Late-phase hypercyanescence during indocyanine green angiography for assessment of myopic choroidal neovascularization

Abstract

Purpose:

Indocyanine green angiography (ICGA) is a major diagnostic modality but the clinical implications of specific staining patterns in active myopic choroidal neovascularization (mCNV) are unclear. We examined the associations of ICGA cyanofluorescence patterns with disease characteristics and response to an as-needed intravitreal ranibizumab (IVR) treatment regimen among active mCNV patients.

Methods:

Twenty-four subjects with active mCNV treated by IVR were enrolled in this retrospective cohort study. Information from medical records were reviewed, including best corrected visual acuity (BCVA), fluorescein angiography (FA) findings, ICGA cyanofluorescence patterns, and spectral-domain OCT (SD-OCT) results. The CNV lesion size, CNV thickness, and central retinal thickness (CRT) were measured from these images.

Results:

Two staining patterns were identified on late-phase ICGA images, hypercyanescence (9/24, 37.5%) and non-hypercyanescence (15/24, 62.5%). There were no differences in baseline BCVA, CNV thickness, and CRT between ICGA pattern groups; however, the hypercyanescence group demonstrated a larger CNV lesion size (p = 0.035) and required more IVR injections than the non-hypercyanescence group (2.67 ± 1.58 vs 1.07 ± 0.27, p = 0.016), while the non-hypercyanescence group demonstrated better final BCVA improvement (p = 0.041). Hypercyanescence could be divided into two types, a uniform type and rim type. A pseudopodia-like protrusion of CNV enlargement with a rim-enhanced type hypercyanescence at the protrusion rim was predictive of required retreatment.

Conclusions:

Hypercyanescence on late-phase ICGA may assist in identifying more active mCNV requiring intensive treatment.