Variation of choroidal thickness and vessel diameter in patients with posterior non-infectious uveitis

Effects of inflammation on myopia: evidence and potential mechanisms

As the most common type of refractive error, myopia has become one of the leading causes of visual impairment. With the increasing prevalence of myopia, there is a growing need to better understand the factors involved in its development. Inflammation, one of the most fundamental pathophysiological processes in humans, is a rapid response triggered by harmful stimuli and conditions. Although controlled inflammatory responses are necessary, over-activated inflammation is the common soil for many diseases. The impact of inflammation on myopia has received rising attention in recent years. Elevated inflammation may contribute to myopia progression either directly or indirectly by inducing scleral remodeling, and myopia development may also increase ocular inflammation. This article provides a comprehensive review of the interplay between inflammation and myopia and the potential biological mechanisms, which may present new targets for understanding the pathology of myopia and developing myopia therapies.

Interpreting posterior uveitis by integrating indocyanine green angiography, optical coherence tomography, and optical coherence tomography angiography data: A narrative review

Posterior uveitis is sight-threatening disease entity that can be caused by infectious and non-infectious entities. Vision loss in posterior uveitis can be following complications such as cystoid macular edema, epiretinal membrane, artery and vein occlusions, vasculitis, papillitis, choroidal neovascular membrane, retinal neovascularization, tractional retinal detachment, vitreous hemorrhage, glaucoma, cataract, among others. Diagnosis of posterior uveitic entities have been revolutionized following introduction of choroidal imaging with techniques such as indocyanine green angiography (ICGA), optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Med Line search and PubMed search was performed pertaining to causes of posterior uveitis, ICGA in posterior uveitis, OCT in posterior uveitis, OCTA in posterior uveitis, retinal and choroidal vascular changes in posterior uveitis, quantification of choriocapillaris lesion area in posterior uveitis, subfoveal choroidal thickness in posterior uveitis, quantification of choriocapillaris in posterior uveitis, vascular indices for quantification of choriocapillaris. This review article highlights various changes in the choroid and the quantification of choroid using various parameters in ICGA, OCT and OCTA.

Retinal Microvascular Alterations in Patients with Quiescent Posterior and Panuveitis Using Optical Coherence Tomography Angiography

PURPOSE

To quantify retinochoroidal vascular parameters using swept-source optical coherence tomography (SS-OCTA) in quiescent posterior and panuveitis.

METHODS

In this cross-sectional study, subjects with quiescent posterior and panuveitis underwent fundus imaging using SS-OCTA (DRI Triton®, Topcon, Japan). The metrics calculated were fractal dimension (FD), foveal avascular zone (FAZ) area, retinal vascularity index (capillary density index-CDI), and choroidal vascularity index (CVI).

RESULTS

We included 38 eyes of 20 patients, 9 males aged 34.7 ± 10.5 years, 30 eyes of 30 age- and gender-matched healthy controls, 10 females aged 33.6 ± 8.5 years. Comparing patients with controls, we found a lower FD (p < .001), larger FAZ (p > .001), lower CDI in the superficial plexus (p = .019), and lower CVI (p < .001). We also found lower retinal and choroidal and thicknesses (p < .001 and p = .025, respectively).

CONCLUSIONS

Patients with quiescent posterior and panuveitis have a significantly reduced retinochoroidal vascular density compared to healthy control subjects.

Quantitative Assessment of the Choroidal Vessel Diameter during the Recovery of Form-Deprivation Myopia in Guinea Pigs

PURPOSE

The development and recovery (REC) of myopia is associated with changing of choroidal thickness (CT) in the model of guinea pigs. Nitric oxide synthase (NOS) is an enzyme which can affect choroidal vasodilatation. This study wants to investigate the changes of choroidal vessel diameter (CVD) and NOS during the REC of form-deprivation (FD) myopia in guinea pigs.

METHODS

Forty-eight guinea pigs were randomly assigned to the normal control (NC) group, FD group (FD for 21 d), and four REC groups: REC1/2 group (removal the deprivation and re-exposure to the normal environment for 1/2 d), REC1 group (1 d), REC 2 group (2 d), and REC7 group (7 d). CT was measured by optical coherence tomography (OCT), and CVD of foveal choroid was quantitatively assessed on OCT angiography images using MATLAB software at each time point. NOS in choroid was measured using enzyme-linked immunosorbent assays. Measurements were compared between groups and correlations between CT, CVD, and NOS were assessed using regression analyses.

RESULTS

CVD and CT in FD group were significantly smaller than in NC group (both p < .05), while the NOS significantly larger (p < .001). When deprivation was removed, CVD and NOS were significantly larger and reached a peak in the REC1 group, while CT reached the peak in the REC2 group, then all gradually decreased, and no significant differences were observed in NC and REC7 group (all p > .05). In the REC and NC groups, there was a significant positive correlation between CVD and NOS (p < .001), CVD and CT (p = .0092), but no correlation was found between NOS and CT (p > .05).

CONCLUSIONS

This study indicated that the CVD in guinea pigs could be significantly dilated following myopia REC, and this change coincides with changes in NOS and CT.

Efficacy of 0.19 mg Fluocinolone Acetonide Implant in Non-infectious Posterior Uveitis Evaluated as Area Under the Curve

Introduction

This study reports the outcomes of fluocinolone acetonide intravitreal implant (FAc, Iluvien^®, SIFI, Italy) in patients affected by macular edema secondary to chronic non-infectious uveitis of the posterior segment (NIU-PS).

Methods

This was a retrospective study of patients with NIU-PS and macular thickening undergoing FAc implant at San Raffaele Hospital (Milan, Italy). Clinical data, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), and central macular thickness (CMT), were collected at the time of FAc administration (baseline) and at 1, 6, and 12 months. The area under the curve (AUC) of the BCVA (AUC_BCVA) and CMT (AUC_CMT) was correlated with baseline factors; β estimates and 95% confidence interval (CI) are provided.

Results

Ten eyes of seven patients (60 ± 12 years; 4 male, 57%) were included. The BCVA significantly improved from month 6 (p = 0.03). The CMT improved from month 1 and was persistently lower than baseline until month 12 (p < 0.001). The AUC_BCVA correlated with baseline BCVA (β = 2.5 logMAR; 95% CI 1.59–3.41; p < 0.001), while the mean AUC_CMT positively correlated with the baseline CMT (β = 2.1 μm; 95% CI 0.41–3.80; p = 0.02). No adverse events were recorded over 1 year.

Conclusions

Better visual acuity at the time of FAc administration was associated with better visual function after FAc. Less severe macular edema correlated with better anatomic response. The FAc implant was a safe option for resolving macular edema secondary to NIU-PS.

Foveal and parafoveal choroidal thickness pattern measuring by swept source optical coherence tomography

OBJECTIVE

To evaluate the choroidal thickness (CT) in foveal and parafoveal regions in Thai adults using swept-source optical coherence tomography (SS-OCT).

METHODS

We enrolled healthy volunteers ≥18 years of age from King Chulalongkorn Memorial Hospital, Thailand, during September 2015 to March 2016. Optical coherence tomography (OCT) of the macula was performed, and subfoveal CT was measured manually using a line scan. Average thicknesses of retinal and choroidal layers in regions of the Early Treatment Diabetic Retinopathy Study grid were measured automatically. A multivariate analysis was conducted to determine correlations between CTs in the foveal and parafoveal regions and retinal layers.

RESULTS

Altogether, 144 eyes from 144 subjects (29 men, 115 women; mean age 41 years) were studied. The mean foveal CT was 282.4 ± 13.8 µm. It was thicker in the temporal fovea than in the nasal fovea (p < 0.001) and thicker in men than in women. Multivariate analysis showed that age and sex were significantly negatively correlated with the thickness of the retina, ganglion cell layer, outer retinal layer, and choroid but not of the nerve fiber layer. Regression analysis revealed that the CT decreased approximately 1.5 μm per year.

CONCLUSIONS

Age and sex significantly influence choroidal thickness. Macular CT in a healthy eye thins with age. CT decreases with age faster at distances away from the foveal center than at the center. Subfoveal CT was greater than the mean CT. Parafoveal CT should be evaluated to identify specific retinal-choroidal disease.

Retinal Pigment Epithelium Humps in High Myopia

PURPOSE

To report on the presence of retinal pigment epithelium (RPE) humps in high myopia, and to describe the distinctive features from pathologic RPE detachments and choroidal neovascularizations (CNVs).

DESIGN

Retrospective cross-sectional study.

METHODS

Charts and imaging studies of highly myopic patients presenting between September 2015 and February 2017 at a university teaching hospital were consecutively reviewed. All patients underwent spectral-domain optical coherence tomography (OCT). RPE humps were defined as RPE elevations above its physiologic profile, without any evidence of pathologic sub-RPE material. Multimodal imaging was analyzed to assess abnormalities of the RPE and choroid.

RESULTS

One hundred and ninety-five eyes of 101 highly myopic patients were included. RPE humps on structural OCT were identified in 99 out of 195 eyes (estimated prevalence of 50.8%; 43.8%-57.8, 95% confidence intervals). In all eyes, RPE humps corresponded to large choroidal vessels lifting the RPE. Patchy, diffuse, or CNV-related atrophy was more common in eyes with RPE humps (60.6% vs 34.4%; P < .05). The presence of a large choroidal vessel elevating the RPE and the absence of abnormal material between the RPE and the Bruch membrane were the features distinctive from pathologic RPE detachments and CNVs.

DISCUSSION

RPE humps were frequently observed in highly myopic eyes and they resulted from the presence of an underlying large choroidal vessel. They are more likely to appear in highly myopic eyes with advanced choroidal atrophy. To prevent unnecessary treatments, they should be distinguished from pathologic RPE detachments and CNVs.

Choroidal and Retinal Anatomical Responses Following Systemic Corticosteroid Therapy in Vogt-Koyanagi-Harada Disease Using Swept-Source Optical Coherence Tomography

PURPOSE

To assess structural changes in retina and choroid after systemic corticosteroid therapy in Vogt-Koyanagi-Harada (VKH) disease using swept-source optical coherence tomography (SS-OCT).

METHODS

SS-OCT was conducted before treatment and during first-month follow-up in 16 eyes treated with systemic corticosteroids for active VKH. Retina was divided into five zones depending on pretreatment choroidal thickness (CT) of <100, >100 to <200, >200 to <300, >300 to <400 and >400μm, and changes in retinal thickness and CT after treatment in these zones were compared with baseline.

RESULTS

Mean CT significantly improved from 83.1±8.75 to 156.4±62.73μm(p = 0.008) in the zone with pre-CT <100μm and significantly decreased from 336.1 ± 17.28 to 266.28 ± 81.39μm(p = 0.008) in the zone with pre-CT > 300μm.

CONCLUSIONS

We have shown choroidal remodeling in VKH. SS-OCT can serve as an important noninvasive tool in assessment of treatment response in patients with VKH disease.

Choroidal thickness in patients with coronary artery disease

Purpose

To evaluate choroidal thickness (CTh) in patients with coronary artery disease (CAD) compared to healthy controls.

Design

Cross-sectional.

Methods

Setting: Ambulatory clinic of a large city hospital. Patient population: Thirty-four patients had documented CAD, defined as history of >50% obstruction in at least one coronary artery on cardiac catheterization, positive stress test, ST elevation myocardial infarction, or revascularization procedure. Twenty-eight age-matched controls had no self-reported history of CAD or diabetes. Patients with high myopia, dense cataracts, and retinal disease were excluded. Observation procedures: Enhanced depth imaging optical coherence tomography and questionnaire regarding medical and ocular history. Main outcome measures: Subfoveal CTh and CTh 2000 μm superior, inferior, nasal, and temporal to the fovea in the left eye, measured by 2 readers.

Results

CTh was significantly lower in patients with CAD compared to controls at the subfoveal location (252 vs. 303 μm, P = 0.002) and at all 4 cardinal macular locations. The mean difference in CTh between the 2 groups ranged from 46 to 75 μm and was greatest in the inferior location. Within the CAD group, CTh was significantly lower temporally (P = 0.007) and nasally (P<0.001) than subfoveally, consistent with the pattern observed in controls. On multivariate analysis, CAD was negatively associated with subfoveal CTh (P = 0.006) after controlling for diabetes, hypertension, and hypercholesterolemia.

Conclusions and relevance

Patients with CAD have a thinner macular choroid than controls, with preservation of the normal spatial CTh pattern. Decreased CTh might predispose patients with CAD to high-risk phenotypes of age-related macular degeneration such as reticular pseudodrusen and could serve as a potential biomarker of disease in CAD.

Choroidal thickness changes determined by EDI-OCT on acute anterior uveitis in patients with HLA-B27-positive ankylosing spondylitis

PURPOSE

To evaluate the choroidal thickness on acute anterior uveitis in patients with HLA-B27-positive ankylosing spondylitis.

METHODS

In this study, 32 eyes of 16 HLA-B27 positive AS patients with anterior uveitis and age-matched 19 eyes for control group were analyzed between January 2014 and April 2015. Assessment criteria were uveitis activity, visual acuity, flare existence, subfoveal choroidal thickness and central macular thickness measurements.

RESULTS

The mean subfoveal choroidal thicknesses in affected eye group (Group 1), unaffected eye group (Group 2) and control group (Group 3) were 348.31 ± 72.7, 301.12 ± 49.2 and 318.0 ± 74.3, respectively, in active periods. (p = 0.04 between Group 1 and Group 2, p = 0.234 between Group 1 and Group 3) The mean central macular thicknesses of Group 1, Group 2 and Group 3 were 268.50 ± 16.5, 267.31 ± 16.3 and 249.7 ± 30.5, respectively, in active periods. (p = 0.84 between Group 1 and Group 2, p = 0.029 between Group 1 and Group 3). However, in convalescence period, the mean subfoveal choroidal thicknesses of Group 1, Group 2 and Group 3 were 322.40 ± 48.5, 300.75 ± 47.7 and 318.0 ± 74.3, respectively. (p = 0.22 between Group 1 and Group 2, p = 0.854 between Group 1 and Group 3) The mean central macular thicknesses of Group 1, Group 2 and Group 3 were 269.75 ± 21.9, 256.62 ± 21.5 and 249.7 ± 30.5, respectively. (p = 0.09 between Group 1 and Group 2, p = 0.03 between Group 1 and Group 3).

CONCLUSIONS

In HLA-B27 positive ankylosing spondylitis patients with anterior uveitis, the choroidal thicknesses of the affected eyes were found as thicker than fellow unaffected one or control eyes in active period. The central macular thicknesses are not affected on both active and convalescent period.

Choroidal Round Hyporeflectivities in Geographic Atrophy

PURPOSE

In geographic atrophy (GA), choroidal vessels typically appear on structural optical coherence tomography (OCT) as hyperreflective round areas with highly reflective borders. We observed that some GA eyes show choroidal round hyporeflectivities with highly reflective borders beneath the atrophy, and futher investigated the charcteristcs by comparing structural OCT, indocyanine green angiography (ICGA) and OCT angiography (OCT-A).

METHODS

Round hyporeflectivities were individuated from a pool of patients with GA secondary to non-neovascular age-related macular degeneration consecutively presenting between October 2015 and March 2016 at the Medical Retina & Imaging Unit of the University Vita-Salute San Raffaele. Patients underwent a complete ophthalmologic examination including ICGA, structural OCT and OCT-A. The correspondence between choroidal round hyporeflectivities beneath GA on structural OCT and ICGA and OCT-A imaging were analyzed.

RESULTS

Fifty eyes of 26 consecutive patients (17 females and 9 males; mean age 76.8±6.2 years) with GA were included. Twenty-nine round hyporeflectivities have been found by OCT in choroidal layers in 21 eyes of 21 patients (42.0%; estimated prevalence of 57.7%). All 29 round hyporeflectivities showed constantly a hyperreflective border and a backscattering on structural OCT, and appeared as hypofluorescent in late phase ICGA and as dark foci with non detectable flow in the choroidal segmentation of OCT-A. Interestingly, the GA area was greater in eyes with compared to eyes without round hyporeflectivities (9.30±5.74 and 5.57±4.48mm2, respectively; p = 0.01).

CONCLUSIONS

Our results suggest that most round hyporeflectivities beneath GA may represent non-perfused or hypo-perfused choroidal vessels with non-detectable flow.

Choroidal Vascularity Index in Vogt-Koyanagi-Harada Disease: An EDI-OCT Derived Tool for Monitoring Disease Progression

Purpose

We assessed the application of the choroidal vascularity index (CVI) in the follow-up of Vogt-Koyanagi-Harada disease (VKH) patients derived from image binarization of enhanced depth imaging optical coherence tomography (EDI-OCT) images with Fiji software. Our secondary objective was to derive the retinochoroidal vascularity index based on en face fundus fluorescein and indocyanine green angiography (FFA and ICGA).

Methods

In this retrospective cohort study, EDI-OCT scans of 18 eyes of 9 patients with VKH were obtained at baseline within 2 weeks of acute presentation, and again at 6 to 12 months. Images with poor quality were excluded. Choroidal thickness (CT) and CVI were analyzed and compared to 13 eyes of 13 healthy controls. En face FFA and ICGA obtained from 12 eyes of 7 patients were segmented to derive retinochoroidal vascularity index.

Results

There was no statistical difference in age or sex between the study group and controls. Choroidal thickness of patients with VKH was 359.23 ± 57.63 μm at baseline, compared to 274.09 ± 56.98 μm in controls (P = 0.003). Follow-up CT in VKH patients was 282.62 ± 42.51 μm, which was significantly decreased from baseline (P = 0.0001). Choroidal vascularity index in VKH patients was 70.03 ± 1.93% at baseline, compared to 64.63 ± 1.92% in controls (P < 0.001). Choroidal vascularity index was 66.94 ± 1.82% at follow-up, significantly reduced from baseline (P < 0.0001). Fundus fluorescein angiography and ICGA retinochoroidal vascularity indices at baseline were 70.67 ± 2.65% and 66.42 ± 2.16%, respectively.

Conclusions

In this small series of VKH patients, EDI-OCT–derived CVI had a statistically significant reduction over time, similar to CT. We propose that OCT, FFA, and ICGA-derived vascularity indices may be potential novel supportive tools in monitoring disease progression in VKH.

Translational Relevance

Choroidal vascularity index can be used potentially to study and analyze the structural changes in choroid. It can be a useful tool to explain the changes in the CT in different retinochoroidal disorders. Choroidal vascularity index also can be used for longitudinal follow-up in patients with VKH disease and other inflammatory disease involving the choroid.

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.