Optical Coherence Tomography Characteristics of Quiescent Type 1 Neovascularization in Eyes with Nonexudative Age-related Macular Degeneration

Abstract

Objectives: To describe the lesion characteristics of nonexudative, quiescent, asymptomatic type 1 neovascularizar ion (NV) on H-scan and en face spectral domain optical coherence tomography (SD-OCT) in eyes with nonexudative age-related macular degeneration (AMD).

Materials and Methods: In this retrospective, observational, consecutive case series, 27 patients who were already being followed and treated for exudative AMD in one eye were included in the study for their fellow eyes, which were initially nonexudative but developed exudative findings during follow-up. Initial B-scan and en face SD-OCT, fluorescein angiography (FA), and indocyanine green angiography (ICGA) images of these 27 eyes were examined retrospectively. The characteristic B-scan SD-OCT features of type 1 NV in this silent and asymptomatic stage were described.

Results: The 27 eyes of 27 patients (13 males and 14 females; mean age 69.5 +/- 8.2 years) with nonexudative AMD had a mean best corrected visual acuity (BCVA) of 0.6 +/- 0.3 Snellen. Initial B-scan OCT images of all eyes (100%) showed retinal pigment epithelium (RPE) elevations and irregularities caused by a moderately reflective material in the sub-RPE space without fluid accumulation in the intraretinal/subretinal or sub-RPE space. Twenty-four eyes (88.8%) showed sub-RPE hyperreflective lesions consistent with type 1 NV on en face OCT images. While none of the eyes showed signs of type 1 NV in FA, macular plaque was observed in 8 eyes (29.6%) in ICGA. The mean time to onset of exudative findings was 8.3 +/- 4.03 months.

Conclusion: In eyes with nonexudative AMD, there may be quiescent and asymptomatic type 1 NV lesions which do not yet show exudative changes. This NV has characteristic features on B-scan SD-OCT and can also be detected with en face OCT. Detection and close monitoring of these quiescent and inactive type 1 NV lesions during the asymptomatic, pre-exudative period are important for early treatment.