Objectives: to evaluate the anterior chamber depth (ACD), axis length (AL), and the relationships between ACD and AL in high myopia patients. Objects and methods: a descriptive study was conducted on 168 eyes (88 patients, ≥12 years old) diagnosed with high myopia (more than -6D). Results: the average myopia degree, ACD, and AL were -8.75±2.61D, 3.72±0.20 mm, and 27.33±1.49 mm, respectively. There was no statistical signification between ACD and myopia degree (r=0.044; p>0.05), strong correlation between AL and myopia degree (r=-0.762; p<0.001), and weak correlation between ACD and AL (r=0.165; p<0.05). Conclusion: myopia degree does not relate to ACD, but has a strong correlation to AL. Measuring the AL on high myopia patients is important for the diagnosis, prognosis, and treatment.

Nanospherical upconversion luminescence particles (UCLPs) Gd2O3:Er3+ and Gd2O3:Er3+@ chitosan (CS) were prepared by step-by-step precipitation and calcination of the available nitrate rare earth sales and chitosan. The morphology and composition of as-prepared samples were characterized by field emission electron spectroscopy and Fourier transform infrared spectroscopy. The synthesized UCLPs were non-agglomerate spheres in uniform nanoscale. The quantitative amount of chitosan was well coated with the gain surface of the UCLPs Gd2O3:Er3+ to obtain Gd2O3:Er3+@CS nanocomposite. The down-conversion luminescent intensity of Gd2O3:Er3+ NSP is lower than Gd2O3:Er3+@CS NSP samples, but luminescent characterizations were non-change. The photoluminescence of the green emission range of all UCLPs samples with chitosan-coated and -uncoated took the leading position. By using a diode laser excitation with 975 nm of wavelength, the detected intensity of red emission is more remarkably detected than green emissions. The two-photon mechanism for both green and red emissions of nanophosphor was observed. As a result, these might be promising opportunities to conjugate with various bio subjects that could be used in medical applications.