To investigate the macular quantitative parameters interchangeability of three different optical coherence tomography angiography (OCT-A) angiocubes (i.e., 3 × 3, 6 × 6, and 12 × 12 mm) on healthy ...subjects and patients affected by diabetic retinopathy (DR) and to assess the interrater reliability of such indices across the different scan protocols.
Retrospective study involving 20 eyes of healthy subjects and 20 eyes with DR. All eyes underwent swept-source OCT-A with 3 × 3-, 6 × 6-, and 12 × 12-mm angiocubes centered on the fovea. Foveal avascular zone (FAZ) area and vessel density on 3 × 3-, 6 × 6-, and 12 × 12-mm macular scans were calculated by three independent operators at all retina, superficial, deep, and choriocapillary vascular layers. Interchangeability and interrater reliabilities were estimated using intraclass correlation coefficient (ICC).
Interscan reproducibility of FAZ area was very strong (ICC > 0.85) at every plexus. On the contrary, vessel density values significantly varied across different scan sizes (ICC < 0.51). Intrascan interrater reliability was high for all retina and superficial FAZ areas, while it was satisfactory at deep capillary plexus only for 3 × 3-mm scan.
FAZ area at all plexuses is a robust parameter even if calculated on angiocubes with different size. However, interrater reliability is higher when measured in smaller scans. Conversely, vessel density results depend on the size of angiocube, although their interrater reliability is extremely high. Studies involving OCT-A should take into consideration that scan size may influence macular perfusion parameters and interrater reliability.
The effects of anti-vascular endothelial growth factor (anti-VEGF) agents on the native ocular vasculature are poorly understood. This pilot study aimed to assess short-term changes in retinal and ...choroidal perfusion after anti-VEGF treatment for neovascular exudative age-related macular degeneration (nAMD) using the relative flow volume (RFV) parameter derived from laser speckle flowgraphy. Ten treatment-naïve nAMD patients underwent measurements of mean, maximum, minimum, and differential RFV within a retinal arteriolar segment and a choroidal vessel segment outside the neovascular area. Measurement of retinal RFV (rRFV), choroidal RFV (cRFV), and subfoveal choroidal thickness (SCT) was repeated 9 and 35 days after a single anti-VEGF injection. The treatment caused a statistically significant decrease in the mean rRFV, mean cRFV, and SCT during the follow-up (p < 0.05). At the intermediate visit, the mean cRFV and SCT were - 17.6% and - 6.4% compared to baseline, respectively. However, at the final measurement, the mean cRFV was not different from the baseline value, which indicated waning of the anti-VEGF effect. In conclusion, a single anti-VEGF injection in treatment-naïve nAMD resulted in a decrease in retinal arteriolar and choroidal perfusion, according to the RFV parameter, which is a promising tool to simultaneously assess retinal and choroidal perfusion changes in response to anti-VEGF therapy.
The aim of this study was to explore the relative prevalence and clinical differences between age-related macular degeneration (AMD) and pachychoroid disease in patients older than 50 years with ...newly diagnosed exudative neovascular maculopathy, and also assess the rate of misdiagnosis between these two disorders. In this retrospective observational study, we reviewed data from patients 50 years of age and older with newly diagnosed treatment-naïve exudative macular neovascularization (MNV) secondary to AMD or pachychoroid disease. Of the 139 patients (139 eyes) who fulfilled the inclusion criteria, 35 patients were graded as being affected by pachychoroid disease complicated by exudative MNV and 104 subjects had neovascular AMD. Therefore, prevalence of pachychoroid disease complicated by exudative MNV was 25.2% (confidence interval-CI 18.2-33.2%). Mean ± SD age was 67.0 ± 8.8 years in the pachychoroid disease group and 80.6 ± 6.6 years in the neovascular AMD group (P < 0.0001). At baseline, BCVA was better in patients with pachychoroid disease complicated by exudative MNV (0.4 ± 0.3 LogMAR vs. 0.7 ± 0.5 LogMAR, P = 0.003). At the 1-year follow-up visit, BCVA was still better in patients with pachychoroid-associated MNV (0.34 ± 0.32 LogMAR vs. 0.59 ± 0.52 LogMAR; P = 0.005). In our study cohort, 19 patients were graded to be affected by pachychoroid disease complicated by exudative MNV even though a diagnosis of neovascular AMD was erroneously reported in their medical records at baseline. In conclusion, pachychoroid disease is a frequent cause of exudative MNV in aged patients with a high rate of misdiagnosis. A correct diagnosis may be important as these two disorders differ in terms of clinical characteristics and prognosis.
There is a lack of treatment aimed at the regression of reticular pseudodrusen (RPD) secondary to age-related macular degeneration (AMD). The aim of this prospective, pilot study is to evaluate the ...safety and short-term efficacy of subthreshold laser treatment (SLT) in patients affected by RPD secondary to dry AMD (dAMD). Twenty eyes of 20 patients (mean age 78.4 ± 6.8 years) with RPD secondary to dAMD were prospectively enrolled. All patients were treated in an extrafoveal area of 1.27 mm
using end-point management yellow subthreshold laser and followed for 3 months. Best-corrected visual acuity was 0.140 ± 0.09 LogMAR at the baseline and no changes were observed during the follow-up (p = 0.232). No significant worsening was disclosed before and after the treatment analyzing the macular sensitivity of the treated area (p = 0.152). No topical and/or systemic side effects were disclosed during the 3-month follow-up. The distribution among the RPD stages changed after the treatment (p < 0.001). In detail, in the treated area, we observed a significant increase in the number of Stage 1 RPD during the follow-up (p = 0.002), associated with a significant decrease of Stage 3 RPD (p = 0.020). Outer nuclear layer (ONL) thickness analysis showed a significant increase after the treatment associated with RPD regression (p = 0.001). End-point management SLT appears a safe treatment for RPD secondary to dAMD, showing short-term safety outcomes. Our results suggest that SLT could be effective in inducing a RPD regression in terms of RPD stage and ONL thickening.
Remarkable improvements in optical coherence tomography (OCT) technology have resulted in highly sophisticated, noninvasive machines allowing detailed and advanced morphological evaluation of all ...retinal and choroidal layers. Postproduction semiautomated imaging analysis with dedicated public-domain software allows precise quantitative analysis of binarized OCT images. In this regard, the choroidal vascularity index (CVI) is emerging as a new imaging tool for the measurement and analysis of the choroidal vascular system by quantifying both luminal and stromal choroidal components. Numerous reports have been published so far regarding CVI and its potential applications in healthy eyes as well as in the evaluation and management of several chorioretinal diseases. Current literature suggests that CVI has a lesser variability and is influenced by fewer physiologic factors as compared to choroidal thickness. It can be considered a relatively stable parameter for evaluating the changes in the choroidal vasculature. In this review, the principles and the applications of this advanced imaging modality for studying and understanding the contributing role of choroid in retinal and optic nerve diseases are discussed. Potential advances that may allow the widespread adoption of this tool in the routine clinical practice are also presented.
To develop a novel scoring system aiming at guiding the differential diagnosis between macular neovascularization secondary to pachychoroid disease (pMNV) and neovascular age-related macular ...degeneration (AMD) in patients aged 50 years and older. In this retrospective study performed at University Vita-Salute San Raffaele (Milan, Italy) and Créteil University Eye Clinic (Créteil, France), we enrolled patients 50 years of age and older, visited between January 2017 and January 2019, who were diagnosed with either treatment-naïve pMNV or neovascular AMD. At the time of diagnosis, all patients underwent a comprehensive ophthalmologic evaluation, spectral-domain optical coherence tomography, fluorescein angiography, indocyanine green angiography, and optical coherence tomography angiography. Univariate comparison between pMNV and neovascular AMD groups was performed to identify the main clinical predictors for pMNV. The selected predictors were taken into a binomial logistic regression and eventually served as the basis for the development of InCASEOf scoring system. Receiver operating characteristic (ROC) curves were used to study the model performance. Forty-eight right eyes from 48 patients with pMNV and 39 right eyes from 39 patients with neovascular AMD were considered in this study. Age (+ 2 points), sex (+ 2 points), choroidal thickness (+ 2 points), early pachyvessels (+ 2 points), and evidence of MNV at OCTA (+ 3 points) turned out to be predictors for pMNV. Four additional factors significant at univariate analysis were considered: type 2 and type 3 MNVs and presence of intraretinal fluid (- 0.5 points each), and presence of subretinal fluid (+ 0.5 points). InCASEOf scoring system was built with a high score of 11.5 points. The cutoff value of 6.5 showed good accuracy in separating pMNVs from neovascular AMDs. InCASEOf is a straightforward clinical scoring system, accessible to comprehensive ophthalmologists, with the purpose of enabling easy distinction and expert-like diagnosis of pMNV and neovascular AMD in patients aged 50 years or older.
Aim
Since its relevance on diagnosis and prognosis of diabetic retinopathy (DR), this review will examine a multimodal imaging approach to detect diabetic macular ischemia (DMI).
Methods
A PubMed ...engine search was carried out using the term “macular ischemia” paired with “diabetes,” and “diabetic macular ischemia” paired to “fluorescein angiography,” “ultra-wide field fluorescein angiography,” “optical coherence tomography angiography,” “octa,” “2D octa,” “ultra-wide field octa,” “3D octa,” “visual acuity.” All studies published in English up to October 2021 irrespective of their publication status were reviewed, and relevant publications were included in this review.
Results
Recently, new technologies have been proposed as an alternative to fluorescein angiography (FA), which is an actual diagnostic gold standard technique. Nowadays, optical coherence tomography angiography (OCTA) has emerged as the most promising and reliable procedure able to provide a qualitative and quantitative description of DMI. Newer three-dimensional (3D) OCTA approach will be discussed too. Moreover, we will discuss how OCTA might identify preclinical alterations before the onset of DR and allow prediction about the progression of disease.
Conclusion
OCTA has significantly expanded our knowledge on diabetic macular ischemia.
The aim of this study was to measure macular perfusion in patients with type 1 diabetes and no signs of diabetic retinopathy (DR) using volume rendered three-dimensional (3D) optical coherence ...tomography angiography (OCTA). We collected data from 35 patients with diabetes and no DR who had OCTA obtained. An additional control group of 35 eyes from 35 healthy subjects was included for comparison. OCTA volume data were processed with a previously presented algorithm in order to obtain the 3D vascular volume and 3D perfusion density. In order to weigh the contribution of different plexuses' impairment to volume rendered vascular perfusion, OCTA en face images were binarized in order to obtain two-dimensional (2D) perfusion density metrics. Mean ± SD age was 27.2 ± 10.2 years range 19-64 years in the diabetic group and 31.0 ± 11.4 years range 19-61 years in the control group (p = 0.145). The 3D vascular volume was 0.27 ± 0.05 mm
in the diabetic group and 0.29 ± 0.04 mm
in the control group (p = 0.020). The 3D perfusion density was 9.3 ± 1.6% and 10.3 ± 1.6% in diabetic patients and controls, respectively (p = 0.005). Using a 2D visualization, the perfusion density was lower in diabetic patients, but only at the deep vascular complex (DVC) level (38.9 ± 3.7% in diabetes and 41.0 ± 3.1% in controls, p = 0.001), while no differences were detected at the superficial capillary plexus (SCP) level (34.4 ± 3.1% and 34.3 ± 3.8% in the diabetic and healthy subjects, respectively, p = 0.899). In conclusion, eyes without signs of DR of patients with diabetes have a reduced volume rendered macular perfusion compared to control healthy eyes.
The introduction of optical coherence tomography angiography (OCTA) has remarkably expanded our knowledge of the ocular vascular alterations occurring in diabetes. In this article, a review of the ...prominent OCTA findings in diabetes is followed by a description of salient histological and anatomical features of microaneurysms, essential for the proper interpretation of in vivo imaging of these retinal vascular abnormalities. The recent employment of a three-dimensional (3D) visualization in OCTA imaging is also discussed. The latter imaging technique has granted a detailed characterization of microaneurysms in vivo.
PDF
