[Clinical applications of OCT angiography]

[Analysis of adverse drug reactions (ADR) in fluorescein angiography (FAG) and indocyanine green angiography (ICGA) and indications before and during the COVID-19 pandemic at a university eye hospital]

BACKGROUND

This study was an analysis of fluorescein angiography (FAG) and indocyanine green angiography (ICGA) at a university eye hospital. The primary objective of the study was to analyze adverse drug reactions (ADRs) and their severity (mild, moderate, severe). The secondary objective was to investigate the indications of FAG and ICGA before and during the COVID-19 pandemic.

METHODS

A retrospective analysis of all FAG and ICGA at the University Eye Hospital in Würzburg from January 2016 to the end of December 2021 was performed. The ADRs, gender, age, examination time points and indications were evaluated. The ADRs were classified into mild, moderate, and severe, following the definition of Kornblau et al. [1] RESULTS: A total of 4900 examinations from 4193 patients were analyzed. An FAG was performed slightly more frequently in men (54.8%) than in women (45.2%) and the mean age was 63.2 ± 16.9 years (median: 65 years). The ADRs occurred in only 1.65% of all FAG, of which 1.27% were mild and 0.39% were moderate. No severe ADRs occurred. The most common ADR was nausea at 59.26%. No ADR occurred in ICGA. The annual number of FAGs averaged 816.7 ± 91.1 and was relatively constant throughout the period except for a significantly reduced number in 2016 (compared with 2018, 2019, and 2021). The most common indication for FAG was venous retinal occlusion at 22.93% (N = 774), showing a significant increase in 2021 compared to 2018-2020. An ICGA was performed in 4.18% of cases, with the most common indication being uveitis at 31.82% (N = 63).

CONCLUSION

Compared to other studies very few ADRs occurred and no life-threatening ADR occurred in any case. Venous retinal occlusions were very common indications for FAG, probably due to the frequent need for repeated examinations in this condition. Briefly, during the first lockdown (18 March-8 May 2020), a decrease in angiographies was observed, but over a longer period, no significant differences were seen compared with the prepandemic period.

Optical coherence tomography angiography parameters after cataract surgery

PURPOSE

To evaluate the changes in macular blood flow after cataract surgery through optical coherence tomography angiography (OCT-A).

METHODS

In this prospective case series, 50 patients who underwent uncomplicated cataract surgery by the resident were included. OCT-A images and complete ocular examinations were performed at baseline, 1 and 3 months postoperatively. The changes in OCT-A parameters including foveal avascular zone (FAZ) area, vessel density (VD) of superficial and deep plexus, and central macular thickness were assessed before and after surgery. Cataract grading, intraocular inflammation, and duration of surgery were analyzed.

RESULTS

FAZ was significantly reduced from 0.36 ± 0.13 mm2 at baseline to 0.32 ± 0.12 mm2 at month 1 (P < 0.001) and this reduction continued until month 3. In the superficial layer, vessel density of the fovea, parafovea, and whole image significantly increased from 13.9 ± 6.8, 43.7 ± 4.7, and 43.2 ± 4.4 at baseline to 18.4 ± 7.9, 45.7 ± 4.9, and 44.9 ± 4.5 at month 1. The increase in the vessel density of the deep layer was similar to the superficial layer. Accordingly, CMT at the fovea was significantly increased from 240.5 ± 21.99 µm at baseline to 253.1 ± 23.2 microns at month 1 (P < 0.001) and the increase significantly continued and reached 259.5 ± 22.6 µm at month 3 (P < 0.001). Accordingly, the FAZ area significantly reduced one month postoperatively. In regression analysis, CMT changes positively correlated with cataract grading. FAZ area negatively correlated with intraocular inflammation on the first postoperative day.

CONCLUSION

The present study shows that CMT and vessel density of the macula significantly increase after uncomplicated cataract surgery, while the FAZ area reduces. Postoperative inflammation could be the possible explanation for the findings of this study.

Investigation of the short-term effects of water drinking test on the eye using Optical Coherence Tomography Angiography in young healthy male subjects

PURPOSE

To evaluate the acute effects of the water drinking test (WDT) on the eye using optical coherence tomography angiography (OCTA) on healthy young male subjects.

METHODS

The study included 25 eyes of 25 male subjects. Selected parameters of the retinal vasculature were measured, including macular flow indices, foveal avascular zone, and vessel densities (VDs) of the macula using OCTA. The measurements were taken on the first day without drinking water at 0 min, 30 min and 60 min, then repeated on the second day before drinking water at 0 min, and after drinking water at 30 min and 60 min. The Paired Samples t-test and repeated measures One-way analysis of variance test were used in the statistical analyses.

RESULTS

The repeated measures analysis of variance test using Bonferroni adjustment demonstrated a significant increase in superficial and deep foveal VD following WDT (p <0.001 for both). Intraocular pressure, retinal nerve fiber layer thickness, foveal avascular zone, flow area of choriocapillaris, flow area of outer retina, foveal non-flow area of superficial layer, and retinal thickness measurements showed no significant changes following WDT.

CONCLUSIONS

WDT is associated with temporary flow modifications in superficial and deep foveal vascular plexus in young male subjects.

Integrated deep learning framework for accelerated optical coherence tomography angiography

Label-free optical coherence tomography angiography (OCTA) has become a premium imaging tool in clinics to obtain structural and functional information of microvasculatures. One primary technical drawback for OCTA, however, is its imaging speed. The current protocols require high sampling density and multiple acquisitions of cross-sectional B-scans to form one image frame, resulting in low acquisition speed. Recently, deep learning (DL)-based methods have gained attention in accelerating the OCTA acquisition process. They achieve faster acquisition using two independent reconstructing approaches: high-quality angiograms from a few repeated B-scans and high-resolution angiograms from undersampled data. While these approaches have shown promising results, they provide limited solutions that only partially account for the OCTA scanning mechanism. Herein, we propose an integrated DL method to simultaneously tackle both factors and further enhance the reconstruction performance in speed and quality. We designed an end-to-end deep neural network (DNN) framework with a two-staged adversarial training scheme to reconstruct fully-sampled, high-quality (8 repeated B-scans) angiograms from their corresponding undersampled, low-quality (2 repeated B-scans) counterparts by successively enhancing the pixel resolution and the image quality. Using an in-vivo mouse brain vasculature dataset, we evaluate our proposed framework through quantitative and qualitative assessments and demonstrate that our method can achieve superior reconstruction performance compared to the conventional means. Our DL-based framework can accelerate the OCTA imaging speed from 16 to 256[Formula: see text] while preserving the image quality, thus enabling a convenient software-only solution to enhance preclinical and clinical studies.

Assessment of macular microvasculature features before and after vitrectomy in the idiopathic macular epiretinal membrane using a grading system: An optical coherence tomography angiography study

PURPOSE

To evaluate pre- and postoperative microvasculature features in eyes with different idiopathic macular epiretinal membrane (iERM) classifications using optical coherence tomography angiography (OCTA).

METHODS

In this retrospective study, 100 eyes with iERM were enrolled; 62 eyes underwent pars plana vitrectomy (PPV). All iERM eyes were evaluated and graded using optical coherence tomography (OCT). According to the thickness of the fovea relative to the surrounding macula from OCT radial line scans, we classified iERM into three grades. Optical coherence tomography angiography (OCTA) was used to measure the foveal avascular zone (FAZ)-related parameters and the superficial and deep capillary plexus layers using 3 × 3 mm scans. Measurements were taken at baseline and 3 months postoperatively. Best corrected visual acuity (BCVA), vessel density (VD), FAZ area, FAZ perimeter (PERIM), acircularity index (AI), and foveal vessel density (FD) were evaluated.

RESULTS

Idiopathic macular epiretinal membrane (iERM) eyes with a higher grade had a lower FAZ area and perimeter (p < 0.0001), higher foveal vessel density (FVD) both in the superficial capillary plexus (SCP) (p < 0.0001) and in the deep capillary plexus (DCP) (p < 0.05), and a lower parafoveal vessel density (PRVD) in the DCP (p < 0.0001). The macular vessel density ratio (MVR = FVD/PRVD) increased with an increase in grade both in the SCP and in the DCP (p < 0.0001). For grade 1 iERM eyes, only PRVD in the DCP significantly changed before versus after the operation (p < 0.05). For grade 2 iERM eyes, the FAZ area and perimeter became larger after the operation (p < 0.05). The MVR of grade 2 iERM eyes decreased postoperatively both in the SCP (p < 0.05) and in the DCP (p < 0.001). For grade 1 and grade 2 iERM eyes, preoperative LogMAR BCVA was negatively correlated with the FAZ area (p < 0.01) and perimeter (p < 0.01), and was positively correlated with the MVR in the SCP (p < 0.05). Postoperative LogMAR BCVA was positively correlated with the FVD in the DCP (p < 0.05).

CONCLUSIONS

Idiopathic macular epiretinal membrane (iERM) eyes of different grades have significant differences in microvasculature features. According to OCTA, eyes with higher grades have more serious microvascular changes. Grading plays a part in predicting postoperative microvascular characteristics, and grade 1 iERM eyes have a better visual outcome compared with grade 2 iERM eyes.

Artifacts in Optical Coherence Tomography Angiography

We performed a comprehensive search of the published literature in PubMed and Google Scholar to identify types, prevalence, etiology, clinical impact, and current methods for correction of various artifacts in optical coherence tomography angiography (OCTA) images. We found that the prevalence of OCTA image artifacts is fairly high. Artifacts associated with eye motion, misidentification of retinal layers, projections, and low optical coherence tomography signal are the most prevalent types. Artifacts in OCTA images are the major limitations of this diagnostic modality in clinical practice and identification of these artifacts and measures to mitigate them are essential for correct diagnosis and follow-up of patients.

Effect of smoking on the macula and optic nerve integrity using optical coherence tomography angiography

OBJECTIVE

To investigate the effect of chronic smoking on the macula and optic nerve integrity using optical coherence tomography angiography (OCTA).

METHODS

This prospective, comparative study involved the right eyes of 160 healthy subjects (80 smokers group, and 80 control group). OCTA scanning was performed for all subjects. All macular subfields thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell complex (GCC) thickness, superficial and deep macular vessel density, foveal avascular zone (FAZ) area, and the macular outer retina flow area, were measured and analyzed.

RESULTS

The thickness of some macular subfields, inferior GCC, and RNFL was statistically significantly lower in the smokers' group (p < 0.05). The FAZ area was 0.409 ± 0.048 mm² in the smokers' group and 0.327 ± 0.055 mm² in the control group (p < 0.001). The superficial foveal VD was 31.35 ± 5.79% in the smokers' group and 33.63 ± 4.78% in the control group (p = 0.06). The deep foveal VD was 39.38 ± 4.56% in the smokers' group and 34.15 ± 6.57% in the control group (p ≤ 0.001). The superficial and deep parafoveal VD was 52.09 ± 4.56% and 59.99 ± 2.25% respectively in the smokers' group, and 54.75 ± 2.30% and 55.58 ± 4.69% respectively in the control group (p < 0.05). The macular outer retina flow area was 1.29 ± 0.12 mm² in the smokers' group and 1.16 ± 0.11 mm² in the control group (p < 0.001).

CONCLUSION

Chronic smoking affected the integrity of the macula and optic nerve. It decreased the macular VD, enlarged the FAZ, and increased outer retinal flow area.

OCTA Multilayer and Multisector Peripapillary Microvascular Modeling for Diagnosing and Staging of Glaucoma

Purpose

To develop and assess an automatic procedure for classifying and staging glaucomatous vascular damage based on optical coherence tomography angiography (OCTA) imaging.

Methods

OCTA scans (Zeiss Cirrus 5000 HD-OCT) from a random eye of 39 healthy subjects and 82 glaucoma patients were used to develop a new classification algorithm based on multilayer and multisector information. The averaged circumpapillary retinal nerve fiber layer (RNFL) thickness was also collected. Three models, support vector machine (SVM), random forest (RF), and gradient boosting (xGB), were developed and optimized for classifying between healthy and glaucoma patients, primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG), and glaucoma severity groups.

Results

All the models, the SVM (area under the receiver operating characteristic [AUROC] 0.89 ± 0.06), the RF (AUROC 0.86 ± 0.06), and the xGB (AUROC 0.85 ± 0.07), with 26, 22, and 29 vascular features obtained after feature selection, respectively, presented a similar performance to the RNFL thickness (AUROC 0.85± 0.06) in classifying healthy and glaucoma patients. The superficial vascular plexus was the most informative layer with the infero temporal sector as the most discriminative region of interest. No significant differentiation was obtained in discriminating the POAG from the NTG group. The xGB model, after feature selection, presented the best performance in classifying the severity groups (AUROC 0.76± 0.06), outperforming the RNFL (AUROC 0.67± 0.06).

Conclusions

OCTA multilayer and multisector information has similar performance to RNFL for glaucoma diagnosis, but it has an added value for glaucoma severity classification, showing promising results for staging glaucoma progression.

Translational Relevance

OCTA, in its current stage, has the potential to be used in clinical practice as a complementary imaging technique in glaucoma management.

Microvascular damage assessed by optical coherence tomography angiography for glaucoma diagnosis: a systematic review of the most discriminative regions

A growing number of studies have reported a link between vascular damage and glaucoma based on optical coherence tomography angiography (OCTA) imaging. This multitude of studies focused on different regions of interest (ROIs) which offers the possibility to draw conclusions on the most discriminative locations to diagnose glaucoma. The objective of this work was to review and analyse the discriminative capacity of vascular density, retrieved from different ROIs, on differentiating healthy subjects from glaucoma patients. PubMed was used to perform a systematic review on the analysis of glaucomatous vascular damage using OCTA. All studies up to 21 April 2019 were considered. The ROIs were analysed by region (macula, optic disc and peripapillary region), layer (superficial and deep capillary plexus, avascular, whole retina, choriocapillaris and choroid) and sector (according to the Garway-Heath map). The area under receiver operator characteristic curve (AUROC) and the statistical difference (p-value) were used to report the importance of each ROI for diagnosing glaucoma. From 96 screened studies, 43 were eligible for this review. Overall, the peripapillary region showed to be the most discriminative region with the highest mean AUROC (0.80 ± 0.09). An improvement of the AUROC from this region is observed when a sectorial analysis is performed, with the highest AUROCs obtained at the inferior and superior sectors of the superficial capillary plexus in the peripapillary region (0.86 ± 0.03 and 0.87 ± 0.10, respectively). The presented work shows that glaucomatous vascular damage can be assessed using OCTA, and its added value as a complementary feature for glaucoma diagnosis depends on the region of interest. A sectorial analysis of the superficial layer at the peripapillary region is preferable for assessing glaucomatous vascular damage.

Prediction of post-treatment retinal sensitivity by baseline retinal perfusion density measurements in eyes with branch retinal vein occlusion

In this study, we investigated the longitudinal correlation between macular sensitivity and perfusion density (PD) in retinas affected by branch retinal vein occlusion. Retinal sensitivity was measured using microperimetry and PD was measured by optical coherence tomography angiography. We also investigated the possibility that the PD, 1 month after anti-vascular endothelial growth factor (VEGF) treatment, is a predictor of retinal sensitivity after 1 year of successful macular oedema management with anti-VEGF. The correlation between measurements of retinal sensitivity and PD at baseline (1 M) and at 6 and 12 months were investigated. There was a significant positive correlation between retinal sensitivity and PD at all time points (baseline (1 M), r = 0.67, P < 0.0001; 6 months, r = 0.59, P < 0.0001; 12 months, r = 0.62, P < 0.0001) and between the PD at 1 month and retinal sensitivity at 12 months (r = 0.63, P < 0.0001). Unlike in areas that showed a mild to moderate decline in PD, retinal sensitivity in areas where the decrease in PD was severe at baseline did not show significant improvement with treatment over time. These findings suggest that the PD value measured using optical coherence tomography angiography at or soon after the baseline can predict retinal sensitivity after 1 year of anti-VEGF treatment.

Evaluation of the acute effects of cigarette smoking on the eye of non-Smoking healthy young male subjects by optical coherence tomography angiography

Purpose: Investigation of the acute effects of cigarette smoking on the eye using optical coherence tomography angiography (OCTA) on young healthy non-smoking male subjects.Materials and methods: The right eye of 25 healthy non-smoking male subjects were included in this study. Selected parameters of the macular and circumpapillary vasculature were measured, including macular flow indices, foveal avascular zone, vessel densities of macula and optic disc using OCTA. The measurements of the subjects were performed on the first day without smoking at 0 min, 5 min, 30 min and 60 min. Measurements were repeated at the same regime on the second day after smoking. Paired samples t-test and repeated measures one-way analysis of variance test was used for the statistical analysis.Results: The repeated measures analysis of variance test using the Bonferroni adjustment demonstrated a significant change for superficial and deep foveal vessel density, flow area of choriocapillaris, and circumpapillary capillary density following smoking (range of p value was <0.001-0.004). Intraocular pressure, foveal avascular zone area, flow area of outer retina and foveal non-flow area of superficial layer measurements did not have any significant changes following smoking (range of p value was 0.192-0.812).Conclusion: In non-smoking cases, even smoking only one cigarette significantly decreased the vessel density parameters at the acute period. Even though there was an increase in measured parameters shortly after smoking, it had lessened when compared to non-smokers, even one hour following smoking.

Optical coherence tomography angiography (OCT-A) in an animal model of laser-induced choroidal neovascularization

Aim of the study was to compare optical coherence tomography angiography (OCT-A) and conventional fluorescein angiography (FA) for quantitative analysis of the retinal and choroidal vasculature in the animal model of laser-induced choroidal neovascularization (CNV). Therefore, Dark Agouti rats underwent argon laser photocoagulation to induce CNV at D0. In vivo imaging using combined confocal scanner laser ophthalmoscopy (cSLO)-based FA and OCT-A (Heidelberg Engineering GmbH, Heidelberg, Germany) was performed before and immediately after laser treatment as well as at day 2, 7, 14 and 21. OCT-A en-face images were compared to cSLO images obtained by conventional FA topographic uptake recorded using a series of different pre-defined focus settings. For a quantitative comparison of CNV imaging by OCT-A and FA, CNV area, vessel density, number of vessel junctions, total vessel length and number of vessel end points were analyzed. Subsequent ex vivo analyses of the CNV included immunofluorescence staining of vessels in retinal and RPE/choroidal/scleral flatmount preparations. We found, that OCT-A allowed for high-resolution non-invasive imaging of the superficial, intermediate and deep retinal capillary plexus as well as the choroidal blood vessels in rats. Compared with OCT-A, visualization of CNV progression by invasive FA was less accurate, in particular the deep vascular plexus was visualized in more detail by OCT-A. The area of neovascularization was mainly detected in the deep retinal vascular plexus, outer nuclear layer (ONL), ellipsoid zone (EZ) and the choroid. Within the laser lesions, signs of CNV formation occurred at day 7 with progression in size and number of small vessels until day 21. Due to leakage and staining effects, CNV areas appeared significantly larger in FA compared to OCT-A images (p ≤ 0.0001 for all tested layers). Vessel density, number of vessel junctions, total vessel length and number of vessel end points were significantly higher in intermediate vascular plexus (IVP) and deep vascular plexus (DVP) in OCT-A compared to FA images. Overall, CNV area in flatmounts was similar to OCT-A results and much smaller compared to the area of dye leakage by FA. This study demonstrates that in vivo OCT-A imaging in small animals is feasible and allows for precise analysis of the formation of new blood vessel formation in the animal model of laser-induced CNV. Given its superior axial resolution, sensitivity and non-invasiveness compared to conventional FA imaging, OCT-A opens the door for a more detailed evaluation of CNV development in such a model and, thus, enables the analysis of the response to novel therapeutic interventions in longitudinal in vivo studies.

Pitfalls in Retinal OCT Imaging

Optical coherence tomography (OCT) imaging plays an important role in the management of retinal diseases. However, limitations and pitfalls should be taken into consideration when applying this noninvasive imaging technology. The aim of this review is to discuss several possible sources of error in the conduct and interpretation of OCT imaging.

Evaluation of Macular Perfusion in Healthy Smokers by Using Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE

To investigate the macular perfusion changes in healthy smokers by using optical coherence tomography angiography (OCTA).

PATIENTS AND METHODS

OCTA measurements were taken for the right eyes of 40 smokers (Group 1) and age- and sex-matched control cases (Group 2). Group 1 underwent OCTA scanning with the XR Avanti AngioVue OCTA (Optovue, Fremont, CA) at baseline and at 5 minutes, 30 minutes, and 60 minutes after one standard cigarette smoking. The same scanning protocol was applied without smoking in Group 2. Macular vessel area density, flow index of the choriocapillaris, foveal avascular zone (FAZ), and central macular thickness were evaluated in both groups.

RESULTS

Group 1 consisted of 28 men and 12 women with a mean age of 41.2 years ± 9.1 years (range: 24 years to 63 years). The mean age of Group 2 was 42.6 years ± 8.4 years (range: 21 years to 65 years), which consisted of 28 men and 12 women. The mean baseline vessel area density, flow index of the choriocapillaris, FAZ, and central macular thickness showed no statistically significant differences between Groups 1 and 2. Although the flow index of choriocapillaris values were similar at the repetitive OCTA measurements in the control group (P > .05), it was decreased from 1.94 ± 0.06 to 1.89 ± 0.08, 1.90 ± 0.08, and 1.91 ± 0.07 at 5 minutes, 30 minutes, and 60 minutes following smoking, respectively, in Group 1 (P < .001).

CONCLUSION

Smoking causes a significant decrease in the blood flow index of the choriocapillary area by the acute effects of nicotine and other chemical substances in cigarettes on peripheral vascular structure, as evaluated by OCTA. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:617-622.].

Evaluating ocular blood flow

Studies have shown that vascular impairment plays an important role in the etiology and pathogenesis of various ocular diseases including glaucoma, age-related macular degeneration, diabetic retinopathy, and retinal venous occlusive disease. Thus, qualitative and quantitative assessment of ocular blood flow (BF) is a topic of interest for early disease detection, diagnosis, and management. Owing to the rapid improvement in technology, there are several invasive and noninvasive techniques available for evaluating ocular BF, with each of these techniques having their own limitations and advantages. This article reviews these important techniques, with a particular focus on Doppler Fourier domain optical coherence tomography (OCT) and OCT-angiography.

Optical Coherence Tomographic Angiography Imaging in Age-Related Macular Degeneration

Optical coherence tomographic angiography (OCTA) is emerging as a rapid, noninvasive imaging modality that can provide detailed structural and flow information on retinal and choroidal vasculature. This review contains an introduction of OCTA and summarizes the studies to date on OCTA imaging in age-related macular degeneration.

Optical Coherence Tomography Angiography of the Foveal Avascular Zone in Retinal Vein Occlusion

PURPOSE

The aim of the study was to visualize and to quantify pathological foveal avascular zone (FAZ) alterations through optical coherence tomography angiography (OCT-A) in eyes with retinal vein occlusion (RVO) in comparison to the unaffected fellow eyes.

PROCEDURES

OCT-A was conducted with the Avanti® RTVue 100 XR system (Optovue Inc., Fremont, Calif., USA). The borders of the superficial vascular layer (SVL) were defined as 3 μm below the internal limiting membrane and 15 μm below the inner plexiform layer, and for the deep vascular layer (DVL) as 15 and 70 μm below the inner plexiform layer, respectively. The length of the horizontal, vertical and maximum FAZ was manually measured for the SVL and DVL in each eye. Additionally, the angle between the maximum FAZ diameter and the papillomacular plane was measured.

RESULTS

OCT-A depicted defects within the perifoveal vasculature in eyes with branch retinal vein occlusion (BRVO; n = 11) and central retinal vein occlusion (CRVO; n = 8). These resulted in an enlargement of the maximum FAZ diameter in eyes with RVO (n = 19) in comparison to the healthy fellow eyes (n = 19; 921 ± 213 vs. 724 ± 145 µm; p = 0.008). Furthermore, a significant correlation was found between best-corrected visual acuity (BCVA) and the maximum FAZ diameter in the DVL (Spearman's x03C1; = -0.423, p < 0.01). Lastly, in the eyes with RVO, the angle between the papillomacular plane and the maximum FAZ diameter was only in 21.05% (SVL) and 15.79% (DVL) of the cases at 0 ± 15 or 90 ± 15°, respectively. In healthy eyes, these angles (which putatively represent a regular FAZ configuration) were more prevalent (SVL 68.42 vs. 21.05%, p = 0.003; DVL 73.68 vs. 15.79%, p < 0.001).

CONCLUSION

OCT-A shows morphological alterations of the FAZ in eyes with CRVO and BRVO. The correlation of the maximum FAZ diameter with BCVA suggests that these alterations are functionally relevant.