ABSTRACT
Objective:To observe the peripapillary atrophy (PPA) and peripapillary choroidal vascularity index (CVI) in patients with different degrees of myopia and to analyze their correlations.Methods:A cross-sectional clinical study. From September 2021 to December 2021, 281 mypoic patients of 281 eyes treated in Eye Hospital of Wenzhou Medical University at Hangzhou were included in this study, and the right eye was used as the treated eye. There were 135 eyes in 135 males and 146 eyes in 146 females. The age was 28.18±5.78 years. The spherical equivalent refraction (SE) was -5.13±2.33 D. The patients were divided into three groups: low myopia group (group A, -3.00 D <SE≤-0.50 D), moderate myopia group (group B, -6.00 D≤SE≤-3.00 D);high myopia group (group C, SE<-6.00 D). The spherical equivalent refraction was statistically different among the three groups ( H=241.353, P<0.05). All of the affected eyes were examined by swept-source optical coherence tomography. Combined with B-scan image,assessment and area measurement of β area, γ area (β-PPA and γ-PPA) were carried out on the en-face image. After binarization of the collected images, the nasal, superior, temporal and inferior CVI of the optic disc were calculated. For comparison between groups, one-way ANOVA was used for continuous variables with normal distribution, Kruskal-Wallis test was used for continuous variables with abnormal distribution, and categorical variables were used χ2 inspection. Linear regression analysis was used for the relationship between β-PPA and γ-PPA area and peripapillary CVI of different regions. Linear regression analysis was used to evaluate the relationships between the area of peripapillary atrophy and peripapillary choroidal vascularity index in different regions. Results:There was no statistical difference in the incidence of β-PPA among the three groups ( χ2=4.672, P=0.097). The incidence of γ-PPA in group A was lower than that in group B anc C, and the difference was statistically different ( χ2=33.053, P<0.001), in which both group A was lower than group B and C. Among the three groups, the area of β-PPA and γ-PPA was statistically significant ( H=36.535, 39.503; P<0.001, 0.001); the β-PPA area of group A and B was lower than that of group C; the γ-PPA area was group A <group B <group C. Peripapillary CVI of different regions in group A, group B and group C was statistically significant ( F=11.450, 5.037, 6.018, 4.489; P<0.05). The temporal CVI in group C was lower than that in group A and B; The inferior CVI of group C was lower than that of group A, and the superior and nasal CVI of group B and C were lower than that of group A. In multivariate analysis, SE ( β=0.374, P<0.001), temporal CVI ( β=-0.299, P<0.001) were correlated with the area of β-PPA (adjusted R2=296, P<0.001); AL ( β=0.452, P<0.001), temporal CVI ( β=-0.220, P<0.001) were correlated with the area of γ-PPA (adjusted R2=0.309, P<0.001). Conclusions:The incidence and area of γ-PPA are increased in the higher degree of myopia group. The area of γ-PPA is positively correlated with the axial length, and both the area of β-PPA and γ-PPA are negatively correlated with temporal CVI.
ABSTRACT
Recently,various eye refractive problems have attracted widespread attentions from scholars.In order to further explore the mechanism of the occurrence and development of eye refractive problems,a large amount of eye imaging technologies and analysis systems were born and applied to eye refractive researches,such as the mechanism of myopia and presbyopia,as well as the whole eye biological parameters measurement.In this literature,combining the research progress of our laboratory,we described the advances of eye imaging technology and its application in the field of ophthalmology.Based on the importance of eye imaging technology in the eye refractive researches,we propose that in order to realize the regulatory effect research of 'visual cognition feedback system monitoring technology',the development of eye imaging technology should be based on the need of 'in vivo,nondestructive,objective and accurate' and develop in the direction of 'real-time,dynamic,intelligent analysis'.
ABSTRACT
Objective To investigate choroid thickness at horizontal meridian with optical coherence tomography (OCT) and compare the choroid thickness difference between first visit myopia children with those children who wear orthokeratology lens for more than 1 year.Methods This retrospective study enrolled 68 myopia children with low to moderate myopia (-1.00--6.00 D) who visited our hospital and took choroid images by OCT.The total subjects were divided into 2 groups.The subjects of 34 children in group 1 visited for myopia initially and wear spectacles.The other one group wear orthokeratology lens more than 1 year.Only the data of right eye were analyzed.Scans through the fovea at horizontal meridian were acquired with OCT.Choroid images were detected by custom software with 500 μm intervals up to 3.5 mm around fovea.Choroid thickness (CT) was calc~ated based on the average of the 7 zones.Statistical analysis was performed to evaluate choroid thickness at each zone.ANOVA was used to compare choroid thickness differences between various zones in each group.Paired t test was used to compare choroid thickness difference at the same zone between two groups.Results The mean age of OK lens group was (12.3 ± 1.8) years old,and the spectacles group was (11.8 ± 1.4) years old,there was no statistical difference.From temple to nasal choroid,the mean CT of the orthokeratology lens group were (296.7 ± 61.8) μm (T3),(290.7 ± 58.9) μm (T2),(285.7 ± 57.4) μm (T1),(278.5 ±57.7) μm (M),(262.2 ±57.9) μm (N1),(239.8 ±59.7) μm (N2),(214.7 ±59.0) μm (N3);And the mean CT of the spectacles group were (294.2 ± 45.4) μm (T3),(292.0±44.0) μm (T2),(283.6 ±45.5) μm (T1),(272.0 ±51.6) μm (M),(255.2 ± 56.3) μm (N1),(236.5 ±58.1)μm (N2),(212.8 ±57.7) μm (N3),respectively.The thicknesses were significantly thicker in temple zones than that in nasal zones in each group (all P ＜ 0.05),but the CT was not significantly different between the two groups in each zone (all P ＞ 0.05).Conclusion The choroid thickness has regional deference in myopia children,the thickest is in the temple and the thinnest in the nasal region.There is no significant difference between the children who initially corrected by spectacles and those who wear OK lens more than 1 year.
ABSTRACT
Background Ultra-long scan depth OCT can achieve imaging of full range of human ocular anterior segment.However,the measurement of the dimension of anterior segment from the OCT image with high speed and precision is a challenge at present.The software of automatic data processing is still lack in analyzing spectral domain OCT.Objective This study was to perform the automatic biometry and data processing of human ocular anterior segment OCT image by using self-developed automatic detection software and evaluate the accuracy and repeatability of this method.Methods Twenty eyes of 10 normal subjects were included in Eye Hospital of Wenzhou Medical University from June to July 2013.The OCT image of anterior eye segments were obtained with custom-made ultra-long scan depth OCT under the informed consent.Anautomatic software algorithm was developed for the biometric measurement on these OCT images,including boundary segmentation,image registration and optical correction of OCT images.The boundary segmentation algorithm utilized the axial gradient information of OCT images and the shortest path search principal based on the dynamic programming to optimize edge finding.Central corneal thickness (CCT),anterior chamber depth (ACD),pupil diameter (PD),lens thickness (LT),radius of lens anterior curvatures (LAC) and radius of lens of posterior curvatures (LPC) were automatically and manually measured,and the validity of automatic detection algorithm was assessed by calculating the intraclass correlation coefficient (ICC) between the automatic and manual measurements,and the repeatability was validated by calculating the coefficient of repeatability (COR) between repeated measurement.This study was approved by the Ethic Committee of Wenzhou Medical University and informed consent was obtained from all subjects.Results There were no significant differences in the results of CCT,ACD,PD,LT,LAC and LPC between the automatic and manual measurements (P =0.205,0.167,0.285,0.127,0.102,0.074).The results were consistent between automatic and manual measurements (all at ICC＞0.75).The repeated measurement values were consistent in CCT,ACD and LT in both automatic and manual modes (all at ICC＞0.75).The reproducibilities of automatic biometry in PD and LAC (ICC =0.793,0.872;COR =2.90,5.79) were better than those of manual mode (ICC =0.631,0.579;COR =5.62,10.46);while the reproducibility of automatic biometry in LPC (ICC =0.663;COR =6.17) was lower than that of manual mode (ICC =0.794,COR =4.79).Conclusions Self-developed automatic detection software appears to be accurate and repeatable in measuring dimension of spectral domain OCT images.This automatic software algorithm can be used for the biometry and monitor of human ocular anterior segment.
ABSTRACT
Background Tear meniscus gained by OCT device is essential to the dry eye diagnosis.Currently,RTVue Fourier-domain optical coherence tomography (FD-OCT) is commercially available to image the tear menisci.However,there were few studies to report the repeatability and reproducibility of lower and upper tear meniscus parameters measured by RTVue FD-OCT.Objective The purpose of this study was to assess the repeatability and reproducibility of lower and upper tear meniscus parameters measured by RTVue FD-OCT in normal and dry eyes.Methods In this prospective study,20 dry eyes of 20 patients were finally recruited,and 20 normal eyes of 20 age-and gender-matched healthy subjects were included during the same period.Successive three-time scans were performed at a 3-minute interval with RTVue FD-OCT in optional eye by one well-trained examiner,and the other operator performed the same measurement 10-15 minutes later.Six parameters of tear meniscus were yielded by custom software,including upper meniscus curvature (UMC),upper meniscus height(UMH),upper meniscus area (UMA),lower meniscus curvature (LMC),lower meniscus height (LMH) and lower meniscus area (LMA).The between-image repeatability was assessed using mean coefficient of repeatability (MCOR),while between-operator reproducibility were evaluated using coefficient of repeatability (COR) and interclass correlation of coefficients (ICC).Results As for the between-image repeatability,the results of MCOR for UMH,UMA,LMH and LMA were 5.11％,3.58％,4.98％ and 4.82％ respectively in the normal eyes and 5.60％,5.80％,5.03％ and 5.74％ respectively in the dry eyes.As for the between-operator reproducibility,the results of COR and ICC for UMA were 5.38％ and O.975,the COR and ICC for LMA were 5.28％ and 0.961 respectively in the normal eyes,and the results of COR and ICC for LMA were 9.69％ and 0.964 in the dry eyes.Conclusions The UMA,LMH and LMA tear meniscus parameters obtained by RTvue FD-OCT show good between-image repeatability,and LMA also presents good between-operator reproducibility.Measurement of tear meniscus parameters with RTVue FD-OCT measuring is a potential diagnostic index for the diagnosis of dry eye.
ABSTRACT
Background Evaluation of intra-retinal layer thickness plays an important role in the diagnosis and monitor of various eye diseases,and spectral domain optical coherence tomography (OCT) is a frequently used tool.Software analysis method was used to measure the retinal thickness in previous study,but the study on the reliability of automatic layered software is lack.Objective This study was to evaluate the repeatability and reproducibility of thickness profile measurement of intra-retinal layers determined by an automated algorithm applied to OCT images from RTVue100 OCT instrument.Methods In this prospective cross-sectional study,retinal thickness images at 6 mm around fovea were obtained from 18 right eyes of 18 normal subjects with RTVue100 OCT instrument.The retinal images were segmented into retinal nerve fiber layer (RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),inner nuclear layer (INL),outer plexiform layer (OPL),outer nuclear layer (ONL),inner segment (IS),outer segment (OS) and retinal pigment epithelial (RPE) layer using automated algorithm method.Then Matlab software was used to analyze the measuring outcome.Interclass correlation coefficient (ICC) and coefficients of reproducibility (COR) were calculated from the results of two-time examination by the same examiner to evaluate the repeatability and from the results of two different examiners to assess the reproducibility.Written informed consent was obtained from each subject prior to any medical procedure.Results The entire retinal thickness measured by RTVue-OCT was (303.22± 14.10) μm in the horizontal meridian and (306.68 ± 13.32) μm in the vertical meridian,with the maximum values of retinal thickness in the GCL+ IPL and ONL.Whether in the horizontal meridian or in the vertical meridian,the ICC and COR were ＜0.60 in the OPL,IS and OS;while those in the RNFL,GCL+IPL,INL,ONL and RPE layer were ＞0.70.Conclusions RTVue OCT with automated algorithm is a useful and reliable approach to the measurement of intra-retinal layer thickness.Automated segmentation can offer accurate and repeatable thickness profile of OCT retinal image.This method may improve the diagnosis and monitoring of retinal diseases.