Measuring changes in Schlemm’s canal and trabecular meshwork in different accommodation states in myopia children: an observational study

Abstract Purpose: Studies were designed to evaluate changes in the size of the Schlemm's Canal (SC) and trabecular meshwork(TM) during accommodation stimuli and cycloplegia states in myopic children. Methods: 34 children were enrolled. A -6D accommodation stimulus was achieved by looking at an optotype through a mirror. Cycloplegia state was induced with 1% tropicamide. Two states were confirmed by measuring the central lens thickness（CLT）, the anterior chamber depth and the pupil diameter. The size of the Schlemm's Canal (SC) and Trabecular Meshwork(TM) was measured using swept-source optical coherence tomography. And the associations between the change of the SC and the CLT were analyzed. Results: When compared with the relaxation state, under -6D accommodation stimuli, the size of SC increased significantly: the SC area (SCA) amplified from 6371±2517μm2 to 7824±2727 μm2; the SC length (SCL) from 249±10 μm to 295±12 μm, and SC width (SCW) from 27±9 μm to 31±8 μm. Under cycloplegia state, the SCA reduced to 5009±2028 μm2; the SCL to 212±μm and the SCW to 22±5 μm. In addition, the changed areas of SCA (r=0. 35; P=0.0007), SCL (r=0. 251; P=0.0172), and SCW (r=0. 253; P=0.016) were significantly correlated with the change in CLT. However, the size of TM did not change substantially when compared with the relaxation state. Only the TM length (TML) increased from 562±45μm to 587±47μm after -6D accommodation stimulus. Conclusion: SC size enlarges after -6D accommodation stimuli and shrinks under cycloplegia. However, for TM, only the TM length increase under accommodation stimulus state. KEYWORDS: Schlemm’s Canal, Trabecular Meshwork, accommodatio

Heats of Formation and Ionization Potentials of Some α-Aminoalkyl Radicals

Heats of formation and ionization potentials of α-aminoalkyl radicals, R2NCR\u272, were derived from measurements of the appearance energies for the fragmentations of a series of ethylenediamines. Stabilization energies, Es, are high and increase with increasing C- or N-alkylation; the converse applies to ionization potentials, IP. For example, in the case of H2NC(Me)2, Es= 17 kcal mol-1 and IP = 5.4 eV. © 1983, American Chemical Society. All rights reserved

ChemInform Abstract: HEATS OF FORMATION AND IONIZATION POTENTIALS OF SOME α-AMINOALKYL RADICALS

Heats of formation and ionization potentials of α-aminoalkyl radicals, R2NCR\u272, were derived from measurements of the appearance energies for the fragmentations of a series of ethylenediamines. Stabilization energies, Es, are high and increase with increasing C- or N-alkylation; the converse applies to ionization potentials, IP. For example, in the case of H2NC(Me)2, Es= 17 kcal mol-1 and IP = 5.4 eV. © 1983, American Chemical Society. All rights reserved