Comparison of optical coherence tomography assessments in the comparison of age-related macular degeneration treatments trials.
OBJECTIVE
To determine agreement between spectral-domain (SD) and time-domain (TD) optical coherence tomography (OCT) image assessments by certified readers in eyes treated for neovascular age-related macular degeneration (AMD).


METHODS
Cross-sectional study within the Comparison of AMD Treatments Trials (CATT).


METHODS
During year 2 of CATT, 1213 pairs of SD OCT and TD OCT scans were compared from a subset of 384 eyes.


METHODS
Masked readers independently graded OCT scans for presence of intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (RPE) fluid and performed manual measurements of retinal, SRF, and subretinal tissue complex thicknesses at the foveal center.


METHODS
Presence of fluid was evaluated with percent agreement, κ coefficients with 95% confidence intervals (CIs), and McNemar tests. Thickness measurements were evaluated with mean difference (Δ) ±95% limits of agreement and intraclass correlation coefficients (ICCs) with 95% CIs.


RESULTS
Between SD OCT and TD OCT, agreement on presence of any fluid was 82% (κ = 0.46; 95% CI, 0.40-0.52), with 5% more SD OCT scans demonstrating fluid (P<0.001). Agreement on presence of SRF was 87% and sub-RPE fluid was 80%, with more SD OCT scans demonstrating fluid (both P < 0.001). Agreement on IRF was 73% (κ = 0.47; 95% CI, 0.42-0.52), with 6% more TD OCT scans demonstrating fluid (P < 0.001). Between SD OCT and TD OCT, mean thickness of the retina was Δ = 5±67 μm, SRF was Δ = 1.5±35 μm, and subretinal tissue complex was Δ = 5±86 μm. Thickness measurements were reproducible for retina (ICC = 0.84; 95% CI, 0.83-0.86), SRF (ICC = 0.88; 95% CI, 0.86-0.89), and subretinal tissue complex (ICC = 0.91; 95% CI, 0.89-0.92), with ≤25-μm difference in these measurements in 71%, 94%, and 61% of paired scans, respectively.


CONCLUSIONS
Agreement on fluid presence and manual thickness measurements between paired scans from each OCT modality was moderate, providing a reasonable basis to compare CATT results with future SD OCT-based trials. Fluid was detected 5% more frequently with SD OCT, which may increase frequency of fluid-based treatment. Lower-resolution and artifactual interpretation of dark areas as cystoid edema may explain the greater frequency of IRF detected with TD OCT.
Department of Ophthalmology, Duke University, Durham, North Carolina.
Francisco A
FA
Folgar
Department of Ophthalmology, Duke University, Durham, North Carolina.
Glenn J
GJ
Jaffe
Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania.
Gui-Shuang
GS
Ying
Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania.
Maureen G
MG
Maguire
Department of Ophthalmology, Duke University, Durham, North Carolina. Electronic address: cynthia.toth@dm.duke.edu.
Cynthia A
CA
Toth
D000328:Adult; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000068258:Bevacizumab; D003430:Cross-Sectional Studies; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000188:drug therapy; D011446:Prospective Studies; D000069579:Ranibizumab; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods* / Q000592:standards
D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D000069579:Ranibizumab