthophyll carotenoids AST and lutein have neuroprotective effects and reduce ocular oxidative stress, and inflammation in the STZ diabetic rat model, which may be mediated by downregulation of NF-κB activity.
1 November 2014 in American Journal of Ophthalmology