Optical Coherence Tomography for the Diagnosis of Neovascular Age-Related Macular Degeneration

A Systematic Review

MM Castillo; G Mowatt; N Lois; A Elders; C Fraser; W Amoaku; JM Burr; AJ Lotery; CR Ramsay; A Azuara-Blanco

Disclosures

Eye. 2014;28(12):1399-1406. 

In This Article

Abstract and Introduction

Abstract

The purpose is to study the diagnostic performance of optical coherence tomography (OCT) and alternative diagnostic tests for neovascular age-related macular degeneration (nAMD). Methods employed are as follows:systematic review and meta-analysis; Index test: OCT including time-domain (TD-OCT) and the most recently developed spectral domain (SD-OCT); comparator tests: visual acuity, clinical evaluation (slit lamp), Amsler chart, colour fundus photographs, infra-red reflectance, red-free images/blue reflectance, fundus autofluorescence imaging (FAF), indocyanine green angiography (ICGA), preferential hyperacuity perimetry (PHP), and microperimetry; reference standard: fundus fluorescein angiography. Databases searched included MEDLINE, MEDLINE In Process, EMBASE, Biosis, SCI, the Cochrane Library, DARE, MEDION, and HTA database. Last literature searches: March 2013. Risk of bias assessed using QUADAS-2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic (HSROC) curves. Twenty-two studies (2 abstracts and 20 articles) enrolling 2124 participants were identified, reporting TD-OCT (12 studies), SD-OCT (1 study), ICGA (8 studies), PHP (3 studies), Amsler grid, colour fundus photography and FAF (1 study each). Most studies were considered to have a high risk of bias in the patient selection (55%, 11/20), and flow and timing (40%, 8/20) domains. In a meta-analysis of TD-OCT studies, sensitivity and specificity (95% CI) were 88% (46–98%) and 78% (64–88%), respectively. There was insufficient information to undertake meta-analysis for other tests. TD-OCT is a sensitive test for detecting nAMD, although specificity was only moderate. Data on SD-OCT are sparse. Diagnosis of nAMD should not rely solely on OCT.

Introduction

Anti-vascular endothelial growth factor (VEGF) therapies have revolutionised the treatment of neovascular age-related macular degeneration (nAMD). Visual outcomes following anti-VEGF[1–4] have been unparalleled by previous therapies which included laser photocoagulation[5,6] and photodynamic therapy.[7] The cost-effectiveness of anti-VEGF drugs depends, however, on the establishment of an early and accurate diagnosis. Fundus fluorescein angiography (FFA) interpreted by an ophthalmologist is the current reference standard for the diagnosis of nAMD,[8,9] as it directly detects the presence of the neovascular tissue that fills with the dye. However, FFA is an invasive and a time-consuming test. Other alternative diagnostic technologies are available of which the most widely used is optical coherence tomography (OCT). OCT, including time-domain (TD-OCT) and the most recently developed spectral domain (SD-OCT), is a lightwave-based technology that allows the imaging of the retina obtaining 'sections' of this neovascular tissue with scan rates and resolution parameters that have greatly improved over the past 10 years. OCT is a non-invasive, non-contact visual test that requires about 5–10 min to assess both eyes. It is user friendly, typically undertaken by trained medical photographers and interpreted by ophthalmologists. However, it might also lead to efficiencies by allowing other categories of health professionals to become involved in the diagnosis of patients.

The aim of this systematic review was to evaluate the diagnostic accuracy, interpretability, and acceptability of OCT, alone or in combination with other tests, for the assessment of newly presenting patients suspected of having nAMD.

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