The presence of threshold and prethreshold findings in retinopathy of prematurity can identify infants at risk for disease progression and in need of closer monitoring and/or ablative therapy.


The presence of Stage IV disease (retinal detachment) indicates disease progression beyond threshold levels.


Criteria for threshold disease - both of the following:

(1) extensive stage III disease in zone 1 or 2, with either (a) 5 contiguous clock hours or (b) 8 noncontiguous clock hours involved

(2) presence of "plus" disease (posterior venous dilatation and arteriolar tortuosity)


Criteria for prethreshold disease:

(1) not threshold disease

(2) one or more of the following:

(a) any stage in zone 1

(b) stage II and "plus" disease in zone 2

(c) stage III in zone 2


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