RETINAL ANGIOMATOUS PROLIFERATION: Natural History and Progression of Visual Loss

Perifoveal vascular anomalous complex and telangiectatic capillaries: An overview of two entities potentially sharing a common pathophysiology

Focal capillary ectasia in the macular region can manifest in distinct clinical scenarios, which can be categorized into 2 main entities: perifoveal vascular anomalous complex (PVAC) and telangiectatic capillaries (TelCaps). PVAC represents a primary, idiopathic condition, whereas TelCaps occur secondary to underlying vascular disorders, including diabetic macular edema and retinal vein occlusion. We provide a comprehensive analysis of these 2 entities, encompassing their clinical presentations, multimodal imaging findings, histological evidence, and differential diagnosis from other retinal microvascular abnormalities, such as Type 1 macular telangiectasia, adult-onset Coats disease, Type 3 macular neovascularization in age-related macular degeneration, and retinal arterial macroaneurysms. Although PVAC and TelCaps are distinct entities, they may share common pathogenic mechanisms, including progressive endothelial dysfunction, pericyte loss, and intraluminal deposition of blood components. Selective laser photocoagulation has emerged as a promising therapeutic approach for both conditions. The proposed standardization of nomenclature for accurate reporting and meaningful cross-study comparisons is expected to facilitate future advancements in this field, ultimately leading to improved patient outcomes.

Aqueous Humor Levels of Vascular Endothelial Growth Factor in Patients With Dry Age-Related Macular Degeneration and Subretinal Drusenoid Deposits

Purpose

We sought to investigate aqueous humor levels of growth factors and cytokines related to human angiogenesis in patients with dry age-related macular degeneration (AMD).

Methods

This prospective study classified patients with dry AMD into two groups of patients-those with soft drusen and those with both soft drusen and subretinal drusenoid deposits (SDDs). Aqueous humor samples were collected from each group and from a control group to analyze intraocular cytokine concentrations and examine their associations with AMD characteristics.

Results

A total of 48 participants, 16 per group, were enrolled in the study. The vascular endothelial growth factor (VEGF)-A level was highest in the soft drusen with SDD group (229.21 ± 88.26 pg/mL) compared to the soft drusen group (167.54 ± 92.71 pg/mL) and the control group (140.73 ± 84.91 pg/mL) (P = 0.021). There were no significant differences in the concentrations of angiopoietin-2, placental growth factor, interleukin-1α, interleukin-1β, interleukin-6, interleukin-10, or tumor necrosis factor-α among the groups (all P > 0.05). In the soft drusen with SDD group, a higher cube root of drusen volume (β = 0.533, P = 0.033) was significantly associated with an elevated VEGF-A level.

Conclusions

In eyes with dry AMD, those with both soft drusen and SDDs exhibited higher intraocular VEGF-A levels than those with only soft drusen, and these levels correlated with the cube root of drusen volume.

Review of type 3 macular neovascularization in age-related macular degeneration: no DRAMA (Deep Retinal Age-related Microvascular Anomalies)

Type 3 macular neovascularization (MNV) is a unique form of neovascular age-related macular degeneration (AMD) that presents distinct pathogenetic features, clinical manifestations, and prognostic considerations when compared to types 1 and 2 MNV. Insights gained from clinicopathological correlations, bridging in vivo examination techniques with ex vivo histological analysis, have significantly enhanced our comprehension of this MNV phenotype, shaped current management strategies and influenced future directions for therapeutics. The particularities of type 3 MNV, which may largely stem from its origin from the retinal vasculature, are critically important for predicting the disease course. Our current understanding suggests that type 3 MNV occurs in response to retinal pigment epithelium (RPE) disruption and photoreceptor loss when neovessels originating from the deep capillary plexus are accompanied by activated Müller glia as they infiltrate sub-retinal pigment epithelium basal laminar deposits. Dysregulation of angiogenic and angiostatic factors are thought to play a key role in its pathogenesis. The prognosis for type 3 MNV is likely bilateral involvement and progression towards macular atrophy. It may be imperative for practitioners to distinguish type 3 MNV from other mimicking pathologies such as intraretinal microvascular anomalies, which are also part of the type 3 disease spectrum. For instance, deep retinal age-related microvascular anomalies (DRAMA) may present with similar features on multimodal imaging yet may necessitate distinct management protocols. Distinguishing between these conditions may be vital for implementing tailored treatment regimens and improving patient outcomes in the diverse landscape of AMD phenotypes in the future.

Long term follow up of patients with MNV3 treated with intra-vitreal Aflibercept

PURPOSE

MNV3 or Retinal angiomatous proliferation is a subtype of neovascular age-related macular degeneration (nAMD). We present the 5 year long term visual and anatomical outcomes of patients with MNV3 lesions treated with intravitreal Aflibercept.

METHODS

This is a prospective study of treatment naïve patients with reading centre graded MNV3 lesions. After the loading phase, the patients received intravitreal Aflibercept as per the View study up to year 3, thereafter it was given on a prn basis. At each visit, best corrected visual acuity (BCVA) and optical coherence tomography (OCT) central macular thickness (CMT) was measured.

RESULTS

Thirty one patients reached study completion. Mean BCVA of treated eyes had decreased by 0.6 ETDRS letters at the end of year 5 compared with baseline. At study completion, 81% of eyes had stable vision while 19% of eyes had gained 15 letters or more. At study end, 26% of eyes had BCVA of 6/12 or better, while 19% had lost 15 letters or more (all had central foveal photoreceptor loss). There was a maximal mean reduction in CMT of 164 microns (p = <0.0001) while 68% of maculae were fluid free at study completion. Eighty seven percent of treated eyes developed nascent GA, of which in 74% of eyes was involving the fovea.

DISCUSSION

Despite initial improvement in mean BCVA, the improvement in BCVA was not maintained despite good overall control of the MNV3 lesions. The loss of BCVA was most likely due to the majority of eyes developing centre involving macular atrophy.

The potential key role of choroidal non-perfusion and rod degeneration in the pathogenesis of macular neovascularization type 3

Macular neovascularization type 3 (MNV3) is a multifactorial disease with distinct epidemiological, clinical, pathomorphological and topographical characteristics. This review of the literature discusses the latest experimental and clinical outcomes that could explain the pathogenesis of retinal neovascularization. Although patients with MNV3 are usually older than those with MNV1 or 2, their lesions do not coexist with, precede, or follow other types in the same eye. The regional distribution of MNV3 lesions is characterized as confined to the parafoveal macula without any involvement of the rod-free foveal area. Focal outer retinal atrophy and choroidal non-perfusion are the main structural features that occur prior to the development of retinal neovascularization. Also, histological and experimental studies of MNV3 and other non-neovascular age-related macular degeneration diseases complicated with MNV3-like lesions strongly suggest rod degeneration contributes to the pathogenesis. Therefore, the retinal neovascularization in MNV3 has a different pathogenesis from the choroidal neovascularization in MNV1 and 2 and emerging evidence indicates that choroidal non-prefusion and rod degeneration play a key role in the pathogenesis of MNV3. Accordingly, we suggest a sequence of pathological events that start with choroidal non-perfusion due to advanced age followed by hypoxia of the outer retina at the parafoveal area. This induces a remarkable degeneration of rods that triggers the growth of retinal neovascularization due to the imbalance of the angiogenic factors in the outer retina.

Functional and structural characteristics in patients with type 3 macular neovascularisation treated with anti-VEGF. Three-year results in real world settings

BACKGROUND

To evaluate the long-term anatomical and functional outcomes of anti-Vascular Endothelial Growth Factor intravitreal injections (anti-VEGF IVI) in patients with type 3 macular neovascularisation (MNV) in real-world settings.

METHODS

Retrospective review of patients with type 3 MNV who received anti-VEGF IVI between 2013 and 2020. Primary outcomes were best corrected visual acuity (BCVA) and central macular thickness (CMT). Secondary outcome was the development of new-onset of foveal-involving geographic atrophy (GA) and disciform scars.

RESULTS

We identified 59 eyes from 48 British patients that met the inclusion criteria. Treatment with anti- VEGF IVI resulted in a statistically significant reduction in median CMT, which was maintained throughout the study period. At 36 months, 24 eyes showed more than 50 μm reduction in CMT, 7 eyes remained stable and only 2 eyes showed an increase in CMT by more than 50μm compared to the baseline. At year three, deterioration was noticed in most eyes (52.78%) and vision remained stable or improved in 47.22% of the eyes. However, the median BCVA was not statistically significant different compared to baseline. During the study period new onset of macula-involving atrophy or scar was noted in 10.2% and 4.3% of the eyes, respectively.

CONCLUSION

In this real-world study, anatomic and functional improvement were recorded 12-months post anti-VEGF IVI in type 3 MNV. Despite sustained anatomical improvement, vision returned back to baseline levels at 36-months. The development of GA and macular scar was only partially responsible for this outcome suggesting a more severe nature of this form of nAMD.

Inactivation of adenosine receptor 2A suppresses endothelial-to-mesenchymal transition and inhibits subretinal fibrosis in mice

Anti-vascular endothelial growth factor therapy has had a substantial impact on the treatment of choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (nAMD), the leading cause of vision loss in older adults. Despite treatment, many patients with nAMD still develop severe and irreversible visual impairment because of the development of subretinal fibrosis. We recently reported the anti-inflammatory and antiangiogenic effects of inhibiting the gene encoding adenosine receptor 2A (Adora2a), which has been implicated in cardiovascular disease. Here, using two mouse models of subretinal fibrosis (mice with laser injury-induced CNV or mice with a deficiency in the very low-density lipoprotein receptor), we found that deletion of Adora2a either globally or specifically in endothelial cells reduced subretinal fibrosis independently of angiogenesis. We showed that Adora2a-dependent endothelial-to-mesenchymal transition contributed to the development of subretinal fibrosis in mice with laser injury-induced CNV. Deficiency of Adora2a in cultured mouse and human choroidal endothelial cells suppressed induction of the endothelial-to-mesenchymal transition. A metabolomics analysis of cultured human choroidal endothelial cells showed that ADORA2A knockdown with an siRNA reversed the increase in succinate because of decreased succinate dehydrogenase B expression under fibrotic conditions. Pharmacological inhibition of ADORA2A with a small-molecule KW6002 in both mouse models recapitulated the reduction in subretinal fibrosis observed in mice with genetic deletion of Adora2a. ADORA2A inhibition may be a therapeutic approach to treat subretinal fibrosis associated with nAMD.

Current Perspectives on Type 3 Macular Neovascularization due to Age-Related Macular Degeneration

BACKGROUND

The aim of this review was to systematically summarize the current knowledge on type 3 macular neovascularization (MNV3) in age-related macular degeneration (AMD).

SUMMARY

Recent histopathologic and multimodal imaging findings led to the consensus definition of the new term "type 3 macular neovascularization" in AMD. MNV3 originates in the deep vascular plexus as a neovascular process without connection with the retinal pigment epithelium in the initial stages. This type has numerous clinical and pathomorphologic features that separate it from the other two types of MNV in AMD. Besides, its frequency appears to be higher than previously thought. In optical coherence tomography (OCT), MNV3 can be classified into stages 1-3. Hyperreflective foci in the outer retina possibly represent a precursor lesion. In addition, MNV3 is characterized by a strong association with reticular pseudodrusen, a high rate of bilaterality, close associations with advanced age and arterial hypertension, decreased choroidal thickness, and decreased choriocapillaris flow signals. Data from latest anti-vascular endothelial growth factor studies in MNV3 suggest that the OCT biomarkers in intraretinal and subretinal fluids should be interpreted differently than in the other types. Additionally, data from MNV3 eyes should be analyzed separately, allowing optimal type-specific treatment strategies in the future.

KEY MESSAGES

This review highlights the need for accurate characterization of neovascular AMD lesions and an MNV type-specific approach, particularly for MNV3.

Anti-vascular endothelial growth factor monotherapy or combined with verteporfin photodynamic therapy for retinal angiomatous proliferation: a systematic review with meta-analysis

Purpose: To assess functional and anatomical outcomes of intravitreal anti-Vascular Endothelial Growth Factor (anti-VEGF) monotherapy versus combined with verteporfin Photodynamic Therapy (PDT) for Retinal Angiomatous Proliferation (RAP). Methods: Studies reporting outcomes of intravitreal anti-VEGF monotherapy and/or in combination with verteporfin PDT in RAP eyes with a follow-up ≥ 12 months were searched. The primary outcome was the mean change in best corrected visual acuity (BCVA) at 12 months. Mean change in central macular thickness (CMT) and mean number of injections were considered as secondary outcomes. The mean difference (MD) between pre- and post-treatment values was calculated along with 95% Confidence Interval (95% CI). Meta-regressions were performed to assess the influence of anti-VEGF number of injections on BCVA and CMT outcomes. Results: Thirty-four studies were included. A mean gain of 5.16 letters (95% CI = 3.30-7.01) and 10.38 letters (95% CI = 8.02-12.75) was shown in the anti-VEGF group and combined group, respectively (anti-VEGF group vs. combined group, p < 0.01). A mean CMT reduction of 132.45 µm (95% CI = from -154.99 to -109.90) and 213.93 µm (95% CI = from -280.04 to -147.83) was shown in the anti-VEGF group and combined group, respectively (anti-VEGF group vs. combined group, p < 0.02). A mean of 4.9 injections (95% CI = 4.2-5.6) and 2.8 injections (95% CI = 1.3-4.4) were administered over a 12-month period in the anti-VEGF group and combined group, respectively. Meta-regression analyses showed no influence of injection number on visual and CMT outcomes. High heterogeneity was found across studies for both functional and anatomical outcomes. Conclusion: A combined approach with anti-VEGF and PDT could provide better functional and anatomical outcomes in RAP eyes compared with anti-VEGF monotherapy.

Characterisation of macular neovascularisation subtypes in age-related macular degeneration to optimise treatment outcomes

The aim of this review is to identify the common characteristics and prognoses of different subtypes of neovascular age-related macular degeneration (nAMD). We also propose recommendations on how to tailor treatments to the subtype of neovessels to optimise patient outcomes. The authors, selected members of the Vision Academy, met to discuss treatment outcomes in nAMD according to macular neovascularisation (MNV) subtypes, using evidence from a literature search conducted on the PubMed database (cut-off date: March 2019). This review article summarises the recommendations of the Vision Academy on how the characterisation of MNV subtypes can optimise treatment outcomes in nAMD. The identification of MNV subtypes has been facilitated by the advent of multimodal imaging. Findings from fluorescein angiography, indocyanine green angiography and spectral-domain optical coherence tomography collectively help refine and standardise the determination of the MNV subtype. To date, three subtypes have been described in the literature and have specific characteristics, as identified by imaging. Type 1 MNV is associated with better long-term outcomes but usually requires more intense anti-vascular endothelial growth factor dosing. Type 2 MNV typically responds quickly to treatment but is more prone to the development of fibrotic scars, which may be associated with poorer outcomes. Type 3 MNV tends to be highly sensitive to anti-vascular endothelial growth factor treatment but may be associated with a higher incidence of outer retinal atrophy, compared with other subtypes. Accurately assessing the MNV subtype provides information on prognosis and helps to optimise the management of patients with nAMD.

Three-Year Outcomes of Intravitreal Aflibercept Injections for Retinal Angiomatous Proliferation According to Disease Stage

INTRODUCTION

To evaluate the outcomes of intravitreal aflibercept injections for retinal angiomatous proliferation (RAP) according to disease stage.

METHODS

This retrospective chart review included 68 eyes of 53 individuals diagnosed as having RAP and 109 neovascular age-related macular degeneration (nAMD) eyes of 109 patients as controls. All patients received intravitreal injections of aflibercept in a real-world setting. The main outcome measures were the changes in the mean of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) as well as the total number of injections received during the 3-year follow-up period.

RESULTS

The average BCVA and CRT changes in eyes affected by RAP and the controls at 3 years were non-significant. Both populations received a similar number of injections. After 3 years of treatment, patients with RAP had visual decline despite stable anatomical outcomes. Approximately 50% of the eyes with stage II RAP exhibited significant BCVA decline at the end of the third year. Among those eyes that had deteriorated BCVA, persistently worsening BCVA and thinning CRT were observed from year 2 to year 3.

CONCLUSION

Similar to treating nAMD, intensive injections or aggressive treatment strategies are required to treat RAP to achieve optimal visual outcomes in a real-world setting. The response to aflibercept treatment at the second year is associated with the final visual outcome of eyes with stage II RAP lesions.

Classifying neovascular age-related macular degeneration with a deep convolutional neural network based on optical coherence tomography images

Neovascular age-related macular degeneration (nAMD) is among the main causes of visual impairment worldwide. We built a deep learning model to distinguish the subtypes of nAMD using spectral domain optical coherence tomography (SD-OCT) images. Data from SD-OCT images of nAMD (polypoidal choroidal vasculopathy, retinal angiomatous proliferation, and typical nAMD) and normal healthy patients were analyzed using a convolutional neural network (CNN). The model was trained and validated based on 4749 SD-OCT images from 347 patients and 50 healthy controls. To adopt an accurate and robust image classification architecture, we evaluated three well-known CNN structures (VGG-16, VGG-19, and ResNet) and two customized classification layers (fully connected layer with dropout vs. global average pooling). Following the test set performance, the model with the highest classification accuracy was used. Transfer learning and data augmentation were applied to improve the robustness and accuracy of the model. Our proposed model showed an accuracy of 87.4% on the test data (920 images), scoring higher than ten ophthalmologists, for the same data. Additionally, the part that our model judged to be important in classification was confirmed through Grad-CAM images, and consequently, it has a similar judgment criteria to that of ophthalmologists. Thus, we believe that our model can be used as an auxiliary tool in clinical practice.

The RAP study, report 3: Discoloration of the macular region in patients with macular neovascularization type 3

BACKGROUND/AIMS

To explore whether the existence and pattern of distribution of macular haemorrhage or exudate can be valuable diagnostic markers for macular neovascularization type 3 (MNV3) in patients with neovascular age-related macular degeneration.

METHODS

Eighty-three eyes of 83 consecutive treatment naïve patients with stage 3 MNV3 were enrolled. The diagnosis was based on fluorescein angiography (FA) and optical coherence tomography (OCT). Subretinal and intraretinal haemorrhage and dense exudates were evaluated on colour fundus photography. Fluorescein angiography (FA) images and OCT scans were used to identify the axial location of the haemorrhage. 83 patients with MNV1 and 83 with MNV2 were included as two control groups.

RESULTS

In the MNV3 group, 62 (75%) eyes had intraretinal haemorrhage and 52 (63%) had dense exudates. 73 (88%) eyes had intraretinal haemorrhage and/or dense exudates. 41 (49%) had both pathologies. The intraretinal haemorrhage was flame shaped over the lesion and punctate or semi-punctate further away from it and directed to the fovea. No subretinal haemorrhage was noticed. In the MNV1 and MNV2 groups, 11 (13%) and 24 (29%) eyes had subretinal haemorrhage or dense exudates, respectively. No intraretinal haemorrhage was seen in the two control groups. The prevalence of exudates and haemorrhage (irrespective of its location) was greater in MNV3 than in MNV1 or 2 (p < 0.0001).

CONCLUSION

The existence and pattern of distribution of intraretinal haemorrhage is pathognomonic of MNV3. It makes (alone or with dense exudates) the diagnose MNV3 possible using fundoscopy or colour fundus photo and without further diagnostic expenditure.

Neovascular age-related macular degeneration: A review of findings from the real-world Fight Retinal Blindness! registry

The use of vascular endothelial growth factor (VEGF) inhibitors has revolutionised the treatment of neovascular age-related macular degeneration (nAMD) since the pivotal Phase III studies demonstrated their efficacy more than 10 years ago. The Fight Retinal Blindness! project was developed to track the treatment outcomes of patients with nAMD in real-world practice. Data from this registry have been used to answer several clinically relevant questions related to the treatment of nAMD including the effect of under-treatment, the comparative effectiveness of different anti-vascular endothelial growth factor agents, long-term treatment outcomes, identifying optimal treatment regimens and the rate and outcomes of rare adverse events. Observational studies are a valuable complement to the shortcomings of clinical trials and a combination of data from real-world settings and clinical trials are necessary to provide evidence on how to achieve the best outcomes for individual patients with nAMD.

Distinguishing retinal angiomatous proliferation from polypoidal choroidal vasculopathy with a deep neural network based on optical coherence tomography

This cross-sectional study aimed to build a deep learning model for detecting neovascular age-related macular degeneration (AMD) and to distinguish retinal angiomatous proliferation (RAP) from polypoidal choroidal vasculopathy (PCV) using a convolutional neural network (CNN). Patients from a single tertiary center were enrolled from January 2014 to January 2020. Spectral-domain optical coherence tomography (SD-OCT) images of patients with RAP or PCV and a control group were analyzed with a deep CNN. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUROC) were used to evaluate the model's ability to distinguish RAP from PCV. The performances of the new model, the VGG-16, Resnet-50, Inception, and eight ophthalmologists were compared. A total of 3951 SD-OCT images from 314 participants (229 AMD, 85 normal controls) were analyzed. In distinguishing the PCV and RAP cases, the proposed model showed an accuracy, sensitivity, and specificity of 89.1%, 89.4%, and 88.8%, respectively, with an AUROC of 95.3% (95% CI 0.727-0.852). The proposed model showed better diagnostic performance than VGG-16, Resnet-50, and Inception-V3 and comparable performance with the eight ophthalmologists. The novel model performed well when distinguishing between PCV and RAP. Thus, automated deep learning systems may support ophthalmologists in distinguishing RAP from PCV.

Evaluating Retinal Angiomatous Proliferation With Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE

To report the imaging features of different stages of retinal angiomatous proliferation (RAP) on optical coherence tomography angiography (OCTA).

PATIENTS AND METHODS

Patients diagnosed with RAP were included in this study. All patients underwent fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), and OCTA. The OCTA features were illustrated and compared with FA, ICGA, and OCT. OCTA was performed at baseline and after injection of anti-vascular endothelial growth factor (VEGF).

RESULTS

A total of 12 eyes of 12 consecutive patients were included. Patients' ages ranged from 57 to 82 years. In all cases, the hot spot lesions found on FA or ICGA were clearly detected on OCTA in the same area (12/12, 100%). Hot spot lesions showed variable patterns. Four patients had multiple hot spot lesions located on the outer retina layer, deep layer, or superior retinal layer. OCTA showed a clearer location and relationship with feeder vessels compared with FA or ICGA. Eight patients had received anti-VEGF therapy 1.75 ± 1.06 times. Follow-up OCTA images demonstrated smaller and fewer hot spot lesions with lesser blood flow signal.

CONCLUSIONS

OCTA is a noninvasive, fast imaging modality for detecting microvascular changes, and it provides more detail of the RAP lesion and related vessels than ICGA or FA. OCTA would be a valuable tool for follow-up observation. The OCTA patterns of RAP may be helpful in understanding its pathology. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:136-144.].

Macrophage to myofibroblast transition contributes to subretinal fibrosis secondary to neovascular age-related macular degeneration

BACKGROUND

Macular fibrosis causes irreparable vision loss in neovascular age-related macular degeneration (nAMD) even with anti-vascular endothelial growth factor (VEGF) therapy. Inflammation is known to play an important role in macular fibrosis although the underlying mechanism remains poorly defined. The aim of this study was to understand how infiltrating macrophages and complement proteins may contribute to macular fibrosis.

METHODS

Subretinal fibrosis was induced in C57BL/6J mice using the two-stage laser protocol developed by our group. The eyes were collected at 10, 20, 30 and 40 days after the second laser and processed for immunohistochemistry for infiltrating macrophages (F4/80 and Iba-1), complement components (C3a and C3aR) and fibrovascular lesions (collagen-1, Isolectin B4 and α-SMA). Human retinal sections with macular fibrosis were also used in the study. Bone marrow-derived macrophages (BMDMs) from C57BL/6J mice were treated with recombinant C3a, C5a or TGF-β for 48 and 96 h. qPCR, Western blot and immunohistochemistry were used to examine the expression of myofibroblast markers. The involvement of C3a-C3aR pathway in macrophage to myofibroblast transition (MMT) and subretinal fibrosis was further investigated using a C3aR antagonist (C3aRA) and a C3a blocking antibody in vitro and in vivo.

RESULTS

Approximately 20~30% of F4/80+ (or Iba-1+) infiltrating macrophages co-expressed α-SMA in subretinal fibrotic lesions both in human nAMD eyes and in the mouse model. TGF-β and C3a, but not C5a treatment, significantly upregulated expression of α-SMA, fibronectin and collagen-1 in BMDMs. C3a-induced upregulation of α-SMA, fibronectin and collagen-1 in BMDMs was prevented by C3aRA treatment. In the two-stage laser model of induced subretinal fibrosis, treatment with C3a blocking antibody but not C3aRA significantly reduced vascular leakage and Isolectin B4+ lesions. The treatment did not significantly alter collagen-1+ fibrotic lesions.

CONCLUSIONS

MMT plays a role in macular fibrosis secondary to nAMD. MMT can be induced by TGF-β and C3a but not C5a. Further research is required to fully understand the role of MMT in macular fibrosis. Macrophage to myofibroblast transition (MMT) contributes to subretinal fibrosis. Subretinal fibrosis lesions contain various cell types, including macrophages and myofibroblasts, and are fibrovascular. Myofibroblasts are key cells driving pathogenic fibrosis, and they do so by producing excessive amount of extracellular matrix proteins. We have found that infiltrating macrophages can transdifferentiate into myofibroblasts, a phenomenon termed macrophage to myofibroblast transition (MMT) in macular fibrosis. In addition to TGF-β1, C3a generated during complement activation in CNV can also induce MMT contributing to macular fibrosis. RPE = retinal pigment epithelium. BM = Bruch's membrane. MMT = macrophage to myofibroblast transition. TGFB = transforming growth factor β. a-SMA = alpha smooth muscle actin. C3a = complement C3a.

Predictive Factors And Long-Term Visual Outcomes After Anti-Vascular Endothelial Growth Factor Treatment Of Retinal Angiomatous Proliferation

Purpose

To report the results of 9-year follow-up examinations and predictive factors for visual acuity outcome after intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents to treat retinal angiomatous proliferation (RAP).

Methods

We conducted a retrospective observational study of 85 treatment-naïve eyes in 61 patients (21 men, 40 women; age range, 70-95 years; mean age, 84.0 years) treated with intravitreal injections of anti-VEGF agents. All patients received three consecutive monthly injections as an induction treatment. During the maintenance phase, the patients received intravitreal injections as needed or fixed dosing. The primary outcome measures were best-corrected visual acuity (BCVA) during the follow-up period. Furthermore, we investigated potential predictive factors of improvement in visual acuity. The proportion of patients who developed specific complications were also analyzed.

Results

The mean BCVA gradually decreased from 0.58 at baseline to 0.70 at 36 months (P = 0.146), 0.82 at 48 months (P = 0.004), and 0.92 at 108 months (P = 0.021). Improvement in visual acuity at the final visits was associated with baseline visual acuity and central foveal thickness. Massive subretinal hemorrhage, fibrotic scars, and macular atrophy developed in 4 (4.7%), 9 (10.6%), and 50 (56.8%) eyes, respectively, at the final visits, and were all significantly associated with final visual acuity (P = 0.013, P < 0.001, and P = 0.001, respectively).

Conclusion

Long-term stabilization of vision in patients with RAP, regardless of treatment modality, was difficult to achieve by using intravitreal injections of anti-VEGF agents. Earlier detection and treatment are important to maintain visual acuity in patients with RAP.

Retinal and choroidal vascular changes in coronary heart disease: an optical coherence tomography angiography study

To reveal the association between retinal microvasculature changes and coronary heart disease (CHD), we assessed the full retinal thicknesses of eight areas, the vessel density of four layers (consisting of nine areas) and the flow area in two layers with optical coherence tomography angiography (OCTA) in CHD patients and healthy controls. The mean vessel density of several layers was significantly lower in patients. The difference in choroid capillary flow (negative correlation) between the two groups was significant. Decreased vessel density and blood flow were associated with coronary artery and branch stenosis. The decreases in retinal vessel density, choroidal vessel density, and blood flow area are closely related to coronary artery and branch stenosis.

Type 3 neovascularisation (retinal angiomatous proliferation) treated with antivascular endothelial growth factor: real-world outcomes at 24 months

Aims

To compare 24 months outcomes of eyes with retinal angiomatous proliferations (RAPs) treated with antivascular endothelial growth factor (anti-VEGF) with a group of controls diagnosed with other neovascular age-related macular degeneration (nAMD) subtypes in a real-world setting.

Methods

Treatment-naïve nAMD eyes that commenced anti-VEGF between January 2006 and November 2015 were identified from a registry of nAMD treatment outcomes. Cases were defined as eyes diagnosed with RAP. Three controls per case were selected among nAMD eyes with non-RAP lesions and matched on baseline visual acuity (VA), year of treatment initiation, anti-VEGF agent first injected and follow-up. Baseline VA was compared with 12 and 24 months VA. Change in VA, number of injections received, proportion of visits with active nAMD and time to first inactivation were compared between RAPs and controls.

Results

157 RAPs and 469 controls were included. Baseline VA (mean (SD)) increased at 12 months (61.4 (15.5) vs 68.7 (14.7) letters, p<0.001) and remained higher (66.6 (17.3) letters) at 24 months (p<0.001) in RAPs. The change from baseline VA (mean(95% CI)) was significantly higher in RAPs than in controls at 12 months (7.3 (5.4 to 9.1) vs 4.1 (2.8 to 5.4) letters, p=0.01) and at 24 months (5.1 (2.8 to 7.3) vs 2.5 (1 to 4) letters, p=0.056). Both groups received a median of 13 injections. RAPs inactivated earlier and were less active than controls (both p<0.001).

Conclusions

RAPs responded well to anti-VEGF, with a significant improvement in VA persisting at 24 months. RAPs had better visual outcomes than controls at 12 and 24 months, tended to inactivate earlier and were less active throughout 2 years follow-up.

Myofibroblasts in macular fibrosis secondary to neovascular age-related macular degeneration - the potential sources and molecular cues for their recruitment and activation

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in developed countries. Neovascular AMD (nAMD) accounts for 90% of AMD-related vision loss. Although intravitreal injection of VEGF inhibitors can improve vision in nAMD, approximately 1/3 of patients do not benefit from the therapy due to macular fibrosis. The molecular mechanism underlying the transition of the neovascular lesion to a fibrovascular phenotype remains unknown. Here we discussed the clinical features and risk factors of macular fibrosis secondary to nAMD. Myofibroblasts are key cells in fibrosis development. However, fibroblasts do not exist in the macula. Potential sources of myofibroblast precursors, the molecular cues in the macular microenvironment that recruit them and the pathways that control their differentiation and activation in macular fibrosis were also discussed. Furthermore, we highlighted the challenges in macular fibrosis research and the urgent need for better animal models for mechanistic and therapeutic studies.

Treatment Effects in Retinal Angiomatous Proliferation Imaged with OCT Angiography

PURPOSE

This prospective case series is aimed at exploring optical coherence tomographic angiography (OCT-A) as a treatment monitoring tool in patients treated for retinal angiomatous proliferation (RAP).

METHODS

Twelve treatment-naïve RAP patients were included, with a median age of 79 years (range 65-90). Patients were imaged with an experimental 1,040-nm swept-source phase-resolved OCT-A instrument before and after treatment. Treatment consisted of either intravitreal bevacizumab or triamcinolone injections with or without photodynamic therapy (PDT). Abnormal blood flow after treatment was graded as increased, unchanged, decreased, or resolved.

RESULTS

OCT-A images before and after treatment could be obtained in 9 patients. The median follow-up period was 10 weeks (range 5-19). After various treatments, the RAP lesion resolved in 7 patients, in 1 patient the OCT-A depicted decreased flow in the lesion, and 1 patient showed unchanged abnormal blood flow. Monotherapy with intravitreal bevacizumab injections resolved RAP in 1 out of 2 patients. Combined therapy of bevacizumab with PDT resolved RAP in 6 out of 7 patients.

CONCLUSIONS

OCT-A visualized resolution of abnormal blood flow in 7 out of 9 RAP patients after various short-term treatment sequences. OCT-A may become an important noninvasive monitoring tool for optimizing treatment strategies in RAP patients.

Incidence and risk factors of massive subretinal hemorrhage in retinal angiomatous proliferation

Objective

To evaluate the incidence and associated risk factors of massive subretinal hemorrhage (SRH) in patients with retinal angiomatous proliferation (RAP).

Methods

A total of 187 eyes of 135 treatment-naıve patients diagnosed with RAP were evaluated retrospectively. Clinical records including the time between the initial visit, last anti-vascular endothelial growth factor (VEGF) treatment, last stable examination, and the date of massive SRH were reviewed. Imaging findings including indocyanine green angiography (ICGA) and optical coherence tomography (OCT) were analyzed.

Results

Massive SRH developed in 18 eyes (9.6%) a median of 20 months after the initial presentation. Kaplan-Meier survival analysis revealed that the incidence (2.8, 5.8, 13.1, and 21.0% after 1,2,5 and 10 years, respectively) continuously increased. Among 14 eyes with discernable vascular anastomosis on baseline ICGA, 13 (92.8%) showed retinal arteriole involvement. On spectral-domain OCT imaging of the last visit prior to the massive SRH, a layered lamellar tissue complex was noted under the retinal pigment epithelium in 9 of 13 eyes, which was significantly associated with massive SRH[hazard ratio(HR),5.883;P = .010]. The average time between the last stable examination/last injection and the massive SRH was 2 and 5 months, respectively. The patients were treated with anti-VEGF, gas and recombinant tissue plasminogen activator injection; however, all except one eye had visual acuity worse than 20/1000 at the final visit.

Conclusions

Massive SRH can occur in RAP in the course of anti-VEGF treatment, resulting in severe vision loss. A proactive dosing regimen may be more appropriate for these RAP eyes.

Projection-resolved optical coherence tomography angiography exhibiting early flow prior to clinically observed retinal angiomatous proliferation

Purpose

The purpose of this study is to analyze early retinal angiomatous proliferation (RAP) utilizing a novel imaging modality, Projection-Resolved Optical Coherence Tomography Angiography (PR-OCTA).

Observations

Five months prior to the diagnosis of a RAP lesion, cross-sectional PR-OCTA demonstrated flow in the outer retina contiguous with the deep retinal capillary plexus (DCP) and adjacent to a small pigment epithelial detachment. After development of a clinically visible RAP lesion, cross-sectional PR-OCTA demonstrated the RAP lesion connecting DCP and sub-retinal pigment epithelial neovascularization.

Conclusions & importance

This is the first report of PR-OCTA demonstrating abnormal flow in the outer retina prior to the development of a clinically detectable RAP lesion. PR-OCTA may be useful for surveillance and to help further characterize and stage RAP lesions.

Short-term efficacy of intravitreal Aflibercept injections for retinal angiomatous proliferation

BACKGROUND

To evaluate the short-term efficacy of intravitreal injections of aflibercept (IVA) to treat retinal angiomatous proliferation (RAP) and identify factors related to functional outcomes.

METHODS

This retrospective case series consisted of 19 eyes in 19 patients with RAP. All 19 eyes received 3 monthly consecutive IVA. The primary outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT) after the last IVA.

RESULTS

Of the 19 treated eyes, 8 (42%) were pre-treated with 1 dose of bevacizumab one month prior to the initiation of treatment with aflibercept. BCVA was significantly improved and CRT was significantly reduced after 3 consecutive IVAs (P = 0.014 and P = 0.0002, respectively). Stabilization or improvement in BCVA was observed in 17 eyes (90%) treated with IVA. Eyes with baseline fibrovascular pigment epithelial detachment (PED) showed no significant gain in BCVA, and fibrovascular PED was negatively correlated with final BCVA (Spearman's correlation coefficient = - 0.481, P = 0.037). The mean follow-up was 3.5 ± 0.5 months.

CONCLUSIONS

In this short-term study, three consecutive IVAs showed efficacy for improving vision and reducing retinal edema in RAP patients. Eyes with fibrovascular PED showed poorer responses, and the presence of fibrovascular PED at baseline was negatively correlated with visual outcomes.

Association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V polymorphisms with retinal angiomatous proliferation compared with typical age-related macular degeneration: a meta-analysis

PURPOSE

To compare the published results of studies on the genotype association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V in cases diagnosed as retinal angiomatous proliferation (RAP) versus neovascular age-related macular degeneration (AMD) or healthy controls.

METHODS

Heterogeneity of studies was evaluated using Cochran's Q test and I-square index. To modify the heterogeneity in the variables, we used random effects model. Meta-analysis was performed using STATA.

RESULTS

Four studies were included with 1076 neovascular AMD patients, 222 RAP cases, and 2276 control subjects. Pooled overall odds ratios for RAP/AMD were 1.15 (95% CI 0.60-2.18) for GT versus GG, 3.52 (95% CI 1.25-9.91) for TT versus GG ARMS2, 0.98 (95% CI 0.22-4.29) for GA versus AA, 1.00 (95% CI 0.25-4.02) for GG versus AA CFHI62V, 0.57 (95% CI 0.35-0.93) for CT versus TT CFH Y402H, and 0.40 (95% CI 0.22-0.74) for CC versus TT CFH Y402H. Regression analysis showed that ARMS2 TT genotype has a statistically significant effect on RAP versus AMD compared to CFH genotypes (P < 0.001).

CONCLUSION

This meta-analysis disclosed a stronger effect of ARMS2 genotypes in RAP cases compared with CFH Y402H and I62V genotypes.

PREVALENCE OF SUBTYPES OF RETICULAR PSEUDODRUSEN IN NEWLY DIAGNOSED EXUDATIVE AGE-RELATED MACULAR DEGENERATION AND POLYPOIDAL CHOROIDAL VASCULOPATHY IN KOREAN PATIENTS

PURPOSE

To evaluate the prevalence and characteristics of subtypes of pseudodrusen in newly diagnosed exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

This retrospective cross-sectional study included 321 eyes of 321 patients who were newly diagnosed with exudative AMD or PCV. Reticular pseudodrusen was classified into dot pseudodrusen and ribbon pseudodrusen; the prevalence of each subtype was estimated and compared between exudative AMD excluding retinal angiomatous proliferation (RAP), PCV, and RAP. Patient age and choroidal thickness were compared between patients with dot pseudodrusen only and those with ribbon pseudodrusen.

RESULTS

The prevalence of reticular pseudodrusen was 13.9% (15 of 108 eyes) in exudative AMD excluding RAP, 3.4% (6 of 175 eyes) in PCV, and 68.4% (27 of 38 eyes) in RAP. Among the eyes with pseudodrusen, dot pseudodrusen and ribbon pseudodrusen were noted in 100% and 40.0%, respectively, in exudative AMD excluding RAP, 100% and 16.7%, respectively, in PCV, and 96.2% and 69.2%, respectively, in RAP. Ribbon pseudodrusen was more frequently observed in RAP (P = 0.032). Patients with ribbon pseudodrusen were significantly older (77.3 ± 6.6 years vs. 72.9 ± 8.1 years, P = 0.042) than those with dot pseudodrusen only.

CONCLUSION

The markedly higher incidence of ribbon pseudodrusen in RAP may suggest possible influence of ribbon pseudodrusen on the development of RAP.

Outcomes in Eyes with Retinal Angiomatous Proliferation in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT)

PURPOSE

To compare baseline characteristics, visual acuity (VA), and morphologic outcomes between eyes with retinal angiomatous proliferation (RAP) and all other eyes among patients with neovascular age-related macular degeneration (NVAMD) treated with anti-vascular endothelial growth factor (VEGF) drugs.

DESIGN

Prospective cohort study within the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

PARTICIPANTS

Patients with NVAMD.

METHODS

Reading center staff evaluated digital color fundus photographs, fluorescein angiography (FA) images, and optical coherence tomography (OCT) scans of eyes with NVAMD treated with either ranibizumab or bevacizumab over a 2-year period. Retinal angiomatous proliferation was identified by the intense intra-retinal leakage of fluorescein in combination with other associated features.

MAIN OUTCOME MEASURES

Visual acuity; fluorescein leakage; scar; geographic atrophy (GA) on FA; retinal thickness, fluid, and subretinal hyperreflective material (SHRM) on OCT; and the number of intravitreal anti-VEGF injections at 1 and 2 years.

RESULTS

Retinal angiomatous proliferation was present in 126 of 1183 (10.7%) study eyes at baseline. Mean VA improvement from baseline was greater (10.6 vs. 6.9 letters; P = 0.01) at 1 year, but similar at 2 years (7.8 vs. 6.2 letters; P = 0.34). At 1 year, eyes with RAP were more likely to have no fluid (46% vs. 26%; P < 0.001) on OCT, no leakage on FA (61% vs. 50%; P = 0.03), and greater reduction in foveal thickness (-240 μm vs. -161 μm; P < 0.001). They were more likely to demonstrate GA (24% vs. 15%; P = 0.01) and less likely to have scarring (17% vs. 36%; P < 0.001) or SHRM (36% vs. 48%; P = 0.01). These results were similar at 2 years. The mean change in lesion size at 1 year differed (-0.27 DA vs. 0.27 DA; P = 0.02), but was similar at 2 years (0.49 DA vs. 0.79 DA; P = 0.26). Among eyes treated PRN, eyes with RAP received a lower mean number of injections in year 1 (6.1 vs. 7.4; P = 0.003) and year 2 (5.4 vs. 6.6; P = 0.025).

CONCLUSIONS

At both 1 and 2 years after initiation of anti-VEGF treatment in CATT, eyes with RAP were less likely to have fluid, FA leakage, scar, and SHRM and more likely to have GA than eyes without RAP. Mean improvement in VA was similar at 2 years.

Col4a1 mutations cause progressive retinal neovascular defects and retinopathy

Mutations in collagen, type IV, alpha 1 (COL4A1), a major component of basement membranes, cause multisystem disorders in humans and mice. In the eye, these include anterior segment dysgenesis, optic nerve hypoplasia and retinal vascular tortuosity. Here we investigate the retinal pathology in mice carrying dominant-negative Col4a1 mutations. To this end, we examined retinas longitudinally in vivo using fluorescein angiography, funduscopy and optical coherence tomography. We assessed retinal function by electroretinography and studied the retinal ultrastructural pathology. Retinal examinations revealed serous chorioretinopathy, retinal hemorrhages, fibrosis or signs of pathogenic angiogenesis with chorioretinal anastomosis in up to approximately 90% of Col4a1 mutant eyes depending on age and the specific mutation. To identify the cell-type responsible for pathogenesis we generated a conditional Col4a1 mutation and determined that primary vascular defects underlie Col4a1-associated retinopathy. We also found focal activation of Müller cells and increased expression of pro-angiogenic factors in retinas from Col4a1(+/Δex41)mice. Together, our findings suggest that patients with COL4A1 and COL4A2 mutations may be at elevated risk of retinal hemorrhages and that retinal examinations may be useful for identifying patients with COL4A1 and COL4A2 mutations who are also at elevated risk of hemorrhagic strokes.

One year results of intravitreal ranibizumab monotherapy for retinal angiomatous proliferation: a comparative analysis based on disease stages

Background

Retinal angiomatous proliferation (RAP) has been known as a variant of exudative age-related macular degeneration (AMD) with a unfavorable prognosis. To evaluate the effect of ranibizumab administered initially as three loading doses for patients with various stages of RAP.

Methods

A retrospective chart review of 40 patients (41 eyes) with RAP was conducted. The study divided patients into three groups of Group I (8 eyes in stage I), Group II (17eyes in stage II), and Group III (16 eyes in stage III). All patients received three initial monthly intravitreal injections (0.5 mg) of ranibizumab and were monitored monthly for 12 months. Reinjection of ranibizumab after three initial monthly doses was administered on as-needed basis. The main outcome measures were the change in the mean of best-corrected Snellen visual acuity (BCVA) and central macular thickness (CMT), and the total number of injections received during the 12 months.

Results

The mean change in BCVA at 12 months was-0.286,-0.165, and-0.151 (logMAR) in Group I, II, and III, respectively. CMT was also reduced by a mean of 32.72 ± 56.75, 57.45 ± 56.48 and 148.37 ± 98.59 μm. The mean number of injections in Group I was significant lower than those in Group II and III (P < 0.001, P < 0.001, and P = 0.15 for Group I versus Group II, Group I versus Group III, and Group II versus Group III, respectively).

Conclusions

The 12-month follow-up outcomes suggest that three consecutive loading doses of intravitreal ranibizumab is an effective treatment on early stage (stage I) of RAP. Patients in stage I showed a significantly lower recurrence rate than patients in later stages.

Long-Term Management of RAP Lesions in Clinical Practice: Treatment Efficacy and Predictors of Functional Improvement

PURPOSE

To evaluate the long-term efficacy of ranibizumab in the treatment of retinal angiomatous proliferation (RAP) and to identify predictors of functional outcome.

METHODS

Retrospective case series comprised 79 eyes of 68 consecutive patients with RAP followed up ≥36 months. Primary end-points were best-corrected visual acuity (BCVA) and central macular thickness (CMT) variation at 36 months and at the last visit.

RESULTS

Mean follow-up time was 59.8 ± 16.0 months. All eyes were treated with pro re nata ranibizumab, with (n = 33) or without (n = 46) photodynamic therapy (PDT). Stabilization or improvement in BCVA was observed in 50.6% of the patients at 36 months, and in 40.5% at the end of the follow-up, where 20.3% preserved reading vision. A significant decrease in CMT was observed at 36 months (p < 0.001), but not at the end of the follow-up. Geographic atrophy (GA) was present in 59.5% of the eyes at the final visit. Baseline subretinal fluid was associated with better visual outcomes (p = 0.001). Results of combination treatment with intravitreal ranibizumab and PDT did not significantly differ from ranibizumab monotherapy.

CONCLUSION

Modest functional outcomes can be expected from the long-term treatment of RAP lesions in clinical practice, most likely due to the advent of GA. Baseline subretinal fluid positively correlated with final BCVA.

Phase-Resolved Doppler Optical Coherence Tomographic Features in Retinal Angiomatous Proliferation

PURPOSE

To study patients diagnosed with retinal angiomatous proliferation (RAP) based on conventional imaging techniques with phase-resolved Doppler optical coherence tomography (OCT) to detect and localize blood flow in RAP lesions; and to compare these findings to conventional imaging, which are mostly invasive and give limited information concerning intra- and transretinal blood flow.

DESIGN

Single-center, consecutive observational case series.

METHODS

Twelve treatment-naïve patients diagnosed with RAP based on fundus examination, fluorescein angiography, and indocyanine green angiography were included. Median age was 79 years (range 65-90). Patients were imaged with an experimental 1040 nm swept-source phase-resolved Doppler OCT instrument. Abnormal flow was defined as intraretinal neovascularization or retinal choroidal anastomosis.

RESULTS

In 11 patients adequate phase-resolved Doppler OCT images were obtained showing abnormal blood flow in the RAP lesion. In 4 patients a retinal choroidal anastomosis was found, 3 patients showed intraretinal neovascularization connected with a pigment epithelial detachment, 2 patients showed only intraretinal neovascularization, and in 2 patients flow was limited to the subretinal or sub-retinal pigment epithelial space.

CONCLUSIONS

Phase-resolved Doppler OCT is able to detect and localize abnormal blood flow within RAP lesions. Blood flow was mostly confined to the intraretinal structures with or without a connecting pigment epithelial detachment; in one-third of patients a retinal choroidal anastomosis was detected. The potential of angiography with phase-resolved Doppler OCT to accurately distinguish between normal and pathologic blood flow in addition to structural OCT data without invasive procedures will help to further elucidate both retinal and choroidal vascular pathologies like RAP.

Environmental and genetic risk factors for retinal angiomatous proliferation

PURPOSE

To identify genetic and environmental risk factors in patients with retinal angiomatous proliferation (RAP), a clinical subtype of age-related macular degeneration (AMD).

METHODS

In this case-control study, 108 AMD cases with RAP, 258 AMD patients with choroidal neovascularization (CNV) without RAP and 443 healthy controls were evaluated. Single nucleotide polymorphisms in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) and various environmental risk factors were analysed. Statistical analysis was performed by univariate and multivariate regression analysis.

RESULTS

High age, female sex and genetic variants in CFH and ARMS2 were identified as risk factors for developing any CNV. In RAP patients, arterial hypertension was also identified as a risk factor (OR 2.39; p = 0.0005). Compared with the 'non-RAP' CNV group, the association with high age (OR 1.05; p = 0.008) and arterial hypertension (OR 1.82; p = 0.02) was significantly higher in RAP patients, while the association with CFH risk alleles (homozygous OR 0.40; p = 0.003) was significantly lower, which was confirmed in a multivariate analysis (OR 0.41; p = 0.03 for the heterozygous risk allele and OR 0.38; p = 0.03 for the homozygous risk allele).

CONCLUSION

The association with the CFH Y402 risk allele was less pronounced in RAP patients than in 'non-RAP' CNV patients, while the association with high age and arterial hypertension appeared to be stronger. These findings stress the importance of detailed phenotyping in AMD to identify homogeneous AMD subtypes and their different risk factors and disease mechanisms.

Incidence and characteristics of neovascularization in fellow eyes of Japanese patients with unilateral retinal angiomatous proliferation

PURPOSE

To describe the incidence and characteristics of neovascularization in fellow eyes of Japanese patients with unilateral retinal angiomatous proliferation (RAP).

METHODS

We retrospectively studied patients with unilateral RAP in one center between 2003 and 2010. The minimal follow-up time was 2 years. The prevalence rates of soft drusen and reticular pseudodrusen in the fellow eyes at the first visit were examined in color fundus photographs and optical coherence tomography images. Stepwise analysis was performed to identify a correlation between the incidence of RAP in the fellow eyes and age, gender, follow-up time, soft drusen, and reticular pseudodrusen.

RESULTS

Twenty eyes were included in this study. The mean follow-up time was 49 months (range, 24-108 months). At the first visit, soft drusen was seen in 19 eyes (95%) and reticular pseudodrusen in 11 eyes (55%). Neovascular age-related macular degeneration developed in 10 eyes, including RAP in 9 eyes (45%) and polypoidal choroidal vasculopathy in 1 eye (5%). Stepwise analysis showed that reticular pseudodrusen and longer follow-up time were correlated significantly (P = 0.0384 and P = 0.0341, respectively) with the incidence of RAP.

CONCLUSION

Bilateral RAP developed in almost half of the eyes initially diagnosed with unilateral RAP and the incidence increased with time. Reticular pseudodrusen is a risk factor for bilateral RAP.

Characterization of a spontaneous retinal neovascular mouse model

BACKGROUND

Vision loss due to vascular disease of the retina is a leading cause of blindness in the world. Retinal angiomatous proliferation (RAP) is a subgroup of neovascular age-related macular degeneration (AMD), whereby abnormal blood vessels develop in the retina leading to debilitating vision loss and eventual blindness. The novel mouse strain, neoretinal vascularization 2 (NRV2), shows spontaneous fundus changes associated with abnormal neovascularization. The purpose of this study is to characterize the induction of pathologic angiogenesis in this mouse model.

METHODS

The NRV2 mice were examined from postnatal day 12 (p12) to 3 months. The phenotypic changes within the retina were evaluated by fundus photography, fluorescein angiography, optical coherence tomography, and immunohistochemical and electron microscopic analysis. The pathological neovascularization was imaged by confocal microscopy and reconstructed using three-dimensional image analysis software.

RESULTS

We found that NRV2 mice develop multifocal retinal depigmentation in the posterior fundus. Depigmented lesions developed vascular leakage observed by fluorescein angiography. The spontaneous angiogenesis arose from the retinal vascular plexus at postnatal day (p)15 and extended toward retinal pigment epithelium (RPE). By three months of age, histological analysis revealed encapsulation of the neovascular lesion by the RPE in the photoreceptor cell layer and subretinal space.

CONCLUSIONS

The NRV2 mouse strain develops early neovascular lesions within the retina, which grow downward towards the RPE beginning at p15. This retinal neovascularization model mimics early stages of human retinal angiomatous proliferation (RAP) and will likely be a useful in elucidating targeted therapeutics for patients with ocular neovascular disease.

Risk of scar in the comparison of age-related macular degeneration treatments trials

OBJECTIVE

To describe risk factors for scar in eyes treated with ranibizumab or bevacizumab for neovascular age-related macular degeneration (AMD).

DESIGN

Prospective cohort study within a randomized clinical trial.

PARTICIPANTS

Patients with no scar on color fundus photography (CFP) or fluorescein angiography (FA) at enrollment in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT).

METHODS

Eyes were assigned to ranibizumab or bevacizumab treatment and to 1 of 3 dosing regimens for 2 years. Masked readers assessed CFP and FA. Baseline demographic characteristics, visual acuity, morphologic features on photography and optical coherence tomography (OCT), and genotypes associated with AMD risk were evaluated as risk factors using adjusted hazard ratios (aHRs) and associated 95% confidence intervals (CIs). Scars were classified as fibrotic with well-demarcated elevated mounds of yellowish white tissue or nonfibrotic with discrete flat areas of hyperpigmentation with varying amounts of central depigmentation.

MAIN OUTCOME MEASURES

Scar formation.

RESULTS

Scar developed in 480 of 1059 eyes (45.3%) by 2 years. Baseline characteristics associated with greater risk of scarring were predominantly classic choroidal neovascularization (CNV) (aHR, 3.1; CI, 2.4-3.9) versus occult CNV, blocked fluorescence (aHR, 1.4; CI, 1.1-1.8), foveal retinal thickness >212 μm (aHR, 2.4; CI, 1.7-3.6) versus <120 μm, foveal subretinal tissue complex thickness >275 μm (aHR, 2.4; CI, 1.7-3.6) versus ≤75 μm, foveal subretinal fluid (aHR, 1.5; CI, 1.1-2.0) versus no subretinal fluid, and subretinal hyperreflective material (SHRM) (aHR, 1.7; CI, 1.3-2.3) versus no SHRM. Eyes with elevation of the retinal pigment epithelium had lower risk (aHR, 0.6; CI, 0.5-0.8) versus no elevation. Drug, dosing regimen, and genotype had no statistically significant association with scarring. Fibrotic scars developed in 24.7% of eyes, and nonfibrotic scars developed in 20.6% of eyes. Baseline risk factors for the scar types were similar except that eyes with larger lesion size or visual acuity <20/40 were more likely to develop fibrotic scars.

CONCLUSIONS

Approximately half of eyes enrolled in CATT developed scar by 2 years. Eyes with classic neovascularization, a thicker retina, and more fluid or material under the foveal center of the retina are more likely to develop scar.

Retinal angiomatous proliferation associated with risk alleles of ARMS2/HTRA1 gene polymorphisms in Japanese patients

Background

The purpose of this study was to investigate the association between ARMS2/HTRA1, CFH, and C3 gene polymorphisms and retinal angiomatous proliferation (RAP), an infrequent and severe form of exudative age-related macular degeneration, which is characterized by intraretinal neovascularization.

Methods

Diagnosis of RAP was based on fundus photographs, images of fluorescein and indocyanine green angiographies, and optical coherence tomography findings. Six single nucleotide polymorphisms (SNPs), A69S (rs10490924) in ARMS2, rs11200638 in HTRA1, I62V (rs800292) in CFH, Y402H (rs1061170) in CFH, R80G (rs2230199) in C3, and rs2241394 in C3, were genotyped in eight Japanese patients with RAP.

Results

The two SNPs in the ARMS2/HTRA1 were in complete linkage disequilibrium. The frequency of the risk T allele in ARMS2 (the risk A allele in HTRA1) was 93.8% in the RAP patients. The frequency of homozygosity for the risk genotype TT of ARMS2 (the risk genotype AA of HTRA1) was 87.5%. The frequency of the non-risk allele (A) of I62V was 100%. The frequencies of risk alleles of Y402H, R80G, and rs2241394 were 12.5%, 0%, and 18.8%, respectively.

Conclusion

Our results suggest that the risk alleles of the ARMS2/HTRA1 SNPs may be associated with development of RAP and play a major role in the pathogenesis of intraretinal angiogenesis.