What is the staging of retinopathy of prematurity?

Some premature babies will suffer from retinal diseases, and some parents do not fully understand the meaning of retinal staging and zoning. In fact, this also represents some meanings. Let us introduce them in detail below.

● Stage 1: occurs at about 34 weeks of corrected gestational age, with a dividing line appearing between the vascular and avascular areas in the temporal periphery of the retina;

● Stage 2: occurs at an average corrected gestational age of 35 weeks (32-40 weeks), with the fundus boundary bulging and ridge-like changes;

● Stage 3: The average onset is 36 weeks of corrected gestational age (32-43 weeks), with dilated and proliferative retinal vessels and fibrous tissue proliferation on the ridge-like lesions at the fundus demarcation line; the average onset of pre-threshold lesions is 36 weeks of corrected gestational age, and the average onset of threshold lesions is 37 weeks of corrected gestational age

● Stage 4: Tractional retinal detachment occurs due to fibrovascular proliferation, starting at the periphery and gradually developing toward the posterior pole. This stage is divided into A and B according to whether the macula is detached or not. Stage 4A means no macula detachment, and stage 4B means macula detachment.

● Stage 5: Complete retinal detachment occurs (approximately 10 weeks after birth). In the late stage of the disease, the anterior margin becomes lighter or disappears, and may be followed by glaucoma, corneal degeneration, and eyeball atrophy.

Retinopathy of prematurity zoning: divided into 3 zones according to the site of occurrence

● Zone I: The area within the circle with the optic disc as the center and the radius of twice the distance from the optic disc to the fovea as the radius. ROP occurring in this area is the most serious.

Zone II: The area outside Zone I is a circle with the optic disc as the center and the distance from the optic disc to the nasal ora serrata as the radius.

●Zone III: The temporal semilunar area outside zone II is the area with the highest incidence of ROP.