SUBRETINAL FIBROSIS AFTER ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY IN EYES WITH MYOPIC CHOROIDAL NEOVASCULARIZATION

Sustained therapeutic effect of an anti-inflammatory peptide encapsulated in nanoparticles on ocular vascular leakage in diabetic retinopathy

Pigment epithelium-derived factor (PEDF), an endogenous Wnt signaling inhibitor in the serine proteinase inhibitors (SERPIN) super family, is present in multiple organs, including the vitreous. Significantly low levels of PEDF in the vitreous are found to associate with pathological retinal vascular leakage and inflammation in diabetic retinopathy (DR). Intravitreal delivery of PEDF represents a promising therapeutic approach for DR. However, PEDF has a short half-life after intravitreal injection, which represents a major hurdle for the long-term treatment. Here we report the prolonged therapeutic effects of a 34-mer peptide of the PEDF N-terminus, encapsulated in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (PEDF34-NP), on DR. PEDF34-NP inhibited hypoxia-induced expression of vascular endothelial growth factor and reduced levels of intercellular adhesion molecule 1 (ICAM-1) in cultured retinal cells. In addition, PEDF34-NP significantly ameliorated ischemia-induced retinal neovascularization in the oxygen-induced retinopathy rat model, and significantly reduced retinal vascular leakage and inflammation in streptozotocin-induced diabetic rats up to 4 weeks after intravitreal injection, as compared to PLGA-NP control. Intravitreal injection of PEDF34-NP did not display any detectable toxicities to retinal structure and function. Our findings suggest that PEDF34-NP can confer sustained therapeutic effects on retinal inflammation and vascular leakage, having considerable potential to provide long-term treatment options for DR.

Long-term Incidence and Risk Factors of Macular Fibrosis, Macular Atrophy, and Macular Hole in Eyes with Myopic Neovascularization

PURPOSE

To identify the risk factors associated with myopic macular neovascularization (mMNV)-related complications in patients treated with intravitreal anti-VEGF agents.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

Myopic eyes (n = 313) with active mMNV and median (interquartile range) follow-up of 42 months (interquartile range, 18-68 months) after initiation of anti-VEGF treatment.

METHODS

Data regarding patients' clinical and mMNV-related characteristics were collected at baseline. Subsequent OCT scans were inspected for mMNV-related complications. Best-measured visual acuity (BMVA) values were retrieved from each visit.

MAIN OUTCOME MEASURES

Incidence rate and hazard ratio (HR, with 95% confidence interval [CI]) of risk factors for fibrosis and macular atrophy calculated with Kaplan-Meier curves and Cox regression models. Crude incidence of macular hole (MH). Longitudinal BMVA changes.

RESULTS

Five-year incidence of fibrosis, atrophy, and MH were 34%, 26%, and 8%, respectively. The rate of fibrosis was 10.3 (95% CI, 8.25-12.6) per 100 person-years. Risk factors were subfoveal mMNV location (HR [95% CI] = 12.7 [2.70-56.7] vs. extrafoveal, P = 0.001) and intraretinal fluid at baseline (HR [95% CI] = 1.75 [1.05-2.98], P = 0.03). The rate of macular atrophy was 6.5 (95% CI, 5-8.3) per 100 person-years. Risk factors were diffuse (HR, 2.20 vs. tessellated fundus; 95% CI, 1.13-5.45; P = 0.02) or patchy chorioretinal atrophy (HR, 3.17 vs. tessellated fundus; 95% CI, 1.32-7.64; P = 0.01) at baseline and more numerous anti-VEGF injections before baseline (HR, 1.21; 95% CI, 1.06-1.38 for each treatment; P = 0.005). Eyes with fibrosis and macular atrophy had faster BMVA decay over follow-up. Twenty eyes (6%) developed MH. Two subtypes of MH were identified: "atrophic" and "tractional."

CONCLUSIONS

Myopic MNV-related complications are common in the long term despite initially successful treatment and have detrimental effects on visual acuity. Insights into their incidence and risk factors may help for future treatments to mitigate sight-threatening outcomes.

Association of Retinal Sensitivity With Optical Coherence Tomography Microstructure in Highly Myopic Patients

Purpose

To investigate the association of retinal sensitivity with microstructural features in optical coherence tomography (OCT) of high myopic eyes.

Methods

This cross-sectional study included 78 eyes (78 patients). Microstructural features on spectral-domain OCT, such as the integrity of the retinal pigment epithelium (RPE), ellipsoid zone (EZ), and external limiting membrane (ELM) and outer retinoschisis, were evaluated at each retinal location corresponding to microperimetric testing points.

Results

For all testing points, retinal sensitivity was significantly associated with the integrity of the RPE, EZ, and ELM (all P < 0.001) based on OCT but not with outer retinoschisis (P = 0.183). A higher category of myopic maculopathy according to the Meta-Analysis of Pathologic Myopia classification was associated with lower mean retinal sensitivity (P < 0.001). In eyes with patchy atrophy (PA), mean retinal sensitivity of testing points adjacent to the PA lesion (15.7 ± 6.8 dB) was greater than points within or at the PA border (2.6 ± 5.2 dB; P < 0.001) but lower than distant points (19.6 ± 4.3 dB; P < 0.001). Microstructural features in OCT were well correlated with the differences in retinal sensitivity according to myopic maculopathy severity and proximity to the PA lesion.

Conclusions

In highly myopic eyes, retinal sensitivity on microperimetry was strongly associated with microstructural features in OCT. Both retinal sensitivity and microstructure were affected by the severity of myopic degeneration and proximity to the PA lesion.

Risk factors for myopic choroidal neovascularization-related macular atrophy after anti-VEGF treatment

Purpose

The study aimed to evaluate risk factors for macular atrophy (MA) associated with myopic choroidal neovascularization (mCNV) during long-term follow-up after intravitreal anti-vascular endothelial growth factor (VEGF) treatment in highly myopic eyes.

Methods

The medical records of patients who received intravitreal injection of anti-VEGF agents as mCNV treatment and were followed-up for more than 36 months were retrospectively reviewed. The risk factors for the development of mCNV-MA, which is the fovea-involving patchy atrophy lesion adjacent to mCNV, were investigated using the Cox proportional hazard model.

Results

A total of 82 eyes (74 patients) were included in the study. The mean age at anti-VEGF treatment was 56.3 ± 12.5 years (range, 26–77), and the mean follow-up period was 76.3 ± 33.5 months (range, 36–154). During follow-up, mCNV-MA developed in 27 eyes (32.9%), and its occurrence was estimated to be 24.5% at 3 years and 37.3% at 5 years after the first anti-VEGF treatment. Old age (hazard ratio [HR] = 1.054, 95% confidence interval [CI]: 1.018–1.091; P = 0.003) and greater CNV size at baseline (HR = 2.396, CI: 1.043–5.504; P = 0.040) were significant factors for mCNV-MA development. Eyes with a thinner subfoveal choroid were more likely to show faster enlargement of the mCNV-MA during follow-up.

Conclusions

In mCNV eyes treated with intravitreal anti-VEGF agents, older age and greater mCNV size at baseline were risk factors for the development of MA during long-term follow-up, which was associated with a poor visual prognosis.

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.

Nonsteroidal anti-inflammatory drugs for retinal neurodegenerative diseases

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common prescription drugs for inflammation, and topical NSAIDs are often used in ophthalmology to reduce pain, photophobia, inflammation, and edema. In recent years, many published reports have found that NSAIDs play an important role in the treatment of retinal neurodegenerative diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, pathological myopia, and retinitis pigmentosa (RP). The aim of the current review is to provide an overview of the role of various NSAIDs in the treatment of retinal neurodegenerative diseases and the corresponding mechanisms of action. This review highlighted that the topical application of NSAIDs for the treatment of retinal degenerative diseases has been studied to a remarkable extent and that its beneficial effects in many diseases have been proven. In the future, prospective studies with large study populations are required to extend these effects to clinical settings.

Dilated choroidal veins and their role in recurrences of myopic macular neovascularisations

AIM

To determine whether there is a correlation between the presence of macular dilated choroidal vein (DCV) and the recurrence of myopic macular neovascularisation (MNV) after antivascular endothelial growth factor (VEGF) treatment.

METHODS

Medical records of 168 eyes of 163 patients with myopic MNV were reviewed for the presence of macular DCV and episodes of recurrences. A macular DCV was defined as a choroidal vein whose diameter was 2× larger than the adjacent veins coursing in the macular area of 5.5 mm diameter.

RESULTS

Macular DCV existed in 47 (28%) of the eyes with myopic MNV. 70 eyes (41.7%) had recurrence during a mean follow-up period of 52.5±23.0 months. Recurrence was found in 28 of the 47 eyes (59.6%) with DCV, which was significantly more frequent than the 42 of the 121 eyes (34.7%) without DCV (p=0.003). Cox model analysis showed that macular DCV was an independent risk factor (HR: 2.0, 95% CI 1.1 to 3.5) for recurrence. The recurrence rate was significantly higher in eyes with DCV within the first 2 years after the onset than in eyes without DCV.

CONCLUSIONS

Macular DCVs may be indicators of a more aggressive phenotype of eyes with myopic MNV. These eyes need careful monitoring after anti-VEGF therapies.

3-Methyladenine Alleviates Experimental Subretinal Fibrosis by Inhibiting Macrophages and M2 Polarization Through the PI3K/Akt Pathway

Purpose: To explore the effects of 3-methyladenine (3-MA), a selective inhibitor of phosphatidylinositol-3-kinase (PI3K), on experimental subretinal fibrosis (SRF) in mice. Methods: The SRF mouse model was established by 532 nm laser photocoagulation at each fundus of mice on day 0. 3-MA was administered every 2 days from day 0 to 35. Immunofluorescence of choroidal flat mounts was performed to evaluate the size of SRF area, local macrophages, and polarization, respectively. Besides, Western blot analysis was carried out to assess the expression levels of macrophage polarization-related genes, Arg-1, Ym-1, and transforming growth factor-β₂ (TGF-β₂). Co-culture and migration experiments were used to demonstrate the inhibitory effect of 3-MA on fibroblasts. The gene knockout and Western blot analysis were used to explore the signal pathways related to macrophage polarization. Results: Compared with the control group, the 3-MA-treated group showed significantly less size of SRF area. 3-MA treatment reduced both circulating and local macrophages, and counteracted M2 polarization. Moreover, 3-MA inhibited fibroblast recruitment. Mechanistically, we proved that 3-MA inhibits macrophage M2 polarization by suppressing PI3K/Akt signal pathway rather than the PI3K-autophagy-related signal pathway. Conclusions: 3-MA exerts antifibrotic effects on experimental SRF by targeting circulating and local macrophages and M2 polarization, through PI3K/Akt signal pathway. These results support the potential use of 3-MA as a new therapeutic modality for SRF associated with neovascular age-related macular degeneration.

Risk factors for subretinal fibrosis after anti-VEGF treatment of myopic choroidal neovascularisation

PURPOSE

To assess the incidence, clinical features and predictive risk factors of subretinal fibrosis after treatment of active myopic choroidal neovascularisation (mCNV) with anti-vascular endothelial growth factor (VEGF).

METHODS

This post-hoc analysis of a randomised controlled trial included a total of 54 patients with active mCNV. The clinical data at baseline, month 3 and month 12 were used. Fundus photography and optical coherence tomography at month 3 were used to determine the presence of subretinal fibrosis after anti-VEGF therapy, and its incidence was calculated. Best-corrected visual acuity (BCVA), Visual Function Questionnaire-25 score, macular integrity index (MI) and their changes were compared between eyes with and without subretinal fibrosis. A logistic regression model was used to evaluate the risk factors of subretinal fibrosis.

RESULTS

Subretinal fibrosis occurred in 22 of 54 eyes with mCNV. Patients with subretinal fibrosis achieved similar BCVA improvement in comparison with those without fibrosis at 3 and 12 months after the treatment; however, they had lower visual acuity, more subfoveal CNV (p=0.002), higher CNV thickness at baseline (p=0.016), larger CNV size (p=0.030), larger leakage area (p=0.021) and higher presence of advanced myopic maculopathy (p=0.035). Age <45 years, BCVA <60 ETDRS letters, and MI index <20 at baseline were the predictors for subretinal fibrosis occurrence in a logistic regression model.

CONCLUSIONS

The incidence of subretinal fibrosis after anti-VEGF therapy was 40.7% in eyes with mCNV. Age, baseline BCVA and MI index could serve as predictive risk factors of subretinal fibrosis after anti-VEGF treatment in patients with mCNV.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FEATURES OF SUBRETINAL FIBROSIS AFTER MYOPIC NEOVASCULARIZATION

PURPOSE

To describe the optical coherence tomography (OCT) angiography features of subretinal fibrosis in eyes with myopic choroidal neovascularization after natural evolution or secondary to intravitreal anti-vascular endothelial growth factor therapy.

METHODS

Retrospective observational case series. All eyes underwent a multimodal imaging examination including fluorescein angiography, spectral domain OCT, OCT angiography, and en face OCT.

RESULTS

Twenty-five eyes of 25 patients with mean age of 56.4 ± 14.9 were included in the study. Subretinal fibrosis was diagnosed at mean 30 (range 6-116) months before inclusion. Within the subretinal fibrosis, an abnormal vascular network was observed in 20/25 (80%) eyes, located typically in the outer retina (18/20, 90%) or the choriocapillaris (14/20, 70%) segmentation. The most prevalent patterns were "round tangle" and "tapered tangle." On en face OCT, the subretinal fibrosis was evidenced in 24/25 (96%) eyes, most prevalently in the outer retina (21/25, 84%) and in the choriocapillaris (18/25, 72%), where main feature was white-hyperreflective (20/21, 95%) and dark-hyporeflective (17/18, 94%) appearance, respectively. The presence of subretinal fibrosis on en face OCT was positively correlated with the presence of abnormal vascular network on OCT angiography in 61% of the cases (P = 0.005).

CONCLUSION

Subretinal fibrosis secondary to myopic choroidal neovascularization frequently contains blood flow within a persistent abnormal vascular network as assessed by OCT angiography.

Efficacy of Sunitinib, Sunitinib-Hesperetin, and Sunitinib-Doxycycline Combinations on Experimentally-Induced Corneal Neovascularization

Purpose: To investigate the preventive effects of topical sunitinib, sunitinib-hesperetin and sunitinib-doxycycline combinations on corneal neovascularization (CNV), apoptosis and fibrosis in a corneal alkali burn model. Materials and Methods: The corneas of 32 Wistar albino rats were cauterized with silver nitrate to induce CNV. Four groups were created receiving artificial tears (sham), sunitinib (0.5 mg/ml), sunitinib-hesperetin (0.5 mg/ml-0.2 mg/ml), and sunitinib-doxycycline (0.5 mg/ml-20 mg/ml) treatments. Corneal photographs were taken on days 0, 7 and 15‎. Photographs of the cornea were digitally analyzed to measure the size of the neovascularization area in comparison to the total corneal surface area. On the 15th day, the animals were euthanized, and the eyes were enucleated for immunohistochemical staining to investigate neovascularization, apoptosis, and fibrosis. Results: CNV areas on the 7th day in the sunitinib (4.8% ± 0.07%) and sunitinib-hesperetin (1.1% ± 0.03%) groups were smaller than those in the sham group (33.9% ± 0.12%) (p = 0.001 and, p < 0.001 respectively). On the 15th day, the CNV area in the sunitinib-hesperetin (20.8% ± 0.37%) group was significantly smaller than that of the sham group (74.6% ± 0.32%) (p = 0.039). The combination groups had lower levels of VEGF, TUNEL and α-SMA positivity than the sunitinib monotherapy group. TUNEL positivity was lowest in the sunitinib-hesperetin and sunitinib-doxycycline groups, and α-SMA positivity was lowest in the sunitinib-hesperetin group. Conclusion: Topical sunitinib-hesperetin was more effective than sunitinib alone and the sunitinib-doxycycline combination in the treatment of CNV. The combination of sunitinib and hesperetin seems to be a promising treatment for preventing corneal fibrosis and apoptosis.

Development and Course of Scars in the Comparison of Age-Related Macular Degeneration Treatments Trials

PURPOSE

To describe risk factors for scar formation and changes to fibrotic scar through 5 years in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT).

DESIGN

Multicenter, prospective cohort study.

PARTICIPANTS

A total of 1061 subjects in CATT.

METHODS

Color photographic and fluorescein angiographic images from baseline and 1, 2, and 5 years were evaluated. Incidence of scar formation was estimated with Kaplan-Meier curves. Risk factors were assessed with Cox regression models.

MAIN OUTCOME MEASURES

Scar formation, fibrotic scar area, and macular atrophy associated with fibrotic scar ("atrophy").

RESULTS

Cumulative proportion of eyes with scar was 32%, 46%, and 56% at years 1, 2, and 5, respectively. Baseline factors associated with increased risk (adjusted hazards ratio [aHR] and 95% confidence interval [CI]) were classic choroidal neovascularization (CNV) (aHR, 4.49; 95% CI, 3.34-6.04) versus occult, hemorrhage >1 disc area (DA) (aHR, 2.28; 95% CI, 1.49-3.47) versus no hemorrhage, retinal thickness >212 μm (aHR, 2.58; 95% CI, 1.69-3.94) versus <120 μm, subretinal tissue complex thickness >275 μm (aHR, 2.64; 95% CI, 1.81-3.84) versus ≤75 μm, subretinal fluid thickness >25 μm (aHR, 1.31; 95% CI, 0.97-1.75) versus no fluid, visual acuity (VA) in fellow eye 20/20 (aHR, 1.72; 95% CI, 1.25-2.36) versus 20/50 or worse, retinal pigment epithelium elevation absence (aHR, 1.71; 95% CI, 1.21-2.41), and subretinal hyperreflective material (aHR, 1.72; 95% CI, 1.25-2.36). Among 68 eyes that developed fibrotic scar at year 1, VA decreased by a mean of additional 13 letters between years 1 and 5. Mean scar area was 1.2, 1.2, and 1.9 DA at 1, 2, and 5 years, respectively. Atrophy was present in 18%, 24%, and 54% of these eyes at years 1, 2, and 5, respectively; the mean areas were 1.6, 2.0, and 3.1 DA, respectively. Atrophy replaced fibrotic scar in 8 eyes at year 5. There was no significant correlation between scar growth and atrophy growth. The rate of growth for both was similar between the clinical trial and observation periods.

CONCLUSIONS

Several morphologic features, including classic CNV and large hemorrhage, are associated with scar formation. Rate of new scar formation declined after 2 years. Most fibrotic scars and accompanying macular atrophy expanded over time, reducing VA.

Anti-Vascular Endothelial Growth Factor Therapy for Myopic Choroidal Neovascularization

Myopic choroidal neovascularization (CNV) is one of the most vision-impairing complications in patients with pathologic myopia. It is also one of the most frequently encountered non.age-related macular degeneration causes of CNV and affects young patients in the working age group. Fluorescein angiography (FA) and spectral domain optical coherence tomography (OCT) are generally indicated to confirm the diagnosis of active myopic CNV before initiation of treatment. Without treatment, natural history studies have shown that the vision outcome can be very poor. More recently, a number of retrospective, prospective and phase 3, multicenter, randomized controlled trials have established the safety and efficacy of intravitreal anti.vascular endothelial growth factor (VEGF) agents for the treatment of myopic CNV. Long-term follow-up studies have found that some of the initial vision gained after intravitreal anti-VEGF therapy may not be maintained, owing to the presence and progression of chorioretinal atrophy (CRA) adjacent to the CNV. Further research on clinical and imaging characteristics may elucidate the prognostic factors that are crucial to optimizing the treatment and prevention of visual impairment associated with myopic CNV.

Effect of bevacizumab on the expression of fibrosis-related inflammatory mediators in ARPE-19 cells

AIM

To investigate the effect of anti-vascular epithelial growth factor (VEGF) agents on the expression of fibrosis-related inflammatory mediators under normoxic and hypoxic conditions, and to further clarify the mechanism underlying fibrosis after anti-VEGF therapy.

METHODS

Human retinal pigment epithelial (RPE) cells were incubated under normoxic and hypoxic conditions. For hypoxia treatment, CoCl₂ at 200 µmol/L was added to the media. ARPE-19 cells were treated as following: 1) control group: no treatment; 2) bevacizumab group: bevacizumab at 0.25 mg/mL was added to the media; 3) hypoxia group: CoCl₂ at 200 µmol/L was added to the media; 4) hypoxia+bevacizumab group: CoCl₂ at 200 µmol/L and bevacizumab at 0.25 mg/mL were added to the media. The expression of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor (TNF)-α were evaluated using real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) at 6, 12, 24 and 48h.

RESULTS

Both mRNA and protein levels of IL-1β, IL-6 and IL-8 were statistically significantly higher in the bevacizumab group than in the control group at each time point, and TNF-α gene and protein expression was only significantly higher only at 24 and 48h (P<0.05). Under hypoxic conditions, bevacizumab significantly increased the expression of IL-1β, IL-6, IL-8 and TNF-α at 6, 12, 24 and 48h (P<0.05). IL-1β, IL-8 and TNF-α peaked at 24h and IL-6 peaked at 12h after the bevacizumab treatment under both normoxic and hypoxic conditions.

CONCLUSION

Treatment of ARPE-19 cells with bevacizumab can significantly increase the expression of fibrosis-related inflammatory mediators under both normoxic and hypoxic conditions. Inflammatory factors might be involved in the process of fibrosis after anti-VEGF therapy, and the up-regulation of inflammatory factors induced by anti-VEGF drugs might promote the fibrosis process.