Optical Coherence Tomography of age-related macular degeneration and choroidal neovascularization

Purpose. We used Optical Coherence Tomography (OCT) to study eyes with age-related macular degeneration (AMD). In patients with untreated exudative AMD, OCT was compared with fluorescein angiography in the classification of choroidal neovascularization (CNV). Methods. OCT was performed on 391 patients with the clinical diagnosis of AMD and was compared with conventional clinical examination to establish the cross-sectional morphology of lesions and to develop a classification scheme for CNV. OCT images and fluorescein angiograms were then independently reviewed and correlated in 90 eyes of 86 patients who had exudative AMD without previous laser treatment. Results. CNV could be morphologically divided into three categories on OCT: well-defined, poorly-defined, and fibrovascular pigment epithelial detachment (PED). CNV classified as well-defined or fibrovascular PED on OCT (23 eyes) had well demarcated boundaries. These membranes included most angiographically classic CNV (8 of 9 eyes) and a subset of angiographically occult CNV (12 of 50 eyes). Angiographically occult CNV which appeared well-defined on OCT (5 eyes) was sometimes due to the presence of hemorrhage blocking the angiogram but not the OCT (3 eyes). OCT was not able to detect occult CNV beneath serous PEDs due to optical shadowing (5 eyes). Conclusions. OCT was useful in quantitatively evaluating subretinal and intraretinal fluid, assessing possible subfoveal involvement of CNV, and in monitoring CNV before and after laser photocoagulation. OCT was unable to detect CNV beneath serous PEDs. OCT may have potential in defining the boundaries of a subset of occult CNV.