Clinical Efficacy and Safety of Current Interventions for Choroidal Neovascularization Associated with Rare Diseases: A Systematic Literature Review.

INTRODUCTION: The aim of this systematic literature review was to evaluate the efficacy and safety of interventions for the treatment of choroidal neovascularization (CNV) secondary to etiologies other than age-related macular degeneration and pathologic myopia.

METHODS: Relevant randomized controlled trials (RCTs) and prospective observational studies were identified by searching MEDLINE, MEDLINE In-Process, EMBASE, and CENTRAL.

RESULTS: The search identified 5 RCTs; no relevant observational studies were identified. The studies differed in terms of underlying cause of CNV, patient numbers (n = 9-178), follow-up time (2-36 months) and quality assessment. In the largest RCT (n = 178 across a range of rare CNV etiologies), intravitreal ranibizumab showed superior efficacy versus sham from baseline to month 2 [mean best-corrected visual acuity (BCVA): + 9.5 vs. - 0.4 letters; p < 0.001]; the gain was maintained up to month 12. In the treatment of CNV secondary to presumed ocular histoplasmosis syndrome (POHS), both intravitreal ranibizumab and photodynamic therapy (PDT) showed significant improvement from baseline BCVA over the 12-month period (n = 9); however, all patients in the PDT group required rescue ranibizumab therapy. Unlicensed intravitreal bevacizumab was associated with a statistically significant improvement in BCVA compared to PDT at 12 months (p < 0.001) in patients with CNV secondary to multifocal choroiditis (n = 27). The use of steroids before PDT showed better BCVA outcomes than PDT alone (p < 0.05) in patients with idiopathic CNV (n = 20). Argon green laser therapy showed limited efficacy in patients with CNV secondary to OHS (n = 134).

CONCLUSION: There is evidence from a relatively large, good-quality study to support the use of intravitreal ranibizumab for the treatment of CNV secondary to rare diseases. However, the limited number of RCTs for this indication and differences in study characteristics between RCTs mean that there is uncertainty regarding comparative clinical effectiveness of interventions. RCTs with an active comparator are required to fully establish the comparative effectiveness of treatments for CNV secondary to rare diseases.

FUNDING: Novartis Pharmaceuticals UK Ltd, Surrey, UK.