Comparison of ultrasound biomicroscopy and spectraldomain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

AIM：To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography（SD-AS-OCT） and ultrasound biomicroscopy（UBM）,and to evaluate the correlations and consistency between SD-AS-OCT and UBM.· METHODS：Fifty-five eyes from 40 patients were examined.Patients were diagnosed with primary angleclosure glaucoma（PACG） remission（11 eyes from 8patients）,primary angle closure（PAC,20 eyes from 20patients） and PAC suspect（24 eyes from 12 patients）.Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy（LPI）.The measurements of SD-AS-OCT were angle open distance（AOD）,anterior chamber angle（ACA）,trabecular iris angle（TIA）,and trabecular iris space area（TISA）.UBM measurements were AOD and TIA.Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed.All parameters were analysed by SPSS 16.0 and MedCalc.· RESULTS：ACA,TIA and AOD measured by SD-ASOCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant.Group parameters of AOD500 and AOD750 showed a linear positive correlation,and AOD750 had less variability.UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT.The results of the two techniques were correlated at the superior,nasal and inferior quadrants.CONCLUSION：Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG.We recommended using parameters at 750 μm anterior to the sclera spur for the screening and follow-up of PACG and PAC.The two methods might be alternatives to each other.

Microperimetry and spectral domain optical coherence tomography in myelinated retinal nerve fibers

Dear Sir,I write to present the correlation between microperimetric （MP） values and the density of myelinated retinal nerve fibers （MNFs） in optical coherence tomography （OCT） imaging.

Comment on “The diurnal variation pattern of choroidal thickness in macular region of young healthy female individuals using spectral domain optical coherence tomography”

Dear Editor,We have read and reviewed the article entitled＂The diurnal variation pattern of choroidal thickness in macular region of young healthy female individuals using spectral domain optical coherence tomography＂by Zhao et al^（[1]）with great interest.

Lens thickness assessment : anterior segment optical coherence tomography versus A-scan ultrasonography

AIMTo assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT) in comparison with A-scan ultrasonography (A-scan US).METHODSThere were 218 adult subjects (218 eyes) aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III). Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA). The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US.RESULTSInterclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74). Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001), and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001)CONCLUSIONAS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

Pseudophakic Malignant Glaucoma Treatment Assisted with Anterior Segment Optical Coherence Tomography: A Case Report

PSEUDOPHAKIC malignant glaucoma is diagnosedbased on the presence of a shallow or flat centraland peripheral anterior chamber in the presenceof patent iridectomy, with intraocular pressure（IOP） of 22 mm Hg or more after lens extraction andintraocular lens implantation.1 Pseudophakic malignantglaucoma is one of the most challenging complicationsfaced by surgeons. Initial medication includes topicalcycloplegics, osmotic agents.

Comparison of Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopy for Iris Parameter Measurements in Patients with Primary Angle Closure Glaucoma

Purpose: To compare the repeatability and consistency of anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in measuring iris parameters in patients with primary angle closure glaucoma. Methods: Twenty-two patients (38 eyes) with primary angle closure glaucoma,including 5 eyes with acute angle closure glaucoma,10 fellow eyes of acute angle closure glaucoma, and 23 eyes with chronic angle closure glaucoma, were recruited consecutively in our hospital. All subjects underwent anterior scanning by AS-OCT and UBM. Peripheral iris thickness (PIT) and iris curvature (IC) in the anterior segment image obtained by AS-OCT and UBM were measured twice. The reproducibility of these two scans was evaluated by the intraclass correlation coefficient (ICC). A paired t-test was used to compare the difference between the two scans and the 95% limits of agreement (LoA) were calculated. Results:The ICCs of PIT and IC measured by UBM were 0.892 and 0.936 respectively, while for AS-OCT these values were 0.629 and 0.859, respectively. UBM had a higher reproducibility in both PIT and IC measurements as compared with AS-OCT.Differences in PIT measurement between AS-OCT and UBM(P=0.331).were not statistically significant, the 95% LoA (-0.178～0.156) mm was 36.1～41.2% of the mean. The IC was 0.053 mm smaller when measured by UBM than by AS-OCT (P=0.017), with the 95% LoA (-0.100～0.206) mm, or 36.2～74.6% of the mean.Conclusion:UBM had a higher reproducibility in measuring iris parameters than AS-OCT. The consistency between AS- OCT and UBM in measuring iris parameters was low in primary angle closure glaucoma patients. (Eye Science 2013; 28:1-6)

Systematic review of macular ganglion cell complex analysis using spectral domain optical coherence tomography for glaucoma assessment

AIM: To review the use of spectral domain optical coherence tomography(SD-OCT) for macular retinal ganglion cells(RGC) and ganglion cell complex(GCC) measurement in glaucoma assessment, specifically for early detection and detection of disease progression. METHODS: A systematic review was performed by searching Pub Med, Medline, and Web of Science for articles published in English through July 2014 describing the various macular SD-OCT scanning strategies developed for glaucoma assessment. The review focused on papers evaluating the use of macular RGC/GCC SDOCT to detect early glaucoma and its progression. The search included keywords corresponding to the index test(macular ganglion cell/RGC/GCC/Spectral domain OCT), the target condition(glaucoma), and diagnostic performance. The RGC/GCC SD-OCT scanning strategies used to assess glaucoma of most commonly used SD-OCT instruments were described and compared. These included the Cirrus high definition-OCT(Carl Zeiss Meditec, Inc., Dublin, CA, United States), RTVue(Optovue, Inc., Fremont, CA, United States), Spectralis(Heidelberg Engineering, Heidelberg, Germany) and the 3D OCT 2000(Topcon Corporation, Tokyo, Japan). Studies focusing on the ability of RGC/GCC SD-OCT to detect early glaucomatous damage and on the correlation between glaucomatous progression and RGC/GCC measurement by SD-OCT were reviewed.RESULTS: According to the literature, macular RGC/GCC SD-OCT has high diagnostic power of preperimetric glaucoma, reliable discrimination ability to differentiate between healthy eyes and glaucomatous eyes, with good correlation with visual filed damage. The current data suggests that it may serve as a sensitive detection tool for glaucomatous structural progression even with mild functional progression as the rate of change of RGC/GCC thickness was found to be significantly higher in progressing than in stable eyes. Glaucoma assessment with RGC/GCC SD-OCT was comparable with and sometimes better than circumpapillary retinal nerve fiber layer thickness measurement.CONCLUSION: An increasing body of evidence supports using macular RGC/GCC thickness as an indicator for early glaucoma. This might be a useful tool for monitoring disease progression.

Application of Tear Meniscus Measurement by Anterior Segment Optical Coherence Tomography in the Diagnosis of Dry Eye

Dry eye,one of the most frequent ocular surface diseases, is caused by complex ocular function and mechanism disorders. Currently, no uniform standard diagnosis of dry eye has been established. Traditional clinical examinations provide inaccurate measurement and poor reproducibility due to various factors.Anterior segment optical coherence tomography (OCT) is applicable in the diagnosis of dry eye due to its high resolution, non-invasiveness, good accuracy, and repeatability.

Choroidal Analysis of Polypoidal Choroidal Vasculopathy by Spectral Domain Optical Coherence Tomography

Purpose: This study was designed to measure the changes in the subfoveal choroidal thickness(SFCT) and choroidal maximal vessel diameter(MVD) of the affected and unaffected fellow eyes in patients with polypoidal choroidal vasculopathy(PCV) and compare them to healthy controls.Methods: In this cross-sectional observational clinical study,SFCT and MVD were measured in both eyes of 53 patients with unilateral PCV. PCV eyes were subgrouped into group A and unaffected fellow eyes into group B. All patients were diagnosed with PCV by fundus fluorescein angiography.(FFA)and indocyanine green angiography.(ICGA). Sixty age- and gender-matched healthy subjects were enrolled in the control group(group C).Results: No statistical difference was observed among groups in age and gender. Overall, SFCT was correlated with MVD in all subjects(P <0.001; correlation coefficient: 0.759). P values were < 0.001 with a correlation coefficient of 0.686,0.801, and 0.808 in groups A, B, and C, respectively. No statistical significance was noted in SFCT among groups A(266.45±99.51 μm),B(269.57 ± 105.10 μm),and C(243.83±99.68 μm)(P =0.335). However, the MVD in group A was(202.55±72.45 μm), significantly larger than that in group C(166.45 ±56.18 μm,P =0.008), while the MVD in group B(194.75±85.27 μm) was equally significantly greater than that in group C(166.45 ± 56.18 μm)(P=0.038).Conclusion: For both PCV patients and healthy subjects,SFCT was positively correlated with MVD. No statistical significance was noted in SFCT between PCV eyes and unaffected fellow / normal eyes. However, MVD was significantly larger in the PCV affected eyes than in unaffected fellow or normal control eyes, suggesting that MVD could be considered as a sensitive indicator to evaluate choroidal perfusion in PCV patients.

Comparison of Intraoperative Ultrasound Pachymetry and Postoperative Optical Coherence Tomography of Anterior Segment in the Measurement of Flap Thickness in Eyes Receiving Laser in situ Keratomileusis

Purpose:To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ keratomileusis (LASIK). Methods: Seventeen patients (34 eyes) received LASIK using a Technolas-217Z100 laser and AMADEUSⅡ mechanical microkeratome(140 μm head). Flap thickness was assessed with an ultrasound pachymeter intraoperatively and a Visante-OCT postoperatively at 1 week and 1 month. Results: The intraoperative mean flap thickness by ultrasound pachymetry was (124±13.9) μm (range: 96.5 to 160 μm), and mean flap thickness by Visante-OCT was (145±7.13) μm (range: 130 to 158 μm) and (143±5.32) μm (range: 132 to 155 μm) postoperatively at 1 week and 1 month respectively (F=63.52,P<0.01). Intraoperative subtraction pachymetry underestimated flap thickness compared with postoperative Visante-OCT.(P<0.01)..There was no significant difference between postoperative Visante-OCT measurements at 1 week and 1 month after LASIK.(P=0.16). The 95% limit of agreement.(LoA).of flap thickness between ultrasound Visante-OCT and pachymetry was -5.40 to 42.10 μm. Conclusion: OCT overestimates flap thickness compared with intraoperative ultrasound pachymetry when using the AMADEUSⅡ mechanical microkeratome.

Spectral Domain Optical Coherence Tomography of Vogt-Koyanagi-Harada Disease: Novel Findings and New Insights into the Pathogenesis

Objective To provide novel spectral domain optical coherence tomography (SD OCT) findings of Vogt-Koyanagi-Harada (VKH) disease as well as new insights into the pathogenesis of this disease. Methods Detailed SD OCT and fluorescein angiography (FA) findings of 18 consecutive VKH patients (11 women and 7 men) from December 2007 to April 2009 who were in acute uveitic stage at presentation were reviewed. All the patients had been followed up for at least 6 months with reevaluation(s) of SD OCT performed in 10 patients. Results Intraretinal cysts were found to be located in various layers of the outer retina. In addition to the photoreceptor layer, they could also be found between the outer plexiform layer and the outer nuclear layer, or spanning the external limiting membrane. On FA, intraretinal cysts could be hypofluorescent, normofluorescent, or hyperfluorescent. Some intraretinal cysts had a characteristic FA pattern, in which a small round hypofluorescent area was surrounded by a ring of hyperfluorescence (donut-shaped dye pooling). Subretinal fibrinoid deposit appeared in acute uveitic stage in two severe VKH patients and seemed to develop from subretinal exudates and evolved into typical subretinal fibrosis. Gradual transfiguration/migration and progressive proliferation/pigmentation of the subretinal fibrinoid deposit/subretinal fibrosis was observed in one patient. Conclusions Intraretinal cysts could form in various layers of the outer retina and may result from extension of choroidal inflammation. Subretinal fibrosis may develop from subretinal exudates in VKH patients and may cause substantial visual impairment.

Spectral domain optical coherence tomography crosssectional image of optic nerve head during intraocular pressure elevation

AIM: To analyze changes of the optic nerve head(ONH) and peripapillary region during intraocular pressure(IOP) elevation in patients using spectral domain optical coherence tomography(SD-OCT).METHODS: Both an optic disc 200×200 cube scan and a high-definition 5-line raster scan were obtained from open angle glaucoma patients presented with monocular elevation of IOP(≥30 mm Hg) using SD-OCT. Additional baseline characteristics included age, gender, diagnosis,best-corrected visual acuity, refractive error, findings of slit lamp biomicroscopy, findings of dilated stereoscopic examination of the ONH and fundus, IOP, pachymetry findings, and the results of visual field.RESULTS: The 24 patients were selected and divided into two groups: group 1 patients had no history of IOP elevation or glaucoma(n =14), and group 2 patients did have history of IOP elevation or glaucoma(n =10). In each patient, the study eye with elevated IOP was classified into group H(high), and the fellow eye was classified into group L(low). The mean deviation(MD)differed significantly between groups H and L when all eyes were considered(P =0.047) and in group 2(P =0.042), not in group 1(P =0.893). Retinal nerve fiber layer(RNFL) average thickness(P =0.050), rim area(P =0.015),vertical cup/disc ratio(P =0.011), cup volume(P =0.028),inferior quadrant RNFL thickness(P =0.017), and clockhour(1, 5, and 6) RNFL thicknesses(P =0.050, 0.012, and0.018, respectively), cup depth(P =0.008), central prelaminar layer thickness(P =0.023), mid-inferior prelaminar layer thickness(P =0.023), and nasal retinal slope(P =0.034)were significantly different between the eyes with groups H and L.CONCLUSION:RNFLaveragethickness,rim area,vertical cup/disc ratio, cup volume, inferior quadrant RNFL thickness, and clock-hour(1, 5, and 6) RNFL thicknesses significantly changed during acute IOP elevation.

Anterior segment optical coherence tomography for identifying muscle status in strabismus surgery

Anterior segment optical coherence tomography （AS-OCT） finds very few indications in the domain of strabismus surgery. Current applications remain restricted to determining limbus-muscle insertion distance and anterior segment changes after strabismus surgery. We discuss two cases of operated strabismus surgery where AS-OCT imaging helped in identifying the operated eye and/or extra ocular muscles （EOM） and thus proved instrumental in planning and management.

Comparison of central macular thickness between two spectral-domain optical coherence tomography in elderly non-mydriatic eyes

AIM: To compare central macular thickness (CMT) measurements obtained by two spectral-domain optical coherence tomography (SD-OCT) exams, and to evaluate measurement reproducibility and agreement between these two exams, and to investigate the relationship between CMT and possible influencing factors such as age, sex, eye (OD/OS), and operators in elderly non-mydriatic eyes. METHODS: Seventy-two normal subjects were included. Every subject underwent CMT measurement twice using one of two SD-OCT (OSE-2000, Moptim, Shenzhen, China & 3-D OCT-1000, Topcon, Tokyo, Japan) instruments respectively where we randomly chose one eye in each patient for the test; these exams were performed by two operators over an hour period with a brief rest between sessions. Comparison of the OSE-2000 and 3-D OCT-1000 CMT measurements was based on paired- t test The mean difference between the CMT measurements was calculated. General linear model analyzed the relationships among eye (OD/OS), operator, sex, and CMT values using age as co-variant. All tests were considered statistically significant at P <0.05. The main outcome measures included CMT. RESULTS: When evaluated with general linear model analysis, CMT measurements were found to have high reproducibility across the two instruments between the two operators for the OSE-2000 single line scan and 3-D OCT-1000 macular scans (P=0.731; P=0.443). There was statistically significant difference in CMT values between the two instruments (P<0.001) and the mean difference was -46.83 mu m at 95% confidence limits (-49.15,-44.51). Age was positively correlated with CMT (beta coefficient =0.516, P=0.001; beta coefficient=0.453, P =0.009) and sex was correlated with CMT from the OSE-2000 (P=0.021) but not with the 3-D OCT-1000 (P=0.056). According to the actual thickness measurements, the CMT of the male was thicker than the female's but there was no statistical difference. There was interaction between sex and eye in OSE-2000 and not in 3-D OCT-1000 (P=0.02; P =0.374). No significant correlation was found between CMT and the influencing factor of eye in both of the instruments (P=0.884; P=0.492). CONCLUSION: Reproducibility of CMT measurement using the two SD-OCTs is excellent in normal eyes according to the operator factor analysis. OSE-2000 has a different posterior retinal boundary of CMT measurement, which results in the CMT value differences, compared with the 3-D OCT-1000. Age is positively correlated with CMT measurement while sex is correlated with CMT in the OSE-2000 but not in the 3-D OCT-1000 and eye (OD/OS) had no correlation with CMT values. Mydriatic drops may not be necessary for CMT measurement using high scan rate SD-OCT in normal eyes in dark room.

1310 nm Source Spectral-Domain Optical Coherence Tomography for Chinese Pigment and Jadeite Research

Optical Coherence Tomography (OCT) technique is a nondestructive optical detection technology based on low-coherence interferometer and it has become an attractive cultural heritage research method. A 1310 nm source spectral-domain optical coherence tomography (SD-OCT) system based on optical fiber Michelson interferometer and optical spectrum analyzer is proposed and demonstrated for Chinese cultural heritage research. The cross-section OCT images of Chinese pigment samples and jadeite samples can provide a lot of valuable microstructure information for the Chinese cultural heritage research and identification works.

The use of high resolution anterior segment optical coherence tomography for the characterization of conjunctival lymphoma, conjunctival amyloidosis and benign reactive lymphoid hyperplasia

Background:Conjunctival lymphoma,conjunctival amyloidosis and benign reactive lymphoid hyperplasia(BRLH)are conditions that often have a similar appearance on the ocular surface.The use of high resolution anterior segment optical coherence tomography(HR-OCT)enables clinicians to evaluate distinctive differences in tissue morphology and cellular patterns in various ocular surface conditions.In this study,we characterize the morphological differences seen in conjunctival lymphoma,conjunctival amyloidosis and BRLH on HR-OCT imaging.Methods:A retrospective chart review was performed of patients with biopsy proven conjunctival lymphoma,conjunctival amyloidosis and BRLH between 2012 and 2019 at the Bascom Palmer Eye Institute.Patients were excluded if HR-OCT imaging was not performed on initial presentation.Results:Thirty-four total eyes of 27 patients were identified.Twenty eyes had conjunctival lymphoma(16 patients),8 eyes had conjunctival amyloidosis(6 patients)and 6 eyes had BRLH(5 patients).All conditions appeared clinically as pink,red or yellow subepithelial lesions but had different features on HR-OCT.In lymphoma,HR-OCT images typically showed homogenous,dark subepithelial lesions with smooth borders,containing monomorphic dot-like infiltrates.HR-OCT images of amyloidosis typically showed heterogeneous,dark lesions with irregular borders,often containing hyperreflective linear infiltrates.HR-OCT images of BRLH showed variable infiltration of the subepithelial tissue,at times with homogenous lesions containing dot-like infiltrates like lymphoma and other times with more hyperreflective,subepithelial tissue.Flow cytometry and gene rearrangement was needed for final differentiation between BRLH and lymphoma lesions.Conclusions:Distinctive features on HR-OCT of conjunctival lymphoma,conjunctival amyloidosis and BRLH can help characterize these lesions beyond what is apparent with the clinical examination.Future studies can further validate this technology’s use with more subtle and challenging lesions.

Measurement of anterior chamber volume with rotating scheimpflug camera and anterior segment optical coherence tomography

Background Measurement of anterior segment parameters plays an important role in diagnosis and treatment of glaucoma. The objective of this study was to evaluate the repeatability and reproducibility of anterior chamber volume （ACV） measurements with rotating scheimpflug camera （RSC） and to examine agreement with anterior segment optical coherence tomography （AS-OCT）. Methods Thirty nine healthy normal subjects were recruited from the Eye Center of Tongren Hospital. ACV was measured using RSC and AS-OCT in a randomly selected eye for each subject. For RSC measurements, both automatic and manual ACV measurements and 2 independent operators＇ ACV measurements were obtained. All subjects were invited for 3 visits within a week to evaluate repeatability and reproducibility of ACV measurement by RSC. Agreement was evaluated between RSC and AS-OCT. Results Good repeatability and reproducibility were found for both automatic and manual ACV measurements obtained by RSC. For intrasession repeatability, coefficient of variation （CVw） and intraclass correlation coefficient （ICC） values for automatic were 3.52% and 0.98; the values for manual were 3.44% and 0.97, respectively. For intersession reproducibility, the respective CVw and ICC values were 3.96% and 0.96. Good agreement was also found in 2 operators for both automatic and manual ACV measurements; nevertheless, poor agreement was found between RSC and AS-OCT （95% confidence interval （CO for agreement of automatic RSC measurement versus AS-OCT were -96.3 to 72.8 pl and 95% CI for agreement of manual RSC measurement versus AS-OCT were between 41.7 to 10.1 #1 ）. Conclusions Both RSC automatic and manual ACV measurements showed good repeatability and reproducibility, and showed comparable agreement between 2 independent operators, but poor agreement was found between RSC and AS-OCT.

Optical coherence tomography angiography for the anterior segment

Optical coherence tomography angiography(OCTA)is a rapid and non-invasive technique for imaging vasculature in the eye.As OCTA can produce high-resolution cross-sectional images and allow depth-resolved analysis for accurate localization of pathology of interest,it has become a promising method for anterior segment imaging.Furthermore,OCTA offers a more patient-friendly alternative to the conventional invasive dye-based fluorescent angiography.However,conventional OCTA systems are typically designed and optimized for the posterior segment of the eye,and thus using OCTA for anterior segment imaging can present several difficulties and limitations.In this review,we summarized the recent developments and clinical applications in anterior segment OCTA(AS-OCTA)imaging,such as for the cornea,iris,sclera and conjunctiva.We also compared commercially available OCTA systems,discussed the limitations of adapting current OCTA technology for the anterior segment imaging,and proposed possible future directions for AS-OCTA systems.AS-OCTA provides potential for future clinical applications such as diagnosis of corneal and iris pathologies,pre-operative surgical planning,assessment of new antiangiogenic therapeutics or evaluation of limbal stem cell deficiency.With further development,OCTA for anterior segment imaging in the clinics may become common in the near future.

Evaluation of dry eye disease in newly diagnosed anxiety and depression patients using anterior segment optical coherence tomography

Background:We aimed to evaluate dry eye diseases(DED)in patients with newly diagnosed depression and anxiety patients.Methods:Forty newly diagnosed depression,35 anxiety patients,and 37 controls without any history of taking psychiatric drugs(or before the beginning of psychiatric medication)and topical ophthalmic drop use,were included in the study.All depression and anxiety diagnoses were performed by an experienced psychiatrist.Beck depression and anxiety tests were used to measure disease severity.Tear film break up time(TBUT),Schirmer’s test,Oxford scores and ocular surface disease index(OSDI)were admiinistered to participants.Anterior segment optical coherence tomography was used to measure tear meniscus heights(TMH),tear meniscus depths(TMD)and tear meniscus areas(TMA).Results:In anxiety and depression groups,Schirmer’s test(mm)(7.24±6.02,6.58±4.9 and 18.79±4.9 respectively,p<0.05)and TBUT(s)(5.62±3.1,5.6±3.5 and 13.37±1.7 respectively,p<0.05)were significantly lower than control group.In addition,OSDI and Oxford scores were significantly higher than controls.OSDI scores were 28.01±19,30.43±18.49,14.38±8.14 respectively(p=0.002)and Oxford scores were 1.9±0.7,2.1±0.6 and 0.7±0.4 respectively(p=0.001).TMD,TMH and TMA values were significantly lower in anxiety and depression groups compared with control groups.Correlations between disease inventory scores and dry eye tests were detected.Conclusions:This study showed a relation between DED and newly diagnosed anxiety and depression patients with no history of psychiatric drug use.The presence of correlation between dry eye tests and disease inventory scores strengthens this association.This is an important knowledge that need to be evaluated in these patients before starting psychiatric medication.

Fast segmentation of anterior segment optical coherence tomography images using graph cut

Background:Optical coherence tomography(OCT)is a non-invasive imaging system that can be used to obtain images of the anterior segment.Automatic segmentation of these images will enable them to be used to construct patient specific biomechanical models of the human eye.These models could be used to help with treatment planning and diagnosis of patients.Methods:A novel graph cut technique using regional and shape terms was developed.It was evaluated by segmenting 39 OCT images of the anterior segment.The results of this were compared with manual segmentation and a previously reported level set segmentation technique.Three different comparison techniques were used:Dice’s similarity coefficient(DSC),mean unsigned surface positioning error(MSPE),and 95%Hausdorff distance(HD).A paired t-test was used to compare the results of different segmentation techniques.Results:When comparison with manual segmentation was performed,a mean DSC value of 0.943±0.020 was achieved,outperforming other previously published techniques.A substantial reduction in processing time was also achieved using this method.Conclusions:We have developed a new segmentation technique that is both fast and accurate.This has the potential to be used to aid diagnostics and treatment planning.