Long-term predictors of anti-VEGF treatment response in patients with neovascularization secondary to CSCR: a longitudinal study.

PURPOSE: To identify the baseline predictors of anti-VEGF treatment response at 3 years in patients affected by choroidal neovascularization (CNV) secondary to central serous chorioretinopathy (CSCR). METHODS: In this retrospective longitudinal study, medical records of patients diagnosed with CNV secondary to CSCR and treated using anti-VEGF injections between April 2015 and May 2020 were reviewed. The potential qualitative and quantitative predictors of treatment response were identified or measured based on the multimodal imaging examination available for each patient at the baseline, including structural OCT, fluorescein angiography (FA), indocyanine green angiography (ICGA), and OCT-angiography (OCT-A). Univariate and multivariate analyses were performed. RESULTS: Twenty-nine eyes from 29 patients affected by CNV complicating CSCR were included in the study. At the end of the 3-year follow-up, the mean BCVA was 20/50 Snellen equivalent (0.38 ± 0.36 LogMAR), and no significant difference with baseline BCVA (0.37 ± 0.29 LogMAR) was found (p = 0.9). Twenty out of 29 eyes (69%) had active lesions at the end of the follow-up. At multivariate analysis, none of the included features was independently associated with the 3-year BCVA outcome. Pigment epithelium detachment (PED) height (ß = 0.017, p = 0.028) and outer limiting membrane (OLM) preservation at the fovea (ß = -5.637, p = 0.026) were independently associated with the CNV activity at 3 years. CONCLUSION: PED height and OLM obliteration at the fovea might be considered baseline predictors of lesion activity at 3-year follow-up in patients with CNV secondary to CSCR treated with anti-VEGF therapy.

NONEXUDATIVE INTRARETINAL FLUID IN INTERMEDIATE AGE-RELATED MACULAR DEGENERATION.

BACKGROUND: To describe the occurrence of nonexudative intraretinal fluid (IRF) in intermediate age-related macular degeneration. METHODS: A retrospective study was designed to include consecutive cases with intermediate age-related macular degeneration associated with IRF. A multimodal imaging approach was used to confirm diagnosis of IRF in intermediate age-related macular degeneration. Multimodal imaging included color fundus photograph, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, optical coherence tomography, and optical coherence tomography angiography. RESULTS: Ten eyes of 10 patients (2 male and 8 female patients, ages 68-80 years) showing IRF in intermediate age-related macular degeneration were included in the study. The mean best-corrected visual acuity was 20/40 Snellen equivalent. Multimodal imaging including fluorescein angiography/indocyanine green angiography and optical coherence tomography demonstrated the absence of macular neovascularization in all cases; optical coherence tomography-angiography did not detect any abnormal flow signal associated with IRF. Seven of 10 patients developed IRF in correspondence of pigment epithelium detachment. Three of 10 patients presented IRF in correspondence of an area of nascent geographic atrophy. CONCLUSION: Nonexudative intraretinal fluid in intermediate age-related macular degeneration is a novel, distinctive feature that is characterized by the presence of IRF with no evidence of macular neovascular lesions. The authors described different phenotypes of IRF in intermediate age-related macular degeneration. The definite diagnosis of this condition requires further studies with thorough application of multimodal imaging.

Artificial intelligence in age-related macular degeneration: state of the art and recent updates.

Age related macular degeneration (AMD) represents a leading cause of vision loss and it is expected to affect 288 million people by 2040. During the last decade, machine learning technologies have shown great potential to revolutionize clinical management of AMD and support research for a better understanding of the disease. The aim of this review is to provide a panoramic description of all the applications of AI to AMD management and screening that have been analyzed in recent past literature. Deep learning (DL) can be effectively used to diagnose AMD, to predict short term risk of exudation and need for injections within the next 2 years. Moreover, DL technology has the potential to customize anti-VEGF treatment choice with a higher accuracy than expert human experts. In addition, accurate prediction of VA response to treatment can be provided to the patients with the use of ML models, which could considerably increase patients' compliance to treatment in favorable cases. Lastly, AI, especially in the form of DL, can effectively predict conversion to GA in 12 months and also suggest new biomarkers of conversion with an innovative reverse engineering approach.

Individual vs. combined imaging modalities for diagnosing neovascular central serous chorioretinopathy.

PURPOSE: To assess the diagnostic accuracy of individual and combined imaging modalities compared with multimodal imaging for the detection of choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC). METHODS: We analyzed patients with CSC with and without CNV who had indocyanine green angiography (ICGA), structural optical coherence tomography (OCT), and OCT angiography (OCTA) obtained on the same day. The presence of CNV was determined using multimodal imaging by a senior retina specialist (i.e., diagnostic reference). Individual and combined (i.e., ICGA + structural OCT) imaging modalities were then graded by two expert readers for the presence of CNV. Sensitivity, specificity, positive (PPV), and negative (NPV) predictive values were computed for individual and combined imaging modalities relative to the diagnostic reference. RESULTS: CNV was detected in 17 eyes in 17 out of 33 CSC patients according to the reference standard. Using ICGA, the identification of CNV had a sensitivity of 66.7%, specificity of 66.7%, PPV of 70.6%, and NPV of 62.5%. Structural OCT had the following diagnostic accuracy values: 83.3% of sensitivity, 53.3% of specificity, 68.1% of PPV, and 72.7% of NPV. Using OCTA, CNV was graded to be present with a sensitivity of 77.8%, specificity of 86.7%, PPV of 87.5%, and NPV of 76.5%. The combination of ICGA and structural OCT granted the identification of CNV with a sensitivity of 83.3%, specificity of 86.7%, PPV of 88.2%, and NPV of 81.3%. CONCLUSIONS: OCTA has an elevated diagnostic accuracy in identifying CSC-associated CNV, though a combination of ICGA and structural OCT has a comparable diagnostic efficiency.

ARTIFICIAL INTELLIGENCE'S ROLE IN DIFFERENTIATING THE ORIGIN FOR SUBRETINAL BLEEDING IN PATHOLOGIC MYOPIA.

PURPOSE: To identify salient imaging features to support human-based differential diagnosis between subretinal hemorrhage (SH) due to choroidal neovascularization (CNV) onset and SH without CNV (simple bleeding [SB]) in pathologic myopia eyes using a machine learning (ML)-based step-wise approach. METHODS: Four different methods for feature extraction were applied: GradCAM visualization, reverse engineering, image processing, and human graders' measurements. GradCAM was performed on a deep learning model derived from Inception-ResNet-v2 trained with OCT B-scan images. Reverse engineering consisted of merging U-Net architecture with a deconvolutional network. Image processing consisted of the application of a local adaptive threshold. Available OCT B-scan images were divided in two groups: the first group was classified by graders before knowing the results of feature extraction and the second (different images) was classified after familiarization with the results of feature extraction. RESULTS: Forty-seven and 37 eyes were included in the CNV group and the simple bleeding group, respectively. Choroidal neovascularization eyes showed higher baseline central macular thickness ( P = 0.036). Image processing evidenced in CNV eyes an inhomogeneity of the subretinal material and an interruption of the Bruch membrane at the margins of the SH area. Graders' classification performance improved from an accuracy of 76.9% without guidance to 83.3% with the guidance of the three methods ( P  = 0.02). Deep learning accuracy in the task was 86.0%. CONCLUSION: Artificial intelligence helps identifying imaging biomarkers suggestive of CNV in the context of SH in myopia, improving human ability to perform differential diagnosis on unprocessed baseline OCT B-scan images. Deep learning can accurately distinguish between the two causes of SH.

Neovascular age-related macular degeneration: advancement in retinal imaging builds a bridge between histopathology and clinical findings.

PURPOSE: To provide a review of the salient histological and imaging features in neovascular age-related macular degeneration (AMD) that will be integrated in order to have a better comprehension of the pathogenesis and clinical aspects of this disease. METHODS: A literature review of histology and imaging features in neovascular AMD was conducted. RESULTS: Histology has granted a detailed characterization of neovascular AMD ex vivo. In details, histological features in these eyes have offered important insights into the pathogenesis of neovascular AMD. In addition, histology donated a detailed characterization of the different types of macular neovascularization (MNV) that may complicate AMD. The introduction of optical coherence tomography angiography (OCTA) has enormously amplified our knowledge of neovascular AMD through in vivo assessment of the anatomical and pathological characteristics of this disease. New insights elucidating the morphological features of the choriocapillaris confirmed that this vascular structure plays a crucial role in the pathogenesis of neovascular AMD. OCTA also offered a detailed visualization of MNV complicating neovascular AMD. CONCLUSIONS: New imaging technologies offer a remarkable chance to build a bridge between histology and clinical findings in neovascular AMD.

INNER AND OUTER CHOROIDAL CHANGES IN THE FELLOW EYE OF PATIENTS WITH UNILATERAL CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To quantitatively evaluate the inner and outer choroidal changes in the fellow eyes of patients with unilateral central serous chorioretinopathy (CSC). METHODS: We analyzed data from patients with a diagnosis of unilateral CSC who had structural optical coherence tomography (OCT) and swept-source OCT angiography obtained. An additional group of age-matched healthy patients was included for comparison. The main outcome measures were: (1) choriocapillaris flow deficits' quantitative metrics; (2) choroidal luminal (LCA) and stromal (SCA) areas; and (3) choroidal vascularity index. RESULTS: Fellow unaffected eyes from 60 patients with unilateral CSC and 30 healthy subjects were included in the analysis. Mean ± SD age was 47.5 ± 9.9 years in the unilateral CSC group and 50.7 ± 10.8 years in the control group (P = 0.410). In the structural OCT assessment, both the LCA and SCA were increased in the unilateral CSC group (0.33 ± 0.11 and 0.29 ± 0.10 mm2) compared with healthy controls (0.28 ± 0.08 and 0.27 ± 0.05 mm2), although only differences in LCA reached a statistical significance (P = 0.041 and P = 0.286 for LCA and SCA, respectively). The choroidal vascularity index was higher in CSC patients (53.7 ± 3.6 and 50.9 ± 5.5%, P = 0.045). In the OCT angiography evaluation, the choriocapillaris flow deficits' percentage and number were increased in those patients affected by unilateral CSC. In multiple regressions, the strongest association with choriocapillaris percentage of flow deficits was with the presence of pachychoroid pigment epitheliopathy signs in the study eye (P < 0.0001). CONCLUSION: Our results corroborate the hypothesis that inner and outer choroidal changes affect both eyes of patients with unilateral disease.

CHOROIDAL VASCULARITY INDEX IS ASSOCIATED WITH GEOGRAPHIC ATROPHY PROGRESSION.

PURPOSE: To investigate the correlation between choroidal vascularity index and the enlargement of geographic atrophy (GA) lesion secondary to age-related macular degeneration during the 2-year follow-up. METHODS: In this longitudinal observational study, 26 eyes (26 patients, mean age 75.7 ± 8.8 years) affected by GA were included. Choroidal vascularity index was calculated in the subfoveal 3000-µm area. The main outcome measure included correlation analysis between baseline choroidal vascularity index and the rate of GA enlargement. RESULTS: During the 2-year follow-up, the mean GA area increased from 6.99 ± 5.28 mm2 to 10.69 ± 6.61 mm2(P < 0.001), accounting for a growth rate of 0.35 ± 0.20 and 0.31 ± 0.17 mm/year after the square root transformation in the first and second year of follow-up, respectively. Stromal choroidal area significantly decreased during the 2-year follow-up (P = 0.002). Interestingly, there was a significant correlation between the baseline choroidal vascularity index and the rate of GA enlargement (r=-0.432, P = 0.027) and between stromal choroidal area and the rate of GA enlargement (r = 0.422, P = 0.032). No other significant relationship was disclosed among choroidal parameters with the rate of GA enlargement. CONCLUSION: Choroidal vascularity index impairment is strictly related to the rate of GA enlargement during the 1-year and 2-year follow-up in patients affected by GA. For this reason, choroidal vascularity index could be considered a predictor of GA progression in the clinical setting, and it could be considered as a new potential biomarker in the efficacy evaluation of new GA interventions.

USING THREE-DIMENSIONAL OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY METRICS IMPROVES REPEATABILITY ON QUANTIFICATION OF ISCHEMIA IN EYES WITH DIABETIC MACULAR EDEMA.

PURPOSE: Two-dimensional (2D) optical coherence tomography angiography (OCTA) is known to be prone to segmentation errors, especially in pathologic eyes. Therefore, our aim was to systematically compare intrasession repeatability between repeated scans for 2D and three-dimensional (3D) OCTA metrics in quantifying retinal perfusion in eyes with diabetic macular edema. METHODS: Diabetic patients with diabetic retinopathy and diabetic macular edema who had two consecutive OCTA imaging scans obtained during the same visit were retrospectively included. A previously validated algorithm was applied to OCTA volume data to measure the 3D vascular volume and perfusion density. Optical coherence tomography angiography en face images were also processed to obtain 2D perfusion density metrics. RESULTS: Twenty patients (20 eyes) with diabetic retinopathy and diabetic macular edema were included. The intraclass correlation coefficient ranged from 0.591 to 0.824 for 2D OCTA metrics and from 0.935 to 0.967 for 3D OCTA metrics. Therefore, compared with the 2D OCTA analysis, the intraclass correlation coefficients of the 3D OCTA analysis were higher (without overlapping of the 95% confidential intervals). Similarly, the coefficient of variation (ranging from 2.2 to 4.2 for 2D OCTA metrics and from 1.9 to 2.0 for 3D OCTA metrics) indicated that the 3D OCTA-based quantifications had the highest interscan intrasession agreements. Differences in interscan 2D OCTA metrics' values were associated with average macular volume. CONCLUSION: Three-dimensional OCTA metrics have higher values of intrasession repeatability, as compared with 2D OCTA metrics. The latter finding seems to be related to the high rate of segmentation errors occurring in diabetic macular edema eyes.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ASSESSMENT OF THE DIABETIC MACULA: A Comparison Study Among Different Algorithms.

PURPOSE: To assess the impact of histogram adjustments and binarization thresholding selection on quantitative measurements of diabetic macular ischemia using optical coherence tomography angiography (OCTA). METHODS: Patients with diabetic retinopathy (DR) who had swept-source OCTA imaging obtained were enrolled. An additional group of 15 healthy control subjects was included for comparison. Previously used brightness/contrast changes and binarization thresholds were applied to original OCTA images to obtain and compare different binarized images. Qualitative and quantitative comparisons were performed. RESULTS: Thirty patients with DR (30 eyes) were included in the analysis. Fifteen eyes displayed the presence of diabetic macular edema. Qualitative grading revealed that binarized images obtained using a global threshold had better quality compared with local or multistep thresholds. The "median" filter was most frequently graded as the histogram adjustment resulting in binarized images with best quality. In the quantitative analysis, local thresholds tended to generate higher values of measured metrics. Differences in OCTA metrics between global and local thresholds were associated with presence of diabetic macular edema and signal strength index value. In the comparison between healthy and DR eyes, differences in OCTA metrics were significantly affected by binarization threshold selection. CONCLUSION: Quantitative OCTA parameters may be significantly influenced by strategies to quantify macular perfusion. Image quality and presence of macular edema can significantly impact OCTA-derived quantitative vascular measurements and differences between global and local binarization thresholds. These findings highlight the importance of consistent strategies to reliably generate quantitative OCTA metrics in patients with DR.

PHOTORECEPTOR OUTER SEGMENT IS EXPANDED IN THE FELLOW EYE OF PATIENTS WITH UNILATERAL CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To quantitatively evaluate the photoreceptor structural changes in the fellow unaffected eyes of patients with unilateral central serous chorioretinopathy (CSC). METHODS: This is a retrospective cross-sectional study. We analyzed data from patients with diagnosis of unilateral CSC, as based on clinical examination and multimodal imaging, who had structural optical coherence tomography obtained. An additional group of age-matched healthy patients was included for comparison. Main outcome measures were as follows: (1) the foveal photoreceptor outer segment lateral surface and (2) the foveal choroidal thickness. RESULTS: One hundred and sixty fellow unaffected eyes of 160 unilateral CSC patients and 50 age-matched controls (50 eyes) were included. The mean ± SD age was 51.6 ± 11.1 years (range 28-80 years) in the unilateral CSC group and 52.8 ± 10.8 years (range 31-74 years) in the control group (P = 0.511). The foveal photoreceptor outer segment lateral surface was significantly increased in the unaffected eyes with CSC in the fellow eye (0.068 ± 0.007 mm2) as compared with control eyes (0.060 ± 0.005 mm2, P < 0.0001). The mean ± SD foveal choroidal thickness was 368.0 ± 105.7 µm in the unilateral CSC group and 302.9 ± 92.2 µm in control patients (P < 0.0001). In the Pearson correlation test, the photoreceptor outer segment lateral surface correlated with the choroidal thickness in the CSC group (R = 0.166, P = 0.016) but not in the control group (R = -0.025, P = 0.864). CONCLUSION: Our results corroborate the hypothesis that retinal and choroidal changes affect both eyes of patients with acute/history of unilateral disease. These structural changes could be intended as an imaging evidence of reduced photoreceptor outer segment turnover secondary to retinal pigment epithelium and choroid dysfunction.

Multimodal Imaging to Detect in vivo Responses to Aflibercept Therapy in a Mouse Model of Type 3 Neovascularization.

PURPOSE: The aim of this study was to characterize the response to aflibercept in a mouse model of type 3 neovascularization, the neoretinal vascularization (NRV) 2 mouse line. METHODS: Twelve NRV2 mice were assigned to one of the following groups: (1) 6 mice were injected with aflibercept 3 µg/g at postnatal day (P) 15 ("aflibercept" group), and (2) the remaining 6 mice did not receive any treatment ("placebo" group). The mice were examined at P30 and P44. RESULTS: The NRV mice's retinas were characterized by regions of depigmentation that were topographically associated with hyperfluorescent lesions seen on fluorescein angiography (FA) images. On optical coherence tomography images, intraretinal neovascularizations were visualized as hyperreflective lesions mainly localized within the outer plexiform and outer nuclear layers. The average number of intraretinal neovascular lesions visualized on FA at P30 was 5.0 ± 2.2 in the aflibercept group and 20.7 ± 2.4 in the placebo group (p < 0.0001). At P44, the average number of intraretinal lesions was still lower in the aflibercept group, although this difference was not statistically significant (p = 0.088). CONCLUSION: Aflibercept therapy was effective in inhibiting pathologic angiogenesis in the NRV2 mouse model. However, the successive treatment washout resulted in an increase in the number of lesions.

Short-term outcomes of patients with neovascular exudative AMD: the effect of COVID-19 pandemic.

PURPOSE: To estimate the impact of delayed care during the coronavirus disease 2019 (COVID-19) pandemic on the outcomes of patients with neovascular age-related macular degeneration (AMD). METHODS: Consecutive patients with diagnosis of neovascular AMD were consecutively enrolled between March 9, 2020, and June 12, 2020, (during and immediately after the Italian COVID-19 quarantine). During the inclusion (or pandemic) visit (V0), patients received a complete ophthalmologic evaluation, including optical coherence tomography (OCT). Best-corrected visual acuity (BCVA) and OCT findings from the two preceding visits (V-1 and V-2) were compared with data at V0. RESULTS: One-hundred patients (112 eyes) were enrolled in this study. The time interval between following visits was 110.7 ± 37.5 days within V0 and V-1 and 80.8 ± 39.7 days within V-1 and V-2, respectively (P < 0.0001). BCVA was statistically worse at the V0 visit as compared with the immediately preceding (V-1) visit (0.50 ± 0.43 LogMAR and 0.45 ± 0.38 LogMAR at the V0 and V-1 visits, respectively; P = 0.046). On structural OCT, 91 out of 112 (81.2%) neovascular AMD eyes displayed the evidence of exudative disease activity at the V0 visit, while 77 (68.7%) eyes exhibited signs of exudation at the V-1 visit (P = 0.022). No differences in terms of BCVA and OCT findings were detected between the V-1 and V-2 visits. In multiple regression analysis, the difference in BCVA between V0 and V-1 visits was significantly associated with the interval time within these two visits (P = 0.026). CONCLUSION: The COVID-19 pandemic-related postponement in patient care proved to be significantly associated with worse short-term outcomes in these patients.

Impact of COVID-19 on outpatient visits and intravitreal treatments in a referral retina unit: let's be ready for a plausible "rebound effect".

PURPOSE: To quantify the shrinking in outpatient and intravitreal injections' volumes in a tertiary referral retina unit secondary to virus causing coronavirus disease 2019 (COVID-19). METHODS: In this retrospective cross-sectional study, we reviewed the charts of all patients who had a visit at a medical retina referral center during the Italian quarantine (from 9th of March 2020 to 3rd of May 2020). Number and characteristics of these data were compared with data from the same period in 2019 (from 9th of March 2019 to 3rd of May 2019). RESULTS: In the 2019 study period, there were 303 patients attending clinic (150 males, 153 females). In the 2020 study period, patients decreased to 75 (48 males, 27 females; P = 0.022 comparing gender prevalence between the two periods) with an overall reduction of 75.2%. Mean ± SD age was 71.4 ± 14.3 years (range 25-93 years) in the 2019 study period and 66.7 ± 13.1 years (range 32-91 years) in the 2020 study period (P = 0.005). The largest drop in outpatient volume was recorded in AMD patients (- 79.9%). Regarding the intravitreal treatments, there were 1252 injections in the 2019 period and 583 injections in the 2020 period (- 53.6% in injections). The drop in intravitreal treatments was larger in patients with posterior uveitis, retinal vein occlusion, and diabetes (- 85.7%, - 61.9%, and - 59.6%, respectively). CONCLUSION: The volume of outpatient visits and intravitreal injections declined during the COVID-19 quarantine. The short- and long-term impacts are that routine in-person visits and intravitreal injections are expected to increase after the quarantine and, even more, after the pandemic.

Multimodal imaging characterization of peripheral drusen.

PURPOSE: To provide an integrate multimodal imaging characterization of peripheral drusen in the eyes with and without macular signs of age-related macular degeneration (AMD) and to analyze their association with macular findings. METHODS: In this retrospective, cross-sectional study, subjects with peripheral drusen were imaged with the Optos (Optos PLC, Dunfermline, Scotland, UK) and Spectralis devices to obtain referenced spectral domain optical coherence tomography (SD-OCT) images. Two experienced graders independently graded the ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) images for the presence of peripheral drusen and analyzed peripheral druse features using OCT. Main outcome measures included quantitative and qualitative assessment of peripheral drusen. RESULTS: Fifty-seven eyes (30 subjects) were included in the analysis. Mean ± SD age was 77.6 ± 9.2 years (range 54-97 years). On pseudocolor images, graders identified the presence of drusen in all the enrolled eyes (Cohen's kappa was 1.0). On FAF images, Cohen's kappa was 0.71. In the topographical assessment, peripheral drusen were detected in 23 cases in the temporal region, in 40 cases in the nasal region, in 40 cases in the inferior region, and in 42 cases in the superior region. On SD-OCT images, peripheral drusen had a high reflective core in 97.1% of cases, while remaining drusen were characterized by a low reflective core. The macula was affected by early/intermediate AMD in 23 eyes (43.5%) and late AMD in 6 eyes (10.5%). CONCLUSIONS: We provided an integrate multimodal imaging assessment of peripheral drusen in the eyes with and without AMD. Peripheral drusen were characterized by distinguished features that may suggest that these lesions constitute a distinct disease, rather than representing an expansion of AMD.

RETINAL ARTERIAL DILATION IS IMPAIRED IN EYES WITH DRUSEN AND RETICULAR PSEUDODRUSEN.

PURPOSE: To analyze static characteristics and dynamic functionality of retinal vessels in eyes with drusen and reticular pseudodrusen (RPD) using dynamic vessel analyzer. METHODS: Patients with clinical diagnosis of isolated RPD or medium-large drusen and healthy controls were enrolled in the study between July 2016 and May 2018. Participants underwent complete ophthalmologic examination, including enhanced depth imaging structural optical coherence tomography, dynamic retinal vessel analysis, and static retinal vessel analysis. RESULTS: Twenty-eight eyes of 23 patients with drusen (9 men, mean age 77 ± 6 years), 22 eyes of 16 patients with RPD (7 men, mean age: 76 ± 6 years), and 22 eyes of 22 control subjects (11 men, mean age of 75 ± 6 years) were enrolled. Static retinal vessel analysis did not show any significant difference between the three groups for the central retinal artery equivalent (P = 0.11), the central retinal vein equivalent (P = 0.27), and the arteriovenous ratio (P = 0.30). Dynamic vessel analysis showed significantly reduced arterial dilation in eyes with drusen (P = 0.0001) and RPD (P = 0.015) compared with control subjects. No significant difference was seen between drusen and RPD groups (P = 0.32). Dynamic vessel analysis of retinal veins showed no differences between the three groups (P = 0.10). CONCLUSION: Dynamic vessel analysis in eyes with drusen and RPD revealed an impaired retinal arterial dilation in response to flicker light stimulation, which further supports the relationship between cardiovascular risk and age-related macular degeneration.

Laser photocoagulation as treatment of non-exudative age-related macular degeneration: state-of-the-art and future perspectives.

PURPOSE: To give an updated review of laser approaches to non-exudative age-related macular degeneration (AMD). METHODS: PubMed and Medline database searches were carried out using the terms "laser" and "photocoagulation" associated with "age-related macular degeneration", and latest publications up to May 2017 have been reviewed. Moreover, the design of an ongoing single-center, non-randomized, phase I-II, pilot study, the PASCAL-GA trial, coordinated by F. Bandello, MD and G. Querques, MD from the IRCCS Ospedale San Raffaele, is described. RESULTS: Either standard or subthreshold laser strategies have been tried to induce regression of distinct phenotypes of AMD, as reticular pseudodrusen (RPD), nascent geographic atrophy (nGA), and drusen-associated geographic atrophy (DAGA), with heterogeneous results. The aim of the PASCAL-GA protocol is to assess if subthreshold laser can restore the retinal pigment epithelium function in eyes with RPD and nGA offering a protective effect against extensive GA. CONCLUSIONS: New-generation medical and surgical approaches, including subthreshold laser photocoagulation, may have some success in downstaging AMD.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN GEOGRAPHIC ATROPHY.

PURPOSE: To analyze choriocapillaris (CC) vessel density (VD) around geographic atrophy (GA) secondary to non-neovascular dry age-related macular degeneration using optical coherence tomography angiography. METHODS: We compared CC VD surrounding GA margin (500 µm radius) with control CC (outside GA margin) in a consecutive series of GA patients presenting between August 2016 and February 2017 at the Medical Retina and Imaging Unit of University Vita-Salute, IRCCS Ospedale San Raffaele in Milan. Images were obtained through thresholding and binarization. We also compared the CC VD in a sample area of 500 µm × 500 µm surrounding GA margin rated as hyperautofluorescent on fundus autofluorescence to a similar area rated as isoautofluorescent. RESULTS: Fifty eyes of 29 patients (19 women and 10 men; mean age 77 ± 6 years) with mean GA area of 9.43 ± 5.08 mm and mean subfoveal choroidal thickness of 164 ± 73 µm were included. Choriocapillaris VD surrounding GA margin as detected by optical coherence tomography angiography revealed a significant impairment compared with control CC outside GA margin (0.317 ± 0.083 vs. 0.461 ± 0.054, P < 0.001), which was even greater in patients with foveal involvement (P = 0.013). Furthermore, mean VD in hyperautofluorescent areas was significantly lower compared with isoautofluorescent areas (0.242 ± 0.112 vs. 0.327 ± 0.130, P = 0.001). A positive correlation was disclosed between VD surrounding GA margin and subfoveal choroidal thickness (r = 0.332, P = 0.019). CONCLUSION: Optical coherence tomography angiography discloses CC impairment surrounding GA margin. Such CC impairment at GA margin seems to precede retinal pigment epithelium alterations at fundus autofluorescence. Optical coherence tomography angiography could be a new valuable tool for detecting CC alterations and to evaluate potential therapeutic responses in clinical studies.

ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY VERSUS PHOTODYNAMIC THERAPY IN THE TREATMENT OF CHOROIDAL NEOVASCULARIZATION SECONDARY TO CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To evaluate the efficacy of photodynamic therapy (PDT) compared with intravitreal vascular endothelial growth factor (VEGF) inhibitors alone or combined with PDT in the treatment of choroidal neovascularization (CNV) secondary to chronic central serous chorioretinopathy (CSCR). METHODS: Retrospective study of a consecutive series of 34 white patients (34 eyes) with angiographic evidence of choroidal neovascularization secondary to chronic central serous chorioretinopathy, divided into two groups followed for at least 12 months: 16 were treated with full fluence PDT (PDT group) and 18 with vascular endothelial growth factor inhibitors (intravitreal [IVT] group). RESULTS: In the PDT group, mean best-corrected visual acuity (BCVA) was 20/40 (0.30 ± 0.69 logMAR) at baseline and did not change after 12 months (20/40; 0.30 ± 0.49 logMAR [P = 0.49]). In the IVT group mean, best-corrected visual acuity was 20/40 (0.30 ± 0.69 logMAR) at baseline and also did not change at the 12-month follow-up (20/32; 0.20 ± 0.49 logMAR [P = 0.20]). There was no statistically significant difference between the two groups in terms of best-corrected visual acuity. A statistical significance difference was found in central macular thickness between the two groups with a better reduction of the thickening in the PDT group (P = 0.05); moreover, indocyanine green angiography analysis revealed that 50% of the polypoidal lesions were closed after PDT and 25% of the polypoidal lesions disappeared after anti-vascular endothelial growth factor therapy at 12-month follow-up. CONCLUSION: PDT and IVT inhibitors alone or combined show similar clinical effects in chronic central serous chorioretinopathy eyes with choroidal neovascularization.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FEATURES OF ANGIOID STREAKS.

PURPOSE: To analyze the optical coherence tomography angiography features of eyes affected with angioid streaks (AS) and to evaluate their ability to predict choroidal neovascularization (CNV) activity. METHODS: Angioid streaks were individuated from a pool of consecutive patients. Eyes with and without CNV were evaluated by multimodal imaging. RESULTS: Thirty-eight eyes of 19 consecutive patients diagnosed with AS were included. Thirty of 38 eyes with CNV and 8 of 38 eyes without CNV were included. In the majority of cases, CNV showed on optical coherence tomography angiography tangled appearance always associated with signs of neovascular inactivity on multimodal imaging (100%-0%, inactive-active, respectively). Choroidal neovascularization cases showing interlacing appearance were often associated with signs of neovascular activity on multimodal imaging (71.4%-28.6%, active-inactive, respectively). Optical coherence tomography angiography revealed a total of 27 AS, of which 20 appeared as a choriocapillary rarefaction, and in 7 AS, optical coherence tomography angiography choriocapillary segmentation revealed an irregular vascular network, possibly representing fibrovascular tissue over the crack-like breaks in Bruch membrane. CONCLUSION: Optical coherence tomography angiography is a noninvasive tool to detect the presence of CNV secondary to AS and to evaluate CNV activity. Optical coherence tomography angiography is able to add a novel element to the multimodal imaging characterization of AS.