CHOROIDAL THICKNESS IN RELATION TO ETHNICITY MEASURED USING ENHANCED DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHY

Retinal and Choroidal Thickness in an Indigenous Population from Ghana: Comparison with Individuals with European or African Ancestry

Purpose

To evaluate the thickness of the macular retina and central choroid in an indigenous population from Ghana, Africa and to compare them with those measured among individuals with European or African ancestry.

Design

Cross-sectional study, systematic review, and meta-analyses.

Participants

Forty-two healthy Ghanaians, 37 healthy individuals with European ancestry, and an additional 1427 healthy subjects with African ancestry from previously published studies.

Methods

Macular retinal thickness in the fovea, parafovea, and perifovea and central choroidal thickness were extracted from OCT volume scans. Associations with ethnicity, age, and sex were assessed using mixed-effect regression models. Monte Carlo simulations were performed to determine the sensitivity of significant associations to additional potential confounders. Pooled estimates of retinal thickness among other groups with African ancestry were generated through systematic review and meta-analyses.

Main Outcome Measures

Macular retinal thickness and central choroidal thickness and their association with ethnicity, age, and sex.

Results

When adjusted for age and sex, the macular retina and central choroid of Ghanaians are significantly thinner as compared with subjects with European ancestry (P < 0.001). A reduction in retinal and choroidal thickness is observed with age, although this effect is independent of ethnicity. Meta-analyses indicate that retinal thickness among Ghanaians differs markedly from that of African Americans and other previously reported indigenous African populations.

Conclusions

The thickness of the retina among Ghanaians differs not only from those measured among individuals with European ancestry, but also from those obtained from African Americans. Normative retinal and choroidal parameters determined among individuals with African or European ancestry may not be sufficient to describe indigenous African populations.

Financial Disclosures

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

Choroidal thickness and effect of sex and age in Africans

Purpose

The purpose of the study is to evaluate choroidal thickness (CT) and the effect of age and gender in healthy Africans using enhanced depth imaging spectral-domain optical coherence tomography.

Materials and Methods

In 172 eyes of 88 volunteers, the CT in the central subfoveal (CSF) area and at 2.5 mm superior, inferior, nasal, and temporal quadrants was measured. Four eyes were excluded due to poor image quality and image decentration. Simple linear regression was used to measure the effect of age on CT, and statistical analysis was done using IBM SPSS Statistics version 22.

Results

The were 88 male and 84 female eyes, aged 30-80 years. The mean CT was CSF 265.44 ± 6.2 μm; inferior 256.19 ± 70.6 μm; superior 249.92 ± 76.2 μm; temporal 235.51 ± 70.3 μm; and nasal 199.53 ± 69.8 μm. The choroid was thickest in the CSF > Inferior > Superior > Temporal, and the nasal quadrant was thinnest in all age groups. There was a considerable decrease in the CSF with increasing age (P < 0.001). CT in males and females was similar since the difference in mean CSF CT between the genders was 2.085 μm (P = 0.858). Menopausal females had thinner CSF CT compared to premenopausal females (P < 0.001), but this was due to the aging effect.

Conclusion

CT decreases significantly with increasing age but shows no gender difference in Africans. A comparison of CT studies from other ethnic nationalities shows some similarity with CT in Africans, suggesting that CT findings from other ethnic groups can be extrapolated to Africans.

IMI-The Dynamic Choroid: New Insights, Challenges, and Potential Significance for Human Myopia

The choroid is the richly vascular layer of the eye located between the sclera and Bruch's membrane. Early studies in animals, as well as more recent studies in humans, have demonstrated that the choroid is a dynamic, multifunctional structure, with its thickness directly and indirectly subject to modulation by a variety of physiologic and visual stimuli. In this review, the anatomy and function of the choroid are summarized and links between the choroid, eye growth regulation, and myopia, as demonstrated in animal models, discussed. Methods for quantifying choroidal thickness in the human eye and associated challenges are described, the literature examining choroidal changes in response to various visual stimuli and refractive error-related differences are summarized, and the potential implications of the latter for myopia are considered. This review also allowed for the reexamination of the hypothesis that short-term changes in choroidal thickness induced by pharmacologic, optical, or environmental stimuli are predictive of future long-term changes in axial elongation, and the speculation that short-term choroidal thickening can be used as a biomarker of treatment efficacy for myopia control therapies, with the general conclusion that current evidence is not sufficient.

Subfoveal choroidal thickness as a potential predictor of treatment response after intravitreal ranibizumab injections for polypoidal choroidal vasculopathy

OBJECTIVE

To evaluate the impact of subfoveal choroidal thickness (SFCT) and other clinical biomarkers in intravitreal anti-vascular endothelial growth factor response in treatment-naive Caucasian patients diagnosed with polypoidal choroidal vasculopathy (PCV/AT1).

DESIGN

Cross-sectional study.

PARTICIPANTS

Treatment-naive patients diagnosed with PCV/AT1 recruited in a single centre from January 2013 to December 2020.

METHODS

Eligibility was determined in treatment-naive PCV patients who received a loading dose of 3 injections of 0.5 mg ranibizumab. A diagnosis of PCV/AT1 was made based on the diagnostic criteria in the efficacy and safety of verteporfin photodynamic therapy in combination with ranibizumab or alone versus ranibizumab monotherapy in patients with sumptomatic macular polypoidal choroidal vasculopathy study. Choroidal thickness was manually measured by enhanced depth imaging technology in Spectralis spectral domain optical coherence tomography.

RESULTS

Eighty-three eyes of 83 patients were included in this study, 47 patients diagnosed with PCV/AT1 with a good response to 3 intravitreal injections of ranibizumab and 36 with a poor response. The receiver operating characteristic curve of treatment effect against the SFCT revealed that the area under the curve was 0.85 (range, 0.74-0.96). Based on the Youden index, the optimal SFCT cut-off point for predicting a poor response to anti-vascular endothelial growth factor is 257 µm. In the multivariate analysis, the SFCT remained statistically significant (odds ratio 1.02 [range, 1.01-1.04]; P = 0.008). The combined effect of treatment effect against clinical biomarkers produced an area under the curve of 0.90 (range, 0.82-0.98).

CONCLUSION

SFCT is a risk factor for a poor response to the 3 loading injections of ranibizumab in treatment-naive PCV/AT1 Caucasian patients. A cut-off point of 257 µm could be a valuable parameter for defining the population at risk for an inadequate response to ranibizumab.

Choroidal Thickness Profiles and Associated Factors in Myopic Children

SIGNIFICANCE

This study addresses the lack of choroidal thickness (ChT) profile information available in European children and provides a baseline for further evaluation of longitudinal changes in ChT profiles in myopic children as a potential biomarker for myopia treatment and identifying children at risk of myopic progression.

PURPOSE

This study aimed to investigate ChT profiles and associated factors in myopic children.

METHODS

Baseline data of 250 myopic children aged 6 to 16 years in the Myopia Outcome Study of Atropine in Children clinical trial were analyzed. Choroidal thickness images were obtained using swept-source optical coherence tomography (DRI-OCT Triton Plus; Topcon Corporation, Tokyo, Japan). The macula was divided into nine Early Treatment of Diabetic Retinopathy Study locations with diameters of 1, 3, and 6 mm corresponding to the central fovea, parafoveal, and perifoveal regions. Multiple linear regression models were used to investigate determinants of ChT.

RESULTS

Choroidal thickness varied across the macular Early Treatment of Diabetic Retinopathy Study locations ( P < .001): thickest in the perifoveal superior region (mean ± standard deviation, 249.0 ± 60.8 μm) and thinnest in the perifoveal nasal region (155.1 ± 50.3 μm). On average, ChT was greater in all parafoveal (231.8 ± 57.8 μm) compared with perifoveal (218.1 ± 49.1 μm) regions except superiorly where the ChT was greater in the perifoveal region. Longer axial length and higher myopic spherical equivalent refraction were consistently associated with thinner ChT at all locations in the multiple linear regression models. Asian race was significantly associated with thinner ChT only at parafoveal and perifoveal superior regions after Bonferroni correction ( P = .004 and P = .001, respectively).

CONCLUSIONS

Choroidal thickness was thinnest in the nasal macular region and varied systematically across all macular locations, with axial length and spherical equivalent refraction being the strongest determinants of ChT. Longitudinal evidence will need to evaluate whether any differences in ChT profiles are predictive of myopic progression and to determine the role of ChT measurements in identifying myopic children most in need of myopia control treatment.

Two-Year Choroidal Thickness Attenuation and Its Associations in Healthy Chinese Adults

Purpose

Identifying clinical associations causing attenuation in choroidal thickness (CT) among healthy Chinese adults.

Methods

A 2-year longitudinal study was conducted in volunteers aged over 30 years from China. All participants had no history of eye disease or surgery. All subjects underwent swept-source optical coherence tomography to measure the CT in the macular region at baseline and at 2-year follow-up. The regression models were based on the generalized estimating equation.

Results

A total of 603 eyes of 336 healthy participants were included in the final analysis (mean [SD] age, 58.88 [8.82] years; 74.70% female). Mean (SD) choroidal thickness (MCT) was reduced significantly from 206.62 (72.42) to 194.02 (72.08) µm (difference, −12.60 µm; 95% confidence interval [CI], −13.62 to −11.57). Among the Early Treatment of Diabetic Retinopathy Study (ETDRS) grid, CT at the subfoveal sector showed the greatest 2-year reduction (difference, −14.55 µm; 95% CI, −15.87 to −13.22). The largest 2-year change was observed in the 50 to 59 years group (difference, −14.51 µm; 95% CI, −16.71 to −12.32). Multivariate regression showed female gender (β = −2.85; 95% CI, −5.65 to −0.56) and baseline MCT (β = −0.040; 95% CI, −0.056 to −0.024) were significantly and independently associated with greater 2-year CT decrease.

Conclusions

These results indicated that CT among Chinese healthy adults decreased during the 2-year follow-up, and the greater choroidal thinning rate was significantly associated with female gender and larger baseline MCT.

Translational Relevance

Longitudinal CT data of healthy adults provide a reference range when evaluating pathologic variations, especially for the age-related retinal-choroidal disorders.

Is there any connection between choroidal thickness and obesity?

Obesity is a health-threatening and epidemic medical condition that can affect individuals of different ages and is potentially associated with an increased risk of systemic and ocular disorders. Despite the well-documented adverse effects of obesity on different parts of the body vasculature, less published data are available concerning obesity-related consequences on the ocular vasculature. As the human choroid is a highly vascularized tissue, its morphology and function might be altered in obese individuals. The micro-structural changes within the choroid could also trigger development of subsequent functional abnormalities of the eye. Previous population-based studies have asserted an association between obesity and choroidal thickness; however, they reported conflicting patterns of association between obesity and changes in choroidal thickness. Therefore, to enhance our understanding of the changes in choroidal morphology secondary to obesity, we reviewed studies describing the micro-structural consequences of obesity on the choroidal thickness profile and its underlying physiological and anatomical basis. This review includes all original publications related to the association between choroidal thickness and obesity published until mid-2021 that were indexed in PubMed, Google Scholar, ScienceDirect, or Scopus.

Evaluation of choroidal thickness in light-coloured eyes

OBJECTIVE

The aim of this study was to determine whether iris colour is related to the choroidal thickness of healthy individuals.

METHODS

Healthy participants were divided into two groups. Group 1 had light-coloured eyes (blue and green), and group 2 had dark-coloured eyes (brown). The main outcome measures were iris thickness, subfoveal choroidal thickness and nasal and temporal choroidal thicknesses 500 µm away from the fovea.

RESULTS

Group 1 comprised 31 subjects with light-coloured eyes, and group 2 had 31 subjects with dark eyes. The mean ages of groups 1 and 2 were 26.7 ± 7.5 years and 24.1 ± 5.8 years, respectively (p = 0.14). The choroidal thicknesses of the subfoveal, nasal and temporal regions were 336.3 ± 52.1 µm, 321.9 ± 43.6 µm and 318.4 ± 49.2 µm, respectively, in group 1 and 396.5 ± 76.9 µm, 372 ± 79.3 µm and 379.6 ± 82.4 µm, respectively, in group 2. All the values in group 1 were statistically lower than those in group 2 (p = 0.001, p = 0.001 and p = 0.003, respectively). The iris thickness in group 1 (493.73 ± 95.44 µm) was thinner than in group 2 (524.61 ± 69.74 µm) but not statistically significant (p = 0.141).

CONCLUSION

The results showed that a thinner choroid can be seen in disease-free light-coloured eyes. The iris colour should be considered among the factors affecting the choroidal thickness, such as age, sex, race and refractive error.

Association of Secondhand Smoking Exposure With Choroidal Thinning in Children Aged 6 to 8 Years: The Hong Kong Children Eye Study

Importance

Secondhand smoking is a risk to adult ocular health, but its effect on children's ocular development is not known.

Objective

To assess the association between choroidal thickness and secondhand smoking exposure in children.

Design, Setting, and Participants

Children aged 6 to 8 years were consecutively recruited from January 2016 to July 2017 from the population-based Hong Kong Children Eye Study at the Chinese University of Hong Kong Eye Centre. All participants underwent detailed ophthalmic investigations. Choroidal thickness was measured by swept-source optical coherence tomography, with built-in software that automatically segmented the choroid layer to analyze its terrain imagery. History of secondhand smoking was obtained from a questionnaire. Multiple linear regression analyses were performed to assess the correlation between choroidal thickness and secondhand exposure when controlling for confounding factors. Analysis began July 2018 and ended in April 2019.

Main Outcomes and Measurements

The association between children's choroidal thickness and their exposure to secondhand smoking.

Results

Of 1400 children, 941 (67.2%) had no exposure to secondhand smoking, and 459 (32.8%) had exposure to secondhand smoking. The mean (SD) age was 7.65 (1.09) years for children in the nonexposure group and 7.54 (1.11) years for children in the exposure group. After adjustment for age, sex, body mass index, axial length, and birth weight, exposure to secondhand smoking was associated with a thinner choroid by 8.3 μm in the central subfield, 7.2 μm in the inner inferior, 6.4 μm in the outer inferior, 6.4 μm in the inner temporal, and 7.3 μm in the outer temporal. Choroidal thinning with also associated with increased number of family smokers and increased quantity of secondhand smoking. An increase of 1 family smoker was associated with choroidal thinning by 7.86 μm in the central subfield, 4.51 μm in the outer superior, 6.23 μm in the inner inferior, 5.59 μm in the outer inferior, 6.06 μm in the inner nasal, and 6.55 μm in the outer nasal. An increase of exposure to 1 secondhand cigarette smoke per day was associated with choroidal thinning by 0.54 μm in the central subfield, 0.42 μm in the inner temporal, and 0.47 μm in the outer temporal.

Conclusions and Relevance

This investigation showed that exposure to secondhand smoking in children was associated with choroidal thinning along with a dose-dependent effect. These results support evidence regarding the potential hazards of secondhand smoking to children.

Comparison of choroidal thicknesses in patients with coronary artery disease and patients at risk of coronary artery disease

PURPOSE

The study aimed to compare choroidal thicknesses (CTh) in patients with coronary artery disease (CAD) and patients at risk of coronary artery disease and investigate whether thinning of the choroid can be used as a biomarker for development of coronary artery disease in patients at risk.

MATERIALS AND METHODS

The study group was composed of 103 eyes of 53 patients with coronary artery disease, and the control group was composed of 62 eyes of 32 patients with diabetes mellitus, hypertension and/or hyperlipidemia without coronary artery disease. CAD was diagnosed in patients with one of the following: myocardial infarction with/without ST segment elevation, clinically proven history of cardiac catheterization testifying greater than 50% obstruction in at least one coronary artery, revascularization operations. The control group consisted of clinically proven patients with normal coronary arteries. The choroidal thickness was measured with enhanced depth imaging optical coherence tomography under the fovea and at six other points, located at 500 micron, 1000 micron and 1500 micron nasal to the fovea and 500 micron, 1000 micron, 1500 micron temporal to the fovea.

RESULTS

The subfoveal choroidal thickness was significantly thinner in the coronary artery disease group compared to the control group (244 µm vs. 289 µm; p < 0,001). In all other measured regions (nasal 500, nasal 1000, nasal 1500, temporal 500, temporal 1000, and temporal 1500 micron), CTh was statistically significant thinner in the CAD group. A negative significant linear relationship (low level) between CAD duration and choroidal thickness in the subfoveal, nasal 1000, nasal 1500, temporal 500, temporal 1000 micron regions was detected.

CONCLUSION

Patients with CAD have a decreased choroidal thickness compared to patients at risk of CAD. Detection of CTh thinning in a patient with diseases, such as diabetes, hypertension and/or hypercholesterolemia, which pose a risk for CAD may be a predictor of development of coronary artery disease. Clinical Trials Registration Kocaeli Derince Training and Research Hospital ethics committee-protocol number: 2020-106.

Choroidal Thickness in Indigenous Australian Children

Purpose

This study aimed to examine the choroidal thickness profiles in visually normal Australian Indigenous children, given the important role of the choroid in refractive error and a range of ocular diseases.

Methods

Choroidal thickness was assessed across the central 5 mm macular region using enhanced depth imaging spectral domain optical coherence tomography, in 250 children enrolled in an elementary school and a secondary school in rural Queensland, Australia. One hundred (40%) of these children identified as Indigenous Australians.

Results

The subfoveal choroid was significantly thicker in Indigenous children (mean 369 ± 75 µm), compared to non-Indigenous children (355 ± 73 µm; P = 0.03). Subfoveal choroidal thickness was also significantly associated with age (β = +7.6, r² = 0.105, P = 0.003), and axial length (β = −19.9, r² = 0.030, P < 0.001). A significantly thicker choroid in Indigenous children was also found in analyses across the central 5 mm macular region (P = 0.008). A significant interaction between Indigenous status and meridian was observed (P = 0.007) with the largest differences between Indigenous and non-Indigenous children being in the nasal and inferonasal meridians.

Conclusions

This study establishes the normative characteristics of macular choroidal thickness in Indigenous Australian children and demonstrates a significantly thicker choroid compared to non-Indigenous children from the same geographic region. These results may have implications for our understanding of factors predisposing or protecting Australian Indigenous people from a range of conditions associated with choroidal thickness.

Translational Relevance

The significantly thicker choroid in Australian Indigenous children should be considered in clinical diagnoses and management of conditions associated with choroidal changes.

Optical Coherence Tomography Angiography Assessment of Macular Choriocapillaris and Choroid Following Panretinal Photocoagulation in a Diverse Population With Advanced Diabetic Retinopathy

PURPOSE

The aim of this study was to evaluate choroidal and retinal microvasculature with optical coherence tomography angiography (OCTA) after panretinal photocoagulation (PRP) for diabetic retinopathy in a primarily Hispanic and Asian population.

DESIGN

Retrospective study.

METHODS

Eyes were examined by OCTA in the macula (3 × 3 mm) just before PRP treatment and 1 to 3 months afterwards. Choroidal thickness (CT) and central retinal thickness (CRT) were measured. Choroidal flow signal voids (CFSV) and choriocapillaris flow signal voids (CCFSV) were acquired. Retinal microvasculature parameters, including superficial and deep vessel density, superficial and deeper perfusion density, foveal avascular zone area, perimeter and circularity, were calculated. Ocular examinations and demographic information were analyzed.

RESULTS

CT at a location 1000 μm temporal to the fovea increased significantly after PRP (from 278.64 μm to 313.44 μm, P = 0.026). CCFSV increased slightly from (46.72 ± 8.52)% to (47.07 ± 10.77)%, but the difference was not statistically significant (P = 0.782). A similar finding was observed in CFSV (increase from 35.81% to 36.64%, P = 0.165). The change in all retinal microvasculature parameters was also not significant. Best-corrected visual acuity (BCVA) decreased from 0.218 ± 0.153 to 0.262 ± 0.147 (P = 0.034). Increased CRT (from 245.41 ± 33.18 μm to 251.14 ± 38.97 μm, P = 0.007) was observed. The change in CRT positively correlated with pre-PRP CRT (r = 0.434, P = 0.019) and BCVA reduction (r = 0.418, P = 0.024). Neither BCVA reduction nor CRT increase correlated with OCTA metrics.

CONCLUSIONS

OCTA demonstrates redistribution of choroidal circulation from the periphery to the macula after PRP, with increased macular CT and stable choroidal blood flow density. Eyes with greater macular thickness are more likely to experience an increase in CRT.

Choroidal Thickness in Young Adults and its Association with Visual Acuity

PURPOSE

To describe the choroidal thickness (ChT) in a large sample of young adults with the aim of establishing a normative ChT profile reference in this demographic cohort and explore its association with best-corrected visual acuity (BCVA).

DESIGN

Cross-sectional study.

METHODS

From a single center, 741 young adults (19-30 years of age, 49% male) were recruited to undergo a comprehensive ophthalmic examination, including BCVA measurement, post-cycloplegic autorefraction, ocular biometry, tonometry, and spectral-domain optical coherence tomography (SD-OCT) imaging. The enhanced depth imaging mode on the SD-OCT was used. The main outcome measure was the central macular ChT (0.5-mm radius around the fovea). The ChTs at the inner (between 0.5-mm and 1.5-mm radius) and outer macular rings (between 1.5-mm and 2.5-mm radius) were also measured.

RESULTS

The median central macular ChT was 370 μm (interquartile range 312-406 μm). The choroid was thickest at the superior-inner, inferior-inner, and central macular regions (370-373 μm) and thinnest nasally at the outer macular region (median 256 μm). Decreased central macular ChT was associated with younger age, female sex, nonwhite ethnicities, and myopia (P ≤ .013). There was a significant association between better BCVA and increased central macular ChT (P < .001), after adjusting for age, sex, ethnicity, and ocular measures. His relationship was only apparent in eyes with central macular ChTs <300 μm (P = .019) and absent in eyes with ChTs >300 μm.

CONCLUSIONS

The central ChT of young adults was 370 μm. There was a significant association between worse BCVA and thinner choroids below a threshold of 300 μm, raising the possibility that ChT could be predictive of visual function.

Choroidal Thickness Profile in Normal Iranian Eyes with Different Refractive Status by Spectral-Domain Optical Coherence Tomography

Purpose

To investigate the choroidal thickness and its association with age, gender, spherical equivalent (SE), and axial length (AL) in a sample of Iranian population with different refractive status using spectral-domain optical coherence tomography (SD-OCT).

Methods

In a cross-sectional study, a total of 469 right eyes of 469 healthy subjects comprising 194 (41.4%) males and 275 (58.6%) females were examined. The mean age was 32.76 ± 15.77 years (range, 4-60 years). All subjects were divided into different groups according to their refractive status, age, and AL. The choroidal thickness was evaluated through enhanced-depth imaging (EDI) modality at subfoveal (Sf), 1, and 3 mm nasal (N1 and N3, respectively), temporal (T1 and T3, respectively), superior (S1 and S3, respectively), and inferior (I1 and I3, respectively) to the foveal center.

Results

In the whole population, the mean subfoveal choroidal thickness (SfChT) was 329.83 ± 70.33 μm, and the choroid was thickest at S1 (342.04 ± 71.28 μm) and thinnest at N3 (209.00 ± 66.0 μm). Our data indicated a significant difference in the mean choroidal thickness across all points in different age groups (P < 0.0001). For emmetropic, myopic, and hyperopic subjects, mean SfChT values were 346.64 ± 59.63, 319.66 ± 73.17, and 364.00 ± 74.54 μm, respectively. Linear regression estimated that SfChT decreased about 12.8 and 8.71 μm for every 10 years of aging and each diopter increasing in myopia, respectively. Additionally, the SfChT decreased as 13.48 μm per mm increase in AL.

Conclusions

The mean SfChT of a sample of Iranian emmetropic subjects was 346.64 ± 59.63 μm. The choroidal thickness has a decreasing trend with increasing age, and the choroid is thinner in myopes and thicker in hyperopes compared with emmetropic subjects. In the whole participants, the thickest and thinnest points were S1 and N3, respectively.

Analysis of central macular thickness and choroidal thickness changes in patients with cardiovascular risk factors

OBJECTIVES

The aim of this study was to evaluate central macular thickness (CMT) and choroidal thickness (CT) in the eyes of patients with cardiovascular risk factors (CVRF).

METHODS

A cross-sectional, prospective observational study of 92 patients with CVRF and 21 healthy individuals was conducted. Patients were divided into four groups according to the SCORE system. CMT was evaluated via spectral-domain-optical coherence tomography (SD-OCT). CT at five defined points (subfoveal) [SF] and nasal 500 μm [N0.5] and 1500 μm [N1.5] and 500 μm [T0.5] and temporal 1500 μm [T1.5] from the center of the fovea were measured via enhanced depth imaging (EDI)-OCT.

RESULTS

Mean SFCT at right eyes (RE) and left eyes (LE) were 311.21 ± 77.7 μm and 303.5 ± 49.6 μm, respectively, in patients with mild CVRF (Group 1); 266.5 ± 63.2 μm and 267.0 ± 62.6 μm, respectively, in patients with moderate CVRF (Group 2); 264.7 ± 57.5 μm and 272.3 ± 64.6 μm, respectively, in patients with high CVRF (Group 3); 272.3 ± 64.6 μm and 271.2 ± 63.4 μm, respectively, in patients with very high-risk CVRF (with coronary arterial disease (CAD) (Group 4); and 352.0 ± 74.4 μm and 363.1 ± 89.0 μm, respectively, in the control group. CT (at both eyes) was significantly lower at the subfoveal location in all study groups (P < 0.05), but at nasal and at temporal quadrants of group 3 and group 4 (P < 0.05). No significant difference in CMT was detected between the study and control groups.

CONCLUSIONS

This study demonstrated that CVRF might result in a remarkably thinner CT. Furthermore, subretinal drusenoid deposits were detected at a higher rate in the patients with CVRF than controls, and that rate increased in accordance with the severity of CAD. In the future, changes in CT may be used as a promising novel biomarker as part of the SCORE system prior to the development of CAD.

Sub-Foveal Choroidal Thickness In Healthy Nepalese Population

PURPOSE

This study was conducted primarily to measure sub-foveal choroidal thickness (SFCT) in healthy Nepalese population. Also, the correlation of SFCT with age, inter-eye difference of SFCT, inter-gender variation and inter-ethnic variation of SFCT was observed.

MATERIALS AND METHODS

A cross-sectional, hospital based study in 162 participants (324 eyes) of six ethnic groups (Brahmin, Chhetri, Newar, Tamang, Muslim, and Gurung) was conducted. The mean age of participants was 37.37 ± 15.02 years. All the participants underwent SFCT measurement using Spectral Domain Optical Coherence Tomography (Spectralis HRA+OCT, Heidelberg Engineering, Germany) with the help of in-built caliber. Age, inter-gender, inter-eye and inter-ethnic differences in SFCT were recorded and analyzed.

RESULTS

The average SFCT of right eye (RE) and left eye (LE) was 307.98 ± 74.64 µm and 312.63 ± 76.90 µm respectively, with average SFCT of 310.31 ± 75.70 µm for both eyes. SFCT of only the RE was selected for further calculation due to insignificant inter-eye difference of SFCT (p = 0.128). There was a significant negative correlation of SFCT with age (r = -0.705, p = 0.01). A regression analysis showed thinning of SFCT by 3.50 ± 0.278 µm per year. In another context, SFCT of male and female was 305.49 ± 79.72 µm and 313.55 ± 70.76 µm respectively. However, there was no significant inter-gender difference (p = 0.51). Similarly, inter-ethnic variations of SFCT was also statistically non -significant (p = 0.74).

CONCLUSION

SFCT was negatively correlated with the age of participants, implying a decrease in choroidal thickness (CT) with an increase in age. Age can be considered as an important factor in the measurement of SFCT. Gender and ethnic groups did not have a significant role in the measurement and comparison of SFCT.

Optical Coherence Tomography Angiography for Diagnosis of Choroidal Neovascularization in Chronic Central Serous Chorioretinopathy after Photodynamic Therapy

The authors evaluated the proportion of choroidal neovascularization (CNV) detected by spectral-domain optical coherence tomography angiography (OCTA) in eyes with chronic central serous chorioretinopathy (CSC) (more than 3 months) with previous treatment via half-dose photodynamic therapy (PDT). All patients were followed up with at least twelve months. Macular angiograms were obtained using spectral-domain OCT (SD-OCT, RTVue XR; Optovue). CNV was defined as flow in the outer retinal slab between the outer plexiform layer and Bruch's membrane. Clinical characteristics were compared between CNV and non-CNV groups. Seventy eyes of 61 patients (51 male and 10 female) were included. The average age was 46.2 years old. The average duration of symptom was 32.9 months. All patients were treated with half-dose PDT initially. Eleven eyes (15.7%) received more than one session of PDT. CNV was diagnosed in 32 of 70 eyes (45.7%) based on OCTA. Only 6 of the 32 eyes (18.8%) needed intravitreal anti- vascular endothelial growth factor (VEGF) therapy for the exudative activity of CNV. Older age (p = 0.059), larger PDT spot size (p = 0.024), and thinner subfoveal choroidal thickness (p = 0.008) were noted in CNV group. The authors conclude that OCTA reveals high rates of CNV associated with chronic CSC after PDT. Patients in the CNV group had older age, larger PDT spot size, and thinner subfoveal choroidal thickness. OCTA may be considered as a first step in identifying CNV in chronic CSC following PDT.

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.

Wide-field choroidal thickness in myopes and emmetropes

There is a paucity of knowledge regarding the normal in-vivo thickness of the choroid beyond the macula (~17°). In this study, the choroidal thickness of 27 healthy young adults was examined across the macular (the central 5 mm including the fovea, parafovea, and perifovea) and extra-macular (a 5-14 mm annulus including the near-periphery and periphery) regions using wide-field optical coherence tomography, and compared between emmetropes (n = 14) and myopes (n = 13). The choroid progressively thinned beyond the parafovea (350 ± 86 µm) towards the periphery (264 ± 44 µm), and was thickest superiorly (355 ± 76 µm) and thinnest nasally (290 ± 79 µm). Choroidal thickness also varied with refractive error; myopes exhibited a thinner choroid than emmetropes in the macular region (311 ± 88 vs. 383 ± 66 µm), however, this difference diminished towards the periphery (251 ± 48 vs. 277 ± 37 µm). Meridional variations in choroidal thickness were not different between myopes and emmetropes. In conclusion, the choroid was thickest within the perifovea; thinned substantially towards the periphery, and exhibited the minimum and maximum peripheral thinning superiorly and nasally across a 55° region respectively. Choroidal thinning associated with myopia was more pronounced in the macular than extra-macular regions.

Choroidal changes in human myopia: insights from optical coherence tomography imaging

The choroid is a vascular tissue which plays a range of critical roles in the normal physiology of the eye, such as supplying the outer retina with oxygen and nutrients and the regulation of intraocular pressure. There is also substantial evidence, particularly from animal studies, that the choroid plays an important role in the regulation of eye growth and the development of common refractive errors like myopia. In recent years, advances in optical coherence tomography technology have improved our ability to image and measure the choroid in the human eye. Research using this technology over the past decade has dramatically improved our knowledge of the normal choroid, and its potential role in the regulation of eye growth and refractive error development. This review aims to provide an overview of recent work examining the normal human choroid, its changes with myopia and the possible role of the choroid in the mechanism regulating eye growth. Studies have demonstrated that choroidal thinning accompanies the development and progression of myopia, and have established a close link between eye growth and choroidal thickness changes. Dramatic thinning of the choroid is seen with high myopia, and associations are also observed between choroidal thinning and reduced vision, and the development of retinal pathology associated with high myopia. In the short-term, environmental factors known to be associated with myopia development and more rapid eye growth typically lead to a thinning of the choroid, whereas factors linked to a slowing of eye growth are typically associated with short-term choroidal thickening. Collectively, these findings suggest that the choroid is an important biomarker of eye growth in the human eye, and additional research to better understand the human choroid is likely to further our knowledge of the signals and pathways regulating eye growth, myopia development and progression.

The Increment of Choroidal Thickness in Euthyroid Graves' Ophthalmopathy: Is It an Early Sign of Venous Congestion?

Objective

Clinical manifestations of Graves' ophthalmopathy (GO) are caused by the overcompression of orbital tissues within the restricted orbital bone cavity. Impaired ocular blood flow may disrupt the retinal microstructure and functions. In this study, we aimed to investigate the macular and choroidal thickness changes in GO compared with healthy subjects.

Materials and Methods

The study group comprised 50 adult patients with previously diagnosed Graves' disease with ophthalmopathy who were on antithyroid treatment. For the assessment of GO activity, the VISA (vision, inflammation, strabismus, and appearance) inflammatory score was used. When euthyroidism was achieved without side effects, the patients were referred to the ophthalmology clinic for spectral-domain optical coherence tomography (SD-OCT) evaluation.

Results

Subfoveal, mean, and temporal choroidal thicknesses were increased significantly in the study group according to the controls. The mean choroidal thickness was elevated.

Conclusions

This elevation is because of the intraorbital inflammation even in this nonsevere GO group. Choroidal thickness might be affected from the venous obstruction and congestion in patients with GO. The elevation of the choroidal thickness might be an early sign of venous congestion that occurs before the elevation of intraocular pressure.

Subfoveal choroidal thickness as a prognostic factor in exudative age-related macular degeneration

AIMS

To investigate the relationship between subfoveal choroidal thickness (SFCT), visual acuity (VA), optical coherence tomography (OCT) features and total anti-vascular endothelial growth factor (VEGF) treatments to determine whether SFCT serves as a prognostic factor in age-related macular degeneration (AMD).

METHODS

This is a retrospective case series of 62 consecutive treatment-naive patients with exudative AMD followed for 1 year and treated with treat-and-extend or pro re nata anti-VEGF protocols. SFCT was measured at three locations using Cirrus HD-OCT (the foveal centre and 500 um nasal and temporal to the fovea) at presentation, 3, 6 and 12 months. Demographic characteristics, OCT imaging biomarkers and VA were recorded.

RESULTS

Mean SFCT at baseline was 187 µm (range: 70-361 µm). There was a trend of decreasing SFCT at 1 year (173 µm) compared with 3 months (175 µm) and baseline (188 µm) (p=0.2). There was no correlation between baseline SFCT and presence of subretinal fluid (p=0.2), intraretinal fluid (p=0.6) or subretinal hyper-reflective material (p=0.4) at baseline. The mean number of injections at 1 year was 6.6 (range: 2-12). Increased SFCT at baseline showed statistically significant correlation with a higher number of intravitreal injections at 1 year (p=0.004). Eyes with SFCT>1 SD above the mean required 50% more injections compared with others. There was no association between SFCT on presentation with baseline and 1 year VA (p=0.7 and p=0.2).

CONCLUSIONS

SFCT in naïve patients with exudative AMD may be an important prognostic tool in determining treatment burden. Patients with thicker subfoveal choroid may require increased intravitreal injections.

Choroidal Thickness in Patients Diagnosed with Human Immunodeficiency Virus Infection: Results from Two Populations of Different Ethnicities

Purpose: To measure the choroidal thickness among subjects with human immunodeficiency virus (HIV) infection from two diverse ethnic populations and to compare it with healthy controls. Methods: Subjects with HIV infection and healthy controls were enrolled in two referring centers in Italy and India. Clinical data were collected. All subjects underwent enhanced-depth imaging optical coherence tomography and measurement of choroidal thickness. Results: A total of 68 eyes from 68 patients with HIV (44 Caucasian, 24 Indians) and 60 eyes from 60 healthy volunteers (36 Caucasian, 24 Indians) were included. Mean choroidal thickness was significantly higher in HIV patients compared to controls (312.91 ± 65 µm vs. 266.57 ± 47 µm; p < 0.001). Choroidal thickness was higher among subjects with HIV-related retinopathy compared to HIV without retinopathy (285 ± 30 µm vs. 352 ± 17 µm; p < 0.01). Conclusions: Patients with HIV infection, especially with HIV microangiopathy, have thicker choroid compared to age- and gender-matched healthy control subjects. These changes may be related to HIV-associated choroidal vascular dysfunction.

CONCURRENT IDIOPATHIC MACULAR TELANGIECTASIA TYPE 2 AND CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To describe cases presenting with features of idiopathic macular telangiectasia (MacTel) Type 2 and central serous chorioretinopathy (CSC).

METHODS

Databases from four tertiary retina centers were searched for cases copresenting CSC and MacTel Type 2.

RESULTS

Five cases were identified (4 men, 1 woman; mean age: 67.2 years). Four patients were referred for chronic or nonresolving CSC, and the diagnosis of MacTel Type 2 was made based on multimodal imaging findings. One patient had advanced MacTel Type 2, and developed acute CSC. Regarding the MacTel Type 2 findings, all subjects presented perifoveal telangiectasia on fluorescein angiography, and four subjects showed intraretinal cavitations typical of MacTel Type 2 on optical coherence tomography, in one or both eyes. Regarding the CSC findings, fluorescein angiography identified focal or extended retinal pigment epithelium alteration in all eyes, and an active leakage in two eyes. Indocyanine green angiography showed choroidal vascular hyperpermeability in four subjects. On optical coherence tomography, pigment epithelial detachments were detected in five eyes (four subjects), and foveal detachments were present in five eyes (three subjects), which spontaneously resolved (two eyes), responded to photodynamic therapy (two eyes), or persisted (one eye). Mean choroidal thickness was 402 ± 99 μm.

CONCLUSION

The codiagnosis of CSC and MacTel Type 2 should be considered in atypical presentations associating features from both disorders.

The linear artifact in enhanced depth imaging spectral domain optical coherence tomography

Optical coherence tomography (OCT) is a valuable ancillary test in the diagnosis and management of chorioretinal disease. The evaluation of choroid thickness using OCT has become the focus of clinical applications. We report a linear artifact that acts as a confounding factor in choroidal thickness measurements by enhanced depth imaging OCT. We found that the linear artifact is located stably at a depth of 485 μm beneath the retinal pigment epithelium in 81.88% of subjects. The study suggested that the linear artifact was a confounding factor in assessing choroidal thickness and that caution should be used in the interpretation of the choroidal thickness, especially when it is approximately 485 μm.

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.

Peripheral leptochoroid: clinical and anatomical findings

BACKGROUND/AIMS

To investigate the clinical findings and anatomical characteristics of patients with a thinned peripheral choroid (leptochoroid) presenting with bilateral macular geographical hyperpigmented fundus and compare with matched controls.

METHODS

A retrospective, observational case series of 44 eyes (24 patients): 22 study eyes (12 study patients) with clinical findings of leptochoroid (geographical hyperpigmented fundus centred in the macula) matched with 22 control eyes (12 control patients). All eyes received enhanced depth imaging optical coherence tomography at Memorial Sloan Kettering Cancer Center. Two independent observers performed all measurements. Statistical analysis was used to correlate interobserver findings, and compare patient and eye characteristics.

RESULTS

Study patients had a female predominance and median age of 70 years. Iris colour and refractive error of these eyes were varied: 8 eyes were myopic (one of which was highly myopic with a refractive error of -9.00) and 14 eyes were emmetropic or hyperopic (up to+3.00). The best-corrected visual acuity was 20/40 or better in all study eyes. The geographical macular areas of relative hyperpigmentation correspond to normal choroidal thickness compared with controls (p=0.74). The relative hypopigmented surrounding fundus had significantly thinner choroid compared with controls (p value=0.0001). Choroidal thickness had a strong interobserver correlation (r=0.99, p<0.0001).

CONCLUSION

Described here is a clinical entity referred to as peripheral leptochoroid. It appears as geographical hyperpigmented fundus centred in the macula, with adjacent relative hypopigmented fundus. Compared with matched normal subjects, the hyperpigmented and hypopigmented fundus correspond with equivocal and decreased choroidal thickness, respectively.

Subfoveal Choroidal Thickness in Central Serous Chorioretinopathy: A Meta-Analysis

Purpose

To evaluate the relationship between subfoveal choroidal thickness (SFCT) and eyes with central serous chorioretinopathy (CSC) versus fellow or control eyes.

Methods

We performed a meta-analysis using databases including PubMed, Embase and ISI Web of Science to find relevant studies. Weighted mean difference (WMD) was calculated for the SFCT in CSC eyes, the unaffected fellow eyes and normal controls.

Results

Twelve studies were selected for this meta-analysis, including 1108 eyes (397 CSC eyes, 228 unaffected fellow eyes and 483 eyes of normal controls). The meta-analysis clearly demonstrated that the subfoveal choiroid of eyes with a clinical presentation of CSC was thickened compared to unaffected fellow eyes (WMD = 52.81, 95% confidence interval (CI), 39.13–66.49, P<0.00001) and was thickened compared to control eyes (WMD = 145.03, 95%CI, 121.33–168.73, P<0.00001). The mean SFCT measurement of the unaffected fellow eyes showed also significantly increased choroidal thickness compared to that of normal control eyes (WMD = 77.20, 95% CI, 44.98–109.42, P<0.00001). Similar results were obtained in a sub-analysis based on the same instrument.

Conclusion

It is demonstrated that SFCT is significantly increased in eyes with clinical manifestation of CSC, and in the clinically non-manifested fellow eyes. These results support the hypothesis that CSC is a bilateral disorder with an initial unilateral clinical presentation.

Subfoveal choroidal thickness in patients with diabetic retinopathy and diabetic macular oedema

PurposeTo investigate the relationship between subfoveal choroidal thickness, severity of diabetic retinopathy (DR), and the presence of diabetic macular oedema (DMO) using enhanced depth imaging spectral domain optical coherence tomography (EDI-OCT) in patients with type 2 diabetes.MethodsA retrospective study of 145 eyes from untreated, type 2 diabetic patients who attended clinic at the Oxford Eye Hospital between January 2012 and February 2013, and underwent fundus photography and EDI-OCT imaging. Eyes were divided into two groups based on the presence or absence of foveal involving DMO and classified according to retinopathy grade: R1 (mild non-proliferative diabetic retinopathy (NPDR), R2 (moderate-severe NPDR), and R3 (proliferative diabetic retinopathy (PDR). Subfoveal choroidal thickness was measured on the EDI-OCT images and statistically analysed using Student's t-test.ResultsIn mild NPDR (n=87), the mean subfoveal choroidal thickness was 217.7 microns. In moderate-severe NPDR (n=37), the mean subfoveal choroidal thickness was 221.7 microns. In PDR (n=21), the mean subfoveal choroidal thickness was 242.1 microns. There was a statistically significant increase in choroidal thickness in PDR when compared with the mild NPDR group, P=0.027. DMO was associated with a non-statistically significant increase in choroidal thickness (225.4 microns) compared with eyes without DMO (209.3 microns), P=0.13.ConclusionSubfoveal choroidal thickness increased with the severity of diabetic retinopathy but showed no statistically significant association with the presence of DMO. This suggests that the choroidal layer is responsive to retinal vascular changes.