Among 21 eyes of 19 patients with newly diagnosed eAMD that met the inclusion and exclusion criteria of this study and were imaged with Fd-OCT, a highly reflective subretinal and/or sub-RPE lesion was visualized in the macula of all 21 eyes by Fd-OCT. These lesions co-localized to the area of CNVM seen on FA. lists the demographic information, the angiographic classification of CNVM, and the Fd-OCT findings. Of the 21 eyes imaged, FA showed classic CNVM in 7 (33%) eyes, minimally classic CNVM in 3 (14%) eyes and an occult CNVM in 11 (53%) eyes. Among eyes with occult CNVM, seven (33%) had late leakage of undetermined source and four (20%) had fibrovascular PED (i.e., occult CNVM with late irregular pooling into the PED).
Summary of Demographics, Angiographic, and High-Resolution Fd-OCT Findings of CNVM Characteristics Associated with eAMD
By analyzing the 100 serial Fd-OCT B-scans of the macula, we determined the anatomic growth pattern of the CNVM in all but one eye (95%). A combined sub-RPE and subretinal growth pattern of varying degrees was noted in 15 (71%) eyes. However, based on the classification of growth pattern as defined by this study, 7 (33%) eyes had >90% sub-RPE (i.e., type 1) growth patterns, 10 (48%) had >90% subretinal (i.e., type 2) growth pattern, and 3 (14%) had a combined growth pattern ().
summarizes the anatomic growth pattern of the CNVM on Fd-OCT for the various angiographic lesion types. Of the seven eyes that had classic CNVM on FA, >90% subretinal (type 2) growth pattern was observed in six (86%) eyes, and one eye was indeterminant. Among those seven eyes, four had a small sub-RPE component that was <10% of the lesion.
Growth Pattern of Classic and Occult CNVM Due to eAMD as Determined by High-Resolution Fd-OCT
Among 11 eyes with occult CNVM, 7 (64%) had >90% sub-RPE (type 1) growth pattern, 2 had >90% subretinal growth pattern, and 2 had a combined growth pattern. The two eyes with occult CNVMs with >90% subretinal (type 2) growth pattern had fibrovascular PED ().
A statistically significant difference in the distribution of type 1 and 2 growth patterns was noted among eyes with classic CNVM when compared with eyes with occult CNVM (χ2 = 10.4, df = 2, P < 0.005)—that is, a type 1, or >90% sub-RPE growth pattern, was more likely to be associated with angiographically occult lesions, whereas type 2, or >90% subretinal growth pattern was more likely associated with classic lesions.
Among the three eyes with minimally classic pattern of leakage on FA, two had a >90% subretinal (type 2) growth pattern () and one had a combined pattern of growth on Fd-OCT.
Figure 2. Fluorescein angiogram and high-resolution Fd-OCT of the left eye in case 8 showing a mostly subretinal growth pattern of CNVM in an eye with a minimally classic angiographic lesion composition. (A) Early phase angiogram shows a well-defined juxtafoveal (more ...)
and summarize the retinal morphologic changes associated with CNVM as seen on Fd-OCT. Among the seven eyes with classic CNVM, three had associated CME and six had associated SRF visible on Fd-OCT. None of the eyes had PED. Among the seven eyes with occult CNVM without PED, all had CME, five had SRF, and five had PED. On Fd-OCT serial B-scans, all eyes with occult CVNM associated with PED (i.e., fibrovascular PED) on FA had PED on Fd-OCT, two eyes had CME, and three eyes had SRF. There was no statistically significant difference in the distribution of these morphologic changes between eyes with classic CNVM and eyes with occult CNVM (χ2 = 5.272, df = 4, P > 0.05) in this small series. Nonetheless, none of the eyes with classic CNVM had an associated PED on Fd-OCT, whereas 9 of 11 eyes with occult CNVM on FA had PED on Fd-OCT. Of note, 71% of eyes with occult CNVM without PED on FA had PED on Fd-OCT.
Associated Retinal Findings on High-Resolution Fd-OCT among Eyes with Classic or Occult CNVMe Due to Degeneration in eAMD
Further analysis of possible association of these morphologic changes in the retina with specific growth pattern of CNVM seen on Fd-OCT showed no statistically significant difference in the distribution of CME, SRF, and PED with type 1 or 2 growth pattern of CNVM seen on Fd-OCT (χ2 = 2.282, df = 4, P > 0.05), but the numbers in each group were small.
Virtual C-scan images of the macula were analyzed serially to determine the GLD of the highly reflective subretinal/sub-RPE lesion seen on serial B-scan Fd-OCT images. In most cases, the GLD could be determined by using a single reconstructed C-scan, but in a few cases (D), serial C-scans were overlaid to obtain a two-dimensional image of the CNVM to obtain the GLD. In all eyes, the highly reflective lesion co-localized with the CNVM seen on FA when the C-scan images were overlaid on FA images. As shown in A, linear regression analysis showed a strong positive correlation between the size of CNVM (GLD) obtained from Fd-OCT C-scans and the size of CNVM (GLD) on FA in eyes with classic CNVM (n = 7; r = 0.99, F1,5 = 214.10, P < 0.0001) despite the small number of eyes. The intercept also did not differ significantly from 0 (t = 0.223, P = 0.831), indicating that there was no offset between the two sets of measurements. For eyes with nonclassic CNVM, including eyes with minimally classic CNVM and eyes with occult CNVM with or without PED, B shows that the relation between the two measures is not as strong, but was still statistically significant, despite the small sample size (n = 14; r = 0.78, F1,12 = 18.44; P < 0.001).
Figure 3. Linear regression analysis comparing the size of CNVM associated with eAMD as determined by high-resolution Fd-OCT when compared with FA. (A) Analysis of eyes with classic CNVM shows a close linear correlation between GLD of the CNVM obtained by Fd-OCT (more ...)