OCT Biomarkers in Neovascular Age-Related Macular Degeneration: A Narrative Review

Abstract

Age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly people. Neovascular AMD (nAMD) is responsible for the majority of cases of severe visual loss in eyes with AMD. Optical coherence tomography (OCT) is the most widely used technology for the diagnosis and follow-up of nAMD patients, which is widely used to study and guide the clinical approach, as well as to predict and evaluate treatment response. The aim of this review is to describe and analyze various structural OCT-based biomarkers, which have practical value during both initial assessment and treatment follow-up of nAMD patients. While central retinal thickness has been the most common and one of the first OCT identified biomarkers, today, other qualitative and quantitative biomarkers provide novel insight into disease activity and offer superior prognostic value and better guidance for tailored therapeutic management. The key importance of retinal fluid compartmentalization (intraretinal fluid, subretinal fluid, and subretinal pigment epithelium (RPE) fluid) will be discussed firstly. In the second part, the structural alterations of different retinal layers in various stages of the disease (photoreceptors layer integrity, hyperreflective dots, outer retinal tubulations, subretinal hyperreflective material, and retinal pigment epithelial tears) will be analyzed in detail. The last part of the review will focus on how alterations of the vitreoretinal interface (vitreomacular adhesion and traction) and of the choroid (sub-RPE hyperreflective columns, prechoroidal clefts, choroidal caverns, choroidal thickness and choroidal volume, and choroidal vascular index) interact with nAMD progression. OCT technology is evolving very quickly, and new retinal biomarkers are continuously described. This up-to-date review article provides a comprehensive description on how structural OCT-based biomarkers provide a valuable tool to monitor the progression of the disease and the treatment response in nAMD patients. Thus, in this perspective, clinicians will be able to allocate hospital resources in the best possible way and tailor treatment to the individual patient’s needs.

Genetic Association Analysis of Anti-VEGF Treatment Response in Neovascular Age-Related Macular Degeneration

“…For example, in our observational study, the criterion defining a dry retina as a positive treatment outcome classified 107 (59.8%) of 179 patients as responders. Several studies suggest the inclusion of additional markers such as CRT or VA [ 36 ]. Still, these parameters have considerable limitations.…”

Advances in Optical Coherence Tomography Imaging Technology and Techniques for Choroidal and Retinal Disorders

“…Diagnostic evaluation in retinal and choroidal diseases are often conducted with OCT, including neovascular age-related macular degeneration (AMD) [ 2 ], central serous chorioretinopathy (CSCR) [ 3 ], vascular retinal disorders [ 4 ], and other vitreoretinal disorders [ 5 ]. OCT biomarkers have also been instrumental in further understanding and monitoring chorioretinal disease status; these biomarkers include central macular thickness, subretinal/intraretinal fluid, neurosensory detachment height, subfoveal choroidal thickness, choroidal vessel diameter, and choroidal vascularity index [ 6 , 7 , 8 ]. More recently, in the attempt to optimize the design of early interventional clinical trials for non-neovascular AMD, a number of structural OCT biomarkers, such as intraretinal hyperreflective foci, subretinal drusenoid deposits, drusen with hyporeflective core, high central drusen volume, have been described as high-risk for AMD progression to late stages [ 9 , 10 , 11 , 12 ].…”

Association between Polymorphisms in CFH, ARMS2, CFI, and C3 Genes and Response to Anti-VEGF Treatment in Neovascular Age-Related Macular Degeneration

“…The current classification of MNVs divides them according to their localization into type 1 (grown from the choroid below the RPE), type 2 (grown from the choroid through RPE), and type 3 (grown from the retina toward the RPE) [ 5 ]. At present, optical coherence tomography (OCT) is the most widely used technology for the diagnosis and follow-up of nAMD patients [ 6 ]. New imaging technologies—optical coherence tomography (OCT) and OCT-angiography—have an ability to detect abnormalities not imaged by previous methods and have greater precision for many entities that are imaged using these technologies [ 1 ].…”

“…New imaging technologies—optical coherence tomography (OCT) and OCT-angiography—have an ability to detect abnormalities not imaged by previous methods and have greater precision for many entities that are imaged using these technologies [ 1 ]. OCT allows one to identify specific retinal biomarkers of nAMD disease activity and to offer personalized management of nAMD, providing comprehensive information about the patient’s visual recovery during treatment [ 6 , 7 ].…”