Gender differences in central serous chorioretinopathy based on the new multimodal imaging classification.

PURPOSE: To analyse the gender-specific differences in central serous chorioretinopathy (CSCR) based on a new multimodal imaging classification system. METHOD: This was a retrospective, multicentric, longitudinal, observational study in patients with a diagnosis of unilateral or bilateral CSCR. Visual acuity outcomes and differences based on 'Simple' and 'Complex' CSCR were analysed. The occurrence of choroidal neovascularization (CNVM) and number of recurrences were also compared. Regression analysis was used to evaluate baseline predictors of final visual acuity. RESULTS: The study included 109 eyes of 58 patients (55 eyes of 28 female patients and 54 eyes of 30 male patients). Simple CSCR was seen in 8 (14.8%) eyes and 21 (38.2%) eyes in male and female groups respectively, while complex CSCR was seen in 46 (85.2%) eyes and 34 (61.8%) eyes in male and female groups respectively (p = 0.005). Recurrence was more commonly seen in males (34 eyes) than in females (23 eyes) (p = 0.03). Males (96.7%) were also significantly more likely to have a bilateral presentation (78.6% in females) (p = 0.03). Conversely, CNVM was more commonly seen in female eyes (8 eyes) than male eyes (4 eyes) (p = 0.23). On multivariable regression analysis, factors affecting reduced need for treatment were history of steroid use, good visual acuity at baseline, and simple CSCR. Factors affecting good final visual acuity were history of steroid use, good visual acuity at baseline, and younger age. CONCLUSION: Males tended to have complex CSCR and recurrence compared to the female sub-group, while females exhibited CNVM more commonly than males.

Multimodal Imaging Based Predictors for the Development of Choroidal Neovascularization in Patients with Central Serous Chorioretinopathy.

This study evaluated predictors for choroidal neovascularization (CNV) associated with central serous chorioretinopathy (CSCR) based on multimodal imaging. A retrospective multicenter chart review was conducted on 134 eyes of 132 consecutive patients with CSCR. Eyes were classified as per the multimodal imaging-based classification of CSCR at baseline into simple/complex CSCR and primary episode/recurrent/resolved CSCR. Baseline characteristics of CNV and predictors were evaluated with ANOVA. In 134 eyes with CSCR, 32.8% had CNV (n = 44) with 72.7% having complex CSCR (n = 32), 22.7% having simple (n = 10) and 4.5% having atypical (n = 2). Primary CSCR with CNV were older (58 vs. 47, p = 0.00003), with worse visual acuity (0.56 vs. 0.75, p = 0.01) and of longer duration (median 7 vs. 1, p = 0.0002) than those without CNV. Similarly, recurrent CSCR with CNV were older (61 vs. 52, p = 0.004) than those without CNV. Patients with complex CSCR were 2.72 times more likely to have CNV than patients with simple CSCR. In conclusion, CNV associated with CSCR was more likely in complex CSCR and older age of presentation. Both primary and recurrent CSCR are implicated in CNV development. Patients with complex CSCR were 2.72 times more likely to have CNV than patients with simple CSCR. Multimodal imaging-based classification of CSCR supports detailed analysis of associated CNV.

Ten-year follow-up and sequential evaluation of multifocal retinal pigment epithelium abnormalities in central serous chorioretinopathy.

PURPOSE: The study aims to analyze the 10-year outcomes in "simple" and "complex" central serous chorioretinopathy (CSCR) and to evaluate the longitudinal changes in multifocal retinal pigment epithelium (RPE) alterations. METHODS: This was a retrospective, multicentric, longitudinal, observational study in patients with a diagnosis of CSCR. Visual acuity outcomes and recurrence characteristics of simple and complex were analyzed. Changes in number of foci of RPE alterations from baseline to last visit were evaluated. RESULTS: Out of 235 eyes screened, the study included 67 eyes of 39 patients (32 males and 7 females) with CSCR (12 simple and 55 complex CSCR). A total of 17 (29.9%) eyes had a unifocal RPE alteration, while the remaining 50 had multifocal RPE alterations at baseline. In eyes with complex CSCR, the 10-year visual acuity was significantly worse (p < 0.001), more number of eyes required treatment (p = 0.03), higher number of RPE alterations were present at baseline and last follow-up (p < 0.001 for both), and number of recurrences were higher (p < 0.001), than simple CSCR. Focal collections of RPE alterations and leakage site corresponded to mid-phase hyper-fluorescent plaques (MPHP) in all eyes. On multivariate regression analysis, a larger area of RPE alteration was associated with a worser 10-year visual acuity (p = 0.004) and complex CSCR was associated with higher number of recurrence (p = 0.005). CONCLUSION: A different course of disease progression was seen in simple and complex CSCR. An evolution in foci of RPE alterations was seen, from a simple area of MPHP, to focal RPE alterations and finally to leakage.

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.

Factors affecting quality of life in keratoconus.

PURPOSE: To identify the factors affecting the quality of life (QoL) in adults with keratoconus, using the disease-specific Keratoconus Outcomes Research Questionnaire (KORQ). METHODS: In this cross-sectional study, 574 patients with keratoconus completed the 29-item KORQ (18-item activity limitations and 11-item symptoms subscales) and demographic information. Based on mean corneal curvature to grade keratoconus severity, participants were categorised into four groups: mild <48 dioptres [D]; moderate: 48 to 53 D; advanced: 54 to 55 D and severe: >55D. Rasch analysis was used to assess the psychometric properties and to score the KORQ. Multivariable regression was performed to determine the independent impact of age, sex, laterality, severity and duration of keratoconus, education, employment status and mode of treatment for keratoconus on activity limitations and symptoms. RESULTS: Mean (SD) age was 24.5 (5.1) years. 304 (53%), 160 (28%), 26 (4%) and 84 (15%) belonged to keratoconus groups 1, 2, 3 and 4, respectively. Rasch analysis demonstrated the 'activity limitations' and 'symptoms' KORQ subscales to possess good psychometric properties. Statistically significant associations were found between activity limitation score and the following measures: visual acuity (VA) in the better-seeing eye (r = -0.10, p = 0.01); VA in the worse-seeing eye (r = -0.09, p = 0.04) and ocular aberrations (r = -0.13, p = 0.008) in the worse-seeing eye. Statistically significant associations were also found between symptoms score and mean corneal curvature in the better-seeing eye (r = -0.10, p = 0.02). In regression models, female sex was associated with 21% worse symptom score than male (ß = -0.33, 95% CI, -0.09, -0.59, p = 0.01) and working people experienced clinically and statistically significantly greater trouble from symptoms compared to those not working (ß =0.44, 95% CI, 0.17, 0.70, p = 0.001). CONCLUSIONS: People with keratoconus have poorer QoL in terms of activity limitations if they have poorer VA and greater wavefront aberrations, and in terms of symptoms if they are female and employed.

Choroidal vasculature analysis in MEK inhibitor-associated retinopathy.

PURPOSE: To evaluate choroidal vascularity index (CVI) in patients developing mitogen-activated protein kinase kinase (MEK) inhibitor-associated retinopathy (MEKAR). METHODS: In this prospective observational study, extensive ophthalmic examination was performed, including enhanced-depth-imaging-optical coherence tomography (EDI-OCT). EDI-OCT scans of patients receiving Cobimetinib, taken at baseline and at MEKAR manifestation, were considered for choroid analysis. Choroidal thickness (CT) was measured on high-resolution b-scans passing through the fovea at three different locations. Same scans were therefore imported for binarization into a previously reported software and CVI was calculated as the ratio of luminal area (LA) to total choroid area (TCA). RESULTS: When compared to baseline, eyes with MEKAR (14 eyes) did not show significative CT variation in subfoveal region (p = 0,57), 750-µm-nasal to the fovea (p = 0,08) and 750-µm-temporal to the fovea (p = 0,07). Similarly, there were no statistically significant differences for TCA (p = 0.54), LA (p = 0.85), stromal area (SA) (p = 0.13), LA/SA (p = 0.34) and CVI (p = 0.47). Best-corrected visual acuity was significantly reduced at fluid accumulation when compared to baseline values (p = 0.03), with complete recovery after fluid resolution (p = 0.73). CONCLUSION: Multiple parameters reflecting the status of the choroid seemed not influenced by Cobimetinib administration. Retinal pigment epithelium toxic disfunction likely represents the crucial step in MEKAR pathogenesis.

In-vivo visualization of the photoreceptors using Spectralis High Magnification Module imaging in central serous chorioretinopathy.

PURPOSE: To visualize photoreceptors using the Spectralis High Magnification Module (HMM) in a case of central serous chorioretinopathy (CSCR) and to correlate the findings with those of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A). OBSERVATIONS: A 35-year-old Caucasian male presenting with chronic CSCR in the left eye was examined using HMM, OCT and OCT-A. The photoreceptors mosaic was assessed both in diseased and apparently uninvolved areas. A partial topographic correlation between the loss of photoreceptors on HMM images and an altered reflectivity of the photoreceptor layer on en-face OCT was noted. Interestingly, a correlation between the photoreceptor damage on HMM and choriocapillaris flow-void areas on OCT-A was seen. CONCLUSIONS AND IMPORTANCE: HMM is a non-invasive imaging modality, allowing the in-vivo visualization of photoreceptor damage in a diseased retina. A focal abnormal perfusion of the choriocapillaris might influence the integrity of the overlying photoreceptors in CSCR.

Real-world outcomes of anti-VEGF therapy in treatment-naïve neovascular age-related macular degeneration diagnosed on OCT angiography: the REVEAL study.

PURPOSE: To compare the 12 months visual and anatomical outcomes of treatment-naïve neovascular age-related macular degeneration (nAMD) patients diagnosed by optical coherence tomography angiography (OCT-A) compared with fluorescein angiography (FA)/indocyanine green angiography (ICGA), after anti-VEGF treatment in a real-world setting. METHODS: Monocentric, observational, parallel-group study of nAMD patients diagnosed with either FA/ICGA or non-invasive OCT-A methods. Patients were treated with a fixed dosing regimen of intravitreal ranibizumab or aflibercept and followed up for 12 months. Primary outcomes were the 12 months functional (BCVA) and anatomical (CST reduction) gains between the two groups. The stratification of BCVA and CST gains by type of neovascular lesion and by anti-VEGF treatment was also assessed. RESULTS: Seventy-two patients received FA/ICGA for the initial diagnosis of nAMD, while 73 received OCT-A. Overall, the mean BCVA gain at 12 months was 11.5 ± 9.6 letters. There were no statistically significant differences between the invasive and non-invasive imaging groups in BCVA gain (p = 0.87) or CST reduction (p = 0.76). No statistically significant outcome differences between different lesion types and the two drugs were observed. CONCLUSION: In a real-world setting, nAMD patients diagnosed with OCT-A showed meaningful improvements in visual and anatomical parameters during 12 months of treatment, without significant differences with those diagnosed by invasive modalities.

One year outcome and predictors of treatment outcome in central serous chorioretinopathy: Multimodal imaging based analysis.

PURPOSE: To evaluate the follow up and treatment outcome of central serous chorioretinopathy (CSCR) based on the new multimodal imaging-based classification and identify the predictors for anatomic and visual outcome. METHODS: Retrospective, multicentric study on 95 eyes diagnosed with CSCR and a follow up of at least 12 months were included. Eyes with macular neovascularization, atypical CSCR or any other disease were excluded. RESULTS: At the baseline, observation was advised to 70% eyes with simple CSCR whereas photodynamic therapy (PDT) was performed in 49% eyes with complex CSCR. Over the follow up, decrease in CMT was significantly higher in simple CSCR as compared to complex CSCR (P = 0.008) and the recurrences were significantly more in eyes with lower CMT at baseline (P = 0.0002). Median time of resolution of SRF was 3 months and 6 months in simple and complex CSCR respectively (P = 0.09). For the 12 months follow up, the median fluid free period was greater (P = 0.03) while number of interventions performed was lesser in eyes with simple CSCR as compared to complex CSCR (P = 0.006). Multiple regression analysis showed baseline best corrected visual acuity (BCVA) and baseline persistent SRF to be significantly predictive of BCVA and persistent SRF at 12 months (P < 0.0001, 0.04) respectively. CONCLUSIONS: Complex CSCR more often required PDT, was associated with shorter fluid free interval and longer time for SRF resolution. Baseline BCVA and persistent SRF were predictive of final visual and anatomical outcome. The new multimodal imaging based classification is helpful in establishing objective criteria for planning treatment approaches for CSCR.

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.

Central serous chorioretinopathy imaging biomarkers.

PURPOSE: To identify the factors predicting the visual and anatomical outcomes in eyes with central serous chorioretinopathy (CSCR) through 12 months. METHODS: Patients with diagnosis of CSCR, either acute or chronic, were included in this multicentric, retrospective study. Demographic factors; systemic risk factors; central macular thickness (CMT), subfoveal choroidal thickness (SFCT), linear extent of ellipsoid zone (EZ) and interdigitation zone damage on optical coherence tomography; details of leak on fluorescein angiography and indocyanine green angiography were included as predictors of anatomical and visual outcomes. Regression analysis was performed to correlate the changes in best corrected visual acuity (BCVA) and resolution of disease activity. RESULTS: A total of 231 eyes of 201 patients with a mean age (49.7±11.8 years) were analysed. A total of 97 and 134 eyes were classified as acute and chronic CSCR. BCVA (0.35±0.31 to 0.24±0.34; p<0.001), baseline optical coherence tomography (OCT) parameters including CMT (p<0.001), subretinal fluid (SRF) height (p<0.001) and SFCT (p=0.05) showed a significant change through 12 months. Multivariate regression analysis showed change in CMT (p≤0.01) and SRF height at baseline (p=0.05) as factors predictive of good visual outcome. Logistic regression analysis revealed changes in both CMT (p=0.009) and SFCT (p=0.01) through 12 months to correlate with the resolution of disease. CONCLUSION: OCT parameters such as changes in both CMT and SFCT along with subfoveal EZ damage can be predictive of disease resolution whereas changes in CMT and baseline SRF height correlate well with changes in BCVA through 12 months.

Novel noninvasive biomarkers of prodromal Alzheimer disease: The role of optical coherence tomography and optical coherence tomography-angiography.

BACKGROUND AND PURPOSE: A reduction of retinal thickness and an alteration of retinal perfusion have been found in Alzheimer disease (AD). Nowadays, retinal layers and retinal perfusion can be evaluated by means of noninvasive imaging techniques, namely, optical coherence tomography (OCT) and OCT-angiography (OCT-A). Here, we have compared the retinal thickness and the perfusion index, measured by means of OCT and OCT-A, in patients with mild cognitive impairment due to AD (MCI-AD) and in age- and sex-matched cognitively healthy controls. METHODS: Twenty-four MCI-AD patients and 13 control subjects were enrolled. MCI-AD patients underwent lumbar puncture; all of them showed a cerebrospinal fluid (CSF) profile compatible with AD. OCT was used for evaluating retinal volumes and thicknesses, whereas with OCT-A we measured fractal dimension (FD), vascular perfusion density (VPD), and vessel length density (VLD) of superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and choriocapillaris. The comparisons between groups were made after adjustment for age, diabetes, and hypertension. RESULTS: A significant reduction of SCP-VLD (p = 0.012), ICP-VPD (p = 0.015), ICP-VLD (p = 0.004), DCP-VPD (p = 0.012), and DCP-VLD (p = 0.009) was found in MCI-AD patients compared to controls. Conversely, FD was higher in MCI-AD than in controls (p = 0.044). CSF Aß42/total tau negatively correlated with FD (r = -0.51, p = 0.010). CONCLUSIONS: OCT-A might have a potential role in detecting new noninvasive biomarkers for early AD detection. Retinal VPD might identify amyloid angiopathy-related chronic injury, and FD could show early vessel recruitment as a compensative mechanism at disease onset. Further studies will be needed to confirm these findings.

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.

OCT-Angiography as a reliable prognostic tool in laser-treated proliferative diabetic retinopathy: The RENOCTA Study.

PURPOSE: To quantitatively assess retinal neovascularizations (RNVs) in proliferative diabetic retinopathy (PDR) before and after photocoagulative laser treatment (PLT) using Optical Coherence Tomography Angiography (OCT-A). METHODS: Consecutive patients with PDR were examined with fluorescein angiography (FA) and OCT-A before and after PLT. Baseline and after-treatment FA images were quantitatively analyzed to assess both the RNVs area and leakage area. On OCT-A RNVs area, vascular perfusion density (VPD), vessel length density (VLD) and fractal dimension were computed. VPD of the full-retina OCT-A underneath the RNV was determined to evaluate potential laser-induced changes in vascular perfusion. RESULTS: Fifteen eyes of 13 patients with PDR were enrolled. The mean area of the RNVs was 0.47 ± 0.50 mm2 in the baseline OCT-A and 0.32 ± 0.40 mm2 in the post-treatment assessment (p = 0.0002). The mean RNV VPD of RNV was 2% ± 4% in pre-treatment and 1% ± 1% for the post-treatment (p = 0.0001). The mean VLD of RNV was 7.26 ± 1.53 at baseline and 6.64 ± 1.65 in the post treatment (p = 0.0002). A significant difference in terms of mean RNVs area and VPD reduction between eyes that needed additional treatment and those that did not (~40% vs ~20%; p < 0.05), was observed. Mean VPD of full-retinal thickness OCT-angiogram was 55% ± 10% for the pre-treatment and 53% ± 8% for the post treatment scan (p = 0.02). CONCLUSION: The quantitative OCT-A assessment of laser-induced changes of RNVs can be a useful non-invasive approach for determining treatment efficacy. A reduction of RNVs area or VPD ⩾ 40% might reveal those eyes that won't require additional treatment. Retinal perfusion impairment seemed to progress independently from the treatment.

Functional correlation between choroidal and retinal vascularity in low-grade diabetic retinopathy.

AIMS: To perform an automated functional assessment of retinal and choroidal microvasculature in eyes with low-grade diabetic retinopathy (DR) using optical coherence tomography angiography (OCT-A) and to identify potential perfusion changes in case of early vascular damage. METHODS: This is an observational, case-control study of consecutive diabetic patients with level 20 DR severity scale score and age-matched healthy subjects. A prototypal OCT-angiography was used to obtain the OCT-angiograms of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) layer. A validated automated microstructural analysis provided data on SCP, DCP and CC vascular perfusion density (VPD). A comparative assessment between different vascular layers and different groups was performed. RESULTS: Twenty-nine diabetic patients (7 females, 24%) and 20 healthy controls were enrolled. VPD values were significantly lower in the DCP (25.1% vs. 26.5%; p = 0.04) and CC (71.2% vs. 86.6%; p = 0.0001) of diabetic patients compared with controls. A statistically significant negative linear correlation was reported between CC VPD and DCP VPD in diabetic patients; at the reverse, a positive linear correlation between the same parameters was noticed in controls. CONCLUSION: Retinal and choroidal vascular networks, although distinct entities, seem functionally interconnected: varying the degree of perfusion may be a mutual compensatory mechanism in response to an ischemic injury.