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Swept-source optical coherence tomography angiography(SS-OCTA)is a new vascular imaging technique that was recently proposed. It has the advantages of being non-invasive, quick, high-resolution, and automated vascular stratification imaging. It is extremely helpful in the early diagnosis of ophthalmology-related diseases, as well as in the evaluation of treatment effectiveness and the tracking of disease progression. Based on the foundation of OCTA, SS-OCTA utilizes a fast-tuning laser with a wavelength of 1 050 nm for deeper penetration and non-invasive depth-resolved imaging of the retinal and choroidal microvascular systems, deepening the understanding of the characteristics of a wide range of ophthalmic diseases(fundus lesions, glaucoma, neurodegenerative diseases, etc.). The structures of the anterior segment of the eye can also be studied using SS-OCTA, including changes in the depth and density of corneal neovascularization as well as changes in iris neovascularization before and after therapy. This approach provides a novel tool for ophthalmic clinical practice. The development of the clinical use of SS-OCTA technology in ophthalmology is reviewed in this article.
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Objective:To evaluate the distribution characteristics of choroidal vascularity index (CVI) in macula among normal children using swept-source optical coherence tomography (SS-OCT), and to investigate the influencing factors.Methods:A cross-sectional study was conducted.Sixty-three children aged 6 to 12 years were enrolled in The First Affiliated Hospital of Zhengzhou University from May 2021 to November 2021.Spherical equivalent refraction, axial length (AL) and other ocular biological parameters were measured.Macula-centered CVI and choroidal thickness (ChT) were measured by SS-OCT angiography.According to the ETDRS partition, the obtained image was divided into macular central fovea (0-1 mm diameter), inner ring (1-3 mm diameter) and outer ring (3-6 mm diameter) zones.Data from the right eye were selected for statistical analysis.CVI in the three rings and four zones (superior, temporal, inferior and nasal zones) of the inner and outer rings were compared.Univariate and multiple linear regression analyses were used to analyze the correlation between CVI and sex, AL, anterior chamber depth (ACD), ChT and pupil diameter.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of The First Affiliated Hospital of Zhengzhou University (No.2021-KY-0399-003). Written informed consent was obtained from each guardian.Results:The average CVI in the macular central fovea, inner ring and outer ring were 0.35±0.12, 0.32±0.10 and 0.27±0.08, respectively, with a significant difference ( F=10.96, P<0.001), and significant differences in CVI were found in pairwise comparisons of the three ring zones (all at P<0.05). Significant differences in CVI were found among superior, temporal, inferior and nasal zones in inner and outer rings ( Fring=11.60, P=0.001; Fzone=12.02, P<0.05). The CVI was smaller in superior and nasal zones in inner ring than in temporal zone, greater in superior, temporal and inferior zones in outer ring than in nasal zone, smaller in superior zone of outer ring than that of the inner ring, and the differences were statistically significant (all at P<0.001). The single factor linear regression analysis showed that ChT in the fovea, inner ring and outer ring were the influencing factors of CVI in the three ring zones (all at β=0.001, P<0.001). Pupil diameter ( β=0.034, P=0.038; β=0.040, P=0.003; β=0.024, P=0.011) and ACD ( β=0.097, P=0.034; β=0.097, P=0.013; β=0.061, P=0.032) were the influencing factors of CVI in fovea, inner ring and outer ring.After multiple linear regression analysis, the regression equations were established as follows: CVI in the macular fovea=0.001×ChT in the macular fovea + 0.001×ChT in the inner ring+ 0.001×ChT in the outer ring-0.301 ( R2=0.514, F=6.875, P<0.001); CVI in the inner ring=0.001×ChT in the macular fovea+ 0.001×ChT in the inner ring+ 0.001×ChT in the outer ring+ 0.088×AL-0.307 ( R2=0.603, F=9.870, P<0.001); CVI in the outer ring=0.001×ChT in the macular fovea+ 0.001×ChT in the inner ring+ 0.001×ChT in the outer ring-0.135 ( R2=0.601, F=9.781, P<0.001). Conclusions:In children aged 6-12 years old, the CVI is higher in the macular central fovea than in inner and outer rings, and the CVI in nasal zone is the smallest in both inner and outer rings.The thicker the ChT, the higher the CVI in all zones in the macular area; the deeper the anterior chamber, the higher the CVI in the inner ring.
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Objective:To evaluate the feasibility of measurement and characteristics of intraocular lens (IOL) tilt using the swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and to explore its potentially relevant parameters.Methods:A cross-sectional study was conducted.Two hundred and forty-two eyes (119 right eyes, 123 left eyes) of 185 patients after phacoemulsification and IOL implantation were included in Beijing Tongren Hospital from July to September 2018.The IOL position, angle κ, angle α, corneal curvature, anterior chamber depth (ACD), pupil diameter (PD), and axial length (AL) were obtained by IOLMaster 700, and the IOL tilt direction and magnitude were calculated.The within-subject standard deviation and intraclass correlation coefficient were used to evaluate the repeatability of three IOL tilt measurements.Binocular symmetry of IOL tilt and the correlation between IOL tilt and different influencing factors were evaluated by Pearson linear correlation analysis or Spearman rank correlation analysis.Influencing factors for IOL tilt were assessed by multiple linear regression analysis.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.TRECKY2018-049). Patients were informed of the purpose and methods of this study and signed the written informed consent.Results:The repeatability of IOL tilt measurements was excellent with a within-subject standard deviation of 5.16° for IOL tilt direction and 0.13° for IOL tilt magnitude.IOL tilt was mirror symmetric in both eyes.The IOL tilt direction in right eyes ranged from -89.60° to 87.53° with a mean of (18.85±29.65)°, and the tilt magnitude ranged from 1.32° to 7.05° with a mean of (4.16±1.26)°.The IOL tilt direction in left eyes ranged from -84.30° to 89.44° with a mean of (21.17±32.38)°, and the tilt magnitude ranged from 0.58° to 7.40° with a mean of (3.80±1.31)°.There were moderate and weak positive correlations of IOL tilt direction and tilt magnitude between both eyes ( r=0.473, P<0.001; r=0.335, P=0.011). IOL tilt magnitude was weakly positively correlated with angle α and IOL diopter ( rs=0.272, P=0.003; r=0.285, P=0.002), and was weakly negatively correlated with ACD, PD and AL ( r=-0.303, P=0.001; r=-0.233, P=0.011; rs=-0.331, P<0.001). In backward stepwise regression analysis, the regression equation of IOL tilt magnitude, angle α, ACD, PD, AL and IOL diopter in multiple linear regression analysis was as follows: IOL tilt magnitude=10.503+ 1.456×angle α-0.532×ACD-0.196×AL ( R2=0.400; F=8.588, P<0.001). Conclusions:The SS-OCT biometer can be an effective method to assess IOL tilt.IOL tilt is mirror symmetric between the right eyes and left eyes.
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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.
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AIM: To evaluate the characteristics of choriocapillary blood flow in different patients with diabetic retinopathy(DR)based on the measurement of choriocapillaris(CC)perfusion density(PFD)using ultra-high-speed swept-source optical coherence tomography angiography(SS-OCTA)METHODS: The cross-sectional observational study was conducted on 139 cases(139 eyes)who admitted to the Second People's Hospital of Hefei, including 115 DR cases(115 eyes)and 24 control cases(24 eyes). The color retinal images were graded according to the Early Treatment Diabetic Retinopathy Study(ETDRS)scale, and the DR eyes were classified into non-DR group, nonproliferative diabetic retinopathy(NPDR)group, NPDR combined with diabetic macular edema(DME)group and proliferative diabetic retinopathy(PDR)group. The ultra-high-speed SS-OCTA was used to scan a 3mm×3mm region centered on the macular central fovea, the CC perfusion area was measured by the built-in software, and PFD was calculated. Multivariable linear regressions were used to evaluate the correlation between PFD of CC and DR degree.RESULTS: The degree of DR had a correlation with blood perfusion of CC after adjusting for various confounding factors. When compared to the control group, the PFD of CC in the central fovea of the NPDR group decreased by 9.358 units(95%CI -18.484～-0.232, P=0.045)and 9.284 units in the paracentral fovea(95%CI -18.487～-0.090, P=0.048); In the NPDR combined with DME group, the central fovea CC PFD decreased by 18.173 units(95%CI -28.583～-7.762, P=0.001), while the paracentral fovea decreased by 17.032 units(95%CI -27.521～-6.544, P=0.002); In the PDR group, the central fovea CC PFD decreased by 28.309 units(95%CI -39.978～-16.640, P<0.001), while the paracentral fovea decreased by 25.841 units(95%CI -37.597～-14.085, P<0.001).CONCLUSION: The macular perfusion can be objectively quantified by the measurement of CC PFD with ultra-high-speed SS-OCTA. The CC PFD in the macular region was significantly reduced in more advanced stages of DR. Furthermore, future research should focus on longitudinal studies in the causal relationship between CC perfusion and DR progression.
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AIM: To explore the feasibility of swept source optical coherence tomography angiography(SS-OCTA)in evaluating early retinal and choroidal microcirculation changes in patients with hypertension.METHODS:Prospective clinical study. A total of 27 patients with grade 2 or 3 essential hypertension(hypertension group)diagnosed in the Department of Cardiology of Xi'an First Hospital from July to November 2022 were included in the study. There were 14 males and 13 females. The mean age was(57.11±3.36)years. During the same period, 27 age- and sex-matched normal people without a history of hypertension were selected as the control group, including 12 males and 15 females. The average age was(55.74±2.95)years old. All patients underwent BCVA(LogMAR), intraocular pressure, axial length, slit lamp examination, fundus color photography and SS-OCTA examination. SS-OCTA was used to scan the macular area of the right eye in the range of 6×6 mm. The retina and choroid were divided into three concentric circles with diameters of 0-1 mm, 1-3 mm and 3-6 mm around the fovea according to ETDRS. Macular vessel density(VD), perfusion area(PA), retinal thickness(CMT), choroidal thickness(CT), choroidal vessel volume(CVV)and choroidal vasculr index(CVI)of the superficial capillary plexus(SCP)and the deep capillary plexus(DCP)in the macular area of 0-1 mm, 1-3 mm and 3-6 mm were analyzed and recorded. The changes in VD, PA, CMT, CT, CVV and CVI were compared between the two groups. Independent sample t-test was used to compare VD, PA, CMT and CVI between the two groups; CT, CVV and LogMAR visual acuity were analyzed by Wilcoxon signed rank test of independent samples.RESULTS:Compared with the control group, the hypertensive group had significantly lower VD in the macular area 0-3 mm(0-1 mm, t=-3.144; 1-3 mm, t=-3.611, P<0.05). VD in the area of 3-6 mm showed a tendency to increase compared with the control group(t=1.715, P>0.05). The CMT in the 0-1mm area of the macular area in the hypertension group was lower than that in the control group(t=-2.624, P<0.05). There was no significant difference in CT, CVV and CVI between the two groups(P>0.05).CONCLUSION:The VD of DCP in the 0-3 mm area and the CMT in the 0-1 mm area are decreased in hypertensive patients. There were no significant differences in CT, CVV and CVI between the two groups. VD and CMT in macular DCP may be used as indicators to evaluate the early changes of retinal and choroidal microcirculation in hypertensive patients.
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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 investigate the changes in retinal and choroidal blood flow after pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR).METHODS: A cross-sectional study was conducted on 35 patients(35 eyes)who were diagnosed as monocular PDR and received 23GPPV in ophthalmology department of the Second People's Hospital of Hefei between September 2020 and July 2022. All eyes underwent swept-source optical coherence tomography angiography(SS-OCTA)examination. Retinal and choroidal vascular parameters within 3mm×3mm of macular zone were measured by built-in analyzer, and its correlation with postoperative best corrected visual acuity(BCVA)was analyzed.RESULTS: The follow-up was 1～22(average 9.72±6.67)mo. At the last follow-up, flow area(FA)of intermediate capillary plexus(ICP)layer in paranasal foveal region was significantly reduced in PPV eyes(0.31±0.06mm2)compared with contralateral eyes(0.38±0.05mm2), and FA of deep capillary plexus(DCP)in temporal foveal region was significantly lower in PPV eyes(0.19±0.08mm2)than contralateral eyes(0.27±0.07mm2; all P<0.05). Choroidal vascularity index(CVI)were lower in PPV eyes than contralateral eyes in parafoveal subregions except temporal region(P<0.05). After PPV, BCVA had a certain correlation with the density and FA of middle and deep retinal vessels.CONCLUSIONS: Eyes with severe PDR may be prone to having a decrease in the DCP and parafoveal choroidal perfusion in the parafoveal regions after PPV than contralateral eyes.
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Purpose: To evaluate the role of swept?source optical coherence tomography (SS?OCT) in the management of acute Vogt–Koyanagi–Harada’s (VKH) disease. Methods: Retrospective analysis of SS?OCT images of acute VKH patients between January 2015 and February 2020 in a tertiary eye care hospital. Results: We studied 34 eyes of 17 patients with acute probable VKH disease. The mean age was 31.6 ± 10.4 years. Twelve patients were women. The mean follow?up was 17.1 ± 9.3 months. The mean visual acuity was 0.86 logMAR (Snellen equivalent: 6/45) at presentation and 0.18 logMAR (Snellen equivalent: 6/9) at the last follow?up. The mean subfoveal choroidal thickness (SFCT) was 784.97 microns at presentation, 431.40 microns at the first month of therapy, 453.94 microns at six months of therapy, and 405.83 microns at the last follow?up. Qualitative features noted on SS?OCT on presentation was subretinal fluid (SRF) in 29 (85%) eyes, subretinal hyperreflective dots in 34 (100%) eyes, subretinal septa in 33 (97%) eyes, RPE undulations in 21 (61.7%) eyes, posterior vitreous cells in 34 (100%) eyes, SRF around disc in 9 (26%) eyes, and disc swelling in 34 (100%) eyes. At the end of 1 year of follow?up, RPE undulations were absent in 30 eyes (88%) and disc swelling was notably absent in all 34 eyes (100%), though SRF around disc was noted in 4 eyes (11.7%) of 2 patients who had recurrences. Conclusion: SFCT, SRF around disc, RPE undulation, and disc swelling may be important indicators on SS?OCT to guide therapy and prognosticate recurrences in acute VKH.
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Purpose: To investigate the retinal and choroidal microcirculation changes in celiac disease (CD) patients via optical coherence tomography angiography (OCT?A). Methods: This cross?sectional study included 44 pediatric patients with newly diagnosed CD and 44 healthy pediatric subjects. The vascular densities (VD) of the superficial, deep, and choriocapillar plexuses (VDs, VDd, and VDcc, respectively) (%), the superficial and deep foveal avascular zones (FAZs and FAZd) (%), the central macular thickness (CMT) (?m), and the subfoveal choroidal thickness (SFCT) (?m) were measured with swept?source OCT?A in addition to a complete ophthalmological examination. Results: Mean ages of the CD patients and the healthy participants were 12.02 ± 2.9 and 13.6 ± 2.3 years, respectively. The central sectors of the VDs and VDd measurements were found to be significantly higher in the study group compared to the control group (p = 0.006; P = 0.001, respectively), and the temporal and nasal values of the VDcc measurements were significantly lower in the study group than in the control group (p ? 0.05 for both values). CMT and FAZ metrics did not differ between the groups (p ? 0.05). SFCT was significantly reduced (p = 0.001), and choroidal thinning was more considerable in female CD patients (p = 0.045). Conclusion: CD seems to affect macular and choroidal microcirculation. The reduced choriocapillaris plexus parameters and choroidal thickness may provide disease activity information.
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@#AIM: To evaluate the repeatability of a swept-source optical coherence tomography(SS-OCT)based biometer-IOL Master 700 in ocular biometrics in cataract eyes, and to investigate its agreement with a partially coherent optical interference based biometer-IOL Master 500. This study was also designed to compare the detection rate of the axial length(AL)measured by the two biometers. <p>METHODS:A total of 225 eyes of 133 cataract patients were included in this cross-sectional study from July to September 2018. Ocular biometric parameters including AL, keratometry(K), anterior chamber depth(ACD), lens thickness(LT), central corneal thickness(CCT)and white to white(WTW)were measured for each participant by both IOL Master 700 and IOL Master 500. <p>RESULTS: The IOL Master 700 measured <i>S<sub>w</sub></i> of AL, K<sub>m</sub>, K<sub>1</sub>, K<sub>2</sub>, ACD, LT, CCT, WTW in cataract patients were 0.027mm, 0.112D, 0.148D, 0.162D, 0.015mm, 0.010mm, 2.355μm and 0.134mm, <i>CoV</i> was 0.115%-1.162%, <i>ICC</i>≥0.923, the maximum <i>ICC</i> of AL is 1.000, and all measurements had high repeatability. The AL measured by IOL Master 700 and IOL Master 500 were(23.805±2.162)mm and(23.782±2.162)mm respectively, the difference was statistically significant(<i>t</i>=33.645, <i>P</i><0.001). However, the 95% <i>LoA</i> was 0.003mm-0.043mm, and the AL measured by the two biometers was significantly correlated(<i>r</i>=1.000, <i>P</i><0.001)with good agreement. The AL detection rates were 93.8%(211/225)for IOL Master 700 and 87.6%(197/225)for IOL Master 500, the difference was statistically significant(χ<sup>2</sup>=5.147, <i>P</i>=0.023).<p>CONCLUSION: IOL Master 700 demonstrates excellent repeatability in ocular biometric measurements including AL, K<sub>m</sub>, K<sub>1</sub>, K<sub>2</sub>, ACD, LT, CCT and WTW for cataract patients, especially in AL measurement. IOL Master 700 is in good agreement with IOL Master 500 in measuring AL, however the IOL Master 700 has a higher detection rate for AL in patients with severe opacity and subcapsular opacity in their lens.
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@#AIM: To compare the detection rate of axial length(AL)in cataract eyes by Tomey OA-2000 and IOL Master 500, and to evaluate the repeatability of OA-2000 in measuring ocular biometrics parameters. <p>METHODS: A cross-sectional study of 270 cataract eyes was implemented in the ophthalmic outpatient department from July to September 2018. Ocular biometric measurements including AL, keratometry readings(K), anterior chamber depth(ACD), lens thickness(LT), central corneal thickness(CCT), pupil diameter(PD)and white to white(WTW)were performed using OA-2000 and IOL Master 500. The detection rates of AL were calculated and compared between the two devices. <p>RESULTS: AL detection rates of 86.3%(233/270)and 97.0%(262/270)were found by IOL Master 500 and OA-2000 respectively. The mean difference in the measured AL by the two devices was(0.007±0.129)mm, and the 95% limits of agreement(95%<i>LoA</i>)of AL was 0.01(-0.24 to 0.26)mm. OA-2000 demonstrated good repeatability in measuring AL, ACD, K(2.5mm and 3mm pupil diameter), LT and CCT, but not in measuring PD and WTW. <p>CONCLUSION: Both OA-2000 and IOL Master 500 showed good agreement in AL measurement in cataract patients. However, compared with IOL Master 500, OA-2000 has a higher detection rate of AL. OA-2000 not only demonstrates excellent repeatability in ocular biometric measurements including AL, ACD, K, LT and CCT, but also more advantageous for the AL measurement of cataract with heavy lens opacity and subcapsular opacity.
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@#In recent years, ocular biometers based on swept-source optical coherence tomography(SS-OCT)technology have emerged in ophthalmic practice. Compared with the earlier ocular biometers such as the partially coherent interference(PCI)based ones, the SS-OCT based devices have a higher signal-to-noise ratio, greater swept light wavelength, better tissue penetration, faster scanning speed, and better axial length(AL)detection rate for cataract patients. This review aims to summarize the advances of a widely used SS-OCT based device-IOL Master 700 in cataract.
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@#AIM: To observe the morphological characteristics of posterior precortical vitreous pocket(PPVP)using swept-source optical coherence tomography(SS-OCT). <p>METHODS:Prospective study. One hundred and thirty-eight eyes of 91 cases with PPVP observed by SS-OCT in Henan Eye Hospital from March 2019 to June 2019 were included in the study. The average width and height size of PPVP was compared among subjects with different genders, age and equivalent spherical.<p>RESULTS: In 138 eyes, 112 eyes(81.2%)were ship shaped, 19 eyes(13.8%)were oval, and 7 eyes(5.1%)were hook shaped. Ninety-nine eyes(71.7%)had PPVP which connected with Martegiani area. The average width of PPVP was 6248.82±1117.87μm, and the average height of PPVP was 562.12±476.94μm. There was no difference in the width and height of PPVP between different genders(<i>P</i>>0.05), and the PPVP' width was positively correlated with age(<i>r</i>=0.32, <i>P</i><0.01). The PPVP' height in low myopia group were lower than that in non-myopia and moderate myopia group eyes(<i>P</i>=0.01, 0.03). <p>CONCLUSION: PPVP is a boat-shaped fluid cavity in front of the macula, which communicates with the Cloquet canal. Its width is related to the age. The existence of PPVP may play a role in the development of PVD and its progress.
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Purpose: To evaluate the potential clinical utility of wide-field swept source optical coherence tomography angiography (SS-OCTA) using a prototype device compared to a wide-field fundus autofluorescence (FAF) for analysis of the disease activity in eyes with tubercular serpiginous-like choroiditis (TBSLC). Methods: Using a prototype SS-OCTA device (PLEX Elite, Carl Zeiss Meditec, Dublin, CA), 17 eyes of 12 consecutive patients with TBSLC were imaged and multiple 12 mm � 12 mm OCTA scans were captured, which were montaged to create wide-field montage OCTA images scans. A wide- FAF (Eidon, CenterVue, Padova, Italy) was performed in the same sitting. Two masked graders independently analyzed OCTA and FAF images for the presence of choroidal lesions, recorded the number of lesions identifiable, and provided a subjective grading for the activity of individual lesion, which were then compared. Results: The total number of lesions identified on FAF were 282 (posterior pole lesions, n = 129 and peripheral lesions n = 153) and on wide-field SS-OCTA were 230 (posterior pole lesions, n = 108 and peripheral lesions n = 122). Active choroidal lesions were comparable on the two machines (n = 28 on FAF and n = 28 on SS-OCTA, respectively); whereas numerous healed lesions were identified on FAF (n = 219) as compared to SS-OCTA (n = 170). There was good correlation among the devices for healed lesions (Pearson correlation, r = 0.82) and active lesions (r = 0.88). Conclusion: There was good correlation between FAF and wide-field SS-OCTA for detection of disease activity in TBSLC; however, FAF depicted greater number of healed lesions compared to wide-field SS-OCTA.
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Purpose: The purpose of this study is to compare the thickness and depth measurements of the lamina cribrosa (LC) obtained using a swept-source optical coherence tomography (SS-OCT) device in idiopathic intracranial hypertension (IIH) patients and healthy subjects. Methods: This retrospective, cross-sectional observational study included 16 eyes with IIH and 20 control eyes. The LC measurements with serial horizontal B scans of the optic nerve head were obtained using SS-OCT (Topcon 3D DRI OCT Triton). The anterior lamina surface (ALS) depth, posterior lamina surface (PLS) depth, and LC thickness measurements were evaluated. Results: In patients with IIH, the mean ALS depth was 225.00 ± 58.57 ?m and the mean PLS depth was 449.75 ± 63.50 ?m. In the IIH control group, the corresponding values were 359.40 ± 105.38 and 570.10 ± 99.41 ?m (P < 0.05). The difference in LC thickness between the IIH and control subjects was not statistically significant. Conclusion: LC can be evaluated using an SS-OCT device. LC was displaced anteriorly in patients with IIH compared with normal controls. The assessment of LC level with SS-OCT in IIH cases is a valuable and reproducible adjunctive imaging method in terms of diagnosis and follow-up.
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Purpose: The purpose of this study is to provide normative database for subfoveal choroidal thickness in Indian eyes using swept-source optical coherence tomography. Methods: This is a cross-sectional study based at a tertiary eye care center in Northern India. Two hundred and thirty eight eyes of 119 healthy subjects were examined in terms of axial length, spherical equivalent, and choroidal thickness. Inclusion criteria included age 19� years, no retinal or choroidal disorder, and patients with clear media and good fixation. Patients with high hypermetropia (>4 D) or myopia (>6 D) or any systemic disease likely to affect choroidal thickness were excluded. Twelve radial line scans were obtained centered on the fovea that were used to calculate choroidal and retinal thickness in 9 early treatment diabetic retinopathy study (ETDRS) zones. Results: The mean age of all the subjects was 28.70 � 11.28 years; mean axial length was 23.63 � 1.96 mm, and mean spherical equivalent was ? 0.92 � 3.08 D. The mean subfoveal choroidal thickness was 299.10 � 131.2 ? and mean foveal thickness was 239.92 � 48.16 ?. A negative correlation was found between subfoveal choroidal thickness and age (r = ?0.0961, P = 0.1392) and axial length (r = ?0.3166, P < 0.001). A statistically significant positive correlation was found between subfoveal choroidal thickness and refractive error (r = 0.2393, P = 0.0002). Conclusion: This study provides normative database for subfoveal choroidal thickness and foveal thickness using swept-source optical coherence tomography. The choroidal thickness measured with swept-source platform is slightly higher than that reported with spectral domain platforms.
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Objective@#To evaluate the repeatability and reproducibility of swept-source optical coherence tomography biometrics (Tomey OA-2000) for measuring the biological parameters of the eyeballs in healthy people.@*Methods@#A diagnostic test was carried out in this study.One hundred and three healthy volunteers who were recuited from July to September 2018 in Affiliated Hospital of North Sichuan Medical College were included, and the right eyes were examined.Two examiners used OA-2000 for 3 consecutive measurements, respectively.One week later, the first examiner used OA-2000 for 3 consecutive measurements.The ocular biological parameters including axial length (AL), anterior chamber depth (ACD), corneal curvature (K), lens thickness (LT), central corneal thickness (CCT), pupil diameter (PD), and white to white (WTW) were measured.The repeatability and reproducibility of each parameter based on within-subject standard deviation (SW), repeatability limit of standard deviation (2.77SW), coefficient of variation (CoV) and intra-class correlation coefficient (ICC) was evaluated.This study followed the Declaration of Helsinki.This study protocol was approved by Ethic Committee of the Affiliated Hospital of North Sichuan Medical College (No.2018ER[A]019).@*Results@#Of the ocular biological parameters measured by OA-2000, CoV was less than 2% while ICC was greater than 0.950, except PD and WTW.The repeatability and reproducibility of K, AL and ACD were all good.For K1(ø=2.5 mm and 3.0 mm), the SW was less than 0.120 D, the 2.77SW was less than 0.350 D, the CoV was less than 0.293%, and the ICC was greater than 0.990; For K2 (ø = 2.5 mm and 3.0 mm) , the SW were less than 0.175 D, the 2.77SW were less than 0.485 D, the CoV was less than 0.396%, the ICC was greater than 0.980; for Km (ø = 2.5 mm and 3.0 mm), the SW were less than 0.099 D, 2.77SW were less than 0.275 D, CoV was less than 0.227%, ICC was greater than 0.996; ACD SW was less than 0.024 mm, 2.77SW was less than 0.066 mm, CoV was less than 0.668%, ICC were greater than 0.993; the SW of AL was less than 0.014 mm, the 2.77SW was less than 0.038 mm, the CoV was less than 0.057%, and all of the ICCs were 1.000.@*Conclusions@#Except PD and WTW, the ocular biological parameters measured by OA-2000 have good repeatability and reproducibility, in which the accuracy of AL measurement is the highest.
ABSTRACT
PURPOSE: To evaluate the accuracy of predicting refractive outcomes of swept-source optical coherence tomography based biometry (ARGOS; Movu Inc., Santa Clara, CA, USA) in nuclear cataracts. METHODS: A total of 107 eyes (107 nuclear cataract patients) were analyzed. Subjects were divided into three groups according to the maximum nuclear density of Pentacam HR (A, lower tertile; B, medium tertile; C, upper tertile). The keratometry and axial length measured by IOLMaster (Carl Zeiss Meditec, Jena, Germany) and ARGOS systems were compared for each group. The correlation between maximum nuclear density and axial length difference readings from the two instruments was evaluated. The mean absolute error between the predicted refraction and 2-month post-operative refraction was compared. RESULTS: The maximum nuclear densities were 28.31 ± 7.30, 51.37 ± 7.82, and 88.63 ± 11.23 for groups A, B, and C, respectively. The axial length measured by ARGOS was significantly longer than that obtained using IOLMaster for groups B and C (respectively, p = 0.035, p < 0.001). A significantly positive correlation was found between the maximum nuclear density and axial length difference of the two devices (p < 0.001). Mean absolute errors were not significantly different between IOLMaster and ARGOS in group A. However, in groups B and C, the mean absolute error using ARGOS (0.31 ± 0.22 D and 0.32 ± 0.20 D, respectively) was significantly lower than that of IOLMaster (0.43 ± 0.21 D and 0.50 ± 0.26 D, respectively) (Group B, p = 0.027; Group C, p = 0.001). CONCLUSIONS: Even in dense nuclear cataracts, accurate refractive outcome prediction was possible using swept-source optical coherence tomography based biometry.