Pigment epithelial detachment composition indices (PEDCI) in neovascular age-related macular degeneration.

We provide an automated analysis of the pigment epithelial detachments (PEDs) in neovascular age-related macular degeneration (nAMD) and estimate areas of serous, neovascular, and fibrous tissues within PEDs. A retrospective analysis of high-definition spectral-domain OCT B-scans from 43 eyes of 37 patients with nAMD with presence of fibrovascular PED was done. PEDs were manually segmented and then filtered using 2D kernels to classify pixels within the PED as serous, neovascular, or fibrous. A set of PED composition indices were calculated on a per-image basis using relative PED area of serous (PEDCI-S), neovascular (PEDCI-N), and fibrous (PEDCI-F) tissue. Accuracy of segmentation and classification within the PED were graded in masked fashion. Mean overall intra-observer repeatability and inter-observer reproducibility were 0.86 ± 0.07 and 0.86 ± 0.03 respectively using intraclass correlations. The mean graded scores were 96.99 ± 8.18, 92.12 ± 7.97, 91.48 ± 8.93, and 92.29 ± 8.97 for segmentation, serous, neovascular, and fibrous respectively. Mean (range) PEDCI-S, PEDCI-N, and PEDCI-F were 0.253 (0-0.952), 0.554 (0-1), and 0.193 (0-0.693). A kernel-based image processing approach demonstrates potential for approximating PED composition. Evaluating follow up changes during nAMD treatment with respect to PEDCI would be useful for further clinical applications.

Choroidal vascularity profile in diabetic eyes using wide field optical coherence tomography.

PURPOSE: To report the wide-field choroidal vascularity up to the mid-equator area in diabetic retinopathy (DR) subjects using wide-field optical coherence tomography (WF-OCT). DESIGN: Prospective, Cross-sectional study. PARTICIPANTS: Forty-seven eyes of 25 DR subjects. METHODS: WF-OCT images (55 degrees) were obtained using Spectralis HRA + OCT (Heidelberg Engineering, Germany) in extremes of gazes in all quadrants and manual montages were created to obtain wide field images up to mid equator. A previously reported semi-automated algorithm was used to calculate choroidal vascularity profile (CVI). Regression analysis was performed to identify the factors influencing CVI. RESULTS: Forty-seven eyes from 25 patients were enrolled in the study. The mean age was 68.4 ± 10.6 years. The refractive error (spherical equivalent) ranged from -2.25 to +3.75 diopters. Most common DR grade among study subjects was moderate NPDR (29.41%) and 74.5% eyes had diabetic macular edema (DME). The mean CVI in the macular area (58.29 ± 3.63) was significantly lower than in any of the other fundus areas (all p ˂ 0.01). The maximum CVI was seen in the nasal region (66.60 ± 5.61), followed by temporal (65.69 ± 3.81), superior (65.01 ± 4.87), and inferior (63.80 ± 5.42). The vertical macular area had the least coefficient of variation (CV) of CVI (0.06) while the inferior quadrant had the highest CV (0.08). CONCLUSION: The current study describes the CVI profile on WF-OCT in DR eyes up to mid-equator. The significant increase of the CVI compared to healthy subjects and its significant regional variations introduce this novel quantitative parameter as a reliable biomarker of the diabetes-induced choroidal microangiopathy.

Long-term retinal changes in progressive geographic atrophy.

BACKGROUND: Age-related macular degeneration (AMD) is one of the leading causes of blindness with loss of retinal layers over long term. We aim to evaluate these changes in eyes with progressive non-exudative AMD with geographic atrophy (GA). METHODS: This retrospective study included patients with GA with a minimum of 4 years follow up. Retinal layers on spectral domain optical coherence tomography (SD-OCT) were segmented based on their reflectivity patterns using validated semi-automated segmentation algorithm. The thickness of the segmented retinal layers was measured. Horizontal length of GA at baseline and last follow-up were also measured. Regression analysis was performed to correlate changes in RPE layer thickness with other retinal layers and the length of GA on OCT. RESULTS: A total of 351-line scans including 17 foveal scans showing presence of GA at final visit that is, a total of 2457 retinal layer bands were analyzed. Outer nuclear layer (ONL) (p = 0.02), outer segment layers (OSL) (p = 0.01), and retinal pigment epithelium (RPE) (p = 0.01) showed a statistically significant variation between baseline and final visit. Regression analysis showed the change in ONL (r = 0.72; p = 0.01) and OSL (r = 0.93, p < 0.01) correlated significantly with change in RPE thickness whereas rest of the layers failed to show significant correlation. CONCLUSION: Outer retinal layers (ONL and OSL) show more significant and widespread changes in retinal thickness and correlated most significantly with RPE thickness changes in eyes with GA due to AMD. Assessment of various retinal layer bands can be used as surrogate quantitative parameters to study eyes with GA.

Wide-field optical coherence tomography imaging in diabetic retinopathy.

PURPOSE: To report the individual retinal layer thicknesses up to mid-equator in patients with diabetic retinopathy (DR) using Spectralis (Heidelberg Engineering, Heidelberg, Germany) wide-field optical coherence tomography (OCT). METHODS: Retinal layers were segmented using a custom designed semi-automated algorithm, where reference points were marked by the examiner to enable software to automatically compute the thickness values of each retinal sublayer at an interval of 1 mm from reference points. The values of individual retinal thicknesses in eyes with varying severity of DR were compared with the values of healthy subjects. Generalized estimating equation was performed to compensate for inclusion of both eyes of patients. RESULTS: A total of 64 patients (119 eyes) with a mean age of 68.97 ± 10.27 years were included. Overall, ganglion cell layer (GCL)/ inner plexiform layer (IPL) complex (-31.67 microns, p < 0.001), outer plexiform layer (-6.78 microns, p = 0.002) and photoreceptor layer (-22.90 microns, p < 0.001) showed significant thinning, while outer nuclear layer thickening ( + 68.19 microns, <0.001) was noted in eyes with DM compared to healthy subjects. Thickness changes were significantly more in the macular segment compared to nasal and temporal segments. GCL/ IPL complex and photoreceptor layers were found to be significantly thin in all grades of DR. CONCLUSION: Retinal thicknesses vary significantly in patients with diabetic retinopathy and understanding patterns of these changes across different segments of the wide field OCT may help better elucidate the natural progression of the disease in terms of retinal anatomy.

En Face Choroidal Vascularity in Both Eyes of Patients with Unilateral Central Serous Chorioretinopathy.

The aim of this study was to evaluate the choroidal vascularity analyzing en face optical coherence tomography (OCT) images in patients with unilateral central serous chorioretinopathy (CSC). We retrospectively evaluated 40 eyes of 20 CSC patients and 20 eyes of 10 gender- and age-matched healthy individuals. The sample consisted of: (1) CSC affected eyes; (2) unaffected fellow eyes; (3) healthy eyes. Multiple cross-sectional enhanced depth imaging OCT scans were obtained to create a volume scan. En face scans of the whole choroid were obtained at 5µm intervals and were binarized to calculate the choroidal vascularity index (CVI). The latter, defined as the proportion of the luminal area to the total choroidal area, was calculated at the level of choriocapillaris, superficial, medium and deep layers. No significant differences between choriocapillaris, superficial, medium and deep CVI were found in both eyes of CSC patients, whereas a significant different trend of changes was found in healthy eyes. Nevertheless, the en face CVI shows no difference between affected fellow and healthy eyes. In conclusion, CSC-affected eyes and fellow eyes showed a similar vascular architecture, with no statistical difference between all choroidal layers.

Water-Drinking Test in Central Serous Chorioretinopathy.

PURPOSE: To evaluate choroidal changes in central serous chorioretinopathy (CSCR) patients after water-drinking test (WDT). METHODS: This prospective study included treatment-naïve acute and chronic CSCR eyes and healthy controls. Intraocular pressure and optical coherence tomography measurements with choroidal vascular index (CVI) measurements were done at baseline. Patients were asked to drink 1 L of water, and tests were repeated at 15, 30, and 45 min. RESULTS: Fifty-six eyes from 42 patients were enrolled. Choroidal area, luminal area, and stromal area were higher at baseline in eyes with acute CSCR compared to healthy controls. Chronic CSCR eyes showed an increase in choroidal area and stromal area and a decrease in the luminal area at 15 min. There was a significant decrease in CVI at 30 and 45 min in chronic CSCR and CVI at 45 min in fellow eyes of acute CSCR. Repeated-measures analysis of variance (ANOVA) showed a significant change in central macular thickness in acute CSCR, choroidal thickness in fellow eyes of acute CSCR, stromal area, and total choroidal area in chronic CSCR. Mixed model ANOVA showed that the change in various choroidal parameters seen had no interaction with the eye type. CONCLUSION: Although change in various parameters was seen in acute CSCR, chronic CSCR, and fellow eyes of acute CSCR following WDT, the change was not significantly different among the groups.

Choroidal Vascularity Map in Unilateral Central Serous Chorioretinopathy: A Comparison with Fellow and Healthy Eyes.

BACKGROUND: To map the choroidal vascularity index and compare two eyes in patients with unilateral central serous chorioretinopathy (CSCR). METHODS: This was a retrospective, observational study performed in patients with unilateral CSCR. Choroidal thickness (CT) and Choroidal vascularity index (CVI) were measured and mapped in various zones according to the early treatment diabetic retinopathy (ETDRS) grid. RESULTS: A total of 20 CSCR patients (20 study and 20 fellow eyes) were included in the study. Outer nasal region CT was seen to be significantly lower than central CT (p = 0.042) and inner nasal CT (p = 0.007); outer ring CT was significantly less than central (p = 0.04) and inner ring (p = 0.01) CT in CSCR eyes. On potting all the CVI values against the corresponding CT values, a positive correlation was seen in CSCR eyes (r = 0.54, p < 0.01), which was slightly weaker in fellow eyes (r = 0.3, p < 0.01) and a negative correlation was seen in healthy eyes (r = -0.262, p < 0.01). CONCLUSIONS: Correlation between CVI and CT was altered in CSCR eyes as compared to fellow and normal eyes with increasing CVI towards the center of the macula and superiorly in CSCR eyes.

Evaluation of Explainable Deep Learning Methods for Ophthalmic Diagnosis.

BACKGROUND: The lack of explanations for the decisions made by deep learning algorithms has hampered their acceptance by the clinical community despite highly accurate results on multiple problems. Attribution methods explaining deep learning models have been tested on medical imaging problems. The performance of various attribution methods has been compared for models trained on standard machine learning datasets but not on medical images. In this study, we performed a comparative analysis to determine the method with the best explanations for retinal OCT diagnosis. METHODS: A well-known deep learning model, Inception-v3 was trained to diagnose 3 retinal diseases - choroidal neovascularization (CNV), diabetic macular edema (DME), and drusen. The explanations from 13 different attribution methods were rated by a panel of 14 clinicians for clinical significance. Feedback was obtained from the clinicians regarding the current and future scope of such methods. RESULTS: An attribution method based on Taylor series expansion, called Deep Taylor, was rated the highest by clinicians with a median rating of 3.85/5. It was followed by Guided backpropagation (GBP), and SHapley Additive exPlanations (SHAP). CONCLUSION: Explanations from the top methods were able to highlight the structures for each disease - fluid accumulation for CNV, the boundaries of edema for DME, and bumpy areas of retinal pigment epithelium (RPE) for drusen. The most suitable method for a specific medical diagnosis task may be different from the one considered best for conventional tasks. Overall, there was a high degree of acceptance from the clinicians surveyed in the study.

Correlation of sectoral choroidal vascularity with angiographic leakage in central serous chorioretinopathy.

PURPOSE: To correlate sectoral choroidal vascularity with angiographic leakage in eyes with central serous chorioretinopathy (CSCR). METHODS: This was a retrospective, cross-sectional study including patients with active CSCR. Multimodal imaging including fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) were performed to identify leakage site and obtain choroidal measurements, respectively. An automated algorithm was used to perform shadow compensation, choroidal boundary localization and binarization, three (3-D) dimensional mapping, and early treatment of diabetic retinopathy study (ETDRS) grid based choroidal quantification that is, choroidal thickness (CT) and choroidal vascularity index (CVI). Nested analysis of variance (ANOVA) was performed to compare CT and CVI in different sectors. RESULTS: Thirty-two eyes with active CSCR were analyzed. CT values varied significantly among the sectors (range, 450.27-482.63 µm; p = 0.005) and rings (range, 459.71-480.45 µm; p < 0.001), however, CVI failed to show significant variation among various segments (sectors, rings, and quadrants; range, 0.53-0.54; all p values > 0.05). Among 25 leaking spots in 25 different sectors, 12 (48%) had an increased CT compared to the overall CT whereas only 24% had increased CVI compared to overall CVI. Mean CT and CVI of the sectors with leakage (427.1 ± 81.1 µm; 0.51 ± 0.05) and remaining sectors without leakage (411.3 ± 73.9 µm; 0.53 ± 0.04) were not statistically different (p = 0.48; p = 0.12, respectively). CONCLUSION: Though CT varied in different segments and increased CT corresponded to leakage points on FFA in 48% of eyes, CVI changes were more diffusely spread and local changes in CVI were not predictive of leakage location in eyes with active CSCR.

Imaging in inherited retinal disorders.

Inherited retinal diseases, which results from mutations in over 260 identified genes, affect more than 2 million people globally. The diseases mostly cause severe vision loss in young working population and have severe impact on social economic status of the population. Advances in retinal imaging techniques along with developments in gene identification and cell biology techniques have yielded to a better understanding of the genetic and biochemical mechanisms causing these diseases. Retinal imaging along with through ophthalmological examination is essential to make an accurate diagnosis, to decrease the burden of unneccessary anciliary tests and to select the potential patients that can get benefit from the gene treatment. The purpose of the review is to yield an update on inherited retinal diseases by highlighting microstructural changes in retina and to summarize the retinal changes detected by currently available multimodal imaging techniques.

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.

En-face choroidal vascularity in central serous chorioretinopathy.

PURPOSE: To evaluate the choroidal vascularity index of eyes for acute and chronic central serous chorioretinopathy patients using swept-source optical coherence tomography generated en-face scans. METHODS: This was a retrospective study, in which slabs of en-face optical coherence tomography scans, at 5 µm intervals, spanning from the retina to choroid, were binarized using a validated algorithm to calculate choroidal vascularity index. The choroidal vascularity index was defined as the ratio between the choroidal vascular luminal area and the total choroidal area. Choroidal vascularity index was calculated for all the slabs of every subject in both the groups. RESULTS: A total of 30 eyes for each acute and chronic central serous chorioretinopathy groups were recruited. The mean choroidal vascularity index of the acute group was 45.21% ± 2.25% at the choriocapillaris, which increased to the maximal value of 48.35% ± 2.06% at 75% depth of the choroidal thickness and 45.31% ± 3.27% at the choroidoscleral interface; whereas for the chronic group, the mean choroidal vascularity index was 44.76% ± 2.60% at the choriocapillaris, which maximized at 50% choroidal depth (48.70% ± 1.32%) and then returned to 45.41% ± 6.02% at the choroidoscleral interface. CONCLUSION: For both groups, the choroidal vascularity index increased from choriocapillaris to maximum values at mid-choroid and returned to almost the choriocapillaris value at the choroidoscleral interface.

Effects of different mydriatics on the choroidal vascularity in healthy subjects.

PURPOSE: To evaluate choroidal vasculature changes after the instillation of mydriatic parasympatholytic and sympathomimetic agents in healthy subjects. METHODS: A total of 95 healthy subjects were enrolled in this prospective, randomized comparative study. Study participants were divided into three different groups depending on the drug to be administered: tropicamide (1%) group (n = 31), tropicamide (0.5%) + phenylephrine (10%) group (n = 30) and control group receiving artificial tears (n = 34). All participants underwent a complete ophthalmological examination including best corrected visual acuity, refractive status and axial length. Subfoveal choroidal thickness (CT), total choroidal area (TCA), luminal and stromal choroidal area (LCA and SCA) and choroidal vascularity index (CVI) were measured before and after eye drops instillation. RESULTS: All the baseline characteristics were matched between the three groups (all P > 0.05). Before the mydriatic instillation, there were no significant differences of CT, TCA, LA, SCA, and CVI among the three groups (all P > 0.05). After drug administration, CT, TCA, LCA, SCA, and CVI did not show any significant change as well (respectively, P = 0.265; P = 0.483; 0.573; P = 0.405 and P = 0.708). CONCLUSIONS: Instillation of mydriatic eye drops did not induce significant changes of the choroidal vasculature, suggesting that their use do not alter CT and CVI evaluation.

Wide-field individual retinal layer thickness in healthy eyes.

PURPOSE: To report the individual retinal layer thickness in healthy subjects using wide-field optical coherence tomography. METHODS: This was a prospective, cross-sectional study involving healthy subjects. A custom-designed semiautomated segmentation algorithm was used to split the retinal layers in seven bands, and individual retinal layer thicknesses were measured in horizontal (nasal, macular, and temporal segments) and vertical meridians (superior, macular, and inferior segments). The variation in retinal thickness was analyzed in different segments at an interval of 1 mm from reference points. Regression analysis was performed to identify the factors affecting retinal thickness. RESULTS: Twenty eyes of 20 healthy subjects with mean age of 28.9 ± 6.3 years were analyzed. Overall, nasal and superior segments (mean ± standard deviation: 279.6 ± 17.0 and 234.4 ± 19.2 µm) had maximum and minimum retinal thicknesses, respectively. A total of seven bands were delineated in each optical coherence tomography b scan in each segment. Retinal nerve fiber layer was thickest immediately nasal to optic disk margin in horizontal scan (72.4 ± 32.4 µm) and near the vascular arcades in vertical meridian. Outer plexiform layer, external limiting membrane-ellipsoid zone and interdigitation zone-retinal pigment epithelium-Bruch's complex showed significant variation in both horizontal and vertical meridians (all p values <0.05). Macular segment in both meridians showed the highest coefficient of variation. Age was the only significant factor affecting retinal thickness in multiple regression analysis (p = 0.001). CONCLUSIONS: Wide-field optical coherence tomography shows significant regional variation in overall and individual retinal layer thicknesses in macular and peripheral areas in healthy eyes with the highest variation in macular segment.

Wide-field choroidal vascular analysis in central serous chorioretinopathy.

PURPOSE: To report the wide-field choroidal vessel analysis in central serous chrorioretinopathy (CSCR) and their fellow eyes. METHODS: Wide-field optical coherence tomography (WF-OCT) images (55°) were obtained using Spectralis HRA + OCT (Heidelberg Engineering, Germany) in extremes of gazes in all quadrants and manual montages were created to obtain wide field images up to equator. Choroidal thickness (CT), large choroidal vessel layer thickness (LCVT), and choroidal vascularity index (CVI) were calculated in macular segment (twice the disc to fovea distance) and all four quadrants. Regression analysis was performed to identify the factors influencing CVI. RESULTS: Thirty-one patients of CSCR including 39 eyes of CSCR (32 chronic, 7 acute) and 23 fellow eyes were analyzed. CT and LCVT were significantly higher in submacular choroid than all extramacular segments in both CSCR and fellow eyes (all p values <0.01). CVI varied significantly in different segments in horizontal (p < 0.01 in both) and vertical meridian (p < 0.01 and p = 0.01 respectively) in CSCR and fellow eyes. Both CSCR and fellow eyes had highest CVI in nasal segment with minimum CVI in macular segment. Age (p = 0.85), gender (p = 0.39), chronicity of the disease (acute vs chronic, p = 0.57), axial length (p = 0.67), SBP (p = 0.81), and DBP (p = 0.94) were not significantly correlated to CVI. CONCLUSION: CVI shows significant regional variation with macular segment showing the lowest CVI whereas nasal segments have highest CVI in both CSCR and their fellow eyes. On the contrary, submacular segment has highest CT and LCVT with taper towards periphery in both CSCR and fellow eyes.

Biomarkers for central serous chorioretinopathy.

Central serous chorioretinopathy (CSCR) is a common chorioretinal disease characterized by serous retinal detachment that most commonly involves the macular region. Although the natural history of the acute form shows a self-limiting course, a significant number of patients suffer from recurrent episodes leading to chronic disease, often leaving patients with residual visual impairment. Visual morbidity is often worsened by a delay in the diagnosis due to the incorrect understanding of the particular biomarkers of the disease. The aim of this review is to provide clinical understanding of the biomarkers of CSCR with an emphasis on the most recent findings in patient demographics, risk factors, clinical imaging findings, and management options. Patients with these biomarkers, age 30-44 years, male gender, increased stress levels, hypercortisolism (endogenous and exogenous exposures), sleep disturbance, pregnancy, and genetic predisposition have increased susceptibility to CSCR. Also, biomarkers on optical coherence tomography (OCT) such as choroidal thickness (CT) and choroidal vascularity index (CVI) showed good diagnostic and prognostic significance in the management of CSCR. There are nonspecific features of CSCR on OCT and OCT angiography such as choroidal neovascularization, photoreceptor alteration/cone density loss, and flat irregular pigment epithelium detachment. We described rare complications of CSCR such as cystoid macular edema (CME) and cystoid macular degeneration (CMD). Patients with CME recovered some vision when treated with anti-vascular endothelial growth factors (anti-VEGFs). Patients with CMD had irreversible macular damage even after treatment with anti-VEGFs.

Peripapillary choroidal vascularity quantification and characterization in healthy individuals.

INTRODUCTION: To characterize the peripapillary choroidal vasculature in healthy individuals using the choroidal vascular index (CVI), a previously established more robust tool of measurement of choroidal vascularity than choroidal thickness. METHODS: The peripapillary choroid in healthy individuals was analyzed using optical coherence tomography. OCT B-scan were analyzed using automated binarization, a previously established technique. This separates the choroidal layer into the stromal and vascular areas. Choroidal vascular index (CVI), the vascular area/total area, was computed for each image over the macula and the peripapillary area of the optic disc. Regression analysis and generalized estimating equation (GEE) were used to analyze various demographics, and CVI in the macula and each quadrant of the optic disc. RESULTS: Fifty eight eyes of 29 healthy individuals were included. Mean age was 42±17 years. Average CVI at the macula was 0.583. Average peripapillary CVI was 0.643 (nasal), 0.598 (temporal), 0.621 (superior) and 0.623 (inferior). Regression analysis of variables demonstrated there was no significant relationship between the demographic variables and macular CVI. However, the analysis demonstrated age and CVI of the peripapillary area were significantly correlated. Further stratification revealed significantly higher CVI in the optic disc in subjects over 45. CONCLUSION: Peripapillary CVI in all quadrants is higher than macular CVI in all age groups. CVI significantly increases after the age of 45 in the peripapillary area but not macular area. This suggests that stromal area decline is greater than the decline of the luminal area in the choroid at the peripapillary area as age increases.

Choroidal Anatomic Alterations After Photodynamic Therapy for Chronic Central Serous Chorioretinopathy: A Multicenter Study.

PURPOSE: To study the early anatomic choroidal alterations in eyes with chronic central serous chorioretinopathy (CSCR) undergoing photodynamic therapy (PDT). DESIGN: Multicenter retrospective cohort study. METHODS: A total of 77 patients and 81 eyes with chronic CSCR treated with PDT and 64 untreated fellow eyes were evaluated. Central macular thickness (CMT) and choroidal features including subfoveal choroidal thickness (SFCT), total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were analyzed. Choroidal vascularity index (CVI) was calculated in all study eyes at baseline and at 1- and 3-months post-PDT. RESULTS: In eyes receiving PDT, Snellen visual acuity (VA) significantly improved at months 1 and 3 (P < .001). CMT and SFCT showed a significant reduction from baseline at months 1 and 3 (P < .001), whereas TCA and LCA showed a significant decrease only at the 1-month follow-up visit. Baseline mean TCA and LCA were 2.30 ± 1.41 mm2 and 1.23 ± 0.73 mm2, respectively, and decreased to 2.07 ± 1.21 mm2 and 1.08 ± 0.63 mm2 at the 1-month follow-up visit, respectively (P = .01). No significant changes were recorded for SCA and CVI. In the fellow eye group, VA, CMT, and all choroidal parameters showed no differences between baseline and any follow-up visits (all P > .05). CONCLUSIONS: After PDT for chronic CSCR we observed sustained reductions in CMT and SFCT, while reductions in TCA and LCA were only noted at the 1-month follow-up interval. These choroidal parameters may provide additional quantitative biomarkers to evaluate the anatomic response to therapy but await further prospective validation.

Analysis of Choroidal Vascularity Index in Keratoconus Patients Using Swept-Source Optical Coherence Tomography-Based Binarization Techniques.

PURPOSE: To analyse the vascular density of the choroid in a keratoconus (KC) population using swept-source optical coherence tomography (SS-OCT). METHODS: Prospective, noninterventional study that analysed 97 eyes from 52 KC patients and 145 eyes from 89 healthy controls. The sample was divided in four different age groups. Inclusion criteria were topographic diagnosis of KC using Pentacam, axial length shorter than 26 mm, good quality of the images, and no other systemic or ocular diseases. A 12 mm horizontal single-line SS-OCT b-scan was performed to create a choroidal thickness (CT) profile. Validated automated segmentation and binarization were used in order to analyse choroidal, stromal, and vascular areas. RESULTS: The percentage of choroidal vascularity (vascular area/total area) was 56.6% in KC patients vs. 49.4% in controls. Aged-adjusted choroidal, stromal, and vascular areas and corrected choroidal percentage of vascularity are statistically increased in KC patients when compared with healthy controls (p < 0.001). All these parameters show a decreasing trend with age. Both stromal and vascular areas were thicker in KC patients (p < 0.001). CONCLUSIONS: Choroidal, stromal, and vascular areas and corrected choroidal percentage of vascularity are statistically increased in KC patients when compared with healthy controls. All these parameters tend to decrease with age.

Association of reduced inner retinal thicknesses with chronic kidney disease.

BACKGROUND: Tissue derived biomarkers may offer utility as indicators of accumulated damage. Reduced thickness of retinal neuronal tissue and the vascular choroid have previously been associated with vascular damage and diabetes. We evaluated associations between retinal thickness, retinal microvascular and choroidal measures, and renal function in a population with a high burden of comorbidity. METHODS: Participants were recruited from nuclear cardiology or renal medicine clinics. Retinal and choroidal thickness were measured from spectral-domain optical coherence tomograms. Retinal microvascular parameters were assessed from digital fundus photographs using a semi-automated software package. MAIN OUTCOME MEASURE: Chronic kidney disease (CKD) categorised as: CKD stages 1-2, eGFR ≥60 ml/min/1.73m2; CKD stage 3, eGFR 30-59 ml/min/1.73m2, and CKD stages 4-5, eGFR ≤29 ml/min/1.73m2. RESULTS: Participants (n = 241) had a mean age of 65 years and a mean eGFR of 66.9 ml/min/1.73m2. Thirty-nine % of the cohort had diabetes and 27% were using diuretics. Thinning of the inner retina and changes to its microvascular blood supply were associated with lower eGFR and CKD stages 4 and 5, while no associations were found between the outer retinal layers or their choroidal blood supply and CKD of any stage. These associations remained following adjustment for age, mean arterial blood pressure, diabetes status, low-density lipoprotein, body mass index, and sex. CONCLUSIONS: Inner retinal thinning and retinal microvascular variation is associated with advanced CKD (stages 4 & 5) independent of important confounding factors, but not with earlier stage CKD (stage 3) and, therefore, its utility as a biomarker for early CKD is not supported in this study.