Optical coherence tomography measurements of choroidal thickness in healthy eyes: correlation with age and axial length

Adult-Onset Foveomacular Vitelliform Dystrophy With Unilateral Presentation: A Case Series

Adult-onset foveomacular vitelliform dystrophy (AOFVD) is a rare condition affecting the macula that presents diagnostic and management challenges due to its varied manifestations and clinical overlap with other retinal disorders. As vitelliform lesions can occur in various conditions, such as Best disease and age-related macular degeneration, clinical presentation, multimodal imaging findings, and genetic testing can aid in accurate diagnosis. Although AOFVD typically affects both eyes, unilateral involvement can occur. This study presents four cases of unilateral AOFVD in female patients aged 43 to 66 years. Each patient was monitored for two years with fundoscopy and multimodal imaging, including color fundus photography, optical coherence tomography (OCT), OCT-angiography, fluorescein angiography, and fundus autofluorescence (FAF). All patients presented with a characterized solitary, subfoveal, yellow lesion on fundoscopy. FAF revealed intense hyperautofluorescence corresponding with the lesions. OCT revealed the accumulation of homogenous hyperreflective material between the retinal pigment epithelium and photoreceptors. No abnormal findings were observed in the fellow eyes. Subfoveal choroidal thickness was measured at 355 μm, 545 μm, 486 μm, and 669 μm in the affected eyes. While AOFVD typically manifests bilaterally, these cases demonstrate a unique unilateral presentation, highlighting the importance of comprehensive examination and differential diagnosis. Distinguishing cases with unilateral presentation from other conditions can be more challenging, so awareness of this unusual phenotype and its clinical characteristics must be raised. Choroidal thickness measurements provide additional insights into AOFVD pathophysiology, suggesting a potential association with the pachychoroid spectrum.

Pachy-Reticular Pseudodrusen

PURPOSE

To characterize the features of a peculiar association between reticular pseudodrusen (RPD) and pachychoroid (pachy-RPD) and to compare them with eyes affected by RPD and normal/leptochoroid.

DESIGN

Observational, retrospective, case-control study.

PARTICIPANTS

Among a cohort of patients with intermediate age-related macular degeneration (AMD), we selected eyes with RPD and pachychoroid (i.e., choroidal thickness of >50 μm). A control group of RPD eyes but without pachychoroid (i.e., a choroidal thickness of <250 μm) was included.

METHODS

Number and stages of RPD were evaluated in each ETDRS subfield. Furthermore, choroidal perfusion was investigated using the choroidal vascularity index (CVI), and choriocapillaris perfusion density (PD) on structural OCT and OCT angiography.

MAIN OUTCOME MEASURES

Description of the multimodal imaging features of pachy-RPD and differences with RPD associated with normal/leptochoroid.

RESULTS

Among 111 RPD eyes, 37 were included in the pachy-RPD group and 74 in the control group. Patients with pachy-RPD were significantly younger than patients with RPD and normal/leptochoroid (mean age, 75 ± 16 and 82 ± 7 years, respectively; P = 0.002). Total RPD number was comparable between the 2 groups (P = 0.220). However, pachy-RPD eyes showed a significantly higher number of stage 1 RPD in comparison to the controls (P < 0.001), and a lower number of stage 3 (P < 0.001) and stage 4 RPD (P = 0.052). The CVI and choriocapillaris PD were greater in pachy-RPD than in the control group (P < 0.001 and P= 0.010, respectively).

CONCLUSIONS

Pachy-RPD are characterized by a different distribution of RPD stages (i.e., more early stages and fewer advanced stages) in comparison to RPD with normal/leptochoroid. Furthermore, pachy-RPD eyes showed greater perfusion indices of the choroid. These features suggest that the presence of pachychoroid could be a protective factor in the RPD evolution to the advanced AMD forms.

FINANCIAL DISCLOSURE(S)

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

Choroidal and Retinal Thicknesses in Healthy Eyes Measured with Ultra-Wide-Field Optical Coherence Tomography

Ultra-wide-field optical coherence tomography (UWF-OCT) has been recently introduced into clinical ophthalmological practice. To date, there are few data on the reference values of the retinal thickness (RT) and choroidal thickness (CT) measured with this technique. This study aimed to analyze the variance in RT and CT in the healthy eyes of white Caucasian patients with UWF-OCT tests performed with the largest available scan size of 23 × 20 mm. The data were analyzed with reference to the patients' age and gender and the axial length of the eyeball. The results of UWF-OCT scanning enabled us to visualize the shape of the retina and choroid in a large portion of the eyeball. Both anatomical entities became significantly thinner at the periphery. The peripheral CT was greater in the upper and temporal sectors; the RT was higher in the nasal compared to the temporal sectors. Both the choroid and retina showed a reduced thickness with age; however, the CT and RT did not show a statistically significant correlation with the axial length after adjusting for age and gender. Age-related variations in thickness were especially prominent in the choroid. The CT in UWF-OCT testing was significantly greater in females, while the RT was greater in males. UWF-OCT testing provides additional information on the anatomical structure of the retina and choroid compared to standard-field OCT.

Retinal Findings and Cardiovascular Risk: Prognostic Conditions, Novel Biomarkers, and Emerging Image Analysis Techniques

Many retinal diseases and imaging findings have pathophysiologic underpinnings in the function of the cardiovascular system. Myriad retinal conditions, new imaging biomarkers, and novel image analysis techniques have been investigated for their association with future cardiovascular risk or utility in cardiovascular risk prognostication. An intensive literature search was performed to identify relevant articles indexed in PubMed, Scopus, and Google Scholar for a targeted narrative review. This review investigates the literature on specific retinal disease states, such as retinal arterial and venous occlusions and cotton wool spots, that portend significantly increased risk of future cardiovascular events, such as stroke or myocardial infarction, and the implications for personalized patient counseling. Furthermore, conditions diagnosed primarily through retinal bioimaging, such as paracentral acute middle maculopathy and the newly discovered entity known as a retinal ischemic perivascular lesion, may be associated with future incident cardiovascular morbidity and are also discussed. As ever-more-sophisticated imaging biomarkers and analysis techniques are developed, the review concludes with a focused analysis of optical coherence tomography and optical coherence tomography angiography biomarkers under investigation for potential value in prognostication and personalized therapy in cardiovascular disease.

Choroidal Changes in Rhesus Macaques in Aging and Age-Related Drusen

Purpose

Choroidal vascular changes occur with normal aging and age-related macular degeneration (AMD). Here, we evaluate choroidal thickness and vascularity in aged rhesus macaques to better understand the choroid's role in this nonhuman primate model of AMD.

Methods

We analyzed optical coherence tomography (OCT) images of 244 eyes from 122 rhesus macaques (aged 4-32 years) to measure choroidal thickness (CT) and choroidal vascularity index (CVI). Drusen number, size, and volume were measured by semiautomated annotation and segmentation of OCT images. We performed regression analyses to determine any association of CT or CVI with age, sex, and axial length and to determine if the presence and volume of soft drusen impacted these choroidal parameters.

Results

In rhesus macaques, subfoveal CT decreased with age at 3.2 µm/y (R2 = 0.481, P < 0.001), while CVI decreased at 0.66% per year (R2 = 0.257, P < 0.001). Eyes with soft drusen exhibited thicker choroid (179.9 ± 17.5 µm vs. 162.0 ± 27.9 µm, P < 0.001) and higher CVI (0.612 ± 0.051 vs. 0.577 ± 0.093, P = 0.005) than age-matched control animals. Neither CT or CVI appeared to be associated with drusen number, size, or volume in this cohort. However, some drusen in macaques were associated with underlying choroidal vessel enlargement resembling pachydrusen in human patients with AMD.

Conclusions

Changes in the choroidal vasculature in rhesus macaques resemble choroidal changes in human aging, but eyes with drusen exhibit choroidal thickening, increased vascularity, and phenotypic characteristics of pachydrusen observed in some patients with AMD.

NORMAL PERIPHERAL CHOROIDAL THICKNESS MEASURED BY WIDEFIELD OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

Choroidal stasis plays an important role in the pathogenesis of many conditions and leads to choroidal thickening. However, the normal peripheral choroidal thickness (PCT) pattern remains unknown. This study investigated PCT and associated factors using ultrawidefield optical coherence tomography in healthy eyes.

METHODS

This cross-sectional study included 120 healthy eyes (57 males; age, 52.0 ± 20.5 years). We used choroidal thickness maps created by ultrawidefield optical coherence tomography (viewing angle, 200°) with real-shape correction. The peripheral area was defined from 60° to 100° and further separated vertically and horizontally. The PCT and the correlations between PCT and subjects' characteristics were examined.

RESULTS

The PCT were 227.1 ± 57.0 µ m, 199.6 ± 53.9 µ m, 196.6 ± 57.1 µ m, and 148.0 ± 38.2 µ m in supratemporal, infratemporal, supranasal, and infranasal areas, respectively. The thickest peripheral sector was most frequently observed in supratemporal (69.2%). The PCT negatively correlated with age in all regions ( P -values < 0.001) and axial length in supratemporal, supranasal, and infranasal areas ( P -values ≤ 0.003). The temporal PCT was thicker on the side contiguous with the posterior pole Haller's vessels ( P -values ≤ 0.020).

CONCLUSION

The PCT is associated with age, axial length, and the running pattern of Haller's vessels.

Choroidal and Retinal Thicknesses in Type 2 Diabetes Mellitus with Moderate Diabetic Retinopathy Measured by Swept Source OCT

Background: To study choroidal thickness (CT) in type 2 diabetes mellitus (DM2) patients with moderate diabetic retinopathy (DR) and to correlate with changes in retinal thickness (RT) with swept-source OCT (SS-OCT) compared to healthy subjects. Methods: Fifty-four DM2 patients with moderate DR without diabetic macular edema (DME) and 73 age-matched healthy subjects were evaluated using SS-OCT to measure changes in total RT and CT in the nine areas of the Early Treatment Diabetic Retinopathy Study (ETDRS) macular grid. Results: The mean age was 64.06 ± 11.98 years and 60.79 ± 8.62 years in the diabetic and control groups, respectively. Total RT showed statistically significant differences in the temporal inner area, with higher values in the DM2 group (p = 0.010). CT did not show differences between the groups. There was a significant negative correlation between RT and age in all of the outer ETDRS areas and a positive significant correlation in the central area for the DM2 group. There was also a negative significant correlation between CT and age in all of the ETDRS areas except for the inferior inner area. In the DM2 group, a negative correlation was observed between RT and CT in the central area (p = 0.039) and in both horizontal parafoveal areas (temporal inner, p = 0.028; nasal inner, p= 0.003). Conclusion: DM2 patients with moderate DR have no changes with regard to CT. Both CT and RT decreased with age in DM2, showing a negative correlation between these factors in the central and horizontal parafoveal areas of the ETDRS grid.

Clinical features of pachyvessels associated with polypoidal choroidal vasculopathy in chronic central serous chorioretinopathy

To investigate the association between clinical features of chronic central serous chorioretinopathy (CSC) and subsequent development of polypoidal choroidal vasculopathy (PCV). Characteristics and treatment response of PCV secondary to CSC were described. This retrospective observational study included 18 patients with chronic CSC (18 eyes) with subsequent PCV and 36 controls (36 eyes) with chronic CSC without PCV development during follow-up. Clinical features were compared between the two groups. A logistic regression model was used to evaluate the risk factor of PCV formation. Treatments for PCV included anti-vascular endothelial growth factor (VEGF) monotherapy, photodynamic therapy (PDT), or PDT and anti-VEGF combination treatment. Subretinal fluid on optical coherence tomography images were assessed after treatments. Significant between-group differences were observed in best-corrected visual acuity after disease resolution and presence of pachyvessels (P = .001 and P = .003, respectively). The presence of pachyvessels in chronic CSC was associated with subsequent PCV (odds ratio = 6.00; 95% CI, 1.74–20.68; P = .005). CSC recurrence and subfoveal choroidal thickness (SFCT) were not significantly associated with subsequent PCV development (P = .393 and P = .911, respectively). The mean age of PCV diagnosis was 51 years, and the mean time from CSC diagnosis to PCV confirmation was 77.8 months. The mean (range) SFCT of PCV was 327.7 (134–599) μm. Nine patients received anti-VEGF monotherapy and 5 had disease remission. Four patients received PDT and anti-VEGF combination treatment and all of the 4 had disease remission. In chronic CSC, pachyvessel characteristics are associated with subsequent PCV development. This result will assist clinicians to evaluate CSC in clinical practice and provide insights into the pathogenesis of PCV.

CHOROIDAL THICKNESS AND VASCULARITY VARY WITH DISEASE SEVERITY AND SUBRETINAL DRUSENOID DEPOSIT PRESENCE IN NONADVANCED AGE-RELATED MACULAR DEGENERATION

PURPOSE

To investigate how choroidal features vary with age-related macular degeneration (AMD) severity in early-intermediate disease.

METHODS

One hundred fifty-one eyes of 151 participants >50 years with no to intermediate AMD were analyzed with enhanced depth imaging optical coherence tomography. Mean macular choroidal thickness (CT), choroidal vascular thickness (CV), and choroidal vascularity index (CVI) were determined, and statistical associations were calculated.

RESULTS

Decreased CT and CV were associated with increased axial length (+30 and +14 µm/mm, respectively; P < 0.0001 each), whereas decreased CVI was associated with increased age (+0.1%/year; P = 0.004). Compared with eyes with no/early AMD (Group 0), eyes with large drusen without late AMD in the fellow eye (Group 1) showed increased CV and CVI (+22 µm, P = 0.03 and +2.2%, P = 0.02, respectively). However, eyes with large drusen and late AMD in the fellow eye (Group 2) resembled Group 0. Eyes with subretinal drusenoid deposits demonstrated lower mean CT/CV/CVI than Group 0 (-57 µm, P = 0.02; -31 µm, P = 0.02; -3.6%, P = 0.007).

CONCLUSION

Early AMD progression seems associated with biphasic alterations in choroidal dimensions, increasing during early drusen formation but decreasing thereafter. Subretinal drusenoid deposits are independently associated with marked reductions in all choroidal parameters. Changes in choroidal vascular anatomy may drive or reflect the pathobiology of AMD progression.

CHORIOCAPILLARIS VASCULAR PARAMETERS IN NORMAL EYES AND THOSE WITH PACHYCHOROID WITH AND WITHOUT DISEASE

PURPOSE

To evaluate the vascular characteristics of the choriocapillaris in eyes with pachychoroid as compared with normal controls.

METHODS

Eyes with pachychoroid disease were defined as those with a history of central serous chorioretinopathy or peripapillary pachychoroid syndrome. Pachychoroid without disease was defined as eyes with no history of disease with a subfoveal choroidal thickness ≥ the age-adjusted 95th percentile thickness. Frame-averaged optical coherence tomography angiography images of the choriocapillaris obtained with a Zeiss Plex Elite were binarized, skeletonized, and evaluated for vascular branching parameters.

RESULTS

There were 7 normal control subjects, 10 subjects with pachychoroid without disease, and 17 pachychoroid disease subjects. Mean choriocapillaris vessel segment length was 12.19 µm in eyes with pachychoroid disease as compared with 11.48 µm in normal controls and 11.62 µm in pachychoroid without disease (P = 0.003 and P = 0.006, respectively). The branches per square millimeter were fewer in pachychoroid disease (1,215), as compared with normal controls (1,471) or pachychoroid without disease (1,384; P < 0.001, and P = 0.002, respectively). The choriocapillaris vessel diameter was larger, but the fractal dimension was smaller in pachychoroid disease eyes as compared with normal eyes or pachychoroid without disease eyes. There was no statistically significant difference between normal controls and pachychoroid without disease for any measured vascular parameter of the choriocapillaris.

CONCLUSION

Choriocapillaris vascular parameters suggest that pachychoroid is not necessarily pathologic. It is possible that choroidal thickening is an epiphenomenon, and there are more significant vascular parameters that are related to disease. These concepts may help guide future prospective studies.

Persistent Hypertransmission Defects on En Face OCT Imaging as a Stand-Alone Precursor for the Future Formation of Geographic Atrophy

PURPOSE

To evaluate the prognostic significance of persistent choroidal hypertransmission defects (HyperTDs) detected on en face OCT imaging for predicting the progression of drusen to geographic atrophy (GA) by analyzing their association with the presence of nascent GA (nGA).

DESIGN

Retrospective, post hoc subgroup analysis of a prospective study.

PARTICIPANTS

Patients with bilateral soft drusen from a natural history study.

METHODS

Participants underwent both Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA) imaging over 36 months at 6-month intervals. The Spectralis SD-OCT B-scans were used to grade nGA. En face imaging of Cirrus SD-OCT scans was used to detect HyperTDs, masked to nGA gradings. Hypertransmission defects with greatest linear dimension (GLD) of 125 μm or more were tracked throughout visits.

MAIN OUTCOME MEASURES

The GLD at baseline for best discrimination between persistent and transient HyperTDs over 36 months and the association between these HyperTDs with nGA assessed with odds ratio.

RESULTS

A total of 157 eyes from 81 patients were enrolled. Cirrus SD-OCT scans were available for 133 eyes at baseline, and 39 HyperTDs lesions from 27 eyes of 22 participants were classified as either persistent (26 lesions) or transient (13 lesions) over 36 months. Receiver operating characteristic curve analysis suggested that HyperTDs with baseline GLD of 250 μm or more or 300 μm fit the definition of persistent. After grading the entire population of 157 eyes, a significant association (P < 0.001) was found between nGA gradings and masked HyperTD gradings with GLD of 250 μm or more (odds ratio, 14.5; 95% confidence interval, 4.8-54.0) or 300 μm (odds ratio, 15.2; 95% confidence interval, 5.0-56.7). Identification of HyperTDs was associated with more nGA false-positive results than false-negative results (P < 0.001). Hypertransmission defects with GLD of 250 μm or more or 300 μm showed excellent negative predictive value of 94% or more, but poor positive predictive value of 40% or less, for detecting nGA.

CONCLUSIONS

Choroidal HyperTDs on en face OCT imaging were associated strongly with nGA. The potential of using HyperTDs with GLD of 250 μm or more or 300 μm as a risk factor for the progression of drusen to GA is promising and requires further study.

Choroidal Thickness Correlates with Clinical and Imaging Metrics of Parkinson's Disease: A Pilot Study

BACKGROUND

Parkinson's disease (PD) is marked clinically by motor symptoms and pathologically by Lewy bodies and dopamine neuron loss in the substantia nigra pars compacta (SNc). Higher iron accumulation, assessed by susceptibility MRI, also is observed as PD progresses. Recently, evidence has suggested that PD affects the retina.

OBJECTIVE

To better understand retinal alterations in PD and their association to clinical and SNc iron-related imaging metrics.

METHODS

Ten PD and 12 control participants (2 eyes each) from an ongoing PD imaging biomarker study underwent enhanced depth imaging optical coherence tomography evaluation. Choroidal (vascular) thickness and nerve layers were measured in 4 subregions [superior, temporal, inferior, and nasal] and at 3 foveal distances (1, 1.5, and 3 mm). These metrics were compared between PD and control groups. For significantly different metrics, their associations with clinical [levodopa equivalent daily dosage (LEDD), motor and visuospatial function] and SNc susceptibility MRI metrics [R2* and quantitative susceptibility mapping (QSM)] were explored.

RESULTS

Compared to control participants, PD participants had a thicker choroid (p = 0.005), but no changes in nerve layers. Higher mean choroidal thickness was associated with lower LEDD (p < 0.01) and better visuospatial function (p < 0.05). Subregion analyses revealed higher choroidal thickness correlated with lower LEDD and better motor and visuospatial measures. Higher mean choroidal thickness also was associated with lower nigral iron MRI (p < 0.05).

CONCLUSION

A small cohort of PD research participants displayed higher choroidal thickness that was related to better clinical performance and less nigral pathology. These intriguing findings warrant further investigation.

Choroidal Thickness and Volume Modifications Induced by Aerobic Exercise in Healthy Young Adults

INTRODUCTION

Our aim was to evaluate the changes in choroidal thickness (CT) and volume (CV) following aerobic physical exercise in healthy young adults.

METHODS

This study included 72 eyes from healthy volunteers between 22 and 37 years old. Using the International Physical Activity Questionnaire, total physical activity was computed. Measurements using an autorefractometer, ocular biometry, and spectral-domain optical coherence tomography using the Enhanced Depth Imaging protocol were taken. OCT was performed as a baseline measurement and after performing 10 min of dynamic physical exercise (3 and 10 min post-exercise). The choroidal layer was manually segmented, and the CT and CV in different areas from the Early Treatment Diabetic Retinopathy Study grid were obtained.

RESULTS

In healthy adults, at 3 min post-exercise, CT was higher in the subfoveal, the 3-mm nasal, and the 6-mm superior areas. Between 3 and 10 min post-exercise, the CT was reduced in all areas, and in some areas, the values were even smaller than the baseline measurements. The CV values showed changes after exercise similar to those of thickness. The total CV recovery after exercise was related to sex and physical activity level.

CONCLUSION

Individuals with higher physical activity habits had greater CV at rest than those with lower physical activity levels. During exercise, healthy young people adjust CT and CV. At 3 min post-exercise, CT and CV increase. Women and individuals with greater physical activity levels reduce their total CV more than others during recovery.

Patterns and Determinants of Choroidal Thickness in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study

PURPOSE

To describe the distribution and determinants of choroidal thickness (CT) in participants in a population study based on spectral-domain (SD)-OCT measurements.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

Ethnic Chinese, Indian, and Malay adults aged more than 50 years without any retinal diseases (e.g., diabetic retinopathy, macular edema, age-related macular degeneration, central serous chorioretinopathy) that might affect the CT were recruited from the Singapore Epidemiology of Eye Diseases Study.

METHODS

Choroidal imaging was performed by SD-OCT (Spectralis, Heidelberg Engineering, Heidelberg, Germany) in enhanced depth imaging (EDI) mode. Subfoveal choroidal thickness (SFCT) was measured on the foveal line scan by 2 retinal experts independently (YS and KT), and the average was used in the analyses. In Chinese and Indian cohorts in whom macular raster scans were captured, the manufacturer-supplied research software (Heyex SP-X version 6.4.8.116; Heidelberg Engineering) was used to obtain automated segmentation yielding mean choroidal thickness in each of the 9 ETDRS grid sectors.

MAIN OUTCOME MEASURES

Subfoveal choroidal thickness and regional CT in the 9 ETDRS grid sectors.

RESULTS

For the SFCT analysis, 2794 eyes of 1619 participants (Chinese, Indian, and Malay ) were included. The mean age was 60.9 years (standard deviation, 7.7), and 797 (49.2%) were male. Mean SFCT was 255.2 μm (standard deviation, 102.6). The normal range of SFCT was 106 to 447 μm (corresponding to 5^th and 95^th percentile limits of SFCT, respectively). In multivariable models, thinner SFCT was associated with older age, female gender, longer axial length, and Malay (vs. Chinese) ethnicity. In the subset of Chinese and Indian eyes (n = 1842) in whom regional variation was evaluated, the choroid was thickest at the superior and temporal sectors and thinner at the inferior and nasal sectors.

CONCLUSIONS

Subfoveal choroidal thickness is influenced by age, gender, and ethnicity along with regional differences even within individual eyes. Subfoveal choroidal thickness also shows a wide range in physiologic limits. These data may be used as a reference in future studies.

Evaluation of the Choroid in Women with Uncomplicated Pregnancy

Purpose

To study the choroid in uncomplicated pregnant women using advanced optical coherence tomography (OCT) imaging and analysis.

Methods

Women with uncomplicated pregnancy in the third trimester (>28 weeks gestational age) and age-matched nonpregnant women were enrolled in this prospective study. All subjects underwent spectral-domain OCT with enhanced depth imaging mode and spectral-domain optical coherent tomography angiography (OCTA). Main outcomes were subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), and choriocapillaris flow deficits (CC FD).

Results

Twenty-two eyes of 12 uncomplicated pregnant women and 23 eyes of 15 nonpregnant, female controls were included. The mean age was 32.27 ± 6.96 years for the pregnant group and 30.08 ± 5.49 years for control group (P > 0.05). Mean SFCT was 238.70 ± 82.96 µm in the pregnant group, and 277.40 ± 61.79 µm in the control group. CVI was 67.58% ± 2.45% in the pregnant group and 67.31% ± 2.62% in the control group. The CC FD% was 54.06 ± 3.95 in the pregnant group, and 55.02 ± 3.78 in the control group. There was no significant difference between the pregnant and control groups (P > 0.05) in SFCT, CVI or CC FD.

Conclusions

Although extensive hemodynamic changes occurred with pregnancy, choroidal measurements by OCT and OCTA demonstrated no differences in uncomplicated third-trimester pregnant women compared with nonpregnant controls.

Translational Relevance

The unaltered choroid in uncomplicated third-trimester pregnancy we described allows clinicians to determine whether abnormal choroidal measurements could be used as a biomarker for complications of pregnancy.

Topographic Variations of Choroidal Thickness in Healthy Eyes on Swept-Source Optical Coherence Tomography

Purpose

To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes.

Methods

This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed.

Results

The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT.

Conclusions

One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states.

CSF1R blockade induces macrophage ablation and results in mouse choroidal vascular atrophy and RPE disorganization

The choroid, which provides vascular supply to the outer retina, demonstrates progressive degeneration in aging and age-related macular degeneration (AMD). However mechanisms that maintain or compromise choroidal homeostasis are obscure. We discovered that the ablation of choroidal macrophages via CSF1R blockade was associated with choroidal vascular atrophy and retinal pigment epithelial (RPE) changes including structural disruption, downregulation of visual cycle genes, and altered angiogenic factor expression. Suspending CSF1R blockade following ablation enabled spontaneous macrophage regeneration, which fully restored original macrophage distributions and morphologies. Macrophage regeneration was accompanied by arrested vascular degeneration and ameliorated pathological RPE alterations. These findings suggest that choroidal macrophages play a previously unappreciated trophic role in maintaining choroidal vasculature and RPE cells, implicating insufficiency in choroidal macrophage function as a factor in aging- and AMD-associated pathology. Modulating macrophage function may constitute a strategy for the therapeutic preservation of the choroid and RPE in age-related retinal disorders.

CHOROIDAL THICKNESS, VASCULAR FACTORS, AND AGE-RELATED MACULAR DEGENERATION: The ALIENOR Study

PURPOSE

To study the associations of subfoveal choroidal thickness with vascular risk factors and age-related macular degeneration.

METHODS

Two hundred sixty-one participants of the Alienor study had gradable enhanced-depth imaging optical coherence tomography scans of the macula and available data on vascular and genetic risk factors (assessed through face-to-face interview and fasting blood samples) and age-related macular degeneration status (assessed from retinal photographs and optical coherence tomography). Subfoveal choroidal thickness was measured manually on one horizontal scan passing through the fovea.

RESULTS

In a multivariate mixed linear model, subfoveal choroidal thickness was independently associated with age greater than 80 years (-21.77 μm, P = 0.02), axial length (-21.77 μm, P < 0.0001), heavy smoking (≥20 pack-years: -24.89 μm, P = 0.05), fasting blood glucose higher than 7 mmol/L (-53.17 μm, P = 0.02), and lipid-lowering treatment (+18.23, P = 0.047). After multivariate adjustment for age, sex, axial length, and vascular and genetic risk factors, subfoveal choroidal thickness was thinner in eyes with central hyperpigmentation (-45.39 μm, P = 0.006), central hypopigmentation (-44.99 μm, P = 0.001), and central pigmentary abnormalities (-44.50 μm, P = 0.001), but not in eyes with late age-related macular degeneration (-18.05 μm, P = 0.33) or soft drusen.

CONCLUSION

These findings indicate a relationship between vascular risk factors and choroidal thinning and suggest an early involvement of the choroid in the pathogenesis of age-related macular degeneration.

Age-Related Changes in Choroidal Thickness and the Volume of Vessels and Stroma Using Swept-Source OCT and Fully Automated Algorithms

PURPOSE

To determine age-related changes in choroidal thickness and the volume of choroidal vessels and stroma using automated algorithms based on structural swept-source OCT (SS-OCT) scans.

DESIGN

Prospective and observational study.

PARTICIPANTS

The study included 144 normal participants with ages ranging from 20 to 88 years.

METHODS

A previously reported strategy was used to automatically segment the choroid using SS-OCT structural images. Attenuation correction was applied on B-scans to enhance the choroidal contrast and facilitate more accurate automatic segmentation of the 3-dimensional choroidal vessel and stroma. The parameters that we investigated included mean choroidal thickness (MCT), choroidal vessel volume (CVV), choroidal stroma volume (CSV), choroid vascularity index (CVI), and the choroidal stroma-to-vessel volume ratio (CSVR). Correlations between MCT and choroidal vessel metrics of CVV, CSV, CVI, and CSVR were studied. Regional distributions of MCT and CVI were analyzed using a grid centered on the fovea. Age-related changes in MCT, CVV, CSV, and CVI were studied in the entire scanning region, as well as in the subregions of the grids.

MAIN OUTCOME MEASURES

Age-related changes in MCT, CVV, CSV, and CVI using 6×6-mm and 12×12-mm SS-OCT scans.

RESULTS

The automated choroid segmentations were validated against manual segmentations, and MCT measurements were shown to be in good agreement (P < 0.0001). Choroidal vessel volume and CSV showed significant correlations with MCT (all P < 0.0001). Interestingly, CVI and CSVR were constant, with little variation among all participants regardless of age and MCT (61.1±1.8% and 0.64±0.05, respectively). Measurements on 12×12-mm and 6×6-mm scans showed excellent agreement in all scan regions (all P < 0.0001). While choroidal thickness and choroidal volume, which includes both choroidal vessels and stroma, decrease with age (all P < 0.0001), the CVI and CSVR vary little among all ages in all regions.

CONCLUSIONS

Whereas MCT, CVV, and CSV decrease with age, the CVI and CSVR remain constant in all regions with age. Ongoing studies are using these automated algorithms on SS-OCT structural datasets to investigate the diagnostic usefulness of these choroidal parameters in a myriad of ocular and systemic diseases.

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.

Age-dependent Changes in the Macular Choriocapillaris of Normal Eyes Imaged With Swept-Source Optical Coherence Tomography Angiography

PURPOSE

Swept-source optical coherence tomography angiography (SS-OCTA) was used to measure the age-dependent changes in macular choriocapillaris (CC) flow deficits (FDs) in normal eyes.

DESIGN

A prospective, cross-sectional study.

METHODS

Subjects with normal eyes ranging in age from their 20s to their 80s were imaged using a 100-kHz SS-OCTA instrument (PLEX Elite 9000, Carl Zeiss Meditec, Dublin, California, USA). Both 3 × 3-mm and 6 × 6-mm scans were used to image the macular CC. Visualization of the CC and quantification of FDs were performed using a previously validated algorithm. The percentage of FDs (FD%) in the central 1-mm circle (C₁), 1.5-mm rim (R_1.5), and 2.5-mm circle (C_2.5) from the 3 × 3-mm and 6 × 6-mm scans and FD% in the 2.5-mm rim (R_2.5) and 5-mm circle (C₅) from the 6 × 6-mm scans were measured and correlated with age and axial length.

RESULTS

A total of 164 subjects were enrolled, with at least 10 subjects from each decade of life. No meaningful correlations were found between FD% and axial length (|r| < 0.30). FD% in all fields increased with increasing age (all r > 0.50; all P < .001); however, the greatest increases were found in the central macula C₁ regions and the smallest increases in the peripheral macula R_2.5 regions.

CONCLUSIONS

In normal aging, the FD% increased with age across the central 5 mm of the macula, but the greatest increase was found in the central 1-mm region of the macula.

Choroidal thickness changes in non-treated eyes of patients with diabetes: swept-source optical coherence tomography study

AIMS

To measure choroidal thickness (CT) in diabetic eyes and its correlation with metabolic status and the severity of diabetic retinopathy (DR).

MATERIALS AND METHODS

Prospective cross-sectional study using swept-source optical coherence tomography. CT maps of 96 treatment naïve eyes of 48 patients with diabetes were compared to 46 eyes of 23 healthy controls. CT changes and their relation to diabetes, age, gender, disease duration, hypertension (HT), hemoglobin A1c level, type and severity of DR were evaluated.

RESULTS

A significantly thinner choroid was measured in patients with diabetes compared to controls (p < 0.009). In the diabetic group age, gender, disease duration and HT were significantly correlated with CT in univariable regression models (p < 0.05). In multivariable analysis, the duration of diabetes significantly negatively correlated with CT (p = 0.02). According to analysis of variance, there was a significant difference among means of CT in different stages of DR (p = 0.002), with thinner CT in cases with more advanced DR. In a multivariable predictive model, thinner CT was associated with an increased risk for the presence of DR (p = 0.02).

CONCLUSIONS

Diabetes mellitus itself and the severity of DR affect CT significantly, even after adjusting for the effects of confounding systemic factors. Disease duration seems to be associated with a reduction of choroidal thickness. Decreased CT proved to be correlated with the severity of DR.

Elevated Choroidal Thickness and Central Serous Chorioretinopathy in the Fellow Eyes of Patients with Circumscribed Choroidal Hemangioma

Objective

To determine whether increased choroidal thickness (CT) is associated with circumscribed choroidal hemangioma (CCH) and whether patients with CCH are predisposed to central serous chorioretinopathy (CSCR).

Methods

We performed a retrospective consecutive observational study of 15 fellow eyes of 15 patients who had CCH. A- and B-scan ultrasonography, fluorescein angiography (FA), and optical coherence tomography (OCT) findings were reviewed to confirm the diagnosis of CCH. Fellow eye CT was measured using enhanced depth imaging OCT. FA, indocyanine green angiography, and OCT images of fellow eyes were reviewed for signs of CSCR.

Results

Mean subfoveal CT was significantly greater in the fellow eyes of patients with CCH than in age-matched normal eyes (p = 0.004). Three of 15 (20.0%) fellow eyes of CCH patients had retinal pigment epithelium disruptions and/or pigment epithelial detachments indicative of previous asymptomatic CSCR.

Conclusion

In this pilot study, elevated CT was associated with a risk of developing CCH as well as CSCR in patients of varying ages. Patients diagnosed with CCH should be screened for CSCR in the fellow eye. Further exploration of this association may reveal useful clues about the biology of abnormally elevated choroidal hyperpermeability and its various clinical manifestations.

The Effect of Acute Hypovolemia on the Eye

INTRODUCTION

To investigate the effects of acute hypovolemia induced by blood donation on the eye. Methods or Study Design: This prospective, observational study included a single eye from each of 48 healthy men between 20 and 40 years of age who had donated 500 ml of blood and 28 eyes of 28 healthy, age- and gender-matched control subjects. The ocular parameters including ocular perfusion pressure (OPP), intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), choroidal and retinal thicknesses, and retinal nerve fiber layer (RNFL) were measured before blood donation and at 10 min and 1, 2, 3, and 4 h after blood donation.

RESULTS

The mean OPP was significantly reduced following blood donation (baseline, 43.4 ± 4.9 vs. 40.8 ± 4.6 mmHg; p = 0.003). The mean subfoveal choroidal thickness (SFCT) was measured as 322.96 ± 76.23, 291.63 ± 77.85, 309.77 ± 75.72, 312.31 ± 75.98, 315.73 ± 75.43, and 317.75 ± 75.73 µm before blood donation, at baseline, 10 min, and 1, 2, 3, and 4 h following donation, respectively [F(2.462, 115.731) = 22.618, p < 0.001]. In the control group, the SFCT was measured as 302.04 ± 32.04, 301.43 ± 35.16, 298.07 ± 37.33, 298.96 ± 39.17, 302.54 ± 39.24, and 301.61 ± 40.41 µm at baseline, 10 min, and 1, 2, 3, and 4 h following donation, respectively [F(2.124, 57.340) = 0.592, p = 0.566]. There was no difference in AL, CCT, RNFL, retinal thicknesses, and IOP measurements performed before and after blood donation (p > 0.05).

CONCLUSIONS

Acute hypovolemia caused a significant reduction in SFCT which persisted for 3 h. This study may pave way for better understanding of choroidal thickness changes in disease states.

[OCT-morphometric and angiographic parallels between different variants of central serous chorioretinopathy]

Central serous chorioretinopathy (CSCR) is a frequent cause of vision deterioration. Often it is associated with type 1 neovascularization under the pigment retinal epithelium (RPE). Optical coherence tomography angiography (OCT-angiography) enables non-invasive and contrast-free detection of neovessels in any retinal layer, which makes the method appropriate for diagnostics in CSCR.

AIM

to investigate OCT-morphometric and angiographic parallels between different CSCR courses.

MATERIAL AND METHODS

The study included 37 patients with CSCR. All the patients underwent standard ophthalmic examination, measurement of the axial eye length (AL) (Lenstar 900, 'Haag-Streit', Switzerland), spectral OCT and OCT-angiography with SSADA algorithm (RTVue xR Avanti, 'Optovue', USA) as well as fundus imaging and fluorescein angiography (FA) (VISUCAM 500, 'Zeiss', Germany). Judging from the results of spectral OCT and intravenous FA, the patients were divided into 2 groups: group 1 - 20 patients with pigment epithelium detachment (PED) and group 2 - 17 patients without PED. AL averaged 23.75±0.27 mm in group 1 and 23.55±0.40 mm in group 2.

RESULTS

Comparative analysis of morphometric parameters in the two groups showed that those patients, whose CSCR manifested with only neurosensory retinal detachment (group 2), demonstrated greater choroidal thickness in the projection of the fovea, central retinal thickness as well as the height and extent of neurosensory retinal detachment. Neovasculature was identified in 11 eyes from group 1 (with PED). Structurally, the neovascular network was either loop-like (7 eyes), or tree-like (4 eyes). In loop-like networks, the maximum neovessel diameter averaged 35.474±4.967 µm and the total area of the neovascular complex was 0.581±0.380 µm2. Tree-like complexes were notable for the generally greater maximum neovessel diameter (65.626±17.316 µm) and area (0.225±0.133 µm2).

CONCLUSION

Non-PED patients show pronounced transudative symptoms and significantly greater subfoveal retinal thicknesses. According to OCT-angiography findings, half of those CSCR patients, with PED, present neovascular networks of either loop-like, or tree-like structure.

ASSOCIATION OF DRUSEN VOLUME WITH CHOROIDAL PARAMETERS IN NONNEOVASCULAR AGE-RELATED MACULAR DEGENERATION

PURPOSE

The choroid is thought to be relevant to the pathogenesis of nonneovascular age-related macular degeneration, but its role has not yet been fully defined. In this study, we evaluate the relationship between the extent of macular drusen and specific choroidal parameters, including thickness and intensity.

METHODS

Spectral domain optical coherence tomography images were collected from two distinct, independent cohorts with nonneovascular age-related macular degeneration: Amish (53 eyes of 34 subjects) and non-Amish (40 eyes from 26 subjects). All spectral domain optical coherence tomography scans were obtained using the Cirrus HD-OCT with a 512 × 128 macular cube (6 × 6 mm) protocol. The Cirrus advanced retinal pigment epithelium analysis tool was used to automatically compute drusen volume within 3 mm (DV3) and 5 mm (DV5) circles centered on the fovea. The inner and outer borders of the choroid were manually segmented, and the mean choroidal thickness and choroidal intensity (i.e., brightness) were calculated. The choroidal intensity was normalized against the vitreous and nerve fiber layer reflectivity. The correlation between DV and these choroidal parameters was assessed using Pearson and linear regression analysis.

RESULTS

A significant positive correlation was observed between normalized choroidal intensity and DV5 in the Amish (r = 0.42, P = 0.002) and non-Amish (r = 0.33, P = 0.03) cohorts. Also, DV3 showed a significant positive correlation with normalized choroidal intensity in both the groups (Amish: r = 0.30, P = 0.02; non-Amish: r = 0.32, P = 0.04). Choroidal thickness was negatively correlated with normalized choroidal intensity in both Amish (r = -0.71, P = 0.001) and non-Amish (r = -0.43, P = 0.01) groups. Normalized choroidal intensity was the most significant constant predictor of DV in both the Amish and non-Amish groups.

CONCLUSION

Choroidal intensity, but not choroidal thickness, seems to be associated with drusen volume in Amish and non-Amish populations. These observations suggest that choroidal parameters beyond thickness warrant further study in the setting of age-related macular degeneration.

Sex-Dependent Choroidal Thickness Differences in Healthy Adults: A Study Based on Original and Synthesized Data

PURPOSE

The purpose of this study is to determine the influence of sex on choroidal thickness (CT) in healthy adults.

METHODS

Healthy Chinese adults were recruited and complete ophthalmic examinations were performed. The choroid was imaged by swept-source optical coherence tomography and the macular CT in Early Treatment Diabetic Retinopathy Study grids was obtained by the intrinsic automated segmentation software. CT in males and females was compared after controlling other factors. All of the published studies in PubMed were systemically tracked, and a syntheses analysis of the combined data of the present study and previous studies was performed to address this issue further.

RESULTS

A total of 104 healthy adults were included, of whom 38 (37%) were male and 66 (63%) were female. Older age and longer axial length (AL) each were significantly associated with thinner CT. After controlling for age and AL, the foveal CT and average macular CT were 25.5 μm (95% CI: 0.5-50.4 μm) and 22.1 μm (95% CI: 2.7-41.4 μm) thicker in men than in women, respectively. Significant differences in CT between males and females were also observed in inner and outer rings after controlling for age and AL (P < 0.05). After strict screening, 15 previously reported studies were determined to be eligible for inclusion. The combination of data collected from 2821 males and 3389 females provided further evidence that the choroid is thicker in males, with a pooled mean difference of 19.5 μm (95% CI: 11.4 to 27.6) for foveal CT and 14.7 μm (95% CI: 6.8 to 22.6) for average CT.

CONCLUSION

Our study of Chinese subjects, along with the syntheses analysis, strengthens the evidence that CT is greater in males than in females, based on OCT measurements. This observation may be pertinent for the sex disparities in some clinical conditions related to CT.

Study of retina and choroid biological parameters of rhesus monkeys eyes on scleral collagen cross-linking by riboflavin and ultraviolet A

To evaluate ocular fundus biological changes after scleral collagen cross-linking (CXL) with riboflavin/ ultraviolet A (UVA) on rhesus monkeys in vivo by analyzing retina and choroid biological parameters. Six 3-year-old male rhesus monkeys (12 eyes) were observed in this study, with scleral CXL procedures applied on superior temporal equatorial sclera on random eyes of all rhesus. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) examination were performed before and 1 week, 1 month, 3 months and 6 months after CXL. The thickness of retina and choroid and the flow density of retinal superficial vascular networks were analyzed respectively in different regions after CXL. As for retina thickness and flow density of retinal superficial vascular networks, no statistical difference was noted between CXL eyes and control eyes at 1 day, 1week, 1 month, 3 months and 6 months (P>0.05). Among choroid parameters, the choroidal thickness in 1500μm temporal to the fovea center of CXL eyes revealed a significant reduction in 1 week postoperatively (P<0.05), but it subsequently increased from 1 month postoperatively, and no statistical difference was found between two groups in the following periods (P>0.05). The choroidal thickness nearby crosslinked region may change temporarily following scleral CXL, and it might recover gradually after 1 month postoperatively. The vascular flow density and thickness of retina were not affected by scleral CXL. Further study should be performed to evaluate the potential adverse effects at the direct vicinity of the application site and the long-term effect of scleral CXL in clinical application.

Swept-Source OCT Angiography of Multiple Evanescent White Dot Syndrome With Inflammatory Retinal Pigment Epithelial Detachment

A 30-year-old woman with photopsias and decreased vision was diagnosed with multiple evanescent white dot syndrome (MEWDS) with an atypical inflammatory subfoveal retinal pigment epithelial detachment (PED) and imaged using swept-source optical coherence tomography (SS-OCT) during several visits. SS-OCT imaging revealed a focal area of attenuated choriocapillaris underneath the PED. An attempt to treat the presumed macular inflammatory lesion with corticosteroids resulted in bilateral exudation consistent with central serous chorioretinopathy. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:145-151.].

Optical Coherence Tomography Predictors of Risk for Progression to Non-Neovascular Atrophic Age-Related Macular Degeneration

PURPOSE

Appearance of geographic atrophy (GA) on color photography (CP) is preceded by specific features on spectral-domain optical coherence tomography (SD OCT). We aimed to build SD OCT-based risk assessment models for 5-year new onset of GA and central GA on CP.

DESIGN

Prospective, longitudinal study.

PARTICIPANTS

Age-Related Eye Disease Study 2 Ancillary SD OCT study participants with age-related macular degeneration (AMD) with bilateral large drusen or noncentral GA and at least 1 eye without advanced disease (n = 317).

METHODS

For 1 eye per participant, qualitative and quantitative SD OCT variables were derived from standardized grading and semiautomated segmentation, respectively, at baseline. Up to 7 years later, annual outcomes were extracted and analyzed to fit multivariate logistic regression models and build a risk calculator.

MAIN OUTCOME MEASURES

New onset of CP-visible GA and central GA.

RESULTS

Over a follow-up median of 4.0 years and among 292 AMD eyes (without advanced disease at baseline) with complete outcome data, 46 (15.8%) developed central GA. Among 265 eyes without any GA on baseline CP, 70 (26.4%) developed CP-visible GA. Final multivariate models were adjusted for age. In the model for GA, the independent predicting SD OCT factors (P < 0.001-0.03) were: hyperreflective foci and retinal pigment epithelium (RPE) layer atrophy or absence, followed by choroid thickness in absence of subretinal drusenoid deposits, photoreceptor outer segment loss, RPE drusen complex volume, and RPE drusen complex abnormal thinning volume. For central GA, the factors (P < 0.001) were RPE drusen complex abnormal thinning volume, intraretinal fluid or cystoid spaces, hyperreflective foci, and RPE layer atrophy or absence. The models yielded a calculator that computes the probabilities of CP-visible, new-onset GA and central GA after 1 to 5 years.

CONCLUSIONS

For AMD eyes with large drusen and no advanced disease, we built a novel risk assessment model-based on age and SD OCT segmentation, drusen characteristics, and retinal pathology-for progression to CP-visible GA over up to 5 years. This calculator may simplify SD OCT grading and with future validation has a promising role as a clinical prognostic tool.

Variability of choroidal and retinal thicknesses in healthy eyes using swept-source optical coherence tomography - implications for designing clinical trials

Aim

The aim was to study the variability of choroidal scleral interface (CSI) thickness in healthy subjects and its relevance for designing future studies.

Methods

A total of 123 volunteers were imaged using swept-source optical coherence tomography. Early treatment diabetic retinopathy grid was used.

Results

Mean central retinal thickness was 285.85±14.53 µm and 287.18±12.93 µm, and mean central CSI thickness was 273.94±77.77 µm and 271.19±78.85 µm for the right and left eyes, respectively. Mean retinal and CSI thicknesses correlated negatively with age (p=0.023, r=−0.208 and p<0.0001, r=−0.426, respectively) and axial length (p=0.016, r=−0.220 and p<0.0001, r=−0.504, respectively). To detect a CSI change of at least 112 µm, a sample size of 11 or 36 per group is needed for a single- or double-arm study, respectively (α=0.05, power =0.90, no loss to follow-up, assuming standard deviation in future studies as 100 µm).

Conclusion

Future clinical studies using CSI as end point are possible with regard to sample size needed.

Choroidal Thickness and Choroidal Vessel Density in Nonexudative Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Imaging

Purpose

To analyze the relationship between choroidal thickness and the distribution of choroidal blood vessels in eyes with nonexudative AMD.

Methods

Eyes with a diagnosis of nonexudative AMD were imaged using a prototype 100-kHz swept-source (SS) optical coherence tomography (OCT) instrument (Carl Zeiss Meditec, Dublin, CA, USA) with a central wavelength of 1050 nm. We used an OCT cube scan pattern consisting of 512 × 512 A-scans over a 12 × 12 mm retinal area. The eyes were partitioned into two groups based on the presence or absence of reticular pseudodrusen (RPD). All scans were segmented using an automated algorithm. In addition, five eyes from each of the two groups were randomly chosen for manual segmentation. Binary choroidal vessels maps were generated from suitable OCT choroidal slabs, and the relationship between the density of large choroidal vessels and choroidal thickness was analyzed using an Early Treatment Diabetic Retinopathy Study–like target centered on the fovea.

Results

Twenty-five eyes were enrolled in each group. The automated algorithm produced accurate choroidal thickness maps with an average difference between the manual and automated segmentations of 13.7 μm. There was a significant and stable correlation between choroidal thickness and choroidal vessel density across the two groups. Both average choroidal thickness and vessel density were significantly lower in eyes with RPD.

Conclusions

Our fully automated choroidal segmentation algorithm was able to capture the different patterns of choroidal thickness over a wide area. Choroidal thickness has a clear relationship with the density of large choroid vessels in our sample, irrespective of the presence or absence of RPD.

Choroidal Imaging with Swept-Source Optical Coherence Tomography in Patients with Birdshot Chorioretinopathy: Choroidal Reflectivity and Thickness

PURPOSE

To characterize choroidal thickness and choroidal reflectivity in the eyes of patients with birdshot chorioretinopathy (BSCR).

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Two hundred twenty BSCR patients and 59 healthy controls.

METHODS

Patients with BSCR and healthy controls underwent imaging of the macula in both eyes with a swept-source optical coherence tomography device (DRI-OCT1 Atlantis; Topcon). Images were exported from the device, and analysis was performed by 2 graders in the Doheny Image Reading Center using Image J software. The choroidal thickness at the foveal center was measured. In addition, the inner and outer boundaries of the choroid and retinal pigment epithelium (RPE) as well as the inner retinal surface all were segmented to allow the brightness and reflectivity of the pixels in the choroid, RPE band, and overlying vitreous to be quantified. An adjusted or normalized choroidal reflectivity, with the RPE as the bright reference standard and the vitreous as the dark reference standard, was computed using the formula: normalized choroidal reflectivity = (choroidal reflectivity-vitreous reflectivity)/RPE reflectivity.

MAIN OUTCOME MEASURES

Choroidal reflectivity and choroidal thickness.

RESULTS

Three hundred eighty-six eyes in the BSCR group and 59 eyes in the control group were included in this analysis. Higher choroidal reflectivity and lower choroidal thickness were documented in inactive BSCR patients compared with active BSCR and controls (P < 0.01). Active BSCR patients showed lower choroidal thickness compared with controls (P < 0.01). There was a negative correlation between choroidal reflectivity and choroidal thickness (r = -0.793; P < 0.001). On multiple regression analysis, choroidal thickness, age, and disease duration (all P < 0.01) all were significant predictors of choroidal reflectivity.

CONCLUSIONS

Choroidal reflectivity and choroidal thickness changes are evident in active and inactive BSCR patients. Novel choroidal parameters such as choroidal reflectivity may warrant further study in the setting of BSCR.

Evolution of choroidal thickness over time and effect of early and sustained therapy in birdshot retinochoroiditis

Purpose

To follow choroidal thickness (ChT) over time in birdshot retinochoroiditis (BRC) using enhanced depth imaging optical coherence tomography (EDI-OCT) and study the effect of early and sustained treatment on ChT.

Patients and methods

Eighteen patients were included and EDI-OCT measurements of ChT were analyzed retrospectively in five groups of patients with follow-up times ranging from 1 year to ≥15 years. The OCT images were evaluated and ChT was calculated under the foveola and 1500 μm temporal, nasal, superior, and inferior to the foveola. To assess the effect of treatment, 13 patients with a disease duration ≥10 years were divided into two groups depending on their treatment status: early and sustained therapy vs insufficient, late, or no treatment. ChT was compared in these two groups along with the number of typical fundus BRC lesions.

Results

The ChT decreased (r=–0.41, P=0.0018) over the disease duration, which ranged from <1 year to ≥15 years. In patients with a disease duration ≥10 years, a significant difference in ChT was noted between adequately and undertreated patients (288.3±76.9 μm vs 161.4±39.2 μm; P=0.004). At the last follow-up, in the group with insufficient therapy 10 of 11 eyes presented typical fundus BRC lesions vs 2 of 13 eyes in the treated group (P≤0.0006, F-test).

Conclusions

Choroidal thickness decreases significantly over time in BRC. If undertreated, patients show thinner choroids compared with adequately treated individuals and present significantly more BRC lesions.

The association of geographic atrophy and decreased renal function in patients with age-related macular degeneration

PurposeThe purpose of the study was to investigate the association between area and presence of geographic atrophy (GA) and renal function, as measured by glomerular filtration rate (GFR).Patients and methodsWe retrospectively identified patients aged 50-90 years who were assigned an ICD-9 diagnosis code for age-related macular generation (AMD) between January 2012 and January 2016. Patients met inclusion criteria if they had at least one macular spectral domain optical coherence tomography volume scan, one provider note, and one GFR value in the electronic medical record. Images were evaluated for the presence of GA, area of GA, drusen, and subretinal drusenoid deposits (SDD) and for subfoveal choroidal thickness (CTh) by standard criteria. Imaging findings were correlated with the most recent GFR from the patient's chart.ResultsWe identified 107 patients who met our inclusion criteria (mean age=74 years, range 50-90 years). Overall, we found a significant correlation between the presence of GA and reduced GFR (P=0.002), which was maintained even after accounting for age and other confounders. No association between GFR and GA area was found. CTh was significantly lower in patients with GA (P=0.038) and those with decreased GFR (P=0.004). Within the SDD-positive population, GA was associated with reduced GFR (P=0.007) but only trended toward significance after controlling for age.ConclusionOur study findings demonstrate an association between impaired renal function and the presence, but not area, of GA within an AMD population. These findings may shed light on common pathogenic mechanisms for these two diseases.

Correlation of Vitreomacular Traction with Foveal Thickness, Subfoveal Choroidal Thickness, and Vitreomacular/Foveal Angle

PURPOSE

To investigate the structure of vitreomacular traction (VMT), specifically, if a correlation exists between 1) the VMT type/grade and the central foveal thickness (CFT) and subfoveal and adjacent choroidal thickness, 2) the vitreomacular/foveal angle (VMFA) and the CFT and subfoveal and adjacent choroidal thickness, and 3) the diameter of vitreomacular adhesion (VMA) and CFT and subfoveal and adjacent choroidal thickness.

MATERIALS AND METHODS

Retrospective, multicenter image analysis study. We analyzed raster scans of the macula taken with spectral-domain optical coherence tomography (SD-OCT) of 61 eyes of 55 patients with VMT. Conventional scans of the vitreoretinal interface were analyzed to measure CFT and the degree of VMFA. Enhanced depth imaging (EDI) scans were analyzed to measure the choroidal thickness in the macula. The multivariate test of means and the t-test were used for statistical comparisons.

RESULTS

There was no statistically significant difference in CFT between focal vs broad and concurrent vs isolated type VMT. Central (p = 0.009), nasal (p = 0.004), and temporal (p = 0.007) subfoveal choroidal thickness was significantly higher in broad VMT compared to focal VMT. There was difference in both CFT (p = 0.035) and central (p = 0.005), nasal (p = 0.01), and temporal (p = 0.001) choroidal thickness between moderate and severe VMT. There was a correlation between VMFA and CFT, where a wider angle was associated with increased CFT (p = 0.026). The broader VMA was associated with increased central subfoveal (p = 0.032), nasal (p = 0.05), and temporal (p = 0.01) choroidal thickness.

CONCLUSIONS

Eyes with broad VMT have thicker choroid than eyes with focal VMT, which have a more open vitreomacular angle. The angle of VMT is related to distinct CFTs.

Choroidal Thickness in Eyes With Central Geographic Atrophy Secondary to Stargardt Disease and Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE

Choroidal thickness (CT) measurements from eyes with similar areas of macular geographic atrophy (GA) secondary to age-related macular degeneration (AMD) and Stargardt disease (STGD) were compared to determine whether GA from different diseases had a similar or different effect on the underlying subfoveal choroid.

PATIENTS AND METHODS

Eyes with the diagnosis of central GA secondary to STGD and AMD were matched, with subfoveal CT measurements obtained from the central B-scan using an enhanced depth imaging protocol. The area of GA was measured using fundus autofluorescence (FAF) imaging. AMD eyes were divided into those with and without reticular pseudodrusen.

RESULTS

A total of 22 eyes of 22 patients were included in the STGD and AMD groups and were matched with respect to the area of GA. The mean age of the STGD patients was 48.9 years (standard deviation [SD]=17.1), and the mean age was 81.8 years (SD=6.2) for the AMD patients. Mean area measurements of GA for the STGD and AMD groups were 5.4 mm2 (SD=4.1) and 5.1 mm2 (SD=4.0), respectively (P=.83). After adjusting for age and axial length, eyes with STGD had a mean CT measurement greater than the AMD eyes (336.1 µm vs. 198.1 µm, respectively; P=.039). However, this difference was driven by AMD eyes with reticular pseudodrusen (RPD) and by a single Stargardt case with a very thick choroid. Eyes with RPD had statistically thinner subfoveal CT measurements when compared with all other groups.

CONCLUSION

A small but statistically significant increase in the CT of STGD eyes was observed when compared with normal controls and AMD eyes without RPD. However, this small increase in CT was driven by a single case with a markedly thicker choroid within the STGD group, so it is unlikely that a clinically significant difference exists. However, AMD eyes with GA and RPD had significantly thinner subfoveal CT measurements.

Scleral and choroidal volume in relation to axial length in infants with retinoblastoma versus adults with malignant melanomas or end-stage glaucoma

PURPOSE

To measure scleral and choroidal volume in eyes of Chinese, and to assess associations with age and axial length.

METHODS

We histomorphometrically examined globes from infants and adults which had been enucleated due to retinoblastoma, uveal melanoma, or absolute painful glaucoma. Thickness of sclera and choroid were measured, and volumes were calculated.

RESULTS

The study included 225 globes (mean axial length: 24.6 ± 4.2 mm; range:17.0-35.7 mm; mean age: 30.4 ± 22.6 years; range: 1-83 years). Mean computed scleral volume was 648 ± 136 mm(3). Scleral volume in children aged <5 years significantly increased with longer axial length (P = 0.001; correlation coefficient r: 0.42) and older age (P = 0.003; r: 0.39) in univariate analysis. In multivariate analysis within the group of children aged ≤2 years, larger scleral volume increased with longer axial length (P = 0.04; standardized correlation coefficient beta: 0.32; correlation coefficient B: 21.6; 95 % confidence interval (CI): 0.52, 42.7) and showed a statistically non-significant tendency to increase with older age (P = 0.06;b eta: 0.30; B: 56.9; 95% CI: -1.5,115). In individuals aged ≥ 5 years, scleral volume was not significantly associated with axial length (P = 0.75) or age (P = 0.13). Mean choroidal volume as measured and calculated in 95 individuals (age: 16-81 years) was 44.1 ± 14.1 mm(3), and was not significantly associated with age (P = 0.47; r: -0.08) or axial length (P = 0.83; r: -0.02).

CONCLUSIONS

This study on children eyes with retinoblastoma and adult eyes with malignant melanomas or end-stage glaucoma suggests that primary eye growth up to an age of 2 years is associated with an increase in scleral volume. After the age of 2 years, scleral volume and choroidal volume remain unchanged, leading to scleral and choroidal thinning with longer axial length, in particular at the posterior pole.

Ultrahigh-Speed, Swept-Source Optical Coherence Tomography Angiography in Nonexudative Age-Related Macular Degeneration with Geographic Atrophy

PURPOSE

To investigate ultrahigh-speed, swept-source optical coherence tomography (SSOCT) angiography for visualizing vascular changes in eyes with nonexudative age-related macular degeneration (AMD) with geographic atrophy (GA).

DESIGN

Observational, prospective, cross-sectional study.

PARTICIPANTS

A total of 63 eyes from 32 normal subjects and 12 eyes from 7 patients with nonexudative AMD with GA.

METHODS

A 1050-nm, 400-kHz A-scan rate SSOCT system was used to perform volumetric optical coherence tomography angiography (OCTA) of the retinal and choriocapillaris (CC) vasculatures in normal subjects and patients with nonexudative AMD with GA. Optical coherence tomography angiography using variable interscan time analysis (VISTA) was performed to assess CC alteration and differentiate varying degrees of CC flow impairment.

MAIN OUTCOME MEASURES

Qualitative comparison of retinal and CC vasculatures in normal subjects versus those in patients with a clinical diagnosis of nonexudative AMD with GA.

RESULTS

In all 12 eyes with GA, OCTA showed pronounced CC flow impairment within the region of GA. In 10 of the 12 eyes with GA, OCTA with VISTA showed milder CC flow impairment extending beyond the margin of GA. Of the 5 eyes exhibiting foveal-sparing GA, OCTA showed CC flow within the region of foveal sparing in 4 of the eyes.

CONCLUSIONS

The ability of ultrahigh-speed, swept-source OCTA to noninvasively visualize alterations in the retinal and CC vasculatures makes it a promising tool for assessing nonexudative AMD with GA. Optical coherence tomography angiography using VISTA can distinguish varying degrees of CC alteration and flow impairment and may be useful for elucidating disease pathogenesis, progression, and response to therapy.