Glaucoma surgery experiments using digital microscope-integrated optical coherence tomography and OCT-compatible instruments

There is a certain failure rate in traditional glaucoma surgery because of the lack of depth information in microscope images.In this work,we present a digital microscope-integrated optical coherence tomography(MIOCT)system and several custom-made OCT-compatible instruments for glaucoma surgery.Sixteen ophthalmologists were asked to perform trabeculectomy and canaloplasty on live porcine eyes using the system and instruments.After surgery,a subjective feedback survey about the user experience was taken.The experiment results showed that our system can help surgeons easily locate important tissue structures during surgery.The custom-made instruments also solved the shadowing problem in OCT imaging.Surgeons preferred to use the system in their future practice.

Observation of the early blood vessels of cutaneous malignant melanoma using Swept Source Optical Coherence Tomography A ngiography(SS-OCTA)

Melanoma,characterized by high mortality,rapid development and accompanied with angio-genesis is the most typical malignant tumor in skin cancer.Hence,the detection of blood vessels is of much significanoe.The early vascular network has small scale.If we remove the tumor early and biopsy it,it will increase the spread of the cancer cells and infection and bleeding.In this case,we presented a new angiography method.A high-resolution OCT system for noninvasive an-giographic imaging of early skin melanoma-Swept Source Optical Coberence Tomography Angiography(SS-OCTA)is proposed.With a high lateral resolution of 10pm in vrivo tomographic angiography,SS-OCTA is used to image and identify the morphology of the early tumor blood vessels.In addition,a control group experiment is conducted to observe the growth of melanoma in the process of rupture,malormation of micro-vessels.The results of the analysis and statistical test(P<0.05)are statistically signifcant.

Time-Effect Relationship of Toxicity Induced by Roundup and Its Main Constituents in Liver of Carassius Auratus

In order to evaluate the eco-toxicological effects of Roundup&reg on Carassius auratus (C. auratus), fish were exposed to 32 μg/L Roundup&reg, isopropylamine salt of glyphosate (G.I.S) and polyoxyethylene amine (POEA) over different periods (0.5, 1, 3, 7 and 14 d). Hydroxyl radical (·OH), malondialdehyde (MDA) and acetylcholinesterase (AChE) in liver were detected in this study. Results showed that the generation of ·OH increased before 7 d, but without significantly difference. ·OH was induced at 1 d for POEA group, 3 d for Roundup&reg group and 7 d for G.I.S group. At 14 d, ·OH generation returned to normal levels. MDA contents all increased significantly (p < 0.01) during 7 days and then reached a normal level at 14 d. AChE activity in all group tests revealed a significant inhibition (p < 0.01) after 7 days exposure and then rebounded a little, but remained below the control after 14 days exposure. The rate of AChE inhibition range from 13% - 42% in Roundup&reg, 6% - 40% in G.I.S, and 21% - 54% in POEA, suggesting that POEA was more toxic compared to Roundup&reg and G.I.S. 32 μg/L Roundup&reg exposure led to the change of physiological and biochemical indexes in C. auratus, which was a reversible process in the long run.

Accuracy characterization of Shack-Hartmann sensor with residual error removal in spherical wavefront calibration

The widely used Shack-Hartmann wavefront sensor(SHWFS)is a wavefront measurement system.Its measurement accuracy is limited by the reference wavefront used for calibration and also by various residual errors of the sensor itself.In this study,based on the principle of spherical wavefront calibration,a pinhole with a diameter of 1μm was used to generate spherical wavefronts with extremely small wavefront errors,with residual aberrations of 1.0×10^(−4)λRMS,providing a high-accuracy reference wavefront.In the first step of SHWFS calibration,we demonstrated a modified method to solve for three important parameters(f,the focal length of the microlens array(MLA),p,the sub-aperture size of the MLA,and s,the pixel size of the photodetector)to scale the measured SHWFS results.With only three iterations in the calculation,these parameters can be determined as exact values,with convergence to an acceptable accuracy.For a simple SHWFS with an MLA of 128×128 sub-apertures in a square configuration and a focal length of 2.8 mm,a measurement accuracy of 5.0×10^(−3)λRMS was achieved across the full pupil diameter of 13.8 mm with the proposed spherical wavefront calibration.The accuracy was dependent on the residual errors induced in manufacturing and assembly of the SHWFS.After removing these residual errors in the measured wavefront results,the accuracy of the SHWFS increased to 1.0×10^(−3)λRMS,with measured wavefronts in the range ofλ/4.Mid-term stability of wavefront measurements was confirmed,with residual deviations of 8.04×10^(−5)λPV and 7.94×10^(−5)λRMS.This study demonstrates that the modified calibration method for a high-accuracy spherical wavefront generated from a micrometer-scale pinhole can effectively improve the accuracy of an SHWFS.Further accuracy improvement was verified with correction of residual errors,making the method suitable for challenging wavefront measurements such as in lithography lenses,astronomical telescope systems,and adaptive optics.