Marginal crack after intravitreal bevacizumab for myopic choroidal neovascularization

Choroidal neovascularization secondary to pathological myopia

Myopic choroidal neovascularization (mCNV), one of the complications of pathological myopia, is also one of the leading causes of visual impairment worldwide. The socioeconomic impact of mCNV in Asian countries is particularly significant due to the rising incidence of pathological myopia. There have been major advances in the treatment of mCNV in the past few years. Previous treatment modalities, such as thermal laser photocoagulation and photodynamic therapy, aimed to prevent vision loss; however, newer modalities such as intravitreal anti-vascular endothelial growth factor (VEGF) agents have been shown to successfully restore vision in many patients. Challenges remain as long term safety and efficacy of anti-VEGF agents are unknown. This article aims to provide a review of the literature of the epidemiology, progression, clinical course and treatment modalities as well as areas of future developments related to myopic CNV.

Intravitreal anti-vascular endothelial growth factor for choroidal neovascularization secondary to pathologic myopia: systematic review and meta-analysis

PURPOSES

To update existing evidence and evaluate intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections for myopic choroidal neovascularization.

METHODS

The authors conducted comprehensive search in PubMed, EMBASE, Cochrane Library, Biosis Preview, and LILACS. Included studies were categorized by study design. Comparative studies were classified as randomized controlled trials (RCTs) and non-RCT studies, and these two types of studies were presented and meta-analyzed separately for the following comparisons: 1) anti-VEGF versus photodynamic therapy, 2) anti-VEGF monotherapy versus combination therapy with photodynamic therapy, 3) single versus 3 monthly injections followed by pro re nata (PRN) treatment, and 4) ranibizumab versus bevacizumab. Noncomparative prospective series were pooled to estimate mean visual gain, mean retinal thickness change, and the average number of anti-VEGF injections required for myopic choroidal neovascularization. Ocular and systemic adverse events were also summarized.

RESULTS

Literature search yielded 18 comparative studies and 83 noncomparative studies. Superiority of anti-VEGF over photodynamic therapy in a 24-month period was confirmed by 2 RCTs and 6 non-RCT studies. The influence of combined photodynamic therapy was uncertain based on two non-RCT studies. Three non-RCT studies showed that the visual outcomes of 3+PRN injections might be slightly better than 1+PRN injections within 1 year. No difference was observed between ranibizumab and bevacizumab in two RCTs and one non-RCT study. The estimated visual improvement was two lines on average. Adverse events were uncommon as reported.

CONCLUSION

Accumulating evidence confirmed that anti-VEGF injections should be the first-line therapy for myopic choroidal neovascularization.

Anti-vascular endothelial growth factor for myopic choroidal neovascularization

Myopic choroidal neovascularization (CNV) is a vision-threatening complication in the eyes with pathological myopia, which is particularly prevalent among young and middle-aged Asians globally. To date, the verteporfin in photodynamic therapy study is the only randomized-controlled study in treatment of subfoveal myopic CNV. However, its long-term benefit is controversial. Recently, intravitreal injections of anti-vascular endothelial growth factors have shown promising results. In the absence of randomized-controlled trial comparing the efficacy of anti-vascular endothelial growth factors with photodynamic therapy and placebo, the purpose of this article is to review the current studies on functional and anatomical outcomes in both subfoveal and juxtafoveal myopic CNV. Furthermore, the influences of various doses and frequencies, as well as age and previous photodynamic therapy treatment on its effect are described.

Evaluation of differential toxicity of varying doses of bevacizumab on retinal ganglion cells, retinal pigment epithelial cells, and vascular endothelial growth factor-enriched choroidal endothelial cells

PURPOSE

To evaluate in vitro the effects of bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, on retinal pigment epithelial cells (RPE) and retinal ganglion cells (RGC), at doses that were inhibitory to VEGF-enriched choroidal endothelial cells (CEC).

METHODS

Monkey CEC (RF6A), human RPE cells (ARPE-19), and rat RGC (RGC-5) were exposed for 24 h to increasing doses of bevacizumab. Cell numbers were quantified with WST-1 assay. Cell death was assessed using propidium iodide (PI) staining via flow cytometry and fluorescent microscopy.

RESULTS

Bevacizumab was inhibitory to RF6A at 2.0 mg/mL (P < 0.005). No effect on cell viability was noted on ARPE-19 and RGC-5 cell lines at this particular dose of bevacizumab. These results were supported by fluorescent microscopy of PI-stained cells.

CONCLUSIONS

VEGF-stimulated proliferation of CEC was inhibited by bevacizumab. Bevacizumab was not cytotoxic to human RPE and rat RGC in vitro at a dose that is inhibitory to monkey CEC.

Bevacizumab for choroidal neovascularization secondary to pathologic myopia: Is there a decline of the treatment efficacy after 2 years?

BACKGROUND

The Verteporfin in Photodynamic Therapy (VIP) Study failed to prove a statistically significant benefit for myopic choroidal neovascularization (CNV) at the end of the second year. Therefore, we wanted to evaluate whether the early effects seen under anti-VEGF treatment can be maintained over longer follow-up intervals.

METHODS

This consecutive case series included all patients at the Centre for Ophthalmology, Tuebingen, with a 2-year follow-up after treatment with 1.25 mg of bevacizumab alone or in combination with photodynamic therapy. Twenty-one eyes from 19 patients were analyzed in the retrospective evaluation of best-corrected visual acuity (BCVA) and central foveal thickness (CFT).

RESULTS

Mean logMAR BCVA improved from 0.64 at baseline to 0.55 after 1 year (p = 0.32) and remained 0.55 at 2 years (p = 0.23). A subgroup analysis showed that mean logMAR BCVA in the monotherapy group improved from 0.7 to 0.5 at 2 years (n = 11, p = 0.06). In the combined therapy group, mean logMAR BCVA changed from 0.55 to 0.59 at 2 years (n = 10, p = 0.69). Mean CFT decreased significantly in both groups by 168 microm (p < 0.001) and 76 microm (p < 0.05) in the monotherapy and in the combined groups, respectively. No complications or adverse effects were observed.

CONCLUSION

Although the limitations of the study design have to be acknowledged and carefully discussed, we found no obvious superiority of a combined treatment for myopic CNV, at least in terms of the functional outcome and the injection frequency. The results indicate that bevacizumab might be beneficial in the treatment of patients with CNV secondary to pathologic myopia.

Intravitreal bevacizumab vs sub-tenon triamcinolone acetonide for choroidal neovascularization attributable to pathologic myopia

PURPOSE

To compare the visual outcomes of intravitreal bevacizumab (Avastin; Genentech Inc, South San Franciso, California, USA) and sub-Tenon triamcinolone acetonide (TA) for choroidal neovascularization attributable to pathologic myopia (mCNV).

DESIGN

Retrospective, comparative, interventional case series.

METHODS

Fifty-four consecutive eyes of 53 patients with mCNV treated with either sub-Tenon TA or intravitreal bevacizumab in an institutional setting were included. Twenty eyes were treated with sub-Tenon TA and 34 eyes were treated with intravitreal bevacizumab. The main outcome measures included best-corrected visual acuity (BCVA) 12 months after the initial injection and logarithm of the minimum angle of resolution gain from baseline compared with analysis of covariance (ANCOVA).

RESULTS

At 12 months, the BCVA improved by 1.9 lines in the intravitreal bevacizumab group and worsened by 0.3 lines in the sub-Tenon TA group. Thus, the intravitreal bevacizumab group had significantly greater visual improvement than the sub-Tenon TA group (P < .01). Statistical analysis (ANCOVA) revealed that age (P = .01), pretreatment BCVA (P < .01), and the treatment choice (intravitreal bevacizumab or sub-Tenon TA; P < .01) correlated significantly with the BCVA and the BCVA gain at 12 months. The refractive error was of borderline significance (P = .06).

CONCLUSIONS

Although this study is limited because of its retrospective nature, intravitreal bevacizumab seems to result in a more favorable visual outcome than sub-Tenon TA in the treatment of mCNV. Patient age, the BCVA before treatment, and the refractive error must be considered to initiate the treatment.

Intravitreal ranibizumab (Lucentis) for the treatment of myopic choroidal neovascularization

BACKGROUND

Macular choroidal neovascularization (CNV) is one of the most vision-threatening complications of myopia, which can lead to severe vision loss. The purpose of this study was to evaluate the safety and efficacy of intravitreal ranibizumab in the treatment of myopic CNV.

METHODS

We conducted a prospective, consecutive, interventional study of patients with subfoveal or juxtafoveal CNV secondary to pathologic myopia (PM) treated with intravitreal injection of ranibizumab in the Jules Gonin University Eye Hospital from June 2006 to February 2008. Best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and fluorescein angiography (FA) were performed at baseline and monthly for all patients. Indications for retreatment were loss in BCVA associated either with persistent leakage from CNV shown on FA, and/or evidence of CNV activity on OCT.

RESULTS

The study included 14 eyes of 14 patients. The mean spherical equivalent refractive error was -12.5 (range, -8.0 D to -16.0 D). Mean time of follow-up was 8.4 months (range from 3 to 16 months, SD: 3). The mean number of intravitreal injections administered for each patient was 2.36 (SD 1.5). The mean initial visual acuity (VA) was 0.19 decimal equivalent (log-MAR: 0.71, SD: 0.3). A statistically significant improvement to a mean VA of 0.48 decimal equivalent (log-MAR:0.32, SD: 0.25) was demonstrated at the final follow-up. VA improved by a mean of 3.86 (SD 2.74) lines. Nine patients (64%) demonstrated a gain of 3 or more lines. Mean central macular thickness (CMT) measured with OCT was 304 microm (SD: 39) at the baseline, and was reduced significantly at the final follow-up to 153 microm (SD: 23). Average CMT reduction was 170 microm (SD: 57). No injection complications or drug-related side effects were noted during the follow-up period.

CONCLUSIONS

In this small series of eyes with limited follow-up, intravitreal ranibizumab was a safe and effective treatment for CNV secondary to PM, resulting in functional and anatomic improvements.