Patients with choroidal neovascularization (CNV) may be undertreated in many cases, even though clinicians may be accurately identifying signs of the condition on spectral domain OCT (SD-OCT) scans, a new study in the British Journal of Ophthalmology suggests. As such, reading center evaluations may be a valuable second-line resource for quality assurance.

The non-interventional ORCA module of the OCEAN study evaluated the quality of SD-OCT image interpretations and treatment decisions by clinicians in Germany and the impact on visual outcomes over 24 months in patients with wet AMD.

The study included 2,286 SD-OCT scans of 205 eyes that were independently evaluated by clinicians and reading centers for signs of CNV activity, including the presence of intraretinal fluid, subretinal fluid and any increase in pigment epithelial detachments. The investigators calculated the agreement between clinicians and reading centers and evaluated the treatment decisions by clinicians and the impact on treatment outcomes.

Reading centers detected CNV on 1,578 scans (69%) compared with clinicians who found CNV on 1,392 scans (60.9%), with agreement in 74.9% of cases. Of the 1,578 reading center scans that detected CNV, clinicians administered anti-VEGF injections only 35.5% of the time. In 19.7% of these cases, lack of treatment was justified by patient request, termination criteria or chronic cystoid spaces without other signs of CNV activity.

Of note: in 44.8% of the cases with CNV activity detected at reading centers, clinicians claimed no treatment was necessary despite having correctly detected CNV activity in about two-thirds of the cases. In 34% of cases with presumed undertreatment, visual acuity declined in the following visit.

Although broad agreement of CNV activity parameters was observed between clinicians and reading centers, correct identification of CNV activity did not always lead to the initiation of re-treatment, the investigators noted.

The study provides strong evidence that misinterpretation of SD-OCT scans not only results in undertreatment, but also in visual loss over time, the researchers said. Lack of treatment appears to also occur even when correct identification of intraretinal fluid, subretinal fluid or pigment epithelial detachments was documented, they added.

“Not only is adequate training or possibly future artificial intelligence assistance in SD-OCT interpretation needed, but also precise guidelines for retreatment and adherence to these is recommended to preserve vision over time,” the researchers wrote in their paper.

Liakopoulos S, Spital G, Brinkmann CK, et al. ORCA study: real-world versus reading centre assessment of disease activity of neovascular age-related macular degeneration (nAMD). Br J Ophthalmol. February 17, 2020. [Epub ahead of print].