The aim of the systematic review «Mowatt G, Hernández R, Castillo M ym. Optical cohe...»1 was to determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected neovascular age-related macular degeneration (nAMD) and in monitoring those previously diagnosed with the disease.
Electronic databases searched included MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Bioscience Information Service, Science Citation Index, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Medion, Health Technology Assessment database, PsycINFO, Applied Social Sciences Index and Abstracts, conference abstracts from the American Academy of Ophthalmology, the Association for Research in Vision and Ophthalmology, the European Association for Vision and Eye Research and current research registers. Searches were carried out from 1995 to March 2013 other than for conference abstracts (2009 to November 2012).
Types of studies considered included direct or indirect comparisons reporting diagnostic outcomes. The population was people with newly suspected nAMD or those previously diagnosed with the disease and under surveillance monitoring. The index test was TD-OCT or SD-OCT and comparator tests considered were clinical evaluation, visual acuity (VA), Amsler grid, colour fundus photographs, infrared reflectance, red-free images or blue reflectance, fundus autofluorescence (FAF) imaging, indocyanine green angiography (ICGA), preferential hyperacuity perimetry (PHP) and microperimetry. The reference standard was FA. Two reviewers independently screened the titles and abstracts of all reports identified by the search strategy and full-text papers were obtained for assessment. Data extraction was undertaken by one reviewer and checked by a second. Two reviewers independently assessed the risk of bias of the studies using the quality assessment of diagnostic accuracy studies, version 2 instrument.
Altogether 22 diagnostic studies with 2124 patients were included in the systematic review. 21 studies reported eyes as an unit of analysis (number of eyes 1754) and one study reported that 155 patients were included. 45.4% (N=742) were male. Age: median 76.0 years (range 51.4–84.6).
Tests reported in the included diagnostic studies; OCT 13 studies (N=1335); TS –OCT 12 studies and SD-OCT 1 (N=19), ICGA 8 studies (N=458), PHP three studies (N=491) and FP (N=185), Amsler grid (N=98) and FAF one study (N=62).
Four studies, all TD-OCT, reported both sensitivity and specificity, providing sufficient data for inclusion in a meta-analysis. The pooled sensitivity and specificity (95% CI) was 88% (46% to 98%) and 78% (64% to 88%), LR+ was 4.08 (95% confidence interval 2.37 to 7.04), LR - 0.15 (95% confidence interval 0.02–0.98) and DOR 26.86 (95% confidence interval 3.36–214.81).
In descriptive analyses, median sensitivity was high for ICGA (93.2%, range 84.6–100.0%; four studies) and FAF (93.3%; one study), followed by PHP (81.5%, range 50.0–84.8%; three studies), colour fundus photography (70.0%; one study) and lowest for Amsler grid (41.7%; one study). Specificity was highest for colour fundus photography (95%; one study), followed by PHP (84.6% and 87.7%; two studies), and was low for FAF (37.1%; one study) and ICGA (36.8%; one study).
Kommentti: Katsauksen laatijoiden mukaan tutkimuksissa oli heterogeenisyyttä ja erityisesti potilasvalinnassa harhan riski.
Consecutive angiographic records of 52 patients with unilateral wet AMD in one eye and drusen in fellow eye undergoing both FA and ICGA were retrospectively reviewed to assess the contribution of ICGA to FA in this patient group «Landa G, Springer A, Bukelman A ym. The diagnostic...»2. Inclusion criteria were as follows; age 50 years or older, wet AMD in one eye, drusen without clinical or fluorescein angiographic evidence of CNV in the fellow eye, clear ocular media, no other retinal disease. Exclusion criteria were as follows; fluorescein angiograms with findings suspicious for CNV due to AMD, other retinal diseases and eyes with geographic atrophy. Drusen were graded according to clinical appearance to low, moderate or high severity. The primary outcome measure was an abnormal hyperfluorescence on ICGA not observed on FA of drusen eyes. Fifty-two pairs of eyes met inclusion criteria and were included into study. Twenty-four (46.2%) patients were men. The mean age of the patients was 76.9 8.2 years (range 63–92). 50 of 52 demonstrated no leakage on both FA and ICGA. ICGA leakage was observed in 20% (2 out of 10) eyes of high severity drusen group, which was not observed on FA. The authors conclude that in eyes of drusen with high grade severity, ICGA enhanced imaging of occult CNV not observed by FA.
An Austrian study «Sulzbacher F, Kiss C, Munk M ym. Diagnostic evalua...»3 was included in the systematic review «Mowatt G, Hernández R, Castillo M ym. Optical cohe...»1. The aim of the study was to evaluate the diagnostic characteristics of type 2 (classic) choroidal neovascularizations secondary to age-related macular degeneration using spectral domain-optical coherence tomography (SD OCT), indocyanine green angiography (ICGA), and fluorescein angiography (FA). Fifty-three consecutive patients who consulted the clinic at the department of Ophthalmology years 2008–2009 were screened for inclusion and 13 eyes were included in this study. The inclusion criteria were type 2 CNV defined as an area of choroidal hyperfluorescence with well-determined boundaries clearly discernible in the early phase of FA, with progressive leakage beyond the initial boundaries of the CNV and an area of early hypercyanescence without marked leakage activity on ICGA.
Patients with neovascular maculopathy from pathologic myopia, angioid streaks, infectious inflammatory chorioretinal disease, tumors, hereditary disorders or, or trauma were excluded.
The greatest horizontal dimension of the retinal leakage area according to ICGA was 1420 +/-670 um and according to to SD OCT was 3473 +/-885 um (p=0.000, Pearson coefficient 0.65). The authors conclude that ICGA and FA seem to underestimate the extension of the neovascular complex and the associated retinal pathological features compared with SD OCT imaging.
According to European Society of Retina Specialists (EURETINA) guideline «Schmidt-Erfurth U, Chong V, Loewenstein A ym. Guid...»4 fluorescein angiography (FA) is the only diagnostic examination that can confirm the mere existence of a CNV and if not contraindicated for systemic risks is routinely mandatory. Indocyanine green angiography (ICGA), when coupled with FA, can further reveal the area of focal hyperfluoresence or polypoidal choroidal vasculopathy.