Stages 4 and 5
Stage 4 ROP: there is partial retinal detachment, with Stage 4A referring to a retinal detachment in which the fovea is still attached (Figures 2G and 2H), and Stage 4B referring to a retinal detachment including the fovea (Figure 2I) with detachment spanning distance from the disc to the laser scars. Subretinal blood and lipid may be noted as well (Figure 2J).
Stage 5 ROP: there is complete retinal detachment, typically funnel-shaped, further defined by the configuration of the funnel as anterior open-posterior open (Figures 2K and 2L), anterior open-posterior closed, anterior closed-posterior open, or closed both anterior and posterior). In advanced cases, there is no view of the posterior pole as a consequence of dense retrolental fibrous proliferation (Figure 2M).
