AIM:To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure(IOP)change following the head-down tilt(HDT)test.METHODS:The study included 21 participants at the Department of...AIM:To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure(IOP)change following the head-down tilt(HDT)test.METHODS:The study included 21 participants at the Department of Ophthalmology of Tongji Hospital.Subjects received the test of I-care tonometry,enhanced depth imaging optical coherence tomography and heart rate variability(HRV)analysis before and after 15 min HDT test.The lumen area of Schlemm’s canal(SCAR),IOP,HRV were calculated.RESULTS:IOP increased significantly after 20°head down position from 14.0±3.0 to 17.0±3.3 mm Hg(P<0.001).SCAR decreased from 13449.0±5454.9μm^(2) at sitting condition to 9576.6±4130.9μm^(2) post 15 min HDT test.High frequency(HF)indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz.Heart rate(HR)decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT.The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT(R^(2)=20%,P=0.04).CONCLUSION:These outcomes perform the first evidence of the activation of autonomic nervous system of HDT may cause the collapse of Schlemm’s canal lumen,which in turn leading to the increased IOP.展开更多
AIM:To observe the changes in Schlemm’s canal(SC),trabecular meshwork(TM),and anterior chamber relevant parameters after small incision lenticule extraction(SMILE) of myopia patients.METHODS:A total of 58 eyes from 3...AIM:To observe the changes in Schlemm’s canal(SC),trabecular meshwork(TM),and anterior chamber relevant parameters after small incision lenticule extraction(SMILE) of myopia patients.METHODS:A total of 58 eyes from 30 patients who underwent SMILE were divided into a low and moderate myopia group(group A,32 eyes) and a high myopia group(group B,26 eyes).The diameter and area of the SC,the width and thickness of TM obtained by CIRRUS HD-OCT5000,and the related anterior chamber parameters obtained by Pentacam anterior segment analysis system,accommodation amplitude(AMP) were observed pre-and postoperatively.The preoperative intraocular pressure(IOP) and postoperative correction of intraocular pressure(IOPcc) were measured.RESULTS:The diameter and area of the SC in the two groups were significantly increased postoperatively(all P<0.01).The TM width of the patients in the two groups were increased at 1mo after surgery(both P<0.01),but the TM thickness did not change(P>0.05).The corneal curvature,central anterior chamber depth,and anterior chamber volume decreased after SMILE surgery(all P<0.01).There was a weak negative correlation between the SC area change and AMP change in group A(r=-0.362,P<0.01).The postoperative IOP decreased after correction by Shah formula(P<0.05).CONCLUSION:SC and TM in myopia patients change in the early postoperative stage of SMILE and the IOP is decline.展开更多
文摘AIM:To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure(IOP)change following the head-down tilt(HDT)test.METHODS:The study included 21 participants at the Department of Ophthalmology of Tongji Hospital.Subjects received the test of I-care tonometry,enhanced depth imaging optical coherence tomography and heart rate variability(HRV)analysis before and after 15 min HDT test.The lumen area of Schlemm’s canal(SCAR),IOP,HRV were calculated.RESULTS:IOP increased significantly after 20°head down position from 14.0±3.0 to 17.0±3.3 mm Hg(P<0.001).SCAR decreased from 13449.0±5454.9μm^(2) at sitting condition to 9576.6±4130.9μm^(2) post 15 min HDT test.High frequency(HF)indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz.Heart rate(HR)decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT.The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT(R^(2)=20%,P=0.04).CONCLUSION:These outcomes perform the first evidence of the activation of autonomic nervous system of HDT may cause the collapse of Schlemm’s canal lumen,which in turn leading to the increased IOP.
基金Supported by the National Natural Science Foundation of China (No.81974133)。
文摘AIM:To observe the changes in Schlemm’s canal(SC),trabecular meshwork(TM),and anterior chamber relevant parameters after small incision lenticule extraction(SMILE) of myopia patients.METHODS:A total of 58 eyes from 30 patients who underwent SMILE were divided into a low and moderate myopia group(group A,32 eyes) and a high myopia group(group B,26 eyes).The diameter and area of the SC,the width and thickness of TM obtained by CIRRUS HD-OCT5000,and the related anterior chamber parameters obtained by Pentacam anterior segment analysis system,accommodation amplitude(AMP) were observed pre-and postoperatively.The preoperative intraocular pressure(IOP) and postoperative correction of intraocular pressure(IOPcc) were measured.RESULTS:The diameter and area of the SC in the two groups were significantly increased postoperatively(all P<0.01).The TM width of the patients in the two groups were increased at 1mo after surgery(both P<0.01),but the TM thickness did not change(P>0.05).The corneal curvature,central anterior chamber depth,and anterior chamber volume decreased after SMILE surgery(all P<0.01).There was a weak negative correlation between the SC area change and AMP change in group A(r=-0.362,P<0.01).The postoperative IOP decreased after correction by Shah formula(P<0.05).CONCLUSION:SC and TM in myopia patients change in the early postoperative stage of SMILE and the IOP is decline.
