Detection of Myopic Choroidal Neovascularization Using Optical Coherence Tomography Angiography

VIDEO COLOR OCT ANGIOGRAPHY FOR MYOPIC CHOROIDAL NEOVASCULARIZATION

PURPOSE

To investigate the myopic macular neovascularization (mMNV) features on dynamic video-color optical coherence tomography (OCT) angiography (OCTA) and the diagnostic rate versus the static, four-segmentations visualization mode.

DESIGN

Retrospective cohort study PARTICIPANTS: Fifty-four patients with mMNV METHODS: Sixty-two eyes with high myopia complicated by mMNV were included. Clinical charts, fluorescein angiography and structural OCT were used as standard reference to assess lesion activity. Static and video-color OCTA were then analysed and compared by two independent reviewers.

MAIN OUTCOME MEASURES

Morphology description of mMNV on video-color OCTA and differences in the proportion of diagnosis between video-colour and static OCTA.

RESULTS

62 eyes from 54 patients (mean age 63,22 years) were enrolled. Thirty-four (55%) mMNV were active and 28 (45%) inactive. Twenty-two (65%) active mMNV presented on video-color OCTA as an interlacing vascular network in the outer retina and the choriocapillaris. A tapered form was the prevalent size (72,7%). In 3 eyes (9%) an abnormal and irregular vascular network (AVN) was disclosed and in 5 (15%) only some blood flow alteration. All the lesions extended both in the outer retinal and the choriocapillaris. Eleven (39%) inactive mMNV presented on video-color OCTA as an interlacing vascular network too, in the outer retina and the choriocapillaris. Eight (29%) had some AVN and 6 (21%) only some blood flow alteration. The diagnostic rate of video-color vs static OCTA was 95% (IC 95% 86% to 99%) vs 77% (IC 95% 86% to 99%, p= 0.0009), and shows an advantage in favour of video-colour OCTA of 15% (CI 95%, 3%-27%) and 22% (CI 95%, 7%-38%) in active and inactive lesions, respectively (p<0.026). Lesion extension within both the outer retina and the choriocapillaris was present in 90% and 69% of cases on dynamic OCTA and static OCTA, respectively, with a proportion difference of 20% (CI 95%, 10%-31%, p= 0.0005). Concordance between the two examiners was high: 0.95 (95%, CI 0.88 to 1.00) and 0.96 (0.91 to 1.00) for active and inactive lesions, respectively.

CONCLUSIONS

Video color-enhanced OCTA may help in diagnosing mMNV and should be considered by clinicians in addition to structural OCT and static OCTA.

Molecular and cellular imaging of the eye

The application of molecular and cellular imaging in ophthalmology has numerous benefits. It can enable the early detection and diagnosis of ocular diseases, facilitating timely intervention and improved patient outcomes. Molecular imaging techniques can help identify disease biomarkers, monitor disease progression, and evaluate treatment responses. Furthermore, these techniques allow researchers to gain insights into the pathogenesis of ocular diseases and develop novel therapeutic strategies. Molecular and cellular imaging can also allow basic research to elucidate the normal physiological processes occurring within the eye, such as cell signaling, tissue remodeling, and immune responses. By providing detailed visualization at the molecular and cellular level, these imaging techniques contribute to a comprehensive understanding of ocular biology. Current clinically available imaging often relies on confocal microscopy, multi-photon microscopy, PET (positron emission tomography) or SPECT (single-photon emission computed tomography) techniques, optical coherence tomography (OCT), and fluorescence imaging. Preclinical research focuses on the identification of novel molecular targets for various diseases. The aim is to discover specific biomarkers or molecular pathways associated with diseases, allowing for targeted imaging and precise disease characterization. In parallel, efforts are being made to develop sophisticated and multifunctional contrast agents that can selectively bind to these identified molecular targets. These contrast agents can enhance the imaging signal and improve the sensitivity and specificity of molecular imaging by carrying various imaging labels, including radionuclides for PET or SPECT, fluorescent dyes for optical imaging, or nanoparticles for multimodal imaging. Furthermore, advancements in technology and instrumentation are being pursued to enable multimodality molecular imaging. Integrating different imaging modalities, such as PET/MRI (magnetic resonance imaging) or PET/CT (computed tomography), allows for the complementary strengths of each modality to be combined, providing comprehensive molecular and anatomical information in a single examination. Recently, photoacoustic microscopy (PAM) has been explored as a novel imaging technology for visualization of different retinal diseases. PAM is a non-invasive, non-ionizing radiation, and hybrid imaging modality that combines the optical excitation of contrast agents with ultrasound detection. It offers a unique approach to imaging by providing both anatomical and functional information. Its ability to utilize molecularly targeted contrast agents holds great promise for molecular imaging applications in ophthalmology. In this review, we will summarize the application of multimodality molecular imaging for tracking chorioretinal angiogenesis along with the migration of stem cells after subretinal transplantation in vivo.

TEN-YEAR VISUAL OUTCOME AND CHANGE IN CHORIORETINAL ATROPHY AFTER INTRAVITREAL RANIBIZUMAB FOR MACULAR NEOVASCULARIZATION IN PATHOLOGIC MYOPIA

PURPOSE

To investigate the 10-year visual outcome and chorioretinal atrophy after a single intravitreal ranibizumab injection followed by a pro re nata regimen for myopic macular neovascularization in pathologic myopia, and to identify the factors associated with 10-year best-corrected visual acuity (BCVA).

METHODS

This retrospective observational study evaluated 26 consecutive treatment-naïve eyes (26 patients) with myopic macular neovascularization in pathologic myopia who underwent a single intravitreal ranibizumab followed by a pro re nata regimen of intravitreal ranibizumab and/or intravitreal aflibercept injection and observed over 10 years. We assessed changes in BCVA and morphological parameters, including the META-PM Study category as a chorioretinal atrophy index.

RESULTS

The logarithm of the minimum angle of resolution BCVA changed from 0.36 (Snellen, 20/45) ± 0.39 to 0.39 (20/49) ± 0.36 over 10 years of observation. Compared to baseline, 1-year BCVA improved ( P = 0.002), whereas 2 to 10-year BCVA was not significantly different. Total injection frequency was 3.8 ± 2.6. In none of the eyes, 10-year BCVA was 20/200 or less. Ten-year BCVA correlated with baseline BCVA ( P = 0.01, r = 0.47). The META-PM Study category progressed in 60% of eyes. There were no drug-induced complications.

CONCLUSION

Best-corrected visual acuity in eyes with myopic macular neovascularization in pathologic myopia was maintained for 10 years after a single intravitreal ranibizumab followed by a pro re nata regimen without drug-induced complications. The META-PM Study category progressed in 60% of eyes, especially those with older baseline age. Early diagnosis and treatment of myopic macular neovascularization are essential to maintain good long-term BCVA.

Does PLEX® Elite 9000 OCT Identify and Characterize Most Posterior Pole Lesions in Highly Myopic Patients?

High myopia (HM) is defined as an axial length (AL) ≥ 26 mm that may result in various pathologies that constitute pathologic myopia (PM). The PLEX^® Elite 9000 (Carl Zeiss AC, Jena, Germany) is a new swept-source optical coherence tomography (SS-OCT) underdevelopment that allows wider, deeper and more detailed posterior-segment visualization; it can acquire ultra-wide OCT angiography (OCTA) or new ultra-wide high-density scans in one image. We assessed the technology's ability to identify/characterize/quantify staphylomas and posterior pole lesions or image biomarkers in highly myopic Spanish patients and estimate the technology's potential to detect macular pathology. The instrument acquired 6 × 6 OCTA, 12 × 12 or 6 × 6 OCT cubes, and at least two high-definition spotlight single scans. A hundred consecutive patients (179 eyes; age, 51.4 ± 16.8 years; AL, 28.8 ± 2.33 mm) were recruited in one center for this prospective observational study. Six eyes were excluded because images were not acquired. The most common alterations were perforating scleral vessels (88.8%), classifiable staphyloma (68.7%), vascular folds (43%), extrafoveal retinoschisis (24%), dome-shaped macula (15.6%), and more uncommonly, scleral dehiscence (4.46%), intrachoroidal cavitation (3.35%), and macular pit (2.2%). The retinal thickness of these patients decreased, and the foveal avascular zone increased in the superficial plexus compared with normal eyes. SS-OCT is a novel potent tool that can detect most main posterior pole complications in PM and may provide us with a better understanding of the associated pathologies; some pathologies were identifiable only with this new kind of equipment, such as perforating scleral vessels, which seem to be the most common finding and not so frequently related to choroidal neovascularization, as previously reported.

Diagnostic accuracy of OCTA and OCT for myopic choroidal neovascularisation: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

The purpose of this project was to systematically review and meta-analyse studies assessing the diagnostic accuracy of optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT) for myopic choroidal neovascularisation (mCNV). Fluorescein angiography (FA) was accepted as the reference standard.

METHODS

PUBMED and EMBASE were searched from inception to March 2021 for studies evaluating the test accuracy of OCTA and/or OCT for diagnosing mCNV. The Preferred Reporting Items for Systematic Reviews and Meta-analyses of Diagnostic Test Accuracy Studies guideline was followed, and the Grading of Recommendations, Assessment, Development and Evaluation approach was used to frame clinical recommendations. Pooled estimates of test accuracy were obtained using a bivariate model.

RESULTS

Of 410 studies assessed for eligibility, 3 studies were identified that compared OCTA to FA and 3 studies were identified that compared spectral domain (SD) OCT to FA. All studies had at least one major methodological flaw leading to an overall high risk of bias. On meta-analysis, the pooled sensitivity of OCTA was 0.89 (95% CI 0.78-0.94) and pooled specificity was 0.93 (95% CI 0.79-0.98). The pooled sensitivity of SD-OCT was 0.99 (95% CI 0.91-1.00). Due to uncertainty in individual studies, the pooled specificity of SD-OCT could not be estimated.

CONCLUSIONS

OCTA can reliably diagnose mCNV in clinically suspected patients, however, SD-OCT may not reliably establish a positive diagnosis of mCNV. Future large, prospective studies with improvements in conduct and reporting are needed to strengthen these clinical recommendations.

Morphological parameters of myopic choroidal neovascularization as predictive factors of anti-VEGF treatment response

The objective of this prospective study was to investigate the morphological changes of myopic choroidal neovascularization (mCNV) after treatment with anti-vascular endothelial growth factor and to identify potential features predictive of the final BCVA. OCT and OCTA features were evaluated at baseline and at 1, 6 and 12 months. Parameters investigated were the maturity pattern, presence of mCNV OCT activity signs, subretinal fibrosis and mCNV area. Forty patients (41 eyes) were included in the study. At the final visit, after a mean of 3.1 ± 1.4 injections, BCVA had improved significantly (p = 0.009) and subretinal hyperreflective exudation, subretinal fluid and intraretinal cysts nearly disappeared at 12 months. At baseline, 20 eyes had an immature CNV that were smaller, required less injections (2.5 ± 1.2 vs 3.8 ± 1.4, p = 0.002), they completely regressed in seven eyes and achieved a better BCVA (0.14 ± 0.15 vs 0.40 ± 0.26 logMAR, p < 0.001) when compared to mature CNV. Subretinal fibrosis developed in 19 eyes (46.3%) with lower final BCVA than eyes without fibrosis (0.19 ± 0.24 vs 0.38 ± 0.22 logMAR, p = 0.012). Baseline immature pattern (p = 0.005) and baseline BCVA (p < 0.001) were predictive of final BCVA. Multimodal imaging is useful to define mCNV changes during treatment. OCTA provides prognostic information which cannot achieved by other imaging techniques.

Predicting lesion shrinkage in eyes with myopic choroidal neovascularization from features on optical coherence tomography angiography

PURPOSE

To identify baseline morphological predictors of lesion shrinkage in eyes with myopic choroidal neovascularization (mCNV) treated with anti-vascular endothelial growth factor (VEGF).

METHODS

This retrospective study included 46 eyes (41 consecutive patients) with active mCNV receiving anti-VEGF treatment. Optical coherence tomography angiography (OCTA) was performed at baseline and 1 year after treatment. Quantitative features were obtained from OCTA images using AngioTool software. Eyes were classified as "high-shrinkage" or "low-shrinkage" according to the median relative change in lesion area. Baseline quantitative morphological features associated with mCNV shrinkage were identified in univariate and multivariate analyses.

RESULTS

The mCNV area was significantly smaller after 1 year (P=0.013), with a median relative change of -16.5%. The relative change in mCNV area was -48.3% in high-shrinkage eyes (n=23) and -5.2% in low-shrinkage eyes (n=23). High-shrinkage eyes had a smaller mCNV area (P=0.013), shorter total vessel length (P=0.023), and higher endpoint density (P<0.001). Multivariate analysis showed significant associations of high shrinkage with endpoint density (β=-0.037, P=0.043) and previous anti-VEGF treatment (β=0.216, P=0.029).

CONCLUSION

Morphological features of neovascularization detected by OCTA can predict lesion shrinkage in eyes with mCNV receiving anti-VEGF therapy. Higher endpoint density contributed to shrinkage, particularly of treatment-naive lesions.

Discerning Between Macular Hemorrhages Due to Macular Neovascularization or Due to Spontaneous Bruch’s Membrane Rupture in High Myopia: A Comparative Analysis Between OCTA and Fluorescein Angiography

Introduction

To evaluate the sensitivity and specificity of optical coherence tomography angiography (OCTA) in comparison to fluorescein angiography (FA) in discerning between macular hemorrhages due to myopic macular neovascularization (m-MNV) and idiopathic macular hemorrhage (IMH) in patients with high myopia (HM).

Methods

In this retrospective study, 14 eyes of 14 patients (mean age 60 ± 16 years) affected by macular hemorrhage due to HM were included. All patients underwent OCTA and FA at the time of macular hemorrhage (i.e., baseline) and were followed for a 3-month follow-up.

Results

By means of FA, 8 out of 14 eyes with macular hemorrhage (57%) were diagnosed as type 2 m-MNV, whereas 6 eyes (43%) were diagnosed as IMH. Interestingly, OCTA displayed the presence of a neovascular network in all cases previously diagnosed as m-MNV using FA, and also excluded the presence of anomalous flow in all IMH eyes. This accounted for the high sensitivity and specificity of OCTA for m-MNV detection in HM cases with macular hemorrhage. After 3-month follow-up, BCVA improved from 0.39 ± 0.15 to 0.21 ± 0.14 logMAR (p = 0.006) in patients with m-MNV treated by a mean of 2.3 ± 0.9 intravitreal anti-VEGF injections. Conversely, BCVA improved without treatment (from 0.55 ± 0.48 to 0.17 ± 0.08 logMAR, p = 0.112) in patients with IMH.

Conclusions

OCTA is able to differentiate with excellent reliability between the presence of m-MNV in patients with HM presenting with a new macular hemorrhage and an IMH. This could be of paramount relevance in the clinical setting for the diagnosis and treatment of patients with HM.

Choroidal Morphologic and Vascular Features in Patients With Myopic Choroidal Neovascularization and Different Levels of Myopia Based on Image Binarization of Optical Coherence Tomography

Purpose: To characterize the choroidal morphologic and vascular features in different levels of myopes and patients with myopic choroidal neovascularization (mCNV). Methods: A total of 148 subjects were enrolled in this cross-sectional study, including 78 low-to-moderate myopes (LMM), 53 high myopes (HM), and 17 high myopic patients with mCNV. Ocular biometrics were measured using an optical low-coherence reflectometry device. Retinal and choroidal imaging was performed using enhanced depth imaging (EDI) spectral domain optical coherence tomography (OCT). Retinal parameters including retinal thickness and retinal volume were obtained from a built-in software. Binarization technique was adopted to investigate choroidal parameters including choroidal thickness (CT), vascular area, stromal area, and choroidal vascularity index (CVI). Choroidal parameters were measured at five locations to cover as much area of choroid as possible, and their patterns of distribution were further analyzed. Results: Patients with mCNV had an atrophic retina of comparable thickness to HM (273.65 ± 17.28 vs. 276.49 ± 13.29 μm, p = 0.47), but the choroid was thinner than that of HM (153.94 ± 15.12 vs. 236.09 ± 38.51 μm, p < 0.001). Subfoveal CVI was greatest in the mCNV eyes (0.651 ± 0.009), followed by HM (0.645 ± 0.012) and LMM eyes (0.636 ± 0.012). Similar to CT, CVI was also found significantly different among these three groups at all five locations (p for trend < 0.001 for all locations). Axial length (AL) was negatively correlated with retinal volume (r = -0.236, p = 0.009), which is the only significant finding in associations between ocular factors and retinal parameters. Strong, negative correlations were identified between AL and subfoveal choroidal thickness (SFCT, r = -0.820, p < 0.001). However, AL was positively correlated with subfoveal CVI (r = 0.668, p < 0.001). CVI was greater in myopic eyes with thinner choroid (r = -0.578, p < 0.001). BCVA exhibited no significant association with CVI (r = 0.139, p = 0.092), but was negatively correlated with SFCT (r = -0.386, p < 0.001) and positively correlated with AL (r = 0.351, p < 0.001). Conclusion: Choroid in patients with mCNV was thinner yet more vascularized than that in HM and LMM subjects. CVI increased with a longer AL which was associated with a smaller SFCT, choroidal vascular area (VA), and total choroidal area (TCA). Better BCVA was achieved in subjects with thicker SFCT and shorter AL.

INTRAVITREAL RANIBIZUMAB IN PREGNANT PATIENT WITH MYOPIC CHOROIDAL NEOVASCULAR MEMBRANE. A CASE REPORT

AIM

To present the case of a patient with myopic choroidal neovascular membrane (mCNV) in the 3rd trimester of pregnancy, who was treated with intravitreal ranibizumab.

CASE REPORT

The 34-year-old patient was referred to the Department of Ophthalmology of the University Hospital Kralovske Vinohrady in January 2020 for mCNV on her right eye (RE). The patient was in the 34th week of pregnancy. Initial best corrected visual acuity (BCVA) was 68 ETDRS letters. Spherical equivalent of the RE was -11.5 dioptres, axial length of the RE was 27.7 mm. Pigmented CNV with small haemorrhage was present on the retina of the RE. Optical coherence tomography (OCT) of the RE showed a hyperreflective mass above the retinal pigment epithelium, central retinal thickness (CRT) was 310 µm. OCT angiography confirmed the presence of a classic CNV in the macula of the RE. Two weeks later, the hyperreflective lesion and oedema in the macula of the RE increased, the CRT was 329 µm, BCVA remained stable. After discussion with the patient and the treating gynaecologist, intravitreal ranibizumab was administered in the RE in the 36th week of pregnancy. On check-up 3 weeks later, we observed the decrease of macular oedema to 276 µm and the improvement of BCVA to 78 ETDRS letters. The patient delivered a healthy baby girl in the 39th week of pregnancy via caesarean section, postnatal adaptation of the newborn was normal. During further visits, the BCVA improved to 83 ETDRS letters and the macular oedema disappeared completely. 8 months after the first ranibizumab injection, the CNV reactivated, BCVA decreased to 72 ETDRS letters, oedema was present in the macula and the CRT was 309 µm. Another ranibizumab was administered into the RE. The patient then discovered that she was pregnant; according to calculations, she was in the 3rd week of pregnancy at the time of the second ranibizumab injection. After the second injection, BCVA improved to 79 ETDRS letters, macular oedema on the OCT disappeared and CRT decreased to 264 µm. The pregnancy was terminated per patients request.

CONCLUSION

Intravitreal administration of ranibizumab in the 3rd trimester of pregnancy led to the improvement of BCVA and decrease of macular oedema in the patient with mCNV. The injection had no adverse effect on the pregnancy or the postnatal adaptation of the newborn. However, it is always necessary to consider the risk/benefit ratio when administering intravitreal antiVEGF drugs in pregnant patients. Thorough discussion with the patient is necessary.

Association between choriocapillaris flow deficit and choroidal neovascularization activity in eyes with myopic choroidal neovascularization

Although choriocapillaris flow deficit (CFD) around choroidal neovascularization (CNV) is less associated with CNV activity in myopic eyes, no reports are investigating its size as an indicator of CNV activity. We investigated the relationship between CFD and high myopia-related CNV. In this retrospective, observational study, patients underwent optical coherence tomography angiography (OCTA) with split-spectrum amplitude-decorrelation angiography for diagnosing pathological myopic CNV (mCNV); CFD features around CNV margins were evaluated. Of the 33 eyes (30 patients), 11 (33.3%) had active mCNV, and 22 (66.7%) had inactive CNV. Six eyes (18.2%) were treatment-naïve, while the remainder previously underwent anti-vascular endothelial growth factor therapy. On OCTA, blood flow signals were detected in CNV in the outer retinal layer in 28 (84.8%) eyes, including all active cases (11 cases) and 17 (77.3%) of 22 inactive cases. CNV flow signal size correlated significantly with activity (P < 0.001). CFD around CNV was observed in 24 eyes (72.7%), including all active cases (11 cases) and 13 (59.1%) of 22 inactive cases. CFD size correlated significantly with CNV activity (P < 0.001). The size of both the CFD area around CNV and CNV flow signal area are useful indicators of CNV activity in eyes with mCNV, which may help determine treatment timing.

Association between the posterior ocular contour pattern and progression of myopia in children: A prospective study based on OCT imaging

PURPOSE

This study aims to reveal the relationship between the posterior ocular contour and the subsequent progression of myopia in children.

METHODS

Children aged 8-12 years with myopia received baseline measurements and were instructed to wear their glasses every day and return for a follow-up visit after one year. Axial length and other ocular parameters were measured using a noncontact biometer. The contour of the posterior eye was calculated and analysed based on images from spectral domain optical coherence tomography (SD-OCT). Univariate and multivariate linear regression models were created to analyse the relationship between the contour of the posterior eye and the progression of myopia.

RESULTS

Baseline posterior ocular contour measurements correlated with baseline axial length and spherical equivalent refraction (SER) (all p < 0.05). Eyes that were more myopic tended to have a more prolate posterior ocular contour. Although the baseline contour of the retinal pigment epithelium (RPE) and chorioscleral interface (CSI) showed no significant relationship with the progression of myopia (all p > 0.05), interestingly, when the baseline contour of the RPE was more prolate than that of the CSI, the axial length increased during the following year (R²  = 0.62; p < 0.01). The multivariate model, when adjusted for other variables, further validated the independent role of this variable.

CONCLUSIONS

The difference between the RPE and CSI contours correlated with the subsequent progression of myopia in children. This finding can help inform clinicians regarding the management of children at the onset of myopia and potentially provide an avenue for experimental research on the mechanism of myopia development.

Myopic foveal detachment associated with pachychoroid characteristics

Purpose

To describe myopic nontractional foveal detachment associated with pachychoroid diseases.

Methods

This retrospective study included 15 myopic eyes which had nontractional serous foveal detachment. The eyes were divided into myopic central serous chorioretinopathy (CSC) group (n = 8) and a myopic pachychoroid neovascularization (PNV) group (n = 7) according to the presence of type 1 choroidal neovascularization on multimodal imaging. The findings of multimodal imaging and treatment response were described.

Results

In myopic CSC group, pachychoroid features such as pachyvessels, choroidal vascular hyperpermeability and punctate hyperfluorescent spots were noted in 8 eyes (100%), 8 eyes (100%), 5 eyes (62.5%) respectively. The above features were noted in 7 eyes (100%), 5 eyes (83.3%), 5 eyes (83.3%), respectively, in the myopic PNV group. Five of 8 eyes in myopic CSC and all 7 eyes received treatment including anti-vascular endothelial growth factor injection and/or photodynamic therapy. However, only five eyes had a complete response.

Conclusions

The pachychoroid phenotype may coexist with high myopia and lead to myopic nontractional serous foveal detachment. Our series suggest that the response to treatment for these conditions would be limited.

Choriocapillaris: Fundamentals and advancements

The choriocapillaris is the innermost structure of the choroid that directly nourishes the retinal pigment epithelium and photoreceptors. This article provides an overview of its hemovasculogenesis development to achieve its final architecture as a lobular vasculature, and also summarizes the current histological and molecular knowledge about choriocapillaris and its dysfunction. After describing the existing state-of-the-art tools to image the choriocapillaris, we report the findings in the choriocapillaris encountered in the most frequent retinochoroidal diseases including vascular diseases, inflammatory diseases, myopia, pachychoroid disease spectrum disorders, and glaucoma. The final section focuses on the development of imaging technology to optimize visualization of the choriocapillaris as well as current treatments of retinochoroidal disorders that specifically target the choriocapillaris. We conclude the article with pertinent unanswered questions and future directions in research for the choriocapillaris.

ASSESSING THE ACTIVITY OF MYOPIC CHOROIDAL NEOVASCULARIZATION: Comparison Between Optical Coherence Tomography Angiography and Dye Angiography

This study evaluated several OCTA characters in assessing the activity of myopic choroidal neovascularization using fundus fluorescein angiography as the gold standard and suggested a novel comprehensive diagnostic procedure by OCTA with good sensitivity and specificity.

Purpose:

This study aims to suggest a novel strategy for assessing the activity of myopic choroidal neovascularization (mCNV) based on optical coherence tomography angiography (OCTA) and to compare it with traditional fundus fluorescein angiography as the gold standard.

Methods:

Macular OCTA images were obtained using RTVue XR Avanti with AngioVue. Morphologic features of mCNV lesions were analyzed. Characteristics of OCTA in 41 eyes with active mCNV and 41 eyes with inactive mCNV were analyzed. Optical coherence tomography angiography parameters associated with mCNV activity and the clinical significance of their sensitivity and specificity were analyzed using fundus fluorescein angiography as the reference.

Results:

Of the total 108 patients, 82 had OCTA images with good quality which were included in this study. Several anatomical features of the CNV lesions, including overall appearance, branching with tiny vessels, presence of anastomoses/loops, and choroidal dark halo, were considered the possible parameters associated with mCNV activity. The intra- and interobserver agreements were substantial. To evaluate the CNV activity, sensitivity of overall appearance, tiny vascular branching, and presence of anastomoses or loops were 65.9%, 82.9%, and 73.2%, respectively, whereas the specificity was 87.8%, 90.2%, and 92.7%, respectively. However, the choroidal dark halo showed low specificity (46.3%) and failed in terms of evaluating the activity of mCNV. A novel comprehensive procedure integrating branching as a major parameter and overall appearance and presence of anastomoses/loops as minor parameters was developed to evaluate mCNV activity with sensitivity of 95.1% and specificity of 85.4%.

Conclusion:

In mCNV, the acquisition rate of clear OCTA images was 75.9%. A novel comprehensive diagnostic procedure combining mCNV appearance, vascular branching, and anastomoses/loops by OCTA may be a valuable strategy to evaluate neovascular activity in mCNV.

Assessing the Use of Incorrectly Scaled Optical Coherence Tomography Angiography Images in Peer-Reviewed Studies: A Systematic Review

Importance

Individual differences in axial length affect the lateral magnification of in vivo retinal images and as a result can affect the accuracy of quantitative measurements made from these images. As measurements from optical coherence tomography angiography (OCTA) images are becoming increasingly used in the diagnosis and monitoring of a wide range of diseases, evaluating which studies use correctly scaled images is crucial to their interpretation.

Objective

To perform a systematic literature review to assess the percentage of articles that report correcting the scale of their OCTA images for individual differences in retinal magnification.

Evidence Review

A PubMed (MEDLINE) search was conducted for articles on OCTA retinal imaging published between June 1, 2015, and June 1, 2018. Initial results included 7552 articles. Initial exclusion criteria removed studies of animal models, as well as reviews, letters, replies, comments, and image-based or photographic essays. Articles not written in English and those that required purchase from non-English language websites were excluded. Articles that did not use OCTA for imaging the retina were also excluded. Remaining articles were reviewed in detail to assess whether the OCTA measurements required correct lateral scaling, and if so, whether axial length was reported or used to scale the images. We also determined the number of articles that mentioned the lack of correct lateral scaling as a limitation of the study.

Findings

A total of 989 articles were included in the detailed review. Of these, 509 were determined to require correct image scaling for their analyses, but only 41 (8.0%) report measuring and using axial length to correct the lateral scale of their OCTA images. Furthermore, of the 468 articles that did not correctly scale their images, only 18 (3.8%) mentioned this as a limitation to their study.

Conclusions and Relevance

These findings suggest that most peer-reviewed articles in PubMed that use quantitative OCTA measurements use incorrectly scaled images. This could call into question the conclusions of such studies and warrants consideration by OCTA manufacturers, physicians, authors, journal reviewers, and journal editors.

Anti-VEGF Therapy in Myopic CNV

In this narrative-review, we report the most recent data from the literature of anti-vascular endothelial growth factor treatment for myopic choroidal neovascularization (mCNV). Myopic CNV is the most frequent sight-threatening complication of pathologic myopia. The natural course of mCNV can result in expanding macular atrophy and /or fibrosis, leading to irreversible visual loss after 5 years. Retinal multimodal imaging is mandatory for early diagnosis and monitoring of the disease during treatment. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is recommended as the first-line treatment option for mCNV. Prompt treatment of active mCNV with intravitreal anti-VEGF therapy has been demonstrated to be effective in terms of visual outcome improvements reducing the occurrence of late-stage complications.

Optical Coherence Tomography Angiography-Based Quantitative Assessment of Morphologic Changes in Active Myopic Choroidal Neovascularization During Anti-vascular Endothelial Growth Factor Therapy

Purpose: To establish quantitative profile of the morphologic changes among patients with active myopic choroidal neovascularization (mCNV) before and after anti-vascular endothelial growth factor (VEGF) therapy using optical coherence tomography angiography (OCTA) to assess the therapeutic response.

Methods: Patients with active mCNV who received anti-VEGF injections between February 2017 to October 2020 and fit the study criteria were retrospectively reviewed. Quantitative analysis of their OCTA images were carried out to evaluate the morphologic features and vascular changes of mCNV lesions in response to anti-VEGF therapy. For further quantitative profiling, mCNV area, fractal dimension, vessel area, vessel density, vessel diameter, vessel length, vessel junction, junction density, and vessel tortuosity were obtained by means of advanced skeletonization postprocessing analyses.

Results: Thirty-one eyes of 29 consecutive patients with OCTA-positive mCNV lesions (mean spherical equivalent: −12.55 ± 3.24 diopters) were included. The 31 cases were divided into two phenotypes at baseline: organized interlacing pattern (83.87%) and disorganized vascular loops pattern (16.13%). The values of mCNV area, fractal dimension, vessel area, vessel length, vessel junction, and junction density decreased remarkably 1 month after the initial anti-VEGF injection (p < 0.001). Although, vessel density, vessel diameter, and vessel tortuosity increased meanwhile, only vessel diameter displayed statistical significance (p = 0.027). Of note, relative ratio analysis showed that vessel junction was the most sensitive biomarker in response to anti-VEGF therapy, reflecting a mean decrease of 50.36%. Sensitivity lowered successively in biomarkers of vessel length, vessel area, junction density, mCNV area, and fractal dimension. In addition, percent change of mCNV area (r = 0.552, p = 0.002), fractal dimension (r = 0.446, p = 0.017), vessel area (r = 0.518, p = 0.005), and vessel length (r = 0.440, p = 0.019) were moderately associated with that of central retinal thickness.

Conclusions: The study showed morphological as well as quantitative changes on OCTA responding to anti-VEGF treatment in mCNV patients, among which vessel junctions might be the most predictive biomarker. OCTA-based analysis, providing intuitive images and a large spectrum of quantitative data at the same time, could promote new insights into the therapeutic response assessment in mCNV patients.

A Comparative Study of Macular and Choroidal Thickness and Blood-Flow Parameters in Patients with Intermediate and Simple Juvenile Moderate Myopia

Objective

This study aimed to compare the macular and choroidal thicknesses and blood-flow parameters of patients with intermediate and simple juvenile moderate myopia in order to provide a greater understanding of the pathogenesis of myopia and a basis for its prevention.

Methods

Participants were selected from patients under the age of 18 with moderate myopia who were treated in our ophthalmic clinic between June and December 2019. Seventy-five right eyes were selected from participants with a mean spherical equivalent ranging from -6.0 to -3.0 D. These samples were divided into two groups based on eye axial length (AL). The thicknesses of the macula and choroid, the area of the foveal avascular zone (FAZ), and the blood flow density of the macular capillaries were measured, intergroup comparison was conducted.

Results

The average area of the FAZ was larger in the intermediate group than in the simple group. PERIM in the upper half was lower in the intermediate group than in the simple group, and the blood-flow density in the lower half of the macular area was higher in the simple group than in the intermediate group. The blood-flow density within 1 mm of the fovea centralis and the downward blood-flow density were higher in the intermediate group than in the simple group. The thicknesses of the lower part of the FAZ, the choroid of the fovea centralis, and the choroid under the retina were all larger in the intermediate group than in the simple group.

Conclusion

The area of the FAZ in patients with intermediate juvenile moderate myopia is larger than that in patients with simple myopia; the choroid in the fovea of macula compensatorily increases, and blood flow density also increases; the thickness of the choroid under the retina increases with myopia.

Complicated Retinal Pigment Epithelium Humps in High Myopia

This study was aimed at reporting a set of complications associated with retinal pigment epithelium (RPE) humps in high myopia. Data included three eyes from three different patients. Complications observed over RPE humps were the development of choroidal neovascularization, active inflammatory lesions of multifocal choroiditis, and simple bleeding. Regular follow-up with appropriate examinations can help to recognize these events and offer the most adequate treatment in a timely manner. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:119-123.].

Flow pattern and perforating vessels in three different phases of myopic choroidal neovascularization seen by swept-source optical coherence tomography angiography

PURPOSE

To compare the choroidal neovascularization (CNV) flow patterns and the relationship between perforating vessels (PVs) and CNV in the three different stages of networks in myopic CNV (mCNV) using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

This retrospective study included 28 eyes with mCNV that was divided into three phases (active, scar, and atrophic) and observed by SS-OCTA. SS-OCTA findings, with special focus on the relationship between the PVs and CNV, were compared among the three phases.

RESULTS

Overall, the CNV signal was detected in 31 of the 34 areas of CNV (91%); in the active, scar, and atrophic phases, respectively, CNV signals were detected in eight of eight areas of CNV (100%), 10 of 11 areas of CNV (91%), and 13 of 15 areas of CNV (86%). Two signal patterns were observed in each phase, i.e., dense and loop; in the atrophic phase, seven eyes were unclassifiable. The ratio between the dense and loop patterns did not differ significantly among the phases. In 30 of 34 areas of CNV for which clear images were obtained, the PVs and CNV were connected directly or indirectly in 19 area of CNV, and in five areas of CNV, trunk-like vessels were connected to the PVs within the CNV. The numbers of foveal or parafoveal CNVs accompanied by PVs were significantly (p=0.0048) greater than those of the extrafoveal CNV.

CONCLUSIONS

OCTA provides detailed observation of mCNV and the relationship between CNV and PVs. Although the CNV signal pattern does not differ depending on the degree of atrophy, there are cases in which only the trunk-like vessels connect to the PVs within the CNV in the atrophic phase without CNV flow signal.

Visual Acuity and Size of Choroidal Neovascularization in Highly Myopic Eyes with a Dome-Shaped Macula

Introduction

A dome-shaped macula (DSM) is an inward convexity or anterior deviation of the macular area. DSM is believed as a protective factor in maintaining visual acuity in highly myopic eyes.

Objective

To investigate the correlation between best-corrected visual acuity (BCVA), choroidal neovascularization (CNV), and a dome-shaped macula (DSM) in highly myopic eyes.

Methods

In this retrospective and observational case series study, BCVA tests and optical coherence tomography (OCT) were performed in a total of 472 highly myopic eyes (refractive error ≥6.5 diopters or axial length ≥26.5 mm). CNV was detected by fundus fluorescein angiography (FFA), and the CNV area was measured by ImageJ software. BCVA, central retinal thickness (CRT), and the CNV area were compared between highly myopic eyes with and without DSM.

Results

The data revealed 13 eyes with DSM complicated by CNV, for an estimated prevalence of 25%. The eyes with CNV in the DSM group showed worse BCVA than those in the non-DSM group (1.59 ± 0.69 and 0.63 ± 0.64, respectively, p < 0.05), and the CNV area in the DSM group was larger than that in the non-DSM group (2793.91 ± 2181.24 and 1250.71 ± 1210.36 pixels, respectively, p < 0.05). After excluding the eyes with CNV, the DSM group had better BCVA than the non-DSM group (0.33 ± 0.17 and 0.44 ± 0.48, respectively, p < 0.05); however, no significant difference was observed in the CRT of eyes with CNV between the DSM group and the non-DSM group.

Conclusion

These results show that DSM might be a protective mechanism for visual acuity, but its protective capability is limited. DSM eyes have better visual acuity within the protective capability. If a more powerful pathogenic factor exceeding the protective capability is present, then the eye will have more severe CNV and worse visual acuity.

Swept source OCT-Angiography assessing a case of aneurysmal type 1 neovascularization secondary to high-myopic posterior staphyloma

AIM

To report an uncommon case of aneurysmal type 1 neovascularization (polypoidal choroidal vasculopathy) secondary to high-myopic staphyloma in a Caucasian patient, assessed with multimodal imaging including swept source OCT-Angiography.

METHODS

Observational case report.

RESULTS

About 73-year-old Caucasian male patient with high myopia (axial length = 27.24 mm). Fundus examination showed a myopic conus and a deep orange-brownish nodular lesion at the edge of a deep haemorrhage and connected to a large choroidal vessel. ICGA showed a circular hyperfluorescent lesion in mid-phase, without any branching vascular network. OCT-Angiography could detect the aneurysmal lesion non-invasively as a small circular high-flow lesion in the outer retina slab, with a shadowing in the choriocapillaris slab. At the level of the aneurysmal lesion, structural OCT showed a high bilobed PED, without any subretinal fluid. A vascular flow was noted within the PED on cross-sectional OCT-A, confirming the vascular aneurysmal nature of this lesion. Additionally, swept source OCT highlighted the presence of an abrupt change in choroidal thickness, from 62 µm in the peripapillary area to 120 µm underneath the polypoidal lesion, with dilated choroidal vessels.

CONCLUSION

To our knowledge, this is the first report of OCT-A findings in aneurysmal (polypoidal) dilation secondary to high-myopic staphyloma. We could demonstrate the usefulness of OCT-A detecting non-invasively the aneurysmal dilation and the usefulness of swept source OCT assessing the choroidal structure to better understand the pathophysiology of this uncommon finding.

Optimizing the Repeatability of Choriocapillaris Flow Deficit Measurement From Optical Coherence Tomography Angiography

PURPOSE

To evaluate the impact of processing technique and slab selection on the repeatability of choriocapillaris (CC) flow deficit (FD) measurements as assessed using optical coherence tomography angiography (OCTA) DESIGN: Prospective, cross-sectional study.

METHODS

Healthy subjects were imaged with 4 consecutive 3 × 3-mm OCTA using a swept-source OCT (PLEX elite 9000; Carl Zeiss Meditec). OCTA images were generated using the Max projection, and three 10-μm-thick slabs starting 11, 21, and 31 μm posterior to the automatically segmented retinal pigment epithelial band. The resultant images were binarized using the Phansalkar method with a 43.94-μm radius and then the CCFD% was computed. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were computed for the 4 acquisitions to assess the repeatability of the CCFD%. This entire analysis was repeated after separately modulating several parameters: (1) Sum instead of the Max projection, (2) retinal pigment epithelial fit instead of the retinal pigment epithelial band as the offset reference, (3) 14.65 and 87.88 μm radius values instead of 43.94 μm.

RESULTS

Twenty-four healthy eyes (mean age; 36.4 years) were enrolled. The CCFD% in the 11-21-, 21-31-, and 31-41-μm slabs generated by the Max algorithm and the retinal pigment epithelial band showed high repeatability values (ICCs = 0.963, 0.975, and 911; CVs = 0.05, 0.05, and 0.05, respectively). As most of the cases were confounded with the hypointense region when the 11-21-μm slab was used, however, this slab could not be included in the subsequent analyses. Those values in the 21-31- and 31-41-μm slabs were higher than those of the corresponding slabs by the Sum algorithm (ICC = 0.916 and 0.776; CV = 0.15 and 0.19, respectively) or by the retinal pigment epithelial fit (ICC = 0.907 and 0.802; CV = 0.06 and 0.06, respectively). The Phansalkar radius of 43.94 μm had the highest ICC numerically, but this was not statistically significantly greater than for a radius of 14.65 μm (ICC = 0.960 and 0.911, respectively) or a radius of 87.88 μm (ICC = 0.958 and 0.897, respectively). Regardless of which parameter was modulated, the 21-31-μm slab was the most repeatable.

CONCLUSIONS

In normal eyes, en face CC OCTA images generated using the Max projection and a 10-μm-thick slab offset of 21 μm below the instrument-generated retinal pigment epithelial band yielded the most repeatable CCFD%. These findings have implications for the design of standardized processing algorithms for quantitative CC assessment.

Assessment of conbercept therapy for high myopia macular neovascularization by optical coherence tomography angiography

This study aimed to evaluate the efficacy and safety of the intravitreal injection of conbercept in the treatment of macular neovascularization (MNV) secondary to high myopia and to observe the application of optical coherence tomography angiography (OCTA) in the treatment follow-up. We reviewed the medical records of 20 patients (21 eyes) with MNV secondary to high myopia who were enrolled in the Department of Ophthalmology of the First Hospital of China Medical University between May 2018 and January 2020. Each patient received one or more intravitreal injections of conbercept (0.5 mg/0.05 mL). The treatment was conducted according to a 1 + PRN (pro re nata) regimen. The changes of best corrected visual acuity (BCVA), central macular thickness (CMT), and selected MNV and flow areas measured by OCTA were observed over a 6-month follow-up period. The mean logarithm of the minimum angle of resolution (logMAR) BCVA was 1.03 ± 0.61 before treatment and improved to 0.83 ± 0.59 (P = 0.007), 0.78 ± 0.62 (P = 0.001), 0.81 ± 0.73 (P = 0.027), and 0.79 ± 0.72 (P = 0.023) at 1 month, 2 months, 3 months, and 6 months after treatment, respectively. The mean CMT was 358.16 ± 206.11 μm before treatment and decreased to 295.38 ± 178.70 μm (P = 0.003), 288.34 ± 165.60 μm (P = 0.004), 284.36 ± 163.07 μm (P = 0.005), and 283.00 ± 160.32 μm (P = 0.004) at 1 month, 2 months, 3 months, and 6 months after treatment, respectively. Nineteen eyes (90.5%) had stable or improved vision at 6 months of follow-up. One month after conbercept injection, in OCTA images, the small-diameter blood vessels of the MNV decreased, the intertwined small blood vessels decreased or even disappeared, and the main or larger-diameter blood vessels were still present. The mean selected MNV and blood flow areas were 0.62 ± 0.81 and 0.22 ± 0.27 mm², respectively, before treatment and decreased to 0.23 ± 0.33 and 0.07 ± 0.08 mm² (P = 0.04 for both), respectively, 1 month after treatment. No drug-related systemic or ocular adverse effects were observed. Our results suggest that conbercept can effectively and safely improve BCVA and reduce CMT in patients with myopic MVN (mMNV). OCTA can be used to observe MNV area, blood flow area, and MNV morphological changes after treatment with conbercept, thus providing a reference for treatment follow-up.

Usefulness of Denoising Process to Depict Myopic Choroidal Neovascularisation Using a Single Optical Coherence Tomography Angiography Image

Quality of single optical coherence tomography angiography (OCTA) images of myopic choroidal neovascularisation (mCNV) is poorer than in averaged images, although obtaining averaged images takes much time. This study evaluated the clinical usefulness of novel denoising process for depicting mCNV. This study included 20 eyes of 20 patients with mCNV. Ten en face images taken in a 3 × 3 mm macular cube were obtained from outer-retina-to-choriocapillaris layer. Three image types were prepared for analysis; single images before and after the denoising process accomplished deep learning (single and denoising groups, respectively) and up to 10 images were averaged (averaging group). Pairwise comparisons showed vessel density, vessel length density, and fractal dimension (FD) were higher; whereas, vessel density index (VDI) was lower in single group than in denoising and averaging groups. Detectable CNV indices, contrast-to-nose ratio, and CNV diagnostic scores were higher in denoising and averaging groups than in single group. No significant differences were detected in VDI, FD, or CNV diagnostic scores between denoising and averaging groups. The denoising process can utilise single OCTA images to provide results comparable to averaged OCTA images, which is clinically useful for shortening examination times with quality similar to averaging.

Characterization of the Three Distinct Retinal Capillary Plexuses Using Optical Coherence Tomography Angiography in Myopic Eyes

Purpose

To segment and quantify three distinct retinal capillary plexuses using optical coherence tomography angiography (OCTA) in myopic eyes.

Methods

We analyzed 96 eyes from 62 subjects with myopia (27.76 ± 7.05 years of age) and evaluated 30 normal eyes from 15 subjects (28.33 ± 3.13 years of age) for controls. En face OCTA images generated by AngioPlex (Carl Zeiss; Oberkochen, Germany) were manually segmented by the progressive matching method into superficial, middle, and deep capillary plexuses (SCPs, MCPs, and DCPs, respectively). Estimated positions for each plexus relative to the reference line were calculated. After strict artifact removal and magnification correction, vessel density (VD) and skeleton density (SD) analyses were performed on each capillary plexus.

Results

Myopic eyes were divided into three groups according to their degree of myopia. We defined the relative estimated positions of the MCP outer boundary to the retinal pigment epithelium fit layer as MCP = –89.317 – 0.178 (central retinal thickness) – 0.580 (ganglion cell inner plexiform thickness); the DCP outer boundary was 38.48 ± 6.24 µm below the inner plexiform layer. VDs were significantly higher in the super-high myopia group than in the control and moderate myopia groups for the DCP (all P < 0.05). SDs in the SCPs were significantly lower in the high myopia and super-high myopia groups than in the control groups (all P < 0.001).

Conclusions

With progressive matching, we segmented three capillary plexuses and defined the relative estimated positions of each capillary plexus to the reference line in myopic eyes. The VD of the DCP increased for more myopic eyes.

Translational Relevance

Our study provides a visual method for OCTA image vascular segmentation for myopic eyes.

Alterations in optical coherence tomography angiography findings in patients with high myopia

PURPOSE

The aim of this study was to determine the macular changes using optical coherence tomography (OCT) and OCT-angiography (OCT-A) in eyes with high myopia. Determining the alterations in vascular structures can provide a clearer understanding of the pathophysiological mechanisms of this disease and help define new treatment options and preventive measures.

MATERIALS AND METHODS

Ninety-two patients with high myopia (axial length ≥ 26 mm) and 70 control cases without any known systemic or ocular diseases were enrolled in this prospective study. One eye of each patient was included in the statistical analyses.

RESULTS

Retinal nerve fiber layer (RNFL) thickness and Early Treatment Diabetic Retinopathy Study (ETDRS) macula map values were lower in myopia compared with the controls. Both superior and inferior ganglion cell complex (GCC) thicknesses were significantly thinner in the high myopia compared with the controls (p < 0.001). Regarding the OCT-A findings, although superficial or deep foveal avascular zones (FAZ) did not significantly differ between the two groups, the density values of superficial and deep microvessels were significantly lower in the high myopia group compared with the control cases.

CONCLUSIONS

In patients with high myopia, with an increase in the axial length and a decrease in RNFL and GCC thicknesses, the vascular densities of the superficial and deep retina were reduced in the macular region.

Presence or absence of choroidal hyper-transmission by SD-OCT imaging distinguishes inflammatory from neovascular lesions in myopic eyes

PURPOSE

To compare the characteristics of choroidal transmission in punctate inner choroidopathy (PIC) with or without choroidal neovascularization (CNV) and myopic CNV (mCNV) using spectral domain optical coherence tomography (SD-OCT).

METHODS

This retrospective observational case series includes 22 consecutive myopic patients (22 eyes) recruited from April 2016 until April 2018 who complained of acute blurring of vision and showed evidence of hyper-reflective material on SD-OCT imaging. Each patient underwent a comprehensive eye examination and imaging with fundus fluorescein angiography (FFA), SD-OCT, and SD-OCT angiography (SD-OCTA). Based on the results of SD-OCTA imaging and the color fundus imaging, the patients were divided into 2 groups: a group with myopic choroidal neovascularization (mCNV group, n = 10 eyes) and a group with PIC and no evidence of CNV at baseline (PIC group, n = 12 eyes). Four eyes diagnosed with PIC developed secondary PIC-CNV during follow-up. The characteristics of choroidal transmission in these eyes using SD-OCT imaging were compared.

RESULTS

At baseline, none of the PIC lesions showed any evidence of blood flow within the lesions on OCTA imaging. However, all of the eyes with mCNV showed flow signals within the subretinal neovascularization on SD-OCTA and subretinal or intra-retinal fluid on SD-OCT imaging. These eyes with mCNV showed subretinal hyper-reflectivity associated with choroidal hypo-transmission accompanied by retinal pigment epithelium (RPE) and ellipsoid zone (EZ) disruption. In eyes with PIC inflammatory lesions, disruption of both the RPE and EZ were observed in 33% of the inflammatory lesions, and disruption of the EZ alone was observed in 67% of the lesions at the baseline. They all showed a hyper-reflective subretinal lesion located above RPE. Three cases (25%) showed evidence of choroidal hyper-transmission at the baseline, while the remaining had normal transmission within the first month after onset. Hyper-transmission then developed in all the lesions as the disease progressed. Four cases of PIC (33%) developed PIC-related CNV that showed choroidal hypo-transmission along with hyper-transmission with disruption of the RPE and EZ. In cases with PIC-related CNV, evidences of neovascularization on SD-OCTA imaging were all detected afterwards. No intra-retinal fluid was detected before secondary CNV occurred.

CONCLUSION

SD-OCT imaging can noninvasively differentiate and track the progression of inflammatory lesions and myopic CNV by using the presence of choroidal hyper-transmission as a sign of just an inflammatory lesion and the presence hypo-transmission as a sign of a secondary CNV, which provides a convenient strategy for diagnosis and treatment of these lesions.

Microvasculature Changes of Myopic Choroidal Neovascularization and the Predictive Value of Feeder Vessel Disappearance after Ranibizumab Treatment Revealed Using Optical Coherence Tomography Angiography

AIM

To investigate vascular changes of myopic choroidal neovascularization (mCNV) after ranibizumab treatment using optical coherence tomography-angiography (OCTA).

METHODS

Consecutive subjects with a diagnosis of mCNV were included. Patients underwent intravitreal injection of ranibizumab treatment with a 6-month follow-up. All patients underwent a complete ophthalmological examination and OCTA evaluation. The 3 × 3 OCTA en face images were analyzed for the absence/presence of mCNV, CNV area, and CNV network morphology. In particular, the morphology of the mCNV was analyzed in order to detect the presence/absence of feeder vessels.

RESULTS

Eleven subjects were evaluated. At baseline, the mCNV was identified in all cases on OCTA. At 6 months, the mean mCNV area was not statically significantly reduced in comparison with baseline values (p > 0.05), while the morphologic analysis revealed a complete disappearance of the feeder vessel in 6 eyes. The subgroup analysis of these latter showed that the CNV area was significantly reduced, visual acuity had improved, and only one intravitreal injection was administrated over the entire follow-up period.

CONCLUSIONS

OCTA allowed the detection of qualitative and quantitative vascular changes in mCNV. The disappearance of the feeder vessel was associated with better anatomical as well as functional outcomes at the last follow-up visit.

Impact of Slab Selection on Quantification of Choriocapillaris Flow Deficits by Optical Coherence Tomography Angiography

PURPOSE

To assess the impact of slab selection on quantitative measurements of choriocapillaris (CC) flow deficits (FDs) using optical coherence tomography angiography (OCTA).

DESIGN

Cross-sectional study.

METHODS

Using a swept-source OCTA device, en face slabs to isolate the CC were first generated using the manufacturer's default setting: a 20-μm-thick slab starting 29 μm posterior to the centerline of the automatically segmented retinal pigment epithelium (RPE) band. The inner and/or outer borders were then adjusted by 2-μm increments to generate CC slabs with a range of offsets relative to the center of the RPE band. FDs of the modified slabs were compared to that of the default slab.

RESULTS

Twenty-seven eyes of healthy subjects (mean age, 42.0 years) were prospectively enrolled. FD% increased when the slab was shifted outward by ≥4 μm and inward by 20 μm (P < .05). Fifteen eyes (55.6%) showed large hypointense regions precluding quantification when the slab was shifted inward by 20 μm. Those without hypointensity demonstrated a decrease in FD% when the slab was shifted inward by 10-18 μm (P < .05). When modulating slab thickness, CC FD% increased and decreased when the slab thickness became thinner or thicker by ≥8 μm, respectively (P < .05).

CONCLUSIONS

Quantitative CC parameters may be significantly influenced by small differences in the slab selection. Slab close to the RPE can be susceptible to segmentation errors. These findings highlight the importance of accurate, precise, and consistent slab definition to reliably generate quantitative CC metrics from OCTA.

Structural and optical coherence tomography angiography in myopic choroidal neovascularization: Agreement with conventional fluorescein angiography

PURPOSE

To evaluate the agreement between fluorescein angiography and structural optical coherence tomography in diagnosing and monitoring the activity of myopic choroidal neovascularization and to provide a comparative analysis with optical coherence tomography angiography.

METHODS

Thirteen patients with active myopic choroidal neovascularization were prospectively enrolled. At the baseline, 2-month, and 6-month visits, each patient underwent a complete ophthalmological examination, including best-corrected visual acuity assessment, fundus examination, fluorescein angiography, and optical coherence tomography with structural and angiographic assessment. Sensitivity and specificity for all optical coherence tomography parameters were evaluated taking fluorescein angiography as the reference examination.

RESULTS

At the baseline, fluorescein angiography confirmed myopic choroidal neovascularization leakage in all patients. Structural optical coherence tomography demonstrated intraretinal or subretinal fluid in 61% of cases, fuzzy borders and absence of external limiting membrane visibility in 84% of cases, and subretinal hyperreflective exudation in 53% of cases. Sensitivity to the presence of retinal fluid and subretinal hyperreflective exudation was lower than sensitivity to fuzzy borders and external limiting membrane visibility, which reached 84%. During ranibizumab therapy, external limiting membrane visibility showed a higher sensitivity (100%) compared with fuzzy borders and subretinal hyperreflective exudation (66.6%) while displaying an equal specificity of 100%. At baseline and final visit, sensitivity increased to 100% when all structural optical coherence tomography parameters were pooled. Optical coherence tomography angiography detected myopic choroidal neovascularization at baseline, 2-month, and 6-month visits in 92%, 76%, and 76% of cases, respectively.

CONCLUSION

The study confirms that the new indicators of myopic choroidal neovascularization activity are more reliable than the presence or absence of retinal fluid. Optical coherence tomography angiography identified myopic choroidal neovascularization in most patients in the diagnostic phase and during treatment monitoring and could be considered as an alternative to fluorescein angiography in selected patients.

Arteriovenous crossing associated with branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is defined as the focal occlusion of a first or second-order branch of retinal vein, which occurs most frequently at an arteriovenous (AV) crossing. Direct ophthalmoscopy, color fundus photography, and fluorescein angiography facilitate observation of AV crossings parallel to the retinal plane. Optical coherence tomography (OCT), with its high-depth resolution, enables observation of retinal lesions perpendicular to the retinal plane. OCT angiography (OCTA) provides depth-resolved images of the retinal vasculature by segmenting three-dimensional data. In this review, we discuss novel findings related to affected AV crossings associated with BRVO obtained via OCT and OCTA. The high-depth resolution of OCT or OCTA is useful for observation of the narrowed vein and determination of the vessel position of the affected AV crossing. Studies using OCT and OCTA have shown that BRVO caused by a venous overcrossing is more prevalent than previously reported, and that venous narrowing was significantly greater in instances caused by a venous overcrossing than in those caused by an arterial overcrossing. Moreover, OCTA also revealed that the retinal nonperfusion area size was larger in eyes with BRVO caused by a venous overcrossing than in those with BRVO caused by an arterial overcrossing. This contrasts with earlier findings obtained by conventional imaging modalities predating OCT, which showed that an arterial overcrossing was more common than a venous overcrossing at the causative venous occlusion site in eyes with BRVO. This review discusses these findings and their significance in the study of AV crossing associated with BRVO.

Diagnostic accuracy of optical coherence tomography angiography for choroidal neovascularization: a systematic review and meta-analysis

BACKGROUND

Optical coherence tomography angiography (OCTA), an innovative image technique, renders visualization of ocular neovascularization through non-invasive means, which has been applied in recent years. Therefore, the present study was designed to assess the diagnostic value of OCTA in detecting the choroidal neovascularization (CNV).

METHODS

In brief, PubMed, Web of Science and Cochrane Library databases were systematically searched from January 2014 to June 2019. Afterwards, a meta-analysis was performed to determine the pooled diagnostic accuracy in a random-effects model using STATA 15.1 and Meta-Disc 1.4 software. Quality Assessment of diagnostic Accuracy Version 2 was used to evaluate the risk of bias of each study by Revman 5.3 software. In addition, a meta-regression model was further conducted to explore potential sources of heterogeneity.

RESULTS

According to pre-set inclusion and exclusion criteria, 16 eligible studies were enrolled in this study. A total of 447 CNV eyes and 414 non-CNV eyes were included to investigate the diagnostic accuracy of OCTA. As a result, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (PLR), diagnostic odds ratio (DOR) and the area under the summary receiver operating characteristic curve (sROC-AUC) were 0.87 (95% CI 0.81-0.92), 0.97 (95% CI 0.92-0.99), 32.7 (95% CI 10.1-105.5), 0.13 (95% CI 0.08-0.20), 252 (95% CI 63-1011) and 0.96 (95% CI 0.94-0.97), respectively.

CONCLUSIONS

In summary, we demonstrated that OCTA was of high diagnostic value for detecting intraocular CNV.

Novel Predictors of Visual Outcome in Anti-VEGF Therapy for Myopic Choroidal Neovascularization Derived Using OCT Angiography

PURPOSE

To explore novel prognostic factors associated with visual function and number of anti-vascular endothelial growth factor (VEGF) treatments in eyes with active myopic choroidal neovascularization (mCNV) using OCT angiography (OCTA).

DESIGN

Prospective case series.

PARTICIPANTS

Twenty-eight treatment-naïve eyes with active mCNV from 27 consecutive patients (mean age, 64.4 ± 11.1 years).

METHODS

All eyes received through injection a single loading dose of intravitreal aflibercept (IVA), followed by additional IVA on a pro re nata (PRN) basis during the subsequent 12 months. At baseline, OCTA images of a 3 × 3-mm macular cube were acquired using an OCTA scanner. On binarized and skeletonized OCTA images of the outer retinal layer, OCTA-derived baseline parameters of mCNV-including lesion size, vessel density, vessel length density (VLD), vessel diameter index, and fractal dimension (FD)-were measured and evaluated for correlation with 12-month best-corrected visual acuity (BCVA) and number of additional injections.

MAIN OUTCOME MEASURES

The primary and secondary outcomes were BCVA 12 months after initial treatment and number of additional injections, respectively.

RESULTS

There was no significant difference between baseline and 12-month BCVA (0.37 ± 0.30 and 0.30 ± 0.35 logarithm of the minimal angle of resolution, respectively; P = 0.23). The number of additional injections was 0.93 ± 1.02 (mean ± standard deviation). Baseline VLD, FD, and BCVA were correlated with 12-month BCVA (P = 0.02, r = 0.46; P = 0.02, r = 0.46; and P = 0.02, r = 0.45, respectively), and VLD also was correlated with the number of additional injections (P = 0.03, r = 0.42).

CONCLUSIONS

Exuberant mCNV, which is characterized by high VLD and FD derived using OCTA, is a predictor of poor visual outcomes after a single IVA injection followed by a PRN regimen. Only baseline VLD was correlated with the number of additional IVA injections, which indicates that this parameter could help to determine the optimal anti-VEGF treatment regimen for individual eyes with mCNV.

Branch Retinal Vein Occlusion: Treatment Outcomes According to the Retinal Nonperfusion Area, Clinical Subtype, and Crossing Pattern

This prospective study examined 58 eyes with branch retinal vein occlusion (BRVO) to investigate the effects of the nonperfusion area (NPA), clinical subtype, and crossing pattern on the 2-year outcomes of ranibizumab therapy for the macular edema (ME). All eyes received three initial monthly injections, followed by additional pro re nata (PRN) injections. The final best corrected visual acuity (BCVA) and ranibizumab injection number were not associated with the macular NPA or total NPA at baseline or month 12, and they showed no significant differences between the clinical subtypes. However, the incidence of neovascular changes was higher in the major BRVO group than in the macular BRVO group (P = 0.030). Twelve and 19 of the 34 eyes with major BRVO exhibited arterial overcrossing and venous overcrossing, respectively. At baseline, the total NPA did not differ according to the crossing pattern, however, the total NPA was significantly larger in the venous overcrossing group at month 12 (P = 0.047). At month 24, the incidence of neovascular changes was higher in the venous overcrossing group (P = 0.030). Following ranibizumab therapy for BRVO-associated ME, the clinical subtype and the arteriovenous crossing pattern may be associated with neovascular changes.

Test performance of optical coherence tomography angiography in detecting retinal diseases: a systematic review and meta-analysis

OBJECTIVE

To investigate the diagnostic accuracy of optical coherence tomography angiography (OCTA) in detecting vascular characteristics of chorio-retinal disease.

METHODS

Evidence acquisition: We searched Web of Science, Scopus, and Medline by the citation of references and complemented these electronic searches by checking the list of references of included and review articles. Screening, selection, assessment, and extraction was performed in parallel by two authors.

RESULTS

Evidence synthesis: Systematic review and exploratory meta-analysis. The ten studies that contributed to the meta-analysis enrolled 440 eyes and allowed constructing ten two-by-two tables. The tables reported on detection of choroidal neovascularization (CNV) in eyes suffering from either age-related macular degeneration (4), central serous chorioretinopathy (2), myopia (2), foveomacular vitelliform dystrophy (1), or a mixed cohort suffering from multiple retinal diseases (1). Of the ten studies, six used a cohort and four a case-control design. We found a pooled sensitivity of 0.90 (95% confidence intervals (CIs): 0.82-0.95) and a pooled specificity of 0.97 (95% CI: 0.89-0.99). Corresponding positive and negative likelihood ratios were 32.3 (95% CI: 7.4-141.6) and 0.10 (95% CI: 0.06-0.20), respectively. No pooling was possible for retinal vascular parameters of diabetic retinopathy, polypoidal choroidal vasculopathy, or detection of CNV activity.

CONCLUSIONS

The results of highly biased and heterogeneous studies assessing the diagnostic performance of OCTA highlight the need for further analyses of methodologically sound and sufficiently sized clinical evaluations.

Myopic maculopathy: Current status and proposal for a new classification and grading system (ATN)

Myopia is a highly frequent ocular disorder worldwide and pathologic myopia is the 4th most common cause of irreversible blindness in developed countries. Pathologic myopia is especially common in East Asian countries. Ocular alterations associated with pathologic myopia, especially those involving the macular area-defined as myopic maculopathy-are the leading causes of vision loss in patients with pathologic myopia. High myopia is defined as the presence of a highly negative refractive error (>-6 to -8 diopters) in the context of eye elongation (26-26.5 mm). Although the terms high myopia and pathologic myopia are often used interchangeably, they do not refer to the same eye disease. The two key factors driving the development of pathologic myopia are: 1) elongation of the axial length and 2) posterior staphyloma. The presence of posterior staphyloma, which is the most common finding in patients with pathologic myopia, is the key differentiating factor between high and pathologic myopia. The occurrence of staphyloma will, in most cases, eventually lead to other conditions such as atrophic, traction, or neovascular maculopathy. Posterior staphyloma is for instance, responsible for the differences between a myopic macular hole (MH)-with and without retinal detachment-and idiopathic MH. Posterior staphyloma typically induces retinal layer splitting, leading to foveoschisis in myopic MH, an important differentiating factor between myopic and emmetropic MH. Myopic maculopathy is a highly complex disease and current classification systems do not fully account for the numerous changes that occur in the macula of these patients. Therefore, a more comprehensive classification system is needed, for several important reasons. First, to more precisely define the disease stage to improve follow-up by enabling clinicians to more accurately monitor changes over time, which is essential given the progressive nature of this condition. Second, unification of the currently-available classification systems would establish standardized classification criteria that could be used to compare the findings from international multicentric studies. Finally, a more comprehensive classification system could help to improve our understanding of the genetic origins of this disease, which is clearly relevant given the interchangeable-but erroneous-use of the terms high and pathologic myopia in genetic research.

Diagnostic algorithm utilising multimodal imaging including optical coherence tomography angiography for the detection of myopic choroidal neovascularisation

PURPOSE

To develop a diagnostic algorithm in patients with pathologic myopia who present with typical symptoms or signs of myopic choroidal neovascularisation (mCNV).

METHODS

Retrospective study. Patients with high myopia and suspected mCNV underwent fluorescein angiography (FFA), structural spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Active mCNV on one imaging modality plus clinical features were considered as the benchmark reference for the other two tests. Sensitivity was calculated for each modality individually and in combination. Morphological features were noted on SD-OCT and OCTA.

RESULTS

Twenty-seven eyes of 26 patients were analysed. Sensitivity of SD-OCT or FFA alone was 85.19% (23/27 eyes). Sensitivity of OCTA was 74.07% (20/27 eyes). The sensitivity for SD-OCT combined with OCTA was 96.16% and combined with FFA was 97.80%. On OCTA, a "tight net" appearance was seen in 16 eyes (80%); a core vessel was visible in seven eyes (35%), all with active lesions. A "perilesional halo" was visible in 11 eyes (55%) of which 10 had active lesions.

CONCLUSION

When combined, OCTA and SD-OCT or SD-OCT and FFA showed similar higher sensitivities than each modality alone. A tight vascular net and the combination of a perilesional halo and a visible core on OCTA may serve as biomarkers of mCNV activity.

Imaging in myopia: potential biomarkers, current challenges and future developments

Myopia is rapidly increasing in Asia and around the world, while it is recognised that complications from high myopia may cause significant visual impairment. Thus, imaging the myopic eye is important for the diagnosis of sight-threatening complications, monitoring of disease progression and evaluation of treatments. For example, recent advances in high-resolution imaging using optical coherence tomography may delineate early myopic macula pathology, optical coherence tomography angiography may aid early choroidal neovascularisation detection, while multimodal imaging is important for monitoring treatment response. However, imaging the eye with high myopia accurately has its challenges and limitations, which are important for clinicians to understand in order to choose the best imaging modality and interpret the images accurately. In this review, we present the current imaging modalities available from the anterior to posterior segment of the myopic eye, including the optic nerve. We summarise the clinical indications, image interpretation and future developments that may overcome current technological limitations. We also discuss potential biomarkers for myopic progression or development of complications, including basement membrane defects, and choroidal atrophy or choroidal thickness measurements. Finally, we present future developments in the field of myopia imaging, such as photoacoustic imaging and corneal or scleral biomechanics, which may lead to innovative treatment modalities for myopia.

Vascular remodeling of choroidal neovascularization in older myopic patients treated with ranibizumab

PURPOSE

To investigate morphological changes in myopic choroidal neovascularization (mCNV) using optical coherence tomography-angiography (OCT-A) after treatment with ranibizumab.

METHODS

Retrospective analysis of consecutive patients over a 24-month period. All treatment-naïve mCNV were imaged at baseline with color pictures, spectral-domain OCT and OCT-A, and fluorescein angiography in selected cases. CNV morphology was classified at baseline and at 6 months. The CNV lesion surface was also compared.

RESULTS

Twenty-nine patients with a mean age of 70.3 ± 10.1 years were included. They received a mean number of 2.65 injections over 6 months. Best-corrected visual acuity improved from 62.2 to 68.5 letters (p = 0.004), with regression of exudation in 24 eyes (82.7%). Baseline CNV was classified into tree-in-bud (16 eyes), medusa (9 eyes), or sea-fan (4 eyes) pattern. At 6 months, no abnormal blood flow was observed in CNV in 13 eyes. Eyes with complete regression or evolution towards an indistinct pattern showed more often a complete regression of exudation than eyes with unchanged pattern (p = 0.007). The mean CNV surface significantly decreased from 0.19 to 0.08 mm² (p < 0.0001).

CONCLUSION

An unchanged pattern was more often associated with exudation persistence, while a complete regression or evolution towards indistinct pattern was always associated with vascular inactivity. However, variable changes in mCNV were observed after anti-VEGF. Thus, OCT-A could be more useful in the diagnosis than in the follow-up of mCNV.

Retinal vascular changes and aqueous humor cytokines changes after aflibercept intravitreal injection in treatment-naïve myopic choroidal neovascularization

The aim of the study was to assess retinal vascular changes using optical coherence tomography angiography (OCTA) and aqueous humour changes of vascular endothelial growth factor (VEGF) and placental growth factor (PIGF) levels in treatment-naïve myopic choroidal neovascularization (mCNV) after aflibercept intravitreal injection. To explore the correlation between clinical and laboratory parameters. Fifteen eyes of 15 patients with treatment-naïve mCNV underwent 2 intravitreal injections of aflibercept. Main outcome measures were best corrected visual acuity (BCVA), central retinal thickness (CRT) and external limiting membrane (ELM) visualization at OCT, lesion area and leakage at fluorescein angiography (FA), OCTA flow area and selected area at baseline and after the injections. Analysis of VEGF and PlGF in the aqueous humor was performed before each injection in cases and prior to cataract surgery on 10 patients as included as controls. Median BCVA increased from 0.6 to 0.3 logMAR (p < 0.001); CRT decreased from 387.5 to 267 micron (p < 0.001); FA area from 0.8 to 0.5 mm² and OCTA area from 0.9 to 0.5 mm² (p = 0.005). PIGF values changed from 1.8 to 1.4 pg/ml (p = 0.019) and VEGF values from 3.4 to 0.5 pg/ml (p = 0.008). A significant correlation was found after treatment between PIGF levels and BCVA (rho = 0.006) and VEGF levels and BCVA (rho = 0.018); between PlGF and CRT (rho = 0.020), PlGF and ELM visualization (rho = 0.002) and PlGF and FA leakage (rho < 0.001). Our results showed a significant reduction of mCNV area after aflibercept in both FA and OCTA measurements; an improvement of BCVA, and a reduction of VEGF and PIGF levels related to inactivity of the disease.

Fluorescein Leakage within Recent Subretinal Hemorrhage in Pathologic Myopia: Suggestive of CNV?

Purpose

To determine whether fluorescein leakage within subretinal hemorrhage is definitely suggestive of choroidal neovascularization (CNV) by multimodal imaging including optical coherence tomography angiography (OCTA).

Methods

Twenty-five consecutive highly myopic patients (25 eyes) with fluorescein leakage within subretinal hemorrhage detected within 1 month were prospectively included. All patients underwent OCTA and spectral-domain optical coherence tomography (SD-OCT). The OCTA and SD-OCT findings at the site of fluorescein leakage were analyzed. In cases of a doubtful diagnosis, indocyanine green angiography (ICGA) was also performed to differentiate myopic CNV from lacquer crack if necessary; all patients were followed up by SD-OCT and/or OCTA for at least 2 weeks.

Results

In terms of the site of fluorescein leakage, OCTA revealed an abnormal vascular network in the outer retina and a choriocapillaris slab in 22 out of 25 eyes (88%), which were confirmed to be CNV. However, no high-flow signal was observed in 3 of 25 eyes (12%). In these 3 cases, SD-OCT showed a focal rupture of the retinal pigment epithelium-Bruch's membrane-choriocapillaris (RPE-BM-CC) complex and a columnar hyperreflective signal of blood originating from defects with a volcanic geyser-like appearance, and no exudative signs were detected. Notably, all ruptures of the RPE-BM-CC complex were located exactly at lacquer crack sites. Moreover, with the absorption of subretinal hemorrhage, ruptures of the RPE-BM-CC complex spontaneously resolved without any intervention. Considering the multimodal imaging appearance and follow-up outcomes, these 3 eyes were eventually diagnosed as simple bleeding associated with lacquer cracks.

Conclusions

Dye leakage within recent subretinal hemorrhage on FA could be caused by new-onset lacquer cracks in pathologic myopia. Multimodal imaging including OCTA is helpful to differentiate lacquer cracks from myopic CNV.

Optical coherence tomography angiography in myopic choroidal neovascularization after intravitreal ranibizumab

PURPOSE:

To describe the optical coherence tomography angiography characteristics of myopic patients with choroidal neovascularization secondary to pathologic myopia during ranibizumab therapy.

METHODS:

Nineteen patients were enrolled in this prospective study (13 females, 6 males, mean age 55.25 ± 9.63 years) for a total of 20 eyes examined (14 right eyes, 6 left eyes). Images were analyzed independently by two examiners.

RESULTS:

Mean follow-up was 5.75 ± 1.88 months, with a mean intravitreal injections of 1.90 ± 0.44. Mean best-corrected visual acuity at baseline was 0.39 ± 0.18 logMAR versus 0.26 ± 0.16 logMAR 6 months after treatment. The neovascular area (Z = -2.091, p = 0.037) was significantly reduced after treatment, whereas vessel density was not (Z = -1.848, p = 0.065). Moreover, the best-corrected visual acuity was increased (Z = -3.055, p = 0.002). Neovascular area was significantly correlated with best-corrected visual acuity, at both baseline and follow-up (p < 0.05).

CONCLUSION:

Our data suggest that optical coherence tomography angiography is a reproducible non-invasive examination with which to monitor changes in the neovascular area in patients with pathologic myopia treated with ranibizumab.