Evaluation of the Macular, Peripapillary Nerve Fiber Layer and Choroid Thickness Changes in Behçet's Disease with Spectral-Domain OCT

Evaluation of optic coherence tomography findings in patients with inflammatory bowel disease

BACKGROUND

Ocular complications are known to appear in inflammatory bowel disease (IBD). Among these, posterior segment complications can lead to substantial morbidity. The aim of the study is to evaluate the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), and macula thickness measurement in patients with IBD.

METHODS

A total of 118 patients with IBD (42 Crohn's disease (CD), 76 ulcerative colitis (UC)) and 52 healthy subjects were included in the study. RNFL, GCIPL, and macula thickness were measured using spectral-domain optical coherence tomography (SD-OCT).

RESULTS

The central macular thickness was increased, mean and all superior quadrants of GCIPL thickness measurements were significantly decreased, but RNFL thickness wasn't changed in CD compared to healthy subjects. Although the central macular thickness increased, no change was observed in mean RNFL and GCIPL in UC compared to healthy subjects. Mean RNFL, GCIPL, and macular thickness did not differ during the remission and active phases of the disease in IBD. There was no difference in RNFL, GCIPL, and macular thicknesses in CD patients in terms of the location and behavior of the disease. A significant thickness increase was found in extensive type UC for inferior RNFL value compared to the left side and proctitis.

CONCLUSIONS

IBD may cause an increase in macular thickness. This finding may be related to the inflammation or ischemia of the retina. The use of SD-OCT in ophthalmologic examination in patients with IBD may enable early detection of retinal changes and alert the clinician to complications of IBD.

OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OVER TIME IN BEHÇET'S UVEITIS

PURPOSE

To analyze the characteristics of macular optical coherence tomography in patients with Behçet's uveitis (BU).

METHODS

Retrospectively analyzing optical coherence tomography images and clinical data of patients with Behçet's uveitis who visited our hospital from January 2010 to July 2022.

RESULTS

One hundred and one patients (174 eyes) were included. We analyzed the development of optical coherence tomography changes in these patients and its relationship with acuity vision and found that cystic macular edema, hyperreflexive retinal spots, inner nuclear layer edema, and outer nuclear layer edema appeared at any time during the disease course. Epiretinal membranes appeared beginning 1 to 2 weeks after onset and worsened over time, and foveal atrophy occurred beginning at 2 to 4 weeks. Foveal atrophy, foveal layers disappear, ellipsoid zone (EZ) disruption, retinal pigment epithelium (RPE) disruption, RPE hyperreflection, and choroidal hyperreflection were correlated with visual acuity. Kaplan‒Meier survival analysis showed at 60 months of follow-up, and almost all patients with foveal atrophy, EZ disruption, RPE disruption, RPE hyperreflection, and choroidal hyperreflection had visual acuity less than logMAR 1.0. EZ disruption and RPE disruption were reversible with aggressive treatment from 4 to 12 months after onset, but was less recoverable after 2 years. In advanced stages, optical coherence tomography manifested as structural disturbances and atrophy of the macular area, highly reflective material deposition in the RPE layer, and a thick macular epimembrane.

CONCLUSION

Optical coherence tomography showed that severe lesions occurred in macula of patients with Behçet's uveitis in early stage. Aggressive treatment can partially reverse it.

Can optical coherence tomography angiography be a first line ophthalmological evaluation in patients with Behçet's disease?

Objectives

This study aimed to investigate whether early ocular findings can be demonstrated with optical coherence tomography angiography in patients with Behçet's disease.

Patients and methods

Thirty-seven eyes of 22 patients with Behçet's disease with ocular involvement, 48 eyes of 26 Behçet patients without any ocular involvement, and 44 eyes of 22 healthy controls were included, for a total of 70 patients (39 males, 31 females; mean age: 42.3±11.7 years; range, 18 to 65 years), in the cross-sectional study conducted between September 2019 and April 2020. The parameters analyzed were the foveal avascular zone (FAZ), central macular thickness, total deep capillary plexus vessel density (DCPVD), parafoveal deep capillary plexus vessel density (PaDCPVD), total superficial capillary plexus vessel density (SCPVD), and parafoveal superficial capillary plexus vessel density (PaSCPVD).

Results

Total DCPVD, total SCPVD, PaDCPVD, and PaSCPVD were found to be low in the ocular involvement group compared to the others, and the FAZ area was larger compared to the control group. Capillary plexus densities were positively correlated with the best-corrected visual acuity and negatively correlated with disease duration. No statistically significant difference was found between patients with Behçet without ocular involvement and the control group in terms of the FAZ area, DCPVD, PaDCPVD, SCPVD, and PaSCPVD.

Conclusion

Optical coherence tomography angiography demonstrated decreased vascularity in Behçet patients with ocular involvement; however, it revealed no microvascular differences between patients with Behçet's disease who do not have ocular involvement and the control group.

Choroidal thickness and retinal nerve fiber layer analysis in chronic spontaneous urticaria

Aim: In this study, we investigated the effects of chronic spontaneous urticaria on the choroid and retinal nerve fiber layer. Material and Method: The patient group consisted of newly diagnosed 54 chronic spontaneous urticaria (CSU ) patient and the control group consisted of 54 healthy volunteer. Choroidal and retinal nerve fiber layer (RNFL) thickness measurements were performed with Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA) 30 minutes after pupil dilation with 0,5% tropicamide. Results: In the patient group, nasal choroidal thickness (NCT) was 290.11±43.16 μm, subfoveal choroidal thickness (SFCT) was 339.17±37.709 μm, temporal choroidal thickness (TCT) was 296.00±42.859 μm, mean choroidal thickness (MCT) was 308.33±35.923 μm and RNFL thickness was 91.11±7.393 μm. NCT was 248.42±35,742 μm, SFCT 276.56±40.04 μm, TCT 253.69±37.384 μm, MCT 259.50±32,986 μm and RNFL thickness 92.19±8.719 μm in the control group. When we examine the p value, it is seen that both groups are similar to each other in terms of RNFL thickness (p=0.326), while there is a significant thickening in all choroidal regions of patients with CSU, including NCT, SFCT, TCT, MCT (p=0.000, p=0.000, p=0.000, p=0.000, respectively). Conclusion: The choroid is affected in CSU and choroidal thickness can be a noninvasive method that can be used in diagnosis CSU. However, studies of longer disease durations may provide more illuminating information about CSU and choroid and RNFL.

Choroidal involvement in systemic vasculitis: a systematic review

Systemic vasculitides are a large group of heterogeneous diseases characterized by inflammatory destruction of blood vessels targeting diverse organs and tissues including the eye. As the most vascularized layer of the eye, the choroid is expected to be affected in multiple systemic rheumatologic diseases with vascular involvement. While there are plenty of studies investigating retinal vascular involvement, choroidal vascular involvement in systemic vasculitides has not been investigated in isolation. However, choroidal manifestations including thickness changes, choroidal vasculitis and ischemia may be the earliest diagnostic features of systemic vasculitic diseases. Thus, multimodal imaging of the choroid may help early detection of choroidal involvement which may also have prognostic implications in these life-threatening diseases. This article aimed to review involvement of the choroid in systemic vasculitic diseases.

Evaluation of retinal and choroidal microcirculation in Behçet's disease

PURPOSE

To investigate retinal perfusion by optical coherence tomography (OCT)-angiography and choroidal vascular features using an OCT-based image binarization method in patients with Behçet's disease (BD) without clinical ocular involvement.

METHODS

This study included 38 patients with non-ocular BD and 35 healthy participants. Macular region was evaluated with OCT-angiography (Optovue, Inc., Fremont, CA). A 6.0 × 6.0 mm rectanglescan centred on the fovea was used to record the scans. The enhanced depth imaging OCT scans (Heidelberg Eye Explorer version 1.8.6.0; Heidelberg Engineering) of the macula and peripapillary scans of the optic nerve head were binarized using ImageJ software (National Institutes of Health, Bethesda, MD, USA). The luminal area (LA), stromal area (SA), total choroidal area (TCA), and choroidal thickness (CT) were analysed. The choroidal vascularity index (CVI) was calculated as the ratio of the LA to the TCA.

RESULTS

Vessel density values of the superficial and deep macular capillary plexus were similar between the two groups (all p > 0.05). There was no significant difference between the groups in terms of the CT and TCA values in the macula and in all peripapillary sectors (all p > 0.05). However, the macula and temporal, nasal, and inferior sectors of the peripapillary area had significantly lower CVI values in the BD group compared with controls (p = 0.009, p = 0.002, p = 0.010, and p = 0.008, respectively).

CONCLUSIONS

Retinal microperfusion deficit was not observed in non-ocular Behçet patients. CVI may be a more robust marker than CT to indicate choroidal perfusion. A reduced CVI may suggest subclinical ocular involvement and choroidal ischemia in these patients.

Novel Findings of Retinal and Choroidal Features Utilizing Optical Coherence Tomography Angiography Analysis in Patients With Autoimmune Posterior Uveitis

Purpose: To analyze the quantitative parameters acquired by optical coherence tomography angiography (OCTA) in patients with autoimmune posterior uveitis. Methods: OCTA images of 65 eyes affected with uveitis and 65 normal control (NC) eyes were obtained. The central macular thickness (CMT), retinal thicknesses, foveal avascular zone (FAZ) area, foveal density 300 μm (FD300), and vascular density (VD) were compared among acute uveitic eyes, chronic uveitic eyes, and NC eyes. VDs were evaluated in the choriocapillaris, outer retina, optic disk, whole and parafovea superficial capillary plexus (SCP), and whole and parafovea deep capillary plexus (DCP). Correlation analysis was used to analyze the relationship between LogMAR best-corrected visual acuity (BCVA) and quantitative parameters from OCTA. Results: Compared with NC eyes, the CMT and retinal thicknesses were increased significantly in eyes with uveitis (p < 0.05, respectively). No significant difference was observed in the FAZ area. FD300, VDs in the optic disk, SCP, and DCP both in whole image and parafovea, choriocapillaris were significantly decreased in uveitis eyes (p < 0.05, respectively) compared with NC eyes, only the acute group had decreased VD of the outer retina and choriocapillaris compared with the NC group (p < 0.05). Moreover, quantitative parameters of OCTA showed a significant correlation with LogMAR BCVA in the patients with uveitis. Whole VD DCP was the best predictive factor for BCVA in the patients with uveitis. Conclusion: Quantitative measurement by OCTA is a promising strategy for objective assessment of autoimmune posterior uveitis.

Choroidal Imaging in uveitis: an update

An important goal of advancements in ocular imaging algorithms and devices has been to improve the image acquisition and resolution of deeper ocular tissues, namely the choroid and its vasculature that are otherwise inaccessible to direct clinical examination. These advancements have contributed to the understanding of the pathophysiology of a number of ocular inflammatory conditions. We focuse on the imaging characteristics of clinical conditions where imaging the choroid has improved or radically changed the understanding of the disease, has helped in differentiation of phenotypically similar but distinct lesions, and where imaging features have proven vital formonitoring disease activity. The last two decades have seen some major developments in ocular imaging relevant to uveitis. The current review addresses both the imaging characteristics and their interpretation on conventional modalities such as fundus photography, fluorescein angiography, indocyanine green angiography and fundus autofluorescence and the recent additions in the armamentarium including optical coherence tomography (OCT) with enhanced depth imaging, swept-source OCT, and OCT angiography.

Post-remission retinal microvascular and choroidal thickness changes in eyes with Behḉet's disease posterior uveitis: an OCTA longitudinal study

PURPOSE

To investigate the retinal microvascular and choroidal thickness changes in eyes with active Behḉet's disease posterior uveitis and post-remission.

PATIENTS AND METHODS

A prospective longitudinal observational analytic study where patients with active Behḉet's posterior uveitis (BU) were assessed by optical coherence tomography angiography (OCTA) and enhanced depth imaging OCT during activity and after remission, for retinal microvascular and subfoveal choroidal thickness (SFCT) changes.

RESULTS

26 eyes of 20 patients were included. With remission of active posterior uveitis, capillary density in both layers increased, only being significant in the superficial capillary plexus (SCP) 1.81 ± 3.57% (p = 0.025), while the foveal avascular zone (FAZ) area increased by 0.036 ± 0.069 mm (p = 0.023).

CONCLUSION

OCTA can be used to monitor the activity of Behḉet's posterior uveitis. Comparing the retinal microvascular changes during activity and after remission, the superficial capillary plexus was found to be more indicative of the activity status, while the deep capillary plexus and foveal avascular zone area-being more irreversible-are more useful as prognostic indicators. Subfoveal choroidal thickness, on the other hand, proved to be a consistent indictor of visual function; however, its change doesn't accurately reflect the activity status.

Choroidal thickness alterations in idiopathic acute retinal vasculitis

Background:

To evaluate changes in sub-foveal choroidal thickness in patients with acute idiopathic retinal vasculitis compared with age-matched healthy subjects and unaffected fellow eyes.

Methods:

This prospective observational study included 36 eyes of 23 acute idiopathic retinal vasculitis patients (group V) which included a sub-group of 10 eyes of 10 patients with unilateral vasculitis (group UV), and 50 eyes of 25 healthy subjects (group N). The assessment involved demographics, systemic examination, comprehensive ocular examination, fundus photography with/without fundus fluorescein angiography, and spectral domain–optical coherence tomography with enhanced depth imaging.

Results:

There was significant difference between the mean sub-foveal choroidal thickness in groups V and N (V: 338.86 ± 28.72 um; N: 296.72 ± 19.45 μm; p< 0.001). The eyes of patients with unilateral vasculitis compared with unaffected fellow eyes had no significant difference in best corrected visual acuity (group UV: median = 0.2; range = (0.0–0.3) and group N: median = 0.2; range = (0.0–0.3); p = 0.35) but the sub-foveal choroidal thickness was significantly increased in the involved eye (group UV: 333.5 ± 16.68 um; group N: 284.4 ± 15.68 um; p⩽ 0.001). The BCVA was significantly lower in the eyes with anterior chamber inflammation (median = 0.2; range = (0.0–0.3) and; median = 0.1; range (0.0–0.3); p = 0.002), but there was no statistically significant difference in sub-foveal choroidal thickness measurement between the two groups of vasculitis patients with and without anterior chamber inflammation (334.3 ± 18.85 um and 336 ± 31.56 um; p = 0.22).

Conclusion:

The sub-foveal choroidal thickness increases during active inflammation in eyes with idiopathic retinal vasculitis compared with unaffected fellow eyes and healthy control eyes. Thus, measurement of the sub-foveal choroidal thickness on optical coherence tomography with enhanced depth imaging can serve as a non-invasive modality in the diagnosis and monitoring of acute idiopathic retinal vasculitis.

Evaluation and Comparison of Choroidal Thickness in Patients with Behçet Disease with versus without Ocular Involvement

Purpose

To assess the subfoveal choroidal thickness (SFCT) in patients with Behçet disease (BD) and compare the SFCT in patients with and without ocular BD (OBD) and between patients with active and quiescent phases of the Behçet's posterior uveitis.

Methods

This prospective cross-sectional study was conducted on patients with BD (n = 51) between October 2016 and October 2018. Complete ocular examinations including slit lamp biomicroscopy and fundus examination with dilated pupils were performed for all patients. The SFCT values were compared between patients with and without OBD. Enhanced depth imaging optical coherence tomography (EDI–OCT) was done to measure the SFCT, and wide field fundus fluorescein angiography (WF-FAG) was performed to evaluate the ocular involvement and determine the active or quiescent phases of the Behçet's posterior uveitis. The correlation between the changes of SFCT and the WF-FAG scores was assessed.

Results

One hundred and two eyes of 51 patients with BD, aged 29 to 52 years were studied. Of these, 23 patients were male. The mean age ± standard deviation in patients with OBD and patients without ocular involvement was 38.71 ± 7.8 and 36.22 ± 10.59 years (P = 0.259) respectively. The mean SFCT in patients with OBD was significantly greater than in patients without OBD (364.17 ± 93.34 vs 320.43 ± 56.70 µm; P = 0.008). The difference of mean SFCT between the active compared to quiescent phase was not statistically significant when only WF-FAG criteria were considered for activity (368.12 ± 104.591 vs 354.57 ± 58.701 µm, P = 0.579). However, when the disease activity was considered based on both WF-FAG and ocular exam findings, SFCT in the active group was higher than the inactive group (393.04 ± 94.88 vs 351.65 ± 58.63 µm, P = 0.060). This difference did not reach statistical significance, but it was clinically relevant.

Conclusion

Choroidal thickness was significantly increased in BD patients with ocular involvement; therefore, EDI-OCT could be a noninvasive test for evaluation of ocular involvement in patients with BD. The increased SFCT was not an indicative of activity in OBD; however, it could predict possible ocular involvement throughout the disease course.

Associations between seven-year C-reactive protein trajectory or pack-years smoked with choroidal or retinal thicknesses in young adults

Inflammation and cigarette smoking predispose to macular diseases, and choroidal and retinal thinning. We explored the choroidal and retinal thicknesses in young adults against their 7-year C-reactive protein (CRP) level trajectory and pack-years smoked. Participants from the Raine study, a longitudinal cohort study, had serum CRP levels analysed at the 14-, 17-, and 20-year follow-ups. Group-based trajectory modelling was used to classify participants according to their 7-year CRP levels. At the 20-year follow-up (at 18–22 years old), participants completed questionnaires on their smoking history, and underwent optical coherence tomography imaging to obtain their choroidal and retinal thicknesses at the macula. Three CRP trajectories were identified: consistently low CRP levels (78% of sample), increasing (11%), or consistently high (11%). 340 and 1035 participants were included in the choroidal and retinal thickness analyses, respectively. Compared to those in the “Low” trajectory group, participants in the “Increasing” and “High” groups had 14–21 μm thinner choroids at most macular regions. Every additional pack-year smoked was linked with a 0.06–0.10 μm thinner retina at the inner and outer macular rings, suggesting a dose-dependent relationship between smoking and thinner retinas. These associations may suggest that an increased risk of future visual impairment or eye disease associated with these risk factors may be present since young adulthood.

Uveitis as a Confounding Factor in Retinal Nerve Fiber Layer Analysis Using Optical Coherence Tomography

PURPOSE

To investigate the retinal nerve fiber layer thickness (RNFLT) in uveitic eyes and search for the associations with uveitis activity, etiology and location.

METHODS

The files of 76 patients with uveitis and 76 controls were scanned. Associations of RNFLT were analyzed using generalized linear models.

RESULTS

The RNFLT was significantly higher in patients with uveitis (p < .001). Active uveitis patients had a thicker RNFL than the controls and the patients with quiescent uveitis (p < .001). Anterior uveitis was associated with thinner RNFL in global and inferotemporal quadrant (p = .011 and 0.013, respectively). Thickening of RNFL was associated with posterior uveitis and Behçet's disease in all quadrants (p < .001) and idiopathic uveitis in the superonasal and nasal quadrants (p = .001).

CONCLUSION

Active uveitis, as well as posterior uveitis and Behcet's disease-associated uveitis, is a major confounding factor in RNFL analysis and therefore detection of glaucoma.

Infliximab therapy provides beneficial effects for choroidal thickness increase in patients with active ankylosing spondylitis: A possible mechanism mediating the suppressing of uveitis attacks

Objectives

This study aims to quantitatively assess the profile of the choroidal thickness (ChT) in patients with ankylosing spondylitis (AS) using optical coherence tomography (OCT), and to examine whether the posterior eye segment abnormalities in active AS patients are reversible by infliximab therapy.

Patients and methods

October 2014 and March 2016 Thirty-one patients with AS (22 males, 9 females; mean age 39.6±12.3 years; range, 22 to 68 years) and 24 healthy controls (16 males, 8 females; mean age 40.8±8.9 years; range, 35 to 61 years) were enrolled. Patients' clinical and demographic characteristics were recorded. Using OCT, we performed retinal nerve fiber layer (RNFL) thickness, ganglion cell complex, and ChT measurements in AS patients before and six months after the initiation of infliximab therapy, and in healthy controls.

Results

At baseline, patients with AS had higher ChT (mean±standard deviation: 347.5±114.4 μm) compared to healthy controls (322.1±62.8 μm), although this did not reach statistical significance level (p=0.283). At six months after the first measurement, the mean ChT was significantly decreased (under infliximab therapy: 326.5±99.7 μm vs. before: 347.5±114.4 μm, p=0.018) in AS group, while no significant change was observed in the control group (p=0.102). RNFL thickness in the AS group was significantly decreased after six months of treatment with infliximab (p=0.008).

Conclusion

By evaluating the posterior eye segment of patients with AS using OCT, this study has demonstrated that active AS patients had higher ChT. The significant reduction in this ChT after infliximab therapy may be mediating the established effective suppressing action of infliximab on uveitis attacks.

Quantitative analysis of retinal microcirculation in optical coherence tomography angiography in cases with Behçet's disease without ocular involvement

PURPOSE

To evaluate the retinal vascular plexus and choriocapillaris structures in patients with non-ocular Behçet's disease (BD) using optical coherence tomography angiography (OCTA).

METHODS

The study included 42 eyes of non-ocular BD patients (study group) and 40 eyes of 20 healthy subjects (control group). Flow area (mm²), mean vascular density (VD) (%) and foveal avascular zone (FAZ) (mm²) were measured using OCTA (Optovue Inc., Fremont, CA, USA). Subfoveal choroidal thickness (CT) (μm) and central macular thickness (CMT) (μm) measurements were also performed.

RESULTS

The mean superficial capillary plexus, deep capillary plexus and choriocapillaris flow area values were found to be significantly lower in the study group than in the control group (p < 0.001, p < 0.001, p = 0.008, respectively). In respect of mean VD, a statistically significant difference was determined between the study and control groups in both superficial and deep VD (p < 0.001). No statistically significant difference was found out between the groups in respect of superficial FAZ, deep FAZ and CMT (p = 0.165, p = 0.477, p = 0.457, respectively). The subfoveal CT was also measured to be significantly thicker in the study group than in the control group (p < 0.001).

CONCLUSION

The results obtained with OCTA revealed that there could be both retinal and choroidal involvement in non-ocular BD patients before the emergence of evident clinical findings.

Comparison of Spectral Domain Optical Coherence Tomography (SD OCT) Findings with Laser Flare Photometry (LFP) Measurements in Behçet's Uveitis

Purpose: This study aims to compare the spectral domain optical coherence tomography (SD OCT) findings and laser flare photometry (LFP) measurements in Behçet's disease (BD).Methods: This study was composed of 4 groups as follows: "Group 1: Healthy volunteers, Group 2: Volunteers with BD and no eye involvement, Group 3: Patients with active uveitis with BD, Group 4: Patients with BD in quiescent phase of uveitis". Laser Flare Photometry (Kowa FM-600, Kowa Acculas, San Jose, CA, USA), SD-OCT and Enhanced Depth Imaging protocol (EDI) (Spectralis®, Heidelberg Engineering Inc., Heidelberg, Germany) and Fundus Florescein Angiography (FFA) (Heidelberg Retina Angiograph 2®; Heidelberg Engineering, Heidelberg, Germany) were performed for all patients.Results: Twenty-four eyes of 12 healthy volunteers (Group 1); 61 eyes without ocular involvement of 31 volunteers with BD (Group 2); 29 active uveitic eyes of 17 patients with BD (Group 3); 35 eyes with quiescent uveitis in 18 patients with BD (Group 4) participated in the evaluation. There was a significant difference between visual acuity, submacular choroidal thickness (SCT), and flare values comparison among the groups(p<0.001,p<0.002, and p<0.001). When compared considering the SCT, choroidal thickness in Group 3 was higher than in the eyes of Group 1 and Group 2 (p:0.005, p:0.006). Central macular thickness (CMT) and disease duration were negatively correlated (rho:-0.453, p<0.001), while CMT and flare values were positively correlated (rho:0.267,p:0.006).Conclusion: Flare is a reliable indicator of the inflammation in Behçet's uveitis. Its concurrent use with OCT to evaluate choroid and macula enables the assessment of inflammation.

Choroidal thickness in non-ocular Behçet's disease - A spectral-domain OCT study

Purpose

To evaluate choroidal thickness in patients with non-ocular Behçet's disease (BD) using spectral domain optical coherence tomography (SD-OCT) and to compare the results to normal eyes.

Methods

In this retrospective observational comparative study, we collected OCT and clinical data from the charts of 4 patients (7 eyes) with BD who had been referred for a screening eye exam and had a normal ocular examination. Data from 9 healthy volunteers (17 eyes) were collected as age-matched controls. The choroid was manually segmented from volume OCT scans using custom Doheny Image Reading Center OCT grading software (3D-OCTOR). Main outcome measures were choroidal thickness and intensity were compared between eyes of patients with BD and those of healthy controls.

Results

Eyes of patients with non-ocular BD had significantly thinner mean central subfield choroidal thickness (227.5 ± 56.93 versus 306.85 ± 17.85, P = 0.04) and central subfield choroidal volume (0.18 ± 0.04 vs 0.24 ± 0.02, P = 0.005). There was no significant difference in mean choroidal thickness in the whole ETDRS grid or in mean choroidal intensity in the central subfield and the whole ETDRS grid between eyes of patients with non-ocular BD and those of controls.

Conclusion

This study demonstrates that BD may have subclinical manifestations in the choroid, resulting in thinning of the choroid relative to normal eyes, even without overt signs of ocular involvement.

Validation of Macular Choroidal Thickness Measurements from Automated SD-OCT Image Segmentation

PURPOSE

Spectral domain optical coherence tomography (SD-OCT) imaging permits in vivo visualization of the choroid with micron-level resolution over wide areas and is of interest for studies of ocular growth and myopia control. We evaluated the speed, repeatability, and accuracy of a new image segmentation method to quantify choroid thickness compared to manual segmentation.

METHODS

Two macular volumetric scans (25 × 30°) were taken from 30 eyes of 30 young adult subjects in two sessions, 1 hour apart. A single rater manually delineated choroid thickness as the distance between Bruch's membrane and sclera across three B-scans (foveal, inferior, and superior-most scan locations). Manual segmentation was compared to an automated method based on graph theory, dynamic programming, and wavelet-based texture analysis. Segmentation performance comparisons included processing speed, choroid thickness measurements across the foveal horizontal midline, and measurement repeatability (95% limits of agreement (LoA)).

RESULTS

Subjects were healthy young adults (n = 30; 24 ± 2 years; mean ± SD; 63% female) with spherical equivalent refractive error of -3.46 ± 2.69D (range: +2.62 to -8.50D). Manual segmentation took 200 times longer than automated segmentation (780 vs. 4 seconds). Mean choroid thickness at the foveal center was 263 ± 24 μm (manual) and 259 ± 23 μm (automated), and this difference was not significant (p = 0.10). Regional segmentation errors across the foveal horizontal midline (±15°) were ≤9 μm (median) except for nasal-most regions closest to the nasal peripapillary margin-15 degrees (19 μm) and 12 degrees (16 μm) from the foveal center. Repeatability of choroidal thickness measurements had similar repeatability between segmentation methods (manual LoA: ±15 μm; automated LoA: ±14 μm).

CONCLUSIONS

Automated segmentation of SD-OCT data by graph theory and dynamic programming is a fast, accurate, and reliable method to delineate the choroid. This approach will facilitate longitudinal studies evaluating changes in choroid thickness in response to novel optical corrections and in ocular disease.

Systemic vasculitis and the eye

PURPOSE OF REVIEW

The primary systemic vasculitides represent a spectrum of rare but life-threatening conditions that may also affect the eye in various forms. This article reviews recently published data on ocular manifestations of systemic vasculitis.

RECENT FINDINGS

Early diagnosis and timely treatment has led to better visual outcomes in giant cell arteritis (GCA). Gene expression from orbital tissues could distinguish granulomatosis with polyangiitis (GPA) from sarcoidosis and Graves disease, but not from idiopathic orbital inflammation. Rituximab was an effective therapeutic option in ocular GPA. An ocular attack severity scoring system, flare levels, fluorescein angiography and optical coherence tomography parameters have been suggested as predictors of visual prognosis in Behçet disease. Efficacy of tumor necrosis factor-alpha inhibitors, interferon α and anti-interleukin-1 agents was shown in noncontrolled studies of ocular Behçet disease.

SUMMARY

Widely used fast-track pathway care as well as ocular imaging to detect subclinical involvement may enable earlier diagnosis of GCA and prevention of permanent visual loss. Orbital inflammation may not remain idiopathic with advances in gene expression profiling of orbital tissues. With an increased availability and the use of biologic agents, visual prognosis will improve in patients with severe ocular complications of systemic vasculitides.

Assessment of Vascular Change Using Swept-Source Optical Coherence Tomography Angiography: A New Theory Explains Central Visual Loss in Behcet's Disease

OBJECTIVE

To evaluate retinal vascular structural change in ocular Behcet's using optical coherence tomography angiography (OCTA) and fluorescein angiography (FA).

METHODS

An analytic cross-sectional study of 37 eyes of 21 Behcet's uveitic patients was performed. Foveal retinal thickness (FRT), perifoveal hypoperfusion areas in superficial capillary plexus (SCP), and deep capillary plexus (DCP) were measured with swept-source optical coherence tomography and OCTA. FA images were used for assessing the vascular features and correlation.

RESULTS

Twenty-one patients were enrolled (52.4% males). The average age at onset was 36.7 ± 12.93 years. The median of disease duration was 5 years (1-25). FRT was 118.1 ± 52.35 μm, which correlated with visual acuity (95% CI -60.47, -13.92). Using OCTA, the area of hypoperfusion in SCP (0.47 ± 0.17 mm²) was smaller than that in DCP (1.94 ± 3.87 mm²) (p < 0.001). Superficial to deep capillary plexus nonperfusion (SCP : DCP) ratio was 0.57 ± 0.27 which had the positive coefficient correlation with visual acuity (95% CI -0.644, -0.015).

CONCLUSIONS

OCTA is an alternative noninvasive method to monitor macular ischemia in Behcet. Behcet's uveitis affects DCP more than SCP. Decreasing SCP : DCP ratio and decrease FRT correlates with poor visual acuity. Macular ischemia and DCP loss can be found early and can explain vision loss in Behcet.

Choroidal Vascularity Index (CVI)--A Novel Optical Coherence Tomography Parameter for Monitoring Patients with Panuveitis?

PURPOSE

To compute choroidal vascularity index (CVI) using an image binarization tool on enhanced depth imaging (EDI)-optical coherence tomography (OCT) scans as a non-invasive optical tool to monitor progression in panuveitis and to investigate the utility of volumetric data from EDI-OCT scans using custom image analysis software.

MATERIALS AND METHODS

In this retrospective cohort study, segmented EDI-OCT scans of both eyes in 19 patients with panuveitis were taken at baseline and at 3-month follow-up and were compared with EDI-OCT scans of normal eyes. Subfoveal choroidal area was segmented into luminal (LA) and stromal interstitial area (SA). Choroidal vascularity index (CVI) was defined as the proportion of LA to the total circumscribed subfoveal choroidal area (TCA).

RESULTS

The mean choroidal thickness was 265.5±100.1μm at baseline and 278.4±102.6μm at 3 months follow up (p = 0.06). There was no statistically significant difference in TCA between study and control eyes (p = 0.08). CVI in the control group was 66.9±1.5% at baseline and 66.4±1.5% at follow up. CVI was 74.1±4.7% at baseline and 69.4±4.8% at 3 months follow up for uveitic eyes (p<0.001). The % change in CVI was 6.2 ±3.8 (4.3 to 8.0) for uveitic eyes, which was significantly higher from % change in CVI for control eyes (0.7±1.1, 0.2 to 1.3, p<0.001).

CONCLUSION

The study reports composite OCT-derived parameters and CVI as a possible novel tool in monitoring progression in panuveitis. CVI may be further validated in larger studies as a novel optical tool to quantify choroidal vascular status.