The COMS Grading Scheme: Graded Features

Retinal capillary nonperfusion

Capillary non-perfusion is most apparent on angiogram as areas of hypofluorescence during the transit phase.  Larger areas can visualized as “ground glass” appearing areas of hypofluorescence in the late phase, often with a surrounding area of mild hyperfluorescence.  There can be no corresponding pigmented lesion or cotton wool spot in the color photograph.  Capillary nonperfusion can only be graded when an angiogram is available.  When capillary nonperfusion involves the foveal avascular zone (FAZ), the involved area is measured and 0.16 DA is subtracted to account for the physiologic avascularity of the FAZ.

Severity

None: not present

Mild:  less than 1/2 disc area (standard photograph 1 with early and late angiograms) click on any image for higher resolution image click on your browser's "back" button to return to this page Early phase Late phase

Moderate: more than 1/2 disc area, but less than 2 disc areas (standard photograph 2 with early and late angiograms) click on any image for higher resolution image click on your browser's "back" button to return to this page Early phase Late phase

Severe: more than 2 disc areas

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