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Objective:To investigate the consistency of swept-source optical coherence tomography(SS-OCT)and time-domain optical coherence tomography(TD-OCT)in measuring the parameters of anterior chamber angle.Methods:A total of 46 myopic patients(92 eyes)were retrospectively selected from Department of Ophthalmology of Army Specialty Medical Center from January 2023 to May 2023.Both SS-OCT and TD-OCT were used to measure respectively the parameters of anterior chamber angle of patients.And then,the differences of central anterior chamber depth(ACD),angle opening distance(AOD500,AOD750),scleral spur angle(SSA),trabecular iris area(TISA500,TISA750)between SS-OCT and TD-OCT were compared and analyzed.The Pearson correlation analysis and Bland-Altman test were adopted to analyze and measure the correlation and consistency of the measures.Results:There was significant difference in ACD between the two kinds of scan methods(t=-6.83,P<0.001).Additionally,the differences of the AOD500,AOD750,SSA500,TISA500 and TISA750 of measured data beside of nose were significant(t=-5.16,5.51,-6.51,-4.75,-5.69,P<0.001),respectively.Similarly,the differences of them beside of temple were significant(t=-5.04,-4.8,-6.06,-3.84,-4.02,P<0.001),respectively.There was positive correlation between the two kinds of scan methods(r=0.71-0.92).The Bland-Altman analysis showed that 2.1% to 8.9% of the measured values were outside the consistency limit by 95%.Conclusion:There are differences between SS-OCT and TD-OCT in the measures of the parameters of anterior chamber angle of myopic patients,and the measured results of them appear positive correlation.
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Advances in imaging technology have revolutionized the field of ophthalmology, changing the understanding, diagnosis, and treatment of ophthalmic diseases. Swept-source optical coherence tomography(SS-OCT)is a non-contact high-resolution imaging technology. It further improves imaging depth and scanning speed, adds new algorithms and features. The application of SS-OCT enables the three-dimensional evaluation of corneal structures, offering curvature and height maps for both the anterior and posterior surfaces of the cornea, as well as precise corneal thickness mapping. These invaluable tools aid ophthalmologists in effectively screening and diagnosing various corneal lesions such as keratoconus, corneal dystrophy, and degeneration. Moreover, the enhanced speed, accuracy, and sensitivity provided by SS-OCT measurements facilitate improved surgical planning and postoperative monitoring for patients undergoing refractive surgery or keratoplasty. This article reviews the development of SS-OCT technology and its potential clinical utility in corneal diseases and surgical application, in order to support more possible future research and clinical treatment.
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AIM:To evaluate the correlation between axial lengths and anterior segment parameters using swept-source optical coherence tomography(SS-OCT).METHODS:For the cross-sectional clinical study, a total of 109 adult volunteers with different degrees of myopia recruited from January 1, 2022, to March 31, 2022, at the ophthalmology clinic of the First Affiliated Hospital of Zhengzhou University were included. Participants were divided into 4 groups based on axial length(AL): group A(AL≤24.0mm), group B(24.0mm<AL≤25.0mm), group C(25.0mm<AL≤26.0mm)and group D(AL>26.0mm). Anterior segment examinations were performed using SS-OCT, including: central corneal thickness(CCT), lens thickness(LT), anterior chamber depth(ACD), anterior chamber width(ACW), angle opening distance(AOD500), angle recess area(ARA500), trabecular iris space area(TISA500), trabecular iris angle(TIA500), crystalline lens rise(CLR). The relationships between these data and AL, spherical equivalent(SE)were analyzed.RESULTS:There was no difference in the comparison of CCT among the four groups(P>0.05). There were differences in SE, LT, ACD, ACW, AOD500, ARA500, TISA500, TIA500 and CLR among the four groups(all P<0.01). SE and LT were negatively correlated with AL(r=-0.75, -0.41, all P<0.01); ACD, ACW and CLR were positively correlated with AL(r=0.58, 0.45, 0.54, all P<0.01); AOD500, ARA500, TISA500 and TIA500(temporal and nasal side)were positively correlated with AL(all P<0.01). ACD and CLR were negatively correlated with SE(r=-0.21,-0.25, all P<0.01), and LT was positively correlated with SE(r=0.21, P<0.05).CONCLUSION:As AL increases, CCT remains unchanged while the ACD and ACW increase. The position of the crystalline lens moves backward and LT decreases.
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AIM: To explore Bland-Altman analysis of corneal curvature and astigmatism measured by new swept-source optical coherence tomography(SS-OCT)and Scheimpflug anterior segment analyzer in patients with age-related cataract.METHODS: A total of 177 patients(282 eyes)with age-related cataract admitted to the hospital between January and December 2021 were enrolled. The steep-axis curvature(Ks), flat-axis curvature(Kf), mean corneal curvature(Km), corneal astigmatism and astigmatism axis of anterior corneal surface, posterior surface and the whole cornea were measured by SS-OCT and Scheimpflug anterior segment analyzer respectively. All parameters were detected by paired sample t-test, intra-group repeatability test, Pearson correlation and Bland-Altman consistency analysis.RESULTS: There was no significant difference in Ks, Kf and Km of anterior corneal surface measured by SS-OCT and Scheimpflug anterior segment analyzer(P&#x003E;0.05). Ks, Kf and Km of posterior corneal surface and whole cornea measured by Scheimpflug anterior segment analyzer were all greater than those measured by SS-OCT(P&#x003C;0.05). There was no significant difference in astigmatism and axial values of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT and Scheimpflug anterior segment analyzer(P&#x003E;0.05). The intraclass correlation coefficient(ICC)of all parameters was greater than 0.88, indicating a good intra-group repeatability. Ks, Kf, Km, astigmatism and axis of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT were positively correlated with those measured by Scheimpflug anterior segment analyzer(P&#x003C;0.05). Bland-Altman consistency analysis showed that Ks, Kf, Km, corneal astigmatism and axis of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT were highly consistent with those measured by Scheimpflug anterior segment analyzer(P&#x003C;0.05).CONCLUSION: The corneal curvature and astigmatism parameters measured by new SS-OCT are highly consistent with those measured by Scheimpflug anterior segment analyzer, which can be applied in the diagnosis of corneal curvature and astigmatism in patients with age-related cataract.