Choroidal thickness in diabetic patients of Indian ethnicity

Choroidal vascularity index as a predictor for the development of retinopathy in diabetic patients

BACKGROUND

Today, limited and controversial data are available on predictive markers for diabetic retinopathy. Choroidal thickness (CT) is an unstable parameter affected by many factors. Also, previous studies had conflicting findings on choroidal thickness. In this study, we aimed to investigate the role of choroidal vascularity index (CVI), a relatively new marker, in evaluating choroidal vascular status and its relationship with diabetic retinopathy (DR).

MATERIALS AND METHODS

A total of 124 subjects, 84 patients with type 2 diabetes mellitus (DM) and 40 healthy controls, were included in the study. The patients were divided into two groups as follows: those without DR and those with non-proliferative DR (NPDRP). All subjects underwent enhanced-depth imaging optical coherence tomography (EDI-OCT), and CT values were noted. To measure CVI, luminal (LA) and stromal areas of the choroidal images were binarized using Image J program. CVI was defined as the proportion of LA to total choroid area (TCA). Demographic and laboratory data of the patients were collected retrospectively.

RESULTS

CVI were found to be lower in diabetic patients compared to non-diabetic patients. CVI values in 3 groups were as follows: 67.9% ± 1.8 (healthy controls), 66.1% ± 2.4 (no DR), and 63.2% ± 2.6 (NPDRP) (p < 0.001). All groups were similar in terms of CT values (p = 0.296). The cut-off value for CVI in predicting retinopathy was 64.7%. Hypertension and current smoking were found to be more frequent in diabetic patients with CVI < 64.7% compared to those with CVI > 64.7%.

CONCLUSIONS

CVI tends to be lower in diabetic patients with or without DR compared to healthy controls. Moreover, patients with DR have a lower CVI than those without DR. CVI can be considered an early and sensitive biomarker for the onset of DR.

[Choroidal changes in patients with diabetes mellitus]

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus (DM) and considered one of the leading causes of vision loss worldwide. The choroid supplies blood to the retina, photoreceptors and the retinal pigment epithelium, it is essential for metabolic exchange in the retina. Many experimental studies have reported that choroidal pathology in diabetic patients may play a role in the development of DR. Choroidal thickness (CT) can be used to assess the vascularization of the choroid. Choroidal vascularity index (CVI) is also used as a marker in assessment of choroidal vascularization. Many studies have been conducted to evaluate choroidal changes in various eye diseases. However, the data on CT in DM patients, especially in those with DR, are conflicting. Thus, the choroidal status in diabetic patients with or without DR remains controversial. In this systematic review we analyze a number of articles dedicated to the relationship between structural changes in the choroid in patients with diabetes mellitus and diabetic retinopathy of different stages, paying particular attention to choroidal thickness and certain other parameters that allow assessment of choroidal changes.

Choroidal Assessment in Patients with Type 2 Diabetes Mellitus and Non-Proliferative Diabetic Retinopathy by Swept-Source Ocular Coherence Tomography and Image Binarization

Background and Objectives: The aim of this study was to evaluate choroidal structure and vascularity indices in patients with non-proliferative diabetic retinopathy (NPDR). Materials and Methods: Sixty-three eyes from sixty-three patients were evaluated: 21 from healthy subjects, 20 with diabetes mellitus (DM) and no diabetic retinopathy (DR), and 22 with DM and non-proliferative diabetic retinopathy without diabetic macular edema (DME). Each patient underwent ocular examination, macular swept-source ocular coherence tomography (SS-OCT) imaging, glycemic control, and systemic high blood pressure (HBP) evaluation. Subfoveal choroidal thickness (SF-CT) was manually assessed on a line scan. Line scan OCT images were exported to ImageJ program. The areas under a 1.5, 3 and 6 mm horizontal line centered on the fovea were assessed by converting the OCT images to binary images, and total choroidal area (TCA), luminal area (LA), stromal area (SA), LA:SA ratio, and choroidal vascularity index (CVI) were evaluated. SF-CT and choroidal parameters were compared between groups, and correlations with ocular and systemic factors were analyzed. Results: SF-CT, TCA, LA, and SA were similar between groups. CVIs were significantly different between groups for all three studied areas (CVI-1.5: 66.21% vs. 66.06% vs. 63.74%, p = 0.003; CVI-3: 65.88% vs. 66.46% vs. 63.79%, p = 0.008; CVI-6: 64.79% vs. 65.40% vs. 63.61%, p = 0.032). NPDR patients had significantly lower CVIs compared to DM patients (p < 0.05). No association of choroidal parameters with glycemic control, DM duration and HBP was found significant (p < 0.05). Conclusions: Choroidal assessment by SS-OCT and image binarization in healthy subjects, subjects with DM without DR, and subjects with DM and NPDR indicated that CVI changes were identifiable and significant in early DR. The lack of association with ocular and systemic factors suggest that CVIs are reliable assessment parameters of choroidal vascular structure.

Choroidal changes and associations with visual acuity in diabetic patients

Background

The variable visual function observed in diabetic retinopathy (DR) patients is not fully explained by the classic staging system. Our purpose was to evaluate choroidal changes, in standardized sectors, in DR patients and to find associations between choroidal measurements and visual function.

Methods

Cross-sectional study that included the right eye of diabetic patients (n = 265) without active edema, ischemia or neovascularization and age-matched controls (n = 73). Optical coherence tomography (OCT) imaging was performed with enhanced depth imaging protocol. Choroidal vascularity index (CVI) was calculated in a 5 mm scan centered in the fovea.

Results

CVI decreased with age (p < 0.001) but was not influenced by axial length. A multivariate analysis adjusting for age confirmed a significant difference in CVI between DR eyes that had previous treatments (intravitreal injections and/or photocoagulation) compared to control eyes (p = 0.013) and to DR eyes that never required treatment (p = 0.002). There was no significant difference between non-DR diabetic patients and normal controls. Considering the group of DR patients that had previous treatments, in eyes without optic media opacification, BCVA correlated with CVI (r = − 0.362, p < 0.001), whereas full retina thickness and individual retinal layer thickness did not (p > 0.066).

Conclusions

A reduction in CVI was observed in patients with a more advanced stage of DR. In treated DR patients with stable disease, choroidal biomarkers correlated with best-corrected visual acuity whereas retinal biomarkers did not.

Trial registration: N/A

Supplementary Information

The online version contains supplementary material available at 10.1186/s40942-021-00355-z.

Intravitreal Ozurdex has no short term influence on choroidal thickness and vascularity index in eyes with diabetic macular edema: A pilot study

AIM:

To analyze choroidal parameters in eyes with diabetic macular edema (DME) treated with intravitreal Ozurdex.

PATIENTS AND METHODS:

Twenty eyes of 14 patients were included in this prospective study. Optical coherence tomography images were obtained before and 8–10 weeks after intravitreal Ozurdex injection; binarized and subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) were calculated.

RESULTS:

Mean SFCT (treatment naïve; 242.22 ± 32.87 reduced to 218.10 ± 22.10, P = 0.158 and previously treated; 330.4 ± 56.72 reduced to 328.93 ± 50.55, P = 0.833) and mean CVI (treatment naïve; 0.64 ± 0.03 changed to 0.65 ± 0.04, P = 0.583 and previously treated; 0.65 ± 0.05 reduced to 0.64 ± 0.03, P = 0.208) showed no significant change.

CONCLUSION:

Intravitreal Ozurdex showed no significant effects on SFCT and CVI in eyes with DME over short term. Larger studies with longer follow-up may allow a better understanding.

Effect of calcium dobesilate on retrobulbar blood flow and choroidal thickness in patients with non-proliferative diabetic retinopathy

INTRODUCTION

Diabetic retinopathy is one of the most common causes of blindness in work-aging adults and develops in one third of diabetic patients. Calcium dobesilate (CaD) treatment have protective effects on blood retinal barrier (BRB) and anti-oxidant as well as anti-inflammatory properties.

OBJECTIVES

To assess effects of CaD administration on retrobulbar blood flow and choroidal thickness in patients with diabetic retinopathy.

METHODS

In this quasi-experimental study, diabetic patients with diabetic retinopathy (DR) were recruited from Shahid Motahari and Poostchi ophthalmology clinic affiliated to Shiraz University of Medical Sciences. Patients were treated with CaD, 1 gr per day for seven days. Before and after CaD administration, retrobulbar blood flow and subfoveal choroidal thickness were assessed. Retrobulbar blood flow were evaluated by measuring peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short ciliary artery (SCA).

RESULTS

In this study, 26 DR patients with a mean age of 56.15 ± 8.93 years and mean diabetes mellitus duration of 15.04 ± 7.64 years were enrolled. Subfoveal choroidal thickness was significantly increased from 316.08 ± 61.69 to 327.81 ± 58.03 after CaD treatment (P value < 0.001). PSV of CRA and EDV of all arteries were significantly increased after CaD administration. In addition, RI of all arteries was significantly reduced after CaD treatment (P < 0.001).

CONCLUSION

CaD treatment may improve the ophthalmic blood flow and increase the subfoveal choroidal thickness in DR patients. These results may be suggestive of protective effects of CaD on endothelium function as well as microvascular circulation.

Indicators of Visual Prognosis in Diabetic Macular Oedema

Diabetic macular oedema (DMO) is an important cause of moderate vision loss in people with diabetes. Advances in imaging technology have shown that a significant proportion of patients with DMO respond sub-optimally to existing treatment options. Identifying associations and predictors of response before treatment is initiated may help in explaining visual prognosis to patients and aid the development of personalized treatment strategies. Imaging features, such as central subfoveal thickness, photoreceptor integrity, disorganization of retinal inner layers, choroidal changes, and macular perfusion, have been reported to be prognostic factors of visual acuity (VA) in DMO. In this review we evaluated each risk factor to understand their relative importance in visual prognostication of DMO eyes post-treatment. Although individually, some of these factors may not be significant predictors, in combination they may form phenotypes that can inform visual prognosis. Stratification based on these phenotypes needs to be developed to progress to personalized medicine for DMO.

Assessment of Diabetic Retinopathy Vascular Density Maps

Purpose

Optical coherence tomography (OCT) and OCTA were used for qualitative and quantitative assessment of retinal vascular density in superficial capillary plexus, deep capillary plexus, foveal avascular zone, and choroidal vascular density map.

Patients and Methods

This study included 64 eyes. Diabetics and control groups were recruited from an internal medicine clinic at Misr University for Science and Technology Hospital and asked to participate in this study. This study was designed as an observational and cross-sectional study in the period from 8/2018 to 8/2019.

Results

There was a decrease in choroidal vascular density in diabetic patients. There was a decrease in retinal thickness in diabetic patients and there were no significant differences in the retinal thickness between control subjects and patients with non-diabetic retinopathy (NDR).

Conclusion

Our study suggests that OCTA can identify preclinical DR before the manifestation of clinically apparent retinopathy. Our findings also highlight the potential role of OCTA in monitoring and quantifying retinal vascular alterations in diabetics.

Choroidal Changes in Diabetic Patients With Different Stages of Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the long-term microvascular complications of diabetes mellitus (DM) and is considered a leading cause of vision loss worldwide. Chronic hyperglycemia can cause microvascular abnormalities to the retina and the choroid as well. The vascular tissue of the choroid supplies blood to the outer retina, photoreceptors, and retinal pigment epithelium. It plays an important role in the metabolic exchange of the retina. Many experimental studies reported that choroidal pathology in diabetic patients might play a role in developing DR. Choroidal thickness (CT) can reflect changes in the vasculature of the choroid and can be used to assess the vascularity of the choroid itself. CT differs between healthy and diseased states of the eye as well as with the aging process. This means that thinner or thicker choroid may indicate an ocular disease. Choroidal vascularity index (CVI) is also used as a marker for choroidal vascularity assessment and indirectly measures choroidal vascularity quantitatively. Many studies have been conducted to evaluate the choroid in many different ocular diseases. However, the results regarding CT in DM, especially in patients with DR, are various as thickened, thinned, or no changes. Thus, the status of the choroid in patients with DM with or without DR remains controversial between researchers. In this systematic review, we reviewed 18 articles that were done to investigate the relationship between structural choroidal changes in diabetic patients with different stages of DR, focusing on CT, CVI, and some other parameters evaluating choroidal changes.

Choroidal Thickness in Diabetic Patients Without Diabetic Retinopathy: A Meta-analysis

PURPOSE

To evaluate the relationship between diabetic eyes without diabetic retinopathy and healthy eyes in subfoveal choroidal thickness.

DESIGN

Systematic review and meta-analysis.

METHODS

An independent retrospective or prospective clinical study comparing diabetic eyes without diabetic retinopathy and healthy control eyes in the subfoveal choroidal thickness was selected. This study compiled data from publications in PubMed and Web of Science between January 1, 2008, and November 15, 2019. Heterogeneity was statistically quantified by I2 statistics, and meta-analysis was performed using a random-effects model.

RESULTS

Seventeen related studies were identified, including a total of 4,213 eyes, which consisted of 1,197 diabetic eyes without diabetic retinopathy and 3,016 healthy eyes. Meta-analysis clearly showed that the subfoveal choroidal thickness of diabetic eyes without retinopathy was significantly thinner than that of healthy control eyes (weighted mean difference = -14.34 μm; 95% confidence interval: -24.37 to -4.32 μm; P < .005). Similar results were obtained in sub-analysis based on the adjustment of the axial length.

CONCLUSIONS

This study suggests that the subfoveal choroidal thickness was thin in diabetic eyes without retinopathy compared to healthy eyes. Subfoveal choroidal thickness might be an important parameter for the development of diabetic retinopathy in diabetic eyes without retinopathy.

En-face choroidal vascularity map of the macula in healthy eyes

PURPOSE

To report the en-face choroidal vascularity index in healthy eyes.

METHODS

Thirty eyes of 30 healthy individuals were studied. Multiple high-density cross-sectional swept source optical coherence tomography scans were obtained to create a volume scan. The choroid was segmented for the whole volume scan and choroidal inner boundaries were flattened. Subsequently, multiple en-face scans separated by 25 µm were obtained and binarized. Choroidal vascularity index was calculated at level of choriocapillaris, medium, and large choroidal vessels.

RESULTS

The mean age of the study cohort was 35.6 ± 8.8 years. The overall mean en-face choroidal vascularity index was 54.25 ± 0.55%. There was a statistically significant difference of choroidal vascularity index in choriocapillaris (53.16 ± 0.43%), medium choroidal vessel (51.38 ± 0.27%), and large choroidal vessel (55.69 ± 0.87%) (p < 0.01). Choroidal vascularity index analysis in three subgroups based on subfoveal choroidal thickness (low: <300 µm, medium: 300-400 µm, high: >400 µm) showed a statistically significant difference (p = 0.001). Choroidal vascularity index showed a significant correlation with subfoveal choroidal thickness (r = 0.441; p = 0.015), whereas there was no significant correlation of age (p = 0.21), refraction (p = 0.20), and gender (p = 0.67) with en-face choroidal vascularity index.

CONCLUSION

En-face choroidal vascularity index shows a significant variation at the level of choriocapillaris, medium choroidal vessel, and large choroidal vessel in normal eyes. Choroidal vascularity index reaches a nadir at the level of medium choroidal vessel and reaches the maximum value at large choroidal vessel near choroidoscleral interface. En-face choroidal vascularity index shows a significant physiological variation and appears to increase with increase in subfoveal choroidal thickness.

Choroidal Thickness and Hemoglobin A1c Levels in Patients with Type 2 Diabetes Mellitus

Purpose

The aim of this study was to assess the correlation of hemoglobin A1c (HbA1c) levels with choroidal thickness in patients with type 2 diabetes mellitus (DM) using spectral domain optical coherence tomography (SD-OCT).

Methods

In this prospective case series, 180 eyes from 90 patients with type 2 DM were classified into three study groups based on HbA1c values: group 1 included patients with good glycemic control (HbA1c ≤ 7%), group 2 included patients with moderate glycemic control (HbA1c between 7% and 8%), and group 3 included patients with poor glycemic control (HbA1c ≥ 8%). Additionally, 50 eyes from 25 non-diabetic subjects were enrolled to group 4 as a control group. Sub-foveal, nasal, and temporal choroidal thickness were measured and compared.

Results

Mean central, nasal, and temporal choroidal thicknesses in diabetic patients (247.80, 238.63, and 239.30 μm) were significantly less than non-diabetic healthy subjects (277.56, 262.92, and 266.32 μm). Additionally, mean central, nasal, and temporal choroidal thickness values in group 4 (277.56, 262.92, and 266.32 μm) were significantly greater than the corresponding values in group 2 (248.34, 237.55, and 236.45 μm) and group 3 (239.81, 234.62, and 233.94 μm), but was not significantly different from corresponding values in group 1 (259.46, 246.12, and 251.00 μm).

Conclusion

HbA1c values have a significant correlation with choroidal thickness in diabetic patients, and better glycemic control with HbA1c ≤ 7% may prevent choroidal thinning.

Choroidal structural analysis in eyes with diabetic retinopathy and diabetic macular edema-A novel OCT based imaging biomarker

PURPOSE

To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans.

METHODS

A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey's test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis.

RESULTS

SFCT was significantly increased in eyes with DME as compared to the controls (334.47±51.81μm vs 284.53±56.45μm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39μm, moderate NPDR = 327.81±47.39μm, severe NPDR = 357.72±62.65μm, proliferative DR (PDR) = 334.59±47.4μm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001).

CONCLUSION

SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.

Choroidal imaging biomarkers

The choroid is the vascular coat of the eye, and its role has been studied in multiple chorioretinal disorders. Recent advancements in choroidal imaging techniques, including enhanced depth imaging optical coherence tomography, swept source optical coherence tomography, en face optical coherence tomography, and optical coherence tomography angiography have facilitated an in-depth analysis of the choroid. The gradual shift from manual to automated segmentation and binarization methods have led to precise and reproducible measurements of choroidal parameters. These qualitative and quantitative parameters, called choroidal imaging biomarkers, have evolved over the past decade from a simple linear subfoveal choroidal thickness to more complex 3D choroidal reconstruction, thus widening the spectrum encompassing multiple parameters. These biomarkers have provided a better understanding of the pathogenesis, are helpful in diagnostic dilemmas, and, in the future may also help to devise treatment options. The lack of normative data, absence of standardized parameters, and limitations of the imaging techniques, however, have led to ambiguity and difficulty in the interpretation of these variables. We attempt to address these lacunae in the literature and provide a basic understanding of the choroid in both health and disease using these choroidal biomarkers.

Change in subfoveal choroidal thickness in diabetes and in various grades of diabetic retinopathy

Background

To evaluate subfoveal choroidal thickness (SFCT) change in diabetes and in various grades of diabetic retinopathy (DR) in comparison to age-matched healthy subjects.

Methods

This prospective observational study included 100 eyes of diabetic patients without DR (group D), 100 eyes with DR (group R), and 100 eyes of healthy subjects (group N). The assessment included demographics, duration of diabetes, comprehensive ocular examination, fundus photography with/without fundus fluorescein angiography, spectral domain optical coherence tomography with enhanced depth imaging to assess SFCT.

Results

The SFCT was comparable between groups N (310.65 ± 37.34 µm) and D (308.48 ± 30.06 µm; P = 0.60), but was significantly lower in R (296.52 ± 21.41 µm; P < 0.01). The SFCT was significantly lower in proliferative DR (n = 36; SFCT = 284.56 ± 21.09 µm) as compared to non-proliferative DR (n = 64; SFCT = 303.25 ± 18.59 µm; P < 0.001). The SFCT had moderately negative correlation with severity of DR (R = − 0.50; P < 0.01). The difference in SFCT when compared with normal subjects was significant only in severe/very severe non-proliferative DR (294.47 ± 15.65 µm; P < 0.01) and in proliferative DR (284.56 ± 21.09 µm; P < 0.01). There was a negative correlation of SFCT with the duration of diabetes (R = − 0.41; P < 0.01).

Conclusion

SFCT decreases with increasing duration of diabetes. The decrease is significant after the onset of severe DR, and is proportionate to the severity of DR.

OUTER RETINAL LAYER THICKNESS AS GOOD VISUAL PREDICTOR IN PATIENTS WITH DIABETIC MACULAR EDEMA

PURPOSE

To evaluate the relationship between outer retinal layer (ORL) thickness in diabetic macular edema to visual acuity (VA).

METHODS

Ninety-five eyes were included in this prospective nonrandomized case-control study. They divided into 30 cases of healthy normal subjects and 65 cases of nonproliferative diabetic retinopathy with diabetic macular edema. Complete ophthalmic examination and spectral domain-optical coherence tomography were done for all cases and analyzed to measure central foveal point thickness (CFT), ORL thickness at fovea, and subfoveal choroidal thickness.

RESULTS

The ORL thickness was significantly thinner in diabetic macular edema group (85.3 μm) than controls (99.9 μm) (P = 0.002). There was higher significant correlation between ORL thickness and logMAR VA (r = -0.87, P < 0.001) than correlation between CFT and VA (r = 0.18, P = 0.16). The cutoff point of the relationship between ORL thickness and VA was 88 μm with moderate sensitivity (81%) and high specificity (88%), below which vision is affected. Outer retinal layer thickness is significantly related to subfoveal choroidal thickness but not CFT.

CONCLUSION

This study revealed reduction in ORL thickness in diabetic macular edema. There is a higher and stronger correlation between ORL thickness and vision than that between CFT and vision.

Choroidal Thickness Change in Patients With Diabetic Macular Edema

BACKGROUND AND OBJECTIVE

To evaluate subfoveal choroidal thickness (SFCT) in diabetic macular edema (DME) and its relationships.

PATIENTS AND METHODS

One hundred and six eyes were included in this prospective, nonrandomized case control study. They were divided into 37 cases of healthy, normal subjects and 69 cases of nonproliferative diabetic retinopathy (NPDR) with DME. Spectral-domain optical coherence tomography was done for all cases and analyzed to measure SFCT and central foveal thickness (CFT).

RESULTS

The SFCT was significantly thinner in the DME group (193.4 μm) than in the control group (282.6 μm) (P = .001). In the DME group, SFCT was significantly related to CFT and vision (P < .05). The cutoff point for the relationship between SFCT and vision was 228 μm below the point at which vision is affected.

CONCLUSIONS

DME is associated with a significant decrease in SFCT. SFCT is directly related to vision and foveal thickness, but it is inversely correlated to age. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:970-977.].

CHOROIDAL THICKNESS IN DIABETIC RETINOPATHY ASSESSED WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

To compare the choroidal thickness (CT) of diabetic eyes (different stages of disease) with controls, using swept-source optical coherence tomography.

METHODS

A multicenter, prospective, cross-sectional study of diabetic and nondiabetic subjects using swept-source optical coherence tomography imaging. Choroidal thickness maps, according to the nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields, were obtained using automated software. Mean CT was calculated as the mean value within the ETDRS grid, and central CT as the mean in the central 1 mm. Diabetic eyes were divided into four groups: no diabetic retinopathy (No DR), nonproliferative DR (NPDR), NPDR with diabetic macular edema (NPDR + DME), and proliferative DR (PDR). Multilevel mixed linear models were performed for analyses.

RESULTS

The authors included 50 control and 160 diabetic eyes (n = 27 No DR, n = 51 NPDR, n = 61 NPDR + DME, and n = 21 PDR). Mean CT (ß = -42.9, P = 0.022) and central CT (ß = -50.2, P = 0.013) were statistically significantly thinner in PDR eyes compared with controls, even after adjusting for confounding factors. Controlling for age, DR eyes presented a significantly decreased central CT than diabetic eyes without retinopathy (β = -36.2, P = 0.009).

CONCLUSION

Swept-source optical coherence tomography demonstrates a significant reduction of CT in PDR compared with controls. In the foveal region, the choroid appears to be thinner in DR eyes than in diabetic eyes without retinopathy.

Diabetic Choroidopathy: Choroidal Vascular Density and Volume in Diabetic Retinopathy With Swept-Source Optical Coherence Tomography

PURPOSE

To compare choroidal vascular density (CVD) and volume (CVV) in diabetic eyes and controls, using en face swept-source optical coherence tomography (SS-OCT).

DESIGN

Prospective cross-sectional study.

METHODS

Setting: Multicenter.

PATIENT POPULATION

Total of 143 diabetic eyes-27 with no diabetic retinopathy (DR), 47 with nonproliferative DR (NPDR), 51 with NPDR and diabetic macular edema (DME), and 18 with proliferative DR (PDR)-and 64 age-matched nondiabetic control eyes.

OBSERVATION PROCEDURES

Complete ophthalmologic examination and SS-OCT imaging. En face SS-OCT images of the choroidal vasculature were binarized.

MAIN OUTCOME MEASURES

CVD, calculated as the percent area occupied by choroidal vessels in the central macular region (6-mm-diameter circle centered on the fovea), and throughout the posterior pole (12 × 9 mm). The central macular CVV was calculated by multiplying the average CVD by macular area and choroidal thickness (obtained with SS-OCT automated software). Multilevel mixed linear models were performed for analyses.

RESULTS

Compared to controls (0.31 ± 0.07), central macular CVD was significantly decreased by 9% in eyes with NPDR + DME (0.28 ± 0.06; ß = -0.03, P = .02) and by 15% in PDR (0.26 ± 0.05; ß = -0.04, P = .01). The central macular CVV was significantly decreased by 19% in eyes with PDR (0.020 ± 0.005 mm3, ß = -0.01, P = .01) compared to controls (0.025 ± 0.01 mm3).

CONCLUSIONS

Choroidal vascular density and volume are significantly reduced in more advanced stages of diabetic retinopathy. New imaging modalities should allow further exploration of the contributions of choroidal vessel disease to diabetic eye disease pathogenesis, prognosis, and treatment response.

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.

Macular Choroidal Thickness May Be the Earliest Determiner to Detect the Onset of Diabetic Retinopathy in Patients with Prediabetes: A Prospective and Comparative Study

PURPOSE

To evaluate the macular and peripapillary choroidal thickness and retinal volume in prediabetes.

MATERIAL AND METHODS

This prospective comparative study included 53 patients with prediabetes and 53 age- and sex-matched healthy subjects. Only right eyes were selected. Choroidal thicknesses (CT) and retinal volume were measured by optical coherence tomography. Macular CT was measured at the seven points including macular center, 1, 2, and 3 mm distances along the temporal and nasal scans. Peripapillary CT was measured at the eight points of the optic disk area. Systemic and laboratory findings of the subjects were also recorded.

RESULTS

There were no significant differences in blood pressures, ocular findings including intraocular pressure, visual acuity, and refractive powers, and macular volumes between the two groups (p > 0.005). Macular and peripapillary CT at all measuring points, body mass index (BMI), fasting blood glucose (FBG), hemoglobinA1C, and lipid profile were significantly higher in prediabetic patients (p < 0.05). There was a significant positive correlation between all points of macular choroidal thicknesses with BMI, FBG, and hemoglobin A1C (p < 0.05).

CONCLUSION

Prediabetic factors including impaired FBG, increased hemoglobinA1C, and BMI are independent risk factors for increase in choroidal thickness. Increased macular choroidal thickness may be the earliest determiner to detect the onset of diabetic retinopathy in prediabetes.