Anti–Vascular Endothelial Growth Factor Therapy for Myopic Choroidal Neovascularization: Do We Need More Evidence?

Safety review of anti-VEGF therapy in patients with myopic choroidal neovascularization

INTRODUCTION

Anti-angiogenesis therapy with intravitreal anti-VEGF agents is now the standard-of-care treatment for myopic choroidal neovascularization (CNV).

AREAS COVERED

We provide a critical review of the safety of all the anti-VEGF agents currently used for treating myopic CNV including ranibizumab, aflibercept, conbercept, bevacizumab, and ziv-aflibercept.

EXPERT OPINION

Anti-VEGF therapy for myopic CNV with the currently available anti-VEGF drugs generally have favorable safety outcomes in the short-term. Nonetheless, ocular adverse events following anti-VEGF therapy for myopic CNV may develop and these include worsening or new development of myopic traction maculopathy, increased risk of retinal detachment, and progression of chorioretinal atrophy. Clinicians should be aware of these potential complications and evaluate them before and after anti-VEGF therapy.

Real-world effectiveness and safety of ranibizumab for the treatment of myopic choroidal neovascularization: Results from the LUMINOUS study

Purpose

To assess the 1-year effectiveness, safety, and treatment patterns of ranibizumab in patients with myopic choroidal neovascularization (mCNV) enrolled in the LUMINOUS study.

Methods

This 5-year, prospective, multicenter, observational, study enrolled 30,138 patients across all approved ranibizumab indications from outpatient ophthalmology clinics. 297 consenting patients (≥18 years) with mCNV who were treatment-naïve or prior-treated with ranibizumab or other ocular treatments were enrolled, and treated with ranibizumab according to the local product label. The main outcomes are visual acuity (VA; Early Treatment Diabetic Retinopathy Study letters or equivalent), adverse events during the study, and treatment exposure over 1 year. Results are presented by prior treatment status of the study eye and injection frequency.

Results

Of the 297 mCNV patients recruited in the study, 108 were treatment-naïve and 175 were prior ranibizumab-treated. At baseline, the mean age of patients was 57.6 years, and 59.0 years and 80.6% and 65.7% were female in the treatment-naïve and prior ranibizumab-treated groups, respectively. Most were Caucasian (treatment-naïve, 88.9%; prior ranibizumab-treated, 86.9%). The mean (±standard deviation [SD]) VA letter changes to 1 year were +9.7 (±17.99) from 49.5 (±20.51) and +1.5 (±13.15) from 58.5 (±19.79) and these were achieved with a mean (SD) of 3.0 (±1.58) and 2.6 (±2.33) injections in the treatment-naïve and prior ranibizumab-treated groups, respectively. Presented by injection frequencies 1–2, 3–4 and ≥5 injections in Year 1, the mean (SD) VA changes were +15.0 (±14.70), +7.7 (±19.91) and −0.7 (±16.05) in treatment-naïve patients and +1.5 (±14.57), +3.1 (±11.53) and −3.6 (±11.97) in prior ranibizumab-treated patients, respectively. The safety profile was comparable with previous ranibizumab studies.

Conclusions

Ranibizumab treatment for mCNV showed robust VA gains in treatment-naïve patients and VA maintenance in prior ranibizumab-treated patients in a clinical practice setting, consisting mainly of Caucasians. No new safety signals were observed during the study.

Long-term outcomes of the intravitreal injection of ranibizumab for the treatment of choroidal neovascularization secondary to pathologic myopia

PURPOSE

To analyze the long-term outcomes and safety of intravitreal ranibizumab injections in myopic choroidal neovascularization (CNV).

METHODS

A retrospective non-randomized analysis of consecutive cases included 17 eyes from 17 patients with subfoveal myopic CNV, treated with intravitreal ranibizumab with at least 30-month follow-up. The patients received three injections monthly, followed by pro re nata regimen. Best-corrected visual acuity (BCVA) measurement, optical coherence tomography and fluorescein angiography were carried out at the baseline and at monthly intervals thereafter.

RESULTS

Mean follow-up period was 51 months (range 30-98 months). In 12 patients (70.6%), BCVA improved by at least 1 Snellen line, with at least 3-line improvement observed in the case of 8 eyes (47%). Mean central foveal thickness (CFT) decreased from 384.65 ± 103.3 µm at the baseline to 264 ± 86.2 µm at the last follow-up examination (p < 0.001). The final OCT examination revealed 59% (10/17) eyes with CNV-related macular atrophy. Mean number of injections over the follow-up period was 4.82 ± 2.04 per person. Nine patients (53%) required re-injection of the anti-VEGF agent; the mean number of re-injections in this group was 3.44 ± 1.34 per person (range 2-6). No significant adverse events were recorded during the study period.

CONCLUSIONS

Intravitreal ranibizumab is an effective and safe treatment for CNV secondary to pathologic myopia, contributing to long-term vision improvement and CFT reduction.

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.

Pathologic Myopia

Pathologic myopia (PM) is the only myopia that causes the loss of best-corrected visual acuity. The main reason for best-corrected visual acuity loss is complications specific to PM, such as myopic maculopathy, myopic traction maculopathy, and myopic optic neuropathy (or glaucoma). The meta-analyses of the PM study group (META-PM study) made a classification system for myopic maculopathy. On the basis of this study, PM has been defined as eyes having atrophic changes equal to or more severe than diffuse atrophy. Posterior staphyloma and eye deformity are important causes of developing vision-threatening complications. Posterior staphyloma is unique to PM, except for inferior staphyloma due to tilted disc syndrome. It is defined as an outpouching of the wall of the eye that has a radius of curvature that is less than the surrounding curvature of the wall of the eye. The mechanical load onto the important region for central vision (optic nerve and macula) is not comparable between eyes with and without posterior staphyloma. Three-dimensional magnetic resonance imaging is a powerful tool to analyze the entire shape of the eye. When ultra-widefield optical coherence tomography is available, it is expected to be a new tool that will surpass 3-dimensional magnetic resonance imaging. In the future, preventive therapies targeting staphyloma and eye deformity are expected before vision-threatening complications develop and it is too late for patients.

Management of Myopic Choroidal Neovascularization: Focus on Anti-VEGF Therapy

Myopic choroidal neovascularization (mCNV) is the second most common form of CNV after age-related macular degeneration (AMD). It is a sight-threatening complication of pathologic myopia (PM) and often affects patients in their working years causing significant impact on quality of life. Previous therapies such as photodynamic therapy with verteporfin have shown limited success. Due to the similarities in pathogenesis of mCNV and AMD CNV, anti-vascular endothelial growth factor therapy (anti-VEGF), which has so far been the mainstay of treatment for AMD CNV, has been shown to be effective in the treatment of mCNV and has become the first-line treatment of choice. This article aims to examine briefly the epidemiology and pathophysiology of mCNV, as well as review the evidence for efficacy, safety, and clinical use of anti-VEGF treatment for mCNV.

A systematic review and meta-analysis comparing intravitreal ranibizumab with bevacizumab for the treatment of myopic choroidal neovascularisation

Intravitreal injections of ranibizumab (IVR) and bevacizumab (IVB) have both been used as treatments for myopic choroidal neovascularisation. We aimed to produce a meta-analysis of published literature comparing IVR with IVB for the treatment of myopic choroidal neovascularisation, by searching electronic databases from January 1950 to March 2013. Our search produced three suitable studies that reported on 117 patients in total. The results of the meta-analysis demonstrated that the mean number of lines improvement after IVR appeared better compared with IVB [fixed effects model: SMD = 0.46, 95% CI (0.09, 0.83), z = 2.44, p = 0.01]. The number of patients who had a greater than 3 line improvement was similar between groups [fixed effects model: RR = 0.95, 95% CI (0.67, 1.32), z = 0.33, p = 0.74]. At follow up there was no difference in number of those who had an absence of leakage [fixed effects model: RR = 1.04, 95% CI (0.93, 1.16), z = 0.64, p = 0.52]. There was no statistical significance between the two groups in relation to the number of injections [random effects model: SMD = −0.25, 95% CI (−1.12, 0.61), z = 0.57, p = 0.57]. Early evidence therefore suggests that intravitreal injections of ranibizumab are comparable to intravitreal injections of bevacizumab in the treatment of myopic choroidal neovascularisation. Both treatments result in a statistically significant increase in visual acuity with high numbers of patients maintaining stable vision. Further studies are still needed to strengthen results.

Forty-two-month outcome of intravitreal bevacizumab in myopic choroidal neovascularization

PURPOSE

To evaluate the long-term efficacy of bevacizumab in the treatment of choroidal neovascularization (CNV) secondary to pathological myopia.

METHODS

In this retrospective single-center non-comparative study the medical records of 29 eyes from 29 patients with naïve CNV secondary to high myopia and at least 42 months of follow up were reviewed. All eyes received a loading dose of one intravitreal injection per month for two consecutive months and were retreated on an as-needed basis during the course of follow up. The main outcome measures were post-treatment ETDRS best-corrected visual acuity (BCVA) and visual stabilization over time. Stepwise linear regression analysis was performed to identify prognostic factors for visual acuity gain and final visual acuity outcome at 42 months.

RESULTS

At 42 months of follow-up bevacizumab was associated with the maintenance of significant benefits in visual acuity compared to baseline. No adverse ocular or systemic effects from treatment were encountered. No statistically significant correlations were found between BCVA change and any of the quantitative variables. However, when final BCVA was taken as a dependent variable and CNV size and pre-treatment VA were included as predictors, a bivariate model was identified by stepwise regression which gave a 75 % of explained variance.

CONCLUSIONS

Bevacizumab treatment was found to be efficacious in the treatment of myopic CNV, resulting in stable gains in visual acuity lasting at least 42 months, without any adverse ocular or general events. Myopic CNV size was identified as a significant prognostic factor.