New Method to Facilitate Tomographic Macular Neovascularization Classification in Age-related Macular Degeneration

Evaluation of contrast-modified optical coherence tomography (OCT) images as a tool for better macular neovascularization (MNV) classification in age-related macular degeneration (AMD) cases.

Twenty-five OCT images obtained with SPECTRALIS (Heidelberg Engineering GmbH) from patients showing MNV (10 type 1, 10 type 2, and 5 type 3) were selected. Two retina specialists (RDM and RGP) classified the MNV lesions and then the same cases were classified by 37 ophthalmologists with different degree of training. A grading tool was designed to classify these cases using standard OCT images (contrast value: 12) followed by reassessment with contrast-modified OCT images (contrast value: 1).

Thirty-seven ophthalmologists were involved: four 1st-year trainees, four 2nd-year trainees, four 3rd-year trainees, 12 4th-year trainees, and 13 consultants from different subspecialties. Average result for correct classification was 13.16 using standard images alone and 14.22 using contrast-modified images showing a significant improvement (P = 0.01). The accuracy was greater for type 1 lesions when using contrast-modified images, whereas there was no improvement with type 2 and 3 lesions (P = 0.039, P = 0.835, P = 0.193). The average correct answers was greater for type 2 (µ = 5.08) than type 1 (µ = 5.08) and type 3 (µ = 2) (P = 0.046). The graders (n; %) classified the utility of contrast-modified images as essential (1; 2,7%), very useful (29; 78.4%), indifferent (5; 13.5%), not very useful (1; 2.7%) and useless (1; 2.7%).

In challenging cases, it might be easier to locate the retinal pigment epithelium (RPE), evaluate RPE integrity, classify MNV, and study subretinal hyperreflective material using contrast enhanced OCT images. The accuracy for MNV classification increases with contrast-modified images in type 1 MNV. It is an accessible tool that could show even better performance as the ophthalmologist gains more experience using it.