Choroidal vascular index in patients with open angle glaucoma and preperimetric glaucoma

Visual Field Prognosis From Macula and Circumpapillary Spectral Domain Optical Coherence Tomography

Purpose

To explore the structural-functional loss relationship from optic-nerve-head- and macula-centred spectral-domain (SD) Optical Coherence Tomography (OCT) images in the full spectrum of glaucoma patients using deep-learning methods.

Methods

A cohort comprising 5238 unique eyes classified as suspects or diagnosed with glaucoma was considered. All patients underwent ophthalmologic examination consisting of standard automated perimetry (SAP), macular OCT, and peri-papillary OCT on the same day. Deep learning models were trained to estimate G-pattern visual field (VF) mean deviation (MD) and cluster MD using retinal thickness maps from seven layers: retinal nerve fiber layer (RNFL), ganglion cell layer and inner plexiform layer (GCL + IPL), inner nuclear layer and outer plexiform layer (INL + OPL), outer nuclear layer (ONL), photoreceptors and retinal pigmented epithelium (PR + RPE), choriocapillaris and choroidal stroma (CC + CS), total retinal thickness (RT).

Results

The best performance on MD prediction is achieved by RNFL, GCL + IPL and RT layers, with R2 scores of 0.37, 0.33, and 0.31, respectively. Combining macular and peri-papillary scans outperforms single modality prediction, achieving an R2 value of 0.48. Cluster MD predictions show promising results, notably in central clusters, reaching an R2 of 0.56.

Conclusions

The combination of multiple modalities, such as optic-nerve-head circular B-scans and retinal thickness maps from macular SD-OCT images, improves the performance of MD and cluster MD prediction. Our proposed model demonstrates the highest level of accuracy in predicting MD in the early-to-mid stages of glaucoma.

Translational Relevance

Objective measures recorded with SD-OCT can optimize the number of visual field tests and improve individualized glaucoma care by adjusting VF testing frequency based on deep-learning estimates of functional damage.

Evaluation of Choroidal Thickness and Choroidal Vascularity Index in Patients with Rheumatoid Arthritis

PURPOSE

To evaluate the choroidal vascularity index and choroidal thickness in patients with rheumatoid arthritis.

METHOD

This study is a case control study. Our study consists of a total of two groups, with 32 individuals diagnosed with rheumatoid arthritis (RA) and 32 healthy volunteers. The thickness of the subfoveal choroid was measured from the 500 micron (µm), 1000 µm, 1500 µm nasal aspect of the fovea, and 500µm, 1000µm, 1500 µm temporal and subfoveal thickness of the fovea. ImageJ version 1.53i (National Institutes of Health, Bethesda, MD, USA) from open access was used for choroidal vascular index calculation.

RESULTS

The mean age (p = 0.064) and gender distribution (p = 0.522) were not statistically different between these two groups. There was no difference between the groups in terms of visual acuity (p = 0.060), intraocular pressures (p=0.056), refractive errors (p = 0.418), and axial lengths (p = 0.280). Temporal 500 µm CT (p = 0.038), temporal 1000 µm CT (p = 0.010), and temporal 1500 µm CT (p = 0.005) differed significantly between the groups. The luminal area was significantly different between the RA group (842.71 ± 192.77) and the control group (957.78 ± 230.83) (p = 0.034). The choroidal vascularity index showed a significant difference between the RA group (64.99 ± 4.71) and the control group (67.34 ± 3.40) (p = 0.026). A significant difference was observed between the seronegative RA and the control group with temporal 1500 µm CT (p = 0.030), temporal 1000 µm CT (p = 0.023), and luminal area (p = 0.034).

CONCLUSION

We demonstrated thinning in CT and decreased CVI for the first time in RA patients by comparing it with the control group.

Comparison of Peripapillary Choroidal Thickness Between Primary Open-angle Glaucoma, Normal Tension Glaucoma, and Normal Eyes: A Systematic Review and Meta-analysis

TOPIC

To investigate differences in peripapillary choroidal thickness (PPCT) between primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and healthy eyes, additionally comparing differences between POAG and NTG eyes.

CLINICAL RELEVANCE

Peripapillary choroidal thickness is a well-established OCT parameter in eyes with glaucoma and other ocular pathologies. The relationship between PPCT and glaucoma, if better understood, may facilitate the development of PPCT as a potential diagnostic and monitoring metric for glaucoma. In particular, there has yet to be a synthesis that directly compares PPCT between POAG eyes and NTG eyes.

METHODS

A comprehensive literature search was performed on PubMed, EMBASE, and Cochrane Library, identifying studies from inception to December 2022. We included studies that measured PPCT using OCT in POAG, NTG, and healthy eyes. Mean difference (MD) among groups was calculated. Statistical analysis was performed using R version 4.2.0. Risk of bias of included studies was assessed using the Newcastle Ottawa Scale (NOS).

RESULTS

Eighteen studies were included in this meta-analysis, with a pooled total of 935 healthy control eyes, 446 NTG eyes, and 934 POAG eyes. There was a significant reduction of PPCT in POAG eyes compared with healthy eyes [MD = -16.32; 95% confidence interval (CI) (-27.55 to -5.09)]. Reduction in PPCT was also significant in NTG eyes compared with healthy eyes [MD = -34.96; 95% CI (-49.97 to -19.95)]. NTG eyes had significantly reduced PPCT compared with POAG eyes [MD = -26.64; 95% CI (-49.00 to -4.28)].

CONCLUSIONS

Glaucomatous eyes appear to have significantly reduced PPCT compared with normal healthy eyes. In addition, PPCT in NTG eyes appear significantly thinner compared with that in POAG eyes.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Choroidal Morphology and Photoreceptor Activity Are Related and Affected by Myopia Development

Purpose

The choroid is critical for the regulation of eye growth and is involved in the pathogenesis of myopia-associated ocular complications. This study explores the relationship among choroidal biometry, photoreceptor activity, and myopic growth in marmosets (Callithrix jacchus) with lens-induced myopia.

Methods

A total of 34 common marmosets aged 92 to 273 days old were included in this study. Axial myopia was induced in 17 marmosets using negative soft contact lenses and 17 marmosets served as untreated controls. Cycloplegic refraction (RE) and vitreous chamber depth (VCD) were measured using autorefraction and A-scan ultrasonography, respectively. Choroidal scans were obtained using spectral-domain optical coherence tomography and binarized to calculate subfoveal choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), and LA/SA. To assess photoreceptor activity, the a-wave of the full-field electroretinogram was measured. Regression models were used to investigate the relationship between outcome measures.

Results

Eyes induced with axial myopia (RE = -7.14 ± 4.03 diopters [D], VCD = 6.86 ± 0.39 mm) showed significant reductions (4.92-21.24%) in all choroidal parameters (ChT, TCA, LA, SA, CVI, and LA/SA) compared to controls (RE = -1.25 ± 0.60 D, VCD = 6.58 ± 0.26 mm, all P < 0.05), which changed as a function of refraction and vitreous elongation, and were associated with a decrease in the a-wave amplitude. Further, multiple regression showed that a combination of ChT and CVI could well predict RE and VCD.

Conclusions

This study reports the existence of significant alterations in choroidal morphology in non-human primate eyes induced with myopia. The changes in choroidal anatomy were associated with reduced light-adapted a-wave amplitude. These findings may represent early markers for reduced visual performance and chorioretinal complications known to occur in eyes with large degrees of myopia.

Macular and peripapillary Choroidal Vascularity Index in children with different refractive status

OBJECTIVES

To characterize choroidal vascular changes in children with different refractive status.

METHODS

A study including 5864 children aged 6-9 years was performed to investigate the choroidal vascular index (CVI) in myopic, emmetropic and hyperopic eyes. Each participant had a comprehensive ocular examination with cycloplegic autorefraction performed, axial length (AL) measured and Swept Source-Optical Coherence Tomography (SS-OCT) scans acquired. Choroidal thickness (ChT) was measured by built-in software, and CVI was calculated using a previously validated self-developed algorithm.

RESULTS

The mean ChT and CVI were 275.88 ± 53.34 μm and 34.91 ± 3.83 in the macula region, and 191.96 ± 46.28 μm and 32.35 ± 4.21 in the peripapillary region. CVI was significantly lowest for myopes, followed by emmetropes and hyperopes (P < 0.001). CVI varied between different sectors separated by the Early Treatment of Diabetic Retinopathy Study (ETDRS) grid (P < 0.001). Macular CVI decreased horizontally from nasal to temporal quadrant with lowest in center fovea, and vertically from superior to inferior quadrants. Peripapillary CVI was highest in the nasal and lowest in the inferior sector. Multiple regression showed that spherical equivalent (SE), AL, intraocular pressure (IOP), ChT, age, and gender were significantly related to CVI (P < 0.05).

CONCLUSIONS

In children, the distribution of CVI in the posterior pole is not uniform. A decreased CVI was observed from hyperopia to myopia and was associated with decreased SE, elongated AL, and choroidal thinning. Further study of changes in CVI during myopia onset and progression is required to better understand the role of the choroidal vasculature in myopia development.

Comparison of the Choroid in Primary Open Angle and Angle Closure Glaucoma Using Optical Coherence Tomography

PRCIS

The current study highlights distinct choroidal alterations in primary open angle (POAG) and primary angle closure (PACG) glaucomas, underscoring the potential of the Choroidal Vascularity Index (CVI) as a valuable indicator for understanding glaucoma pathogenesis.

PURPOSE

To evaluate choroidal structural changes in patients with POAG and PACG and healthy controls utilizing the CVI and subfoveal choroidal thickness by enhanced depth imaging optical coherence tomography.

METHODS

This study was cross-sectional. A total of 171 eyes of 171 subjects, comprising 69 eyes with untreated POAG, 58 eyes with untreated PACG, and 44 healthy eyes, were enrolled in this study. Subfoveal choroidal thickness, luminal area (LA), stromal area (SA), and total choroidal area were measured on enhanced depth imaging-optical coherence tomography scans. The CVI parameter is calculated as the proportion of LA to the total choroidal area.

RESULTS

This study included 69 patients with POAG with a mean age of 51.4 ± 13.3 years, 58 patients with PACG with a mean age of 57.0 ± 7.3 years, and 44 healthy subjects with a mean age of 51.11 ± 10.7 years. The CVI in the POAG and PACG groups was significantly lower than that in the control group ( P = 0.001 and P = 0.005, respectively); however, not significantly different between the two glaucoma groups ( P = 1.000). POAG eyes had significantly lower LA than PACG and controls ( P = 0.014 and P = 0.049, respectively), whereas PACG eyes had significantly greater SA than controls ( P = 0.041).

CONCLUSIONS

The CVI of POAG and PACG eyes was significantly lower than that of normal eyes. A reduced LA was observed mainly in eyes with POAG, and an increased SA was observed mainly in eyes with PACG. The role of the choroid may differ between POAG and PACG eyes.

Choroidal vascularity index in hereditary optic neuropathies

PURPOSE

To assess the choroidal vascularity index (CVI) in patients affected by Leber hereditary optic neuropathy (LHON) compared to patients affected by dominant optic atrophy (DOA) and healthy subjects.

METHODS

In this retrospective study, we considered three cohorts: LHON eyes (48), DOA eyes (48) and healthy subjects' eyes (48). All patients underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) acquisition. OCT parameters as subfoveal choroidal thickness (Sub-F ChT), mean choroidal thickness (ChT), total choroidal area (TCA), luminal choroidal area (LCA) were calculated. CVI was obtained as the ratio of LCA and TCA.

RESULTS

Subfoveal ChT in LHON patients did not show statistically significant differences compared to controls, while in DOA a reduction in choroidal thickness was observed (p = 0.344 and p = 0.045, respectively). Mean ChT was reduced in both LHON and DOA subjects, although this difference reached statistical significance only in DOA (p = 0.365 and p = 0.044, respectively). TCA showed no significant differences among the 3 cohorts (p = 0.832). No changes were detected in LCA among the cohorts (p = 0.389), as well as in the stromal choroidal area (SCA, p = 0.279). The CVI showed no differences among groups (p = 0.898): LHON group was characterized by a similar CVI in comparison to controls (p = 0.911) and DOA group (p = 0.818); the DOA group was characterized by a similar CVI in comparison to controls (p = 1.0).

CONCLUSION

CVI is preserved in DOA and LHON patients, suggesting that even in the chronic phase of the neuropathy the choroidal structure is not irreversibly compromised.

Postoperative Choroidal Vascular Biomarkers in Eyes with Rhegmatogenous Retinal Detachment-Related Giant Retinal Tears

PURPOSE

Choroidal vascularity index (CVI) and choriocapillaris flow area (CFA) are perfusion biomarkers relevant to retinal disease management. There is limited knowledge regarding these biomarkers in eyes that have been successfully treated for rhegmatogenous retinal detachment (RRD) due to giant retinal tears (GRTs). This study aimed to analyze the relationship between choroidal perfusion biomarkers and functional outcomes in surgically treated eyes with GRT-associated RRD and their fellow eyes.

METHODS

A total of 33 GRT eyes and 29 fellow eyes were included in this study. All RRD-GRT eyes were treated with vitrectomy and categorized into two groups based on whether additional scleral buckles (SB) were placed. Visual and choroidal features were compared between the groups.

RESULTS

The subjects had an average age of 55.18 years, a mean time of 2.36 weeks before surgery, and a mean follow-up time of 25.9 months. Best-corrected visual acuity (BCVA) was substantially worse in GRT eyes (1.9 logMAR) than in fellow control eyes (0.23 logMAR) but substantially improved after surgery (0.59 logMAR). There were no differences in the presurgical characteristics and BCVA between the eyes that did and did not undergo SB. Long-term CVI and CFA were lower in eyes with GRT than in their fellow eyes. Among eyes with GRT, those with SB had significantly lower CVI and CFA. Correlation analysis revealed that the CVI and CFA were positively correlated with visual outcomes (negative correlation with logMAR).

CONCLUSION

Despite successful surgical repair, long-term functional and choroidal evaluations showed permanent changes in eyes with GRT. Positive correlations between perfusion biomarkers and visual function suggest that better choroidal vasculature is associated with better visual outcomes. The results of this study highlight the benefits of analyzing choroidal vasculature biomarkers and the relationship between the choroidal anatomy and vision.

Oxidative Stress Induced Dysfunction of Protein Synthesis in 661W Mice Photoreceptor Cells

Photoreceptor cells are highly susceptible to oxidative-stress-induced damage due to their high metabolic rate. Oxidative stress plays a key role in driving pathological events in several different ocular diseases, which lead to retinal degeneration and ultimately blindness. A growing number of studies have been performed to understand downstream events caused by ROS induced oxidative stress in photoreceptor cells; however, the underlying mechanisms of ROS toxicity are not fully understood. To shed light on ROS induced downstream pathological events, we employed a tandem mass tag (TMT) labelling-based quantitative mass-spectrometric approach to determine proteome changes in 661W photoreceptor cells following oxidative stress induction via the application of different concentrations of H2O2 at different time points. Overall, 5920 proteins were identified and quantified, and 450 differentially expressed proteins (DEPs) were identified, which were altered in a dose and time dependent manner in all treatment groups compared to the control group. These proteins were involved in several biological pathways, including spliceosome and ribosome response, activated glutathione metabolism, decreased ECM-receptor interaction, oxidative phosphorylation, abnormally regulated lysosome, apoptosis, and ribosome biogenesis. Our results highlighted ECM receptor interaction, oxidative phosphorylation and spliceosome pathways as the major targets of oxidative stress that might mediate vascular dysfunction and cellular senescence.

Postoperative choroidal vascularity index after the management of macula-off rhegmatogenous retinal detachment

BACKGROUND

Rhegmatogenous retinal detachment (RRD) is a vision-threatening condition that can be treated with various surgical approaches. The role of scleral buckling remains controversial because of its potential long-term deleterious effects on choroidal vascular perfusion and the limited knowledge of this entity.

METHODS

A total of 135 eyes were retrospectively selected, including 115 with surgically resolved RRD and 20 healthy control eyes. Of the surgically treated eyes, 64 underwent vitrectomy alone, while 51 underwent scleral buckling combined with vitrectomy. Best-corrected visual acuity (BCVA) was evaluated along with the choroidal vascularity index (CVI) as a metric for the state of the choroidal vasculature. BCVA was compared before and after surgery, and the postoperative BCVA was analyzed with the CVI using correlation and multivariate regression analyses.

RESULTS

The preoperative BCVA of the RRD eyes was significantly worse than that of the control eyes, and significantly improved after surgery. However, the long-term postsurgical BCVA was still inferior to that of the control eyes. No significant differences in visual function were found between the two surgical groups. The average CVI was 57.35% in the control eyes, 63.76% in the eyes that underwent vitrectomy, and 53.37% in buckled eyes. The differences in CVI were significant among the three groups. Among the surgical patients, negative Pearson's correlations were found between CVI and postoperative BCVA (expressed in logMAR). A multivariate linear regression model containing four parameters revealed that CVI was the only variable with a significant influence on postoperative BCVA, while the length of time with a detached macula did not have an effect.

CONCLUSIONS

RRD surgery drastically restored vision, but the effect of RRD lingered, as postsurgical visual acuity remained inferior to that of the control eyes. The CVI varied between the treatment groups, likely due to both disease pathology and the impact of the surgery. The correlation between CVI and BCVA indicates the important role that the choroidal vasculature plays in visual function.

Peripapillary and Macular Structural and Vascular Parameters in Age-Related Choroidal Atrophy

PRCIS

The macular and peripapillary structural and vascular alterations in elderly patients with age-related choroidal atrophy may mimic glaucomatous degeneration.

PURPOSE

To evaluate the peripapillary retinal nerve fiber layer (pRNFL), macular nerve fiber layer (mNFL), ganglion cell layer (mGCL), inner plexiform layer (mIPL) thicknesses, and choroidal vascularity index (CVI) values in patients with age-related choroidal atrophy (ARCA) and to compare with the those of age and sex-matched healthy controls.

METHODS

The cross-sectional, observational study included 95 eyes of 95 patients. The patients were divided into 2 groups according to subfoveal choroidal thickness (sCT) values. Forty eight eyes with sCT<125 µm constituted ARCA group (group 1), and 47 eyes with sCT>125 µm constituted control group (group 2). Peripapillary RNFL, mNFL, mGCL, mIPL, sCT values and fundus autofluorescence images were acquired with spectral domain-optical coherence tomography. Enhanced depth imaging mode spectral domain-optical coherence tomography images were binarized to show the luminal and stromal areas of choroid. CVI (%) was defined as the ratio of the luminal area to the total choroidal area with defined borders.

RESULTS

The mean age was 78.47±6.07 years in group 1 and 76.95±6.68 years in group 2. The mean, superior and inferior quadrants pRNFL thicknesses were significantly lower in group 1 than in group 2 ( P <0.05 for all). The mean mNFL, mGCL, mIPL thickness values were also statistically lower in group 1 than group 2 ( P <0.05 for all). The CVI value was 61.29±4.52 in group 1, and 64.81±3.80 in group 2 ( P <0.001).

CONCLUSION

The patients with ARCA had decreased pRNFL, inner macular layer thickness and CVI values when compared with healthy control eyes. These findings should be considered in the differential diagnosis and the follow up of eyes with glaucoma.

The role of the adaptive immune system and T cell dysfunction in neurodegenerative diseases

The adaptive immune system and associated inflammation are vital in surveillance and host protection against internal and external threats, but can secondarily damage host tissues. The central nervous system is immune-privileged and largely protected from the circulating inflammatory pathways. However, T cell involvement and the disruption of the blood-brain barriers have been linked to several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Under normal physiological conditions, regulatory T cells (Treg cells) dampen the inflammatory response of effector T cells. In the pathological states of many neurodegenerative disorders, the ability of Treg cells to mitigate inflammation is reduced, and a pro-inflammatory environment persists. This perspective review provides current knowledge on the roles of T cell subsets (e.g., effector T cells, Treg cells) in neurodegenerative and ocular diseases, including uveitis, diabetic retinopathy, age-related macular degeneration, and glaucoma. Many neurodegenerative and ocular diseases have been linked to immune dysregulation, but the cellular events and molecular mechanisms involved in such processes remain largely unknown. Moreover, the role of T cells in ocular pathologies remains poorly defined and limited literature is available in this area of research. Adoptive transfer of Treg cells appears to be a vital immunological approach to control ocular pathologies. Similarities in T cell dysfunction seen among non-ocular neurodegenerative diseases suggest that this area of research has a great potential to develop better therapeutic agents for ocular diseases and warrants further studies. Overall, this perspective review article provides significant information on the roles of T cells in numerous ocular and non-ocular neurodegenerative diseases.

Association between Choroidal Vascularity and Prelaminar Tissue Thickness in Healthy and Glaucomatous Eyes

Purpose: To assess the association between the choroidal vascularity index (CVI) and prelaminar tissue thickness (PTT) in healthy and glaucomatous eyes.Methods: The study included 86 eyes with perimetric glaucoma (PG), 86 with pre‐perimetric glaucoma (PPG), and 43 agematched healthy eyes. Total choroidal area (TCA) and CVI were measured by image binarization of spectral‐domain optical coherence tomography (SD‐OCT) 3.5 mm from the center of Bruch’s membrane opening. The CVI was the percentage of choroidal vasculature to choroidal tissue. The association between CVI and PTT measured on a center‐horizontal scan of enhanced depth imaging SD‐OCT was assessed.Results: The CVI was lowest in PG (61.67% ± 4.11%), followed by PPG (63.36% ± 3.54%), and healthy (64.84% ± 3.13%) eyes (p < 0.001). PG (102.05 ± 44.01 μm) had a significantly thinner PTT than PPG (106.16 ± 38.03 μm) and the healthy (154.98 ± 79.46 μm) eyes (p < 0.001). In a multivariate regression analysis, CVI was associated with PTT and TCA in all subjects, including healthy and glaucomatous eyes (p < 0.05).Conclusions: The CVI and PTT had significantly lower values in glaucomatous eyes than in healthy eyes, and the two parameters were positively associated in all subjects, including healthy and glaucomatous eyes.

Choroidal Vascularity Index Changes After Exercise in Patients With Glaucoma

Purpose: To investigate the changes in choroidal vascular structures after exercise in patients with glaucoma using an image binarisation algorithm with enhanced-depth imaging optical coherence tomography.

Methods: Thirty-four eyes of 19 patients with primary open-angle glaucoma and 40 eyes of 20 normal subjects were included in the glaucoma and control groups, respectively. All subjects were evaluated before, immediately after, and 30 min after 20-min running at moderate speed. The subfoveal choroidal area was segmented into the luminal area (LA) and stromal area (SA), and the choroidal vascularity index (CVI) was measured by calculating the ratio of LA to the total choroidal area (TCA). The mean intraocular pressure (IOP), subfoveal choroidal thickness, CVI, SA, CA, and TCA were compared within and between both groups. The correlation between CVI, IOP, and other vascular indexes was investigated.

Results: In the glaucoma group, a significantly lower CVI was found immediately after exercise and recovered 30 min after exercise. Higher TCA and LA levels were demonstrated 30 min after exercise compared to immediately after exercise. In both groups, IOP decreased immediately after exercise but was restored after a 30-min rest. In the glaucoma group, there was a higher correlation between CVI and other choroidal vascular parameters than in the control group. There was no difference in IOP or choroidal parameters between the groups at different time points.

Conclusion: In patients with glaucoma, CVI decreased significantly immediately after exercise, indicating that the choroidal layer is affected by exercise and an unhealthy vascular regulatory mechanism.

Choroidal vascularity index in thyroid eye disease: comparison with controls and application in diagnosing non-inflammatory active disease

PURPOSE

To report the differences in choroidal vascularity index (CVI) in thyroid eye disease (TED) and normals and its discriminatory value for differentiating various stages of TED.

METHODS

Prospective, cross-sectional, non-interventional imaging study. Ninety-four eyes of 54 patients were included and divided into 5 groups - normal controls (C), inactive TED (I), active TED (A), non-inflammatory active TED (NIA) and systemic hyperthyroid disorder but no TED (SYS). Choroidal images were acquired using the swept-source optical coherence tomography and the choroid was binarized to calculate the CVI.

RESULTS

Ninety-four eyes were included. Mean age was 44.52 ± 10.02 years (median 46 years, range 19-65 years). Mean IOP was 16.1 ± 3.37 mm Hg (median 16 mm Hg, range 16-24 mm Hg). Mean Spherical equivalent (SE) was -0.08 ± 1.86 diopters (median 0, range -2.5 to +2.25). Intra-rater agreement was 0.84 (p < 0.001). Inter-rater agreement was noted to be 0.85 (p < 0.001) for consistency and 0.77 (p < 0.001) for absolute agreement. CVI in the A group was 70.11 ± 3.38% and in the NIA group was 69.32 ± 3.5%. Both were comparable to each other and significantly higher than the C, I and SYS groups (p < 0.001). Multiple regression showed that the Clinical Activity Score (CAS) had a positive effect and spheroequivalent had a negative effect on the CVI. At CVI of 66.83%, active TED can be diagnosed with sensitivity of 91.67% and specificity of 82.14%                 .

CONCLUSIONS

CVI is significantly higher in active TED and NIA TED compared to other groups. It has a good value in differentiating the non-inflammatory active TED eyes from the inactive eyes.

Associations Between the Choroidal Vascularity Index and Malignant Glaucoma After Trabeculectomy for Primary Angle Closure Glaucoma

Purpose: To compare the choroidal vasculature characteristics by using the choroidal vascularity index (CVI) in eyes with malignant glaucoma (MG), fellow eyes with non-MG, and eyes with uncomplicated primary angle-closure glaucoma (PACG) after trabeculectomy by spectral-domain optical coherence tomography (SD-OCT). Methods: This case-control study included 53 patients diagnosed with MG after trabeculectomy. Eyes with MG (n = 53) and the fellow eyes with non-MG (n = 50) were included. Eyes with PACG without MG after trabeculectomy (n = 60) were also enrolled as controls. The choroidal parameters, including CVI and the subfoveal choroidal thickness (SFCT), were measured by using SD-OCT images. Results: Eyes with MG and the fellow eyes showed a significantly lower CVI than eyes with PACG controls (p < 0.001). After adjusting for age, sex, axial length (AL), and intraocular pressure (IOP), eyes with the greater CVI [odds ratio (OR), 0.44] were significantly related to MG. The area under the receiver operating characteristic curve of the CVI was greater than that of the SFCT in the diagnosis of MG (0.911 vs. 0.840, p = 0.034). Conclusion: Eyes with MG showed a significantly lower macular CVI than eyes with PACG controls. A higher macular CVI was an associated factor of eyes with MG. The CVI serves as a more stable and sensitive indicator for MG than the SFCT in this group of patients with PACG.

Observation of Peripapillary Choroidal Vascularity in Natural Disease Course and After Gene Therapy for Leber's Hereditary Optic Neuropathy

Purpose: To compare peripapillary choroidal vascularity among Leber's Hereditary Optic Neuropathy (LHON) patients at different stages of natural course and healthy controls using optical coherence tomography (OCT), and to evaluate peripapillary choroidal vascularity changes in LHON patients before and after gene therapy.

Methods: 57 LHON patients and 15 healthy controls were enrolled in this prospective clinical study. LHON patients were divided into three duration groups based on stage of disease progression. Both patients and healthy controls underwent OCT scans focused on the optic disc at baseline with Heidelberg Spectralis, and patients underwent OCT at 1, 3, and 6 months after gene therapy. OCT images were converted and binarized using ImageJ software. Choroidal thickness (CT), total choroidal area (TCA), and choroidal vascularity index (CVI) in each quadrant of OCT images were measured to evaluate peripapillary choroidal vascularity.

Results: At baseline, the average CT was not significantly different between LHON patients at different stages and between healthy controls (P = 0.468). Although average TCA and average CVI were slightly higher in LHON patients at different stages than in healthy controls, the difference was not statistically significant (P = 0.282 and 0.812, respectively). After gene therapy, The average TCA at 1 month after gene therapy was significantly higher than that before gene therapy (P = 0.003), while no significant differences were found in the average CT or average CVI in LHON patients before and 1,3 and 6 months after gene therapy using pairwise comparisons (all P > 0.05).

Conclusions: No significant difference was found in choroidal vascularity of LHON patients at different stages and healthy controls. Choroidal vascularity seems to stay stable after gene therapy.

Macular and submacular choroidal microvasculature in patients with primary open-angle glaucoma and high myopia

AIMS

To characterise the influence of primary open-angle glaucoma (POAG) and high myopia (HM) on the macular and choroidal capillary density (CD).

METHODS

Two hundred and seven eyes were enrolled, including 80 POAG without HM, 50 POAG with HM, 31 HM without POAG and 46 normal controls. A fovea-centred 6×6 mm optical coherence tomography angiography scan was performed to obtain the CD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris. Macular and choroidal CDs were compared among the groups and the association of CDs with visual field mean deviation (MD) was determined using linear regression models.

RESULTS

Compared with normal eyes, SCP CD was decreased in the POAG without HM group (p<0.05), while DCP CD was significantly decreased in the HM without POAG group (p<0.05). Both SCP and DCP CDs were significantly decreased in the POAG with HM group (p<0.05). CD reduction occurred mainly in the outer rather than inner ring of the 6×6 mm scan size. In multivariate regression analysis, worse MD was associated with lower CD in the outer ring of the SCP in all the HM eyes (p<0.05).

CONCLUSIONS

POAG and HM reduced macular CD in different layers of the retinal capillary plexus and both particularly in the outer ring of the 6×6 mm scans. Furthermore, assessment of the CD in the outer ring of the SCP may facilitate the diagnosis of glaucoma in eyes with HM.

Characterization of macular choroid in normal-tension glaucoma: a swept-source optical coherence tomography study

PURPOSE

To investigate the features of the small-to-medium (choriocapillaris and Sattler's layer) and large (Haller's layer) sized vessel layers of the macular choroid in normal-tension glaucoma (NTG) patients using swept-source optical coherence tomography (SS-OCT).

METHODS

We conducted an observational cross-sectional study in 234 NTG eyes from 134 patients, and 203 normal eyes from 109 non-glaucomatous control subjects. We used Image J to segment the choroidal layer and then a Python script to measure the average macular choroidal thickness (MCT) and choroidal vascular index (CVI) of two vessel layers at five different locations. Quantitative optical coherence tomography angiography (OCTA) metrics for the superficial capillary plexus (SCP) and deep capillary plexus (DCP) at macular region were also measured by a customized MATLAB program. Generalized estimating equations (GEE) models were performed to determine ocular and demographic factors associated with the choroidal metrics, adjusting for inter-eye correlation.

RESULTS

Significant average MCT thinning was found in NTG eyes at all five locations of the two layers, in comparison with controls (all p ≤ 0.05). In addition, compared with control eyes, significant decrease in CVI was found in NTG eyes at all five sections of the large sized vessel layer: 500 µm nasal and temporal to macula (p = 0.002), 1500 µm nasal (p < 0.001), 2500 µm nasal (p = 0.001), 1500 µm temporal (p < 0.001) and 2500 µm temporal (p = 0.004). In contrast, no significant CVI difference was detected in the small-to-medium sized vessel layer. In the comparison of OCTA metrics of SCP and DCP at macular region between NTG and normal eyes, there were no significant difference of parafoveal vessel density (VD), foveal avascular zone (FAZ) area, FAZ circularity and fractal dimension (FD) in both layers.

CONCLUSION

We found significant alterations in macular choroidal vascularity (reduced CVI and thinner layer) in NTG patients. Such alterations are more pronounced in the Haller's layer, rather than the choriocapillaris & Sattler's layer, in NTG. Choroidal layer may be more related to vasculature changes at macular region in NTG.

Posterior ocular structural changes and glaucoma susceptibility in patients with hemifacial spasm

PURPOSE

To evaluate the changes in the posterior ocular structures and glaucoma susceptibility in patients with hemifacial spasm (HFS).

STUDY DESIGN

Prospective observational clinical study.

METHODS

This study included 46 long-standing HFS patients with a minimum follow-up of 12 months. The participants' eyes were divided into three groups: (1) 46 affected eyes of patients with clinical HFS; (2) 46 unaffected fellow eyes and, (3) 46 eyes of healthy sex and age-matched controls. All participants were assessed by a detailed clinical examination and optical coherence tomography (OCT) with enhanced depth imaging (EDI). EDI-OCT images were binarized using ImageJ software. Peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), choroidal thickness (CT), and choroidal vascularity index (CVI) were used to compare the structural characteristics of the affected eyes with fellow and control eyes. The CT measurements were performed from the subfoveal and locations at 750 μm and 3000 μm intervals from the foveal center, and the average of CT measurements at 5 locations was accepted as mean CT.

RESULTS

The demographic and clinical characteristics among the groups were similar (for all, P > 0.05). Mean peripapillary RNFL thickness of the inferior quarter was significantly lower in affected eyes, compared to fellow eyes (P = 0.023) and control eyes (P = 0.040). Mean GCC thickness significantly decreased in affected eyes, compared to fellow eyes (P = 0.019) and healthy controls (P = 0.008). Mean CT thickness significantly decreased in affected eyes, compared to fellow eyes (P = 0.002) and healthy controls (P < 0.001). Mean subfoveal CVI (65.94% ± 1.46) was found to be significantly thinner than the unaffected fellow (68.19% ± 1.84, P = 0.011) eyes and control eyes (67.23% ± 0.84, P = 0.044).

CONCLUSIONS

This study's outcomes show that long-standing HFS is associated with glaucoma-associated morphological OCT findings and decreased both CT and subfoveal choroidal vascularity. These findings may be related to the fact that the posterior ocular structures are affected by long-lasting paroxysmal orbicularis contractions.

Comparison of Choroidal Vascularity Index in Patients with Pseudoexfoliation Glaucoma, Pseudoexfoliation Syndrome, and Healthy Controls

PURPOSE

To compare peripapillary choroidal vascularity index (CVI) parameters in pseudoexfoliation glaucoma (PEG), pseudoexfoliation (PEX) syndrome, and healthy controls.

METHODS

A total of 240 eyes of 240 patients were included in this cross-sectional prospective study, and the three groups consisted of (i) 80 eyes of 80 patients with PEG, (ii) 80 eyes of 80 patients with PEX syndrome, and (iii) 80 healthy control eyes. Peripapillary enhanced depth imaging optical coherence tomography images were binarized via standard protocols with the ImageJ software. CVI was analyzed in all sectors of the peripapillary region.

RESULTS

Peripapillary CVI was found to be significantly lower in the PEG group (61.6 ± 2.32) compared with the PEX group (64.7 ± 3.15) and the control group (67.5 ± 2.44) (p < .001), and patients with PEX also had significantly lower values compared to controls (p < .001). Peripapillary CVI values were significantly lower in the temporal, nasal, superotemporal, superonasal, inferotemporal and inferonasal sectors of the PEG group compared to both the PEX group and controls (p < .001). Peripapillary CVI was also found to be lower in all sectors in the PEX group compared to controls (p < .001). Global peripapillary choroidal thickness was significantly thinner in the PEG group than the PEX and control groups (133.37 ± 39.16, 154.36 ± 33.28 and 157.82 ± 36.77 μm, respectively, p < .001).

CONCLUSIONS

In the current study, it was shown that the presence of PEX caused a decrease in CVI value and this decrease was highest in patients with PEG. CVI may be a useful parameter to show vascular dysfunction in PEG and PEX syndrome.

Choroidal vascularity index in pseudoexfoliative glaucoma

PURPOSE

To evaluate choroidal vascular involvement in pseudoexfoliative glaucoma (PEXG) by applying the choroidal vascularity index (CVI) to optic coherence tomography (OCT) images.

METHODS

Seventy-eight eyes from 40 subjects were included the study. Group 1 included healthy eyes (n = 20), group 2 eyes with PEX (n = 16), and group 3 eyes with PEXG (n = 42). OCT imaging of macular and peripapillary regions and retinal nerve fiber layer (RNFL) analyses were performed. CVI was calculated using ImageJ software.

RESULTS

The mean age was 64.89 ± 5.8, 71.2 ± 7.8, and 68.24 ± 7.4 years in groups 1, 2, and 3, respectively (p = 0.046). There were no significant differences between the groups in terms of sex (p = 0.777). In macula, mean CVI rates were 66.97 ± 1.9%, 64.23 ± 1.2%, and 64.63 ± 1.6%, and in the peripapillary areas, mean CVI rates were 67.04 ± 1.5%, 65.20 ± 1.5%, and 64.14 ± 2.1% in groups 1, 2, and 3, respectively (group 1 vs. group 2 and 3, p = 0.000; group 2 vs. group 3, p > 0.05). The decrease in average RNFL thickness was statistically significant in group 3 compared to groups 1 and 2.

CONCLUSION

CVI could be used to assess choroidal vascular changes in ocular diseases. CVI was found to be reduced in PEX and PEXG, indicating an ocular vascular involvement in pseudoexfoliative process.

REPEATABILITY OF CHOROIDAL VASCULARITY INDEX MEASUREMENTS USING DIRECTIONAL OPTICAL COHERENCE TOMOGRAPHY IMAGES

PURPOSE

To investigate the repeatability of choroidal vascularity index (CVI) measurements in centered and decentered (regarding pupil entry position of the beam) directional subfoveal optical coherence tomography (OCT) scans with (CVI1) and without (CVI2) brightness adjustment.

METHODS

Thirty-two eyes of 32 healthy volunteers were included in this prospective study. First, the fovea was evaluated by a single horizontal enhanced depth imaging OCT scan in a centered direction. Then, the same subfoveal horizontal line was scanned in a decentered direction. The agreement between CVIs obtained from these centered and decentered directional OCT scans was investigated using Bland-Altman analysis and intraclass correlation coefficient.

RESULTS

Intraclass correlation coefficient between centered and decentered CVI1 was 0.71 (95% CI: 0.48-0.85, P value < 0.001). Intraclass correlation coefficient between centered and decentered CVI2 was 0.73 (95% CI: 0.5-0.86, P value < 0.001). The mean difference between centered and decentered directional measurements for CVI1 and CVI2 were 0.5 and 0.8, respectively.

CONCLUSION

There is moderate agreement between CVIs obtained from centered and decentered directional single OCT scans of the same subfoveal area. Studies investigating choroidal vascularity should be standardized by using the same OCT beam direction in all scans.

Analysis of the Peripapillary Choroidal Vascular Characteristics in Papilledema Associated with Pseudotumor Cerebri

SIGNIFICANCE

Choroidal vascularity index measured by image binarization method from peripapillary optical coherence tomography sections has been found significantly lower in papilledema patients than healthy controls.

PURPOSE

The purpose of this study was to compare peripapillary choroidal parameters in papilledema patients with control subjects.

METHODS

Peripapillary spectral domain optical coherence tomography scans of 34 patients with papilledema and 34 healthy controls are acquired for the study. Images are binarized with the ImageJ software (National Institutes of Health, Bethesda, MD) to calculate total choroidal area, stromal area, luminal area, and choroidal vascularity index.

RESULTS

Total choroidal area, luminal area, and choroidal vascularity were significantly lower in papilledema patients compared with healthy controls on right (1.343 ± 0.286 vs. 1.694 ± 0.344, P < .001; 0.880 ± 0.209 vs. 1.167 ± 0.255, P < .001; 65.28 ± 2.99% vs. 68.68 ± 2.81%, P < .001, respectively) and left eyes (1.376 ± 0.308 vs. 1.647 ± 0.339, P < .001; 0.899 ± 0.231 vs. 1.134 ± 0.237, P < .001; 64.92 ± 3.44 vs. 68.84 ± 3.23, P < .001, respectively). No difference was found between active and remitted stages of papilledema in terms of choroidal parameters.

CONCLUSIONS

Peripapillary total choroidal area, luminal area, and choroidal vascularity index are significantly reduced in patients with papilledema. These parameters might be beneficial tools for evaluating choroidal vascularity in papilledema quantitatively and differential diagnosis for optic disc edema.

Choroidal vascularity index in thyroid-associated ophthalmopathy: a cross-sectional study

Background

Hemodynamic changes have been observed in patients with Graves’ disease. The aim of our study was to evaluate choroidal vascular change using the choroidal vascularity index (CVI) in patients with thyroid-associated ophthalmopathy (TAO).

Methods

In this cross-sectional observational study, 40 patients affected by TAO were recruited. Forty healthy individuals, matched for age and sex, served as controls. Foveal enhanced-depth imaging optical coherence tomography scans were obtained from all participants. Images were binarized using the ImageJ software and luminal area (LA) and total choroidal area (TCA) were measured. CVI was calculated as the proportion of LA to TCA. The relation between CVI or subfoveal choroidal thickness (SFCT) and clinical activity score, exophthalmometric value, diplopia status, gender, and age was evaluated.

Results

CVI was significantly higher in patients with TAO (P = 0.004). No significant difference was observed in SFCT (P = 0.200) and TCA (P = 0.153) comparing TAO patients and healthy controls. LA was significantly higher in TAO group (P = 0.045). On multiple regression analysis, CVI was associated with TCA (P = 0.043). No association was found between SFCT or CVI and TCA, clinical activity score, exophthalmometric value, Inami value, diplopia status, gender or age (P > 0.05).

Conclusions

This is the first study that has demonstrated an increase in CVI in eyes with TAO compared with healthy controls and has assessed its association with clinical features.

Choroidal vascularity index: a step towards software as a medical device

The choroidal vascularity index (CVI) is a relatively new parameter, calculated off optical coherence tomography (OCT) images, for the quantitative evaluation of choroid vascularity. It is defined as the ratio of vascular area to the total choroidal area, presented as a percentage. The choroid is an important vascular bed, often implicated in ocular and systemic conditions. Since the introduction of CVI, multiple studies have evaluated its efficacy as a tool for disease prognostication and monitoring progression, with promising results. The CVI was born out of the need for more robust and accurate evaluations of choroidal vasculature, as prior parameters such as choroidal thickness and choroidal vessel diameter had their limitations. In this review, we summarise current literature on the CVI, explain how the CVI is derived and explore its potential integration into future research and translation into clinical care. This includes the application of CVI in various disease states, and ongoing attempts to produce an automated algorithm which can calculate CVI from OCT images.

Use of choroidal vascularity index for choroidal structural evaluation in smokers: an optical coherence tomography study

PURPOSE

To compare the choroidal vascularity index (CVI) and choroidal thickness (CT) in smokers and healthy non-smoking subjects using spectral-domain optical coherence tomography (SD-OCT).

METHODS

Forty-two smokers with no systemic disorders and 46 age-sex matched healthy volunteers were included in the study. SD-OCT was used to measure choroidal thickness at the fovea and 1500 µm intervals from the foveal centre in both nasal and temporal directions. Choroidal images were binarized and segmented to the luminal area (LA), stromal area (SA), and total choroidal area (TCA) using ImageJ software. The choroidal vascularity index was calculated as the ratio of LA to TCA. Smoking subjects were divided into three groups according to pack-year exposure: 10-20 pack-years, 20-30 pack-years, and >30 pack-years. Subgroup analysis was performed to evaluate the relationship between CT/CVI/LA/SA/TCA and pack-years.

RESULTS

The mean age of the smokers and non-smokers was 43.1 ± 7.26 years and 41.82 ± 9.92 years, respectively (p = 0.51). The mean subfoveal choroidal thickness was 301.57 ± 55.04 µm in smokers and 303.38 ± 53.42 µm in non-smokers (p = 0.826). No significant difference was observed between groups for CT values in the subfoveal location or at 1500 µm intervals in the nasal and temporal direction from the fovea. The CVI was significantly lower in smokers (65.4 ± 2.3%) than in non-smokers (66.3 ± 2.5%) (p = 0.021). In the subgroup analysis, subjects with >20 pack-years of smoking had a significantly lower CVI than non-smokers, but those between 10-20 pack-years did not. A negative correlation was found between the CVI and smoking, as measured by cigarette pack-years (r = -0.226, p = 0.04).

CONCLUSION

The CVI was significantly decreased in smokers compared to healthy controls. The study results suggest that the CVI could be a non-invasive tool for evaluating choroidal vascular changes in smokers.

Choroidal Vascularity Index: An In-Depth Analysis of This Novel Optical Coherence Tomography Parameter

Remarkable improvements in optical coherence tomography (OCT) technology have resulted in highly sophisticated, noninvasive machines allowing detailed and advanced morphological evaluation of all retinal and choroidal layers. Postproduction semiautomated imaging analysis with dedicated public-domain software allows precise quantitative analysis of binarized OCT images. In this regard, the choroidal vascularity index (CVI) is emerging as a new imaging tool for the measurement and analysis of the choroidal vascular system by quantifying both luminal and stromal choroidal components. Numerous reports have been published so far regarding CVI and its potential applications in healthy eyes as well as in the evaluation and management of several chorioretinal diseases. Current literature suggests that CVI has a lesser variability and is influenced by fewer physiologic factors as compared to choroidal thickness. It can be considered a relatively stable parameter for evaluating the changes in the choroidal vasculature. In this review, the principles and the applications of this advanced imaging modality for studying and understanding the contributing role of choroid in retinal and optic nerve diseases are discussed. Potential advances that may allow the widespread adoption of this tool in the routine clinical practice are also presented.