ICROP Documentation of ROP
When screening an infant for ROP, the zone indicates how far retinal vessels have developed and where the abnormalities lie. Zone 1 is the area closest to the optic nerve, Zone 2 is the next progression of development toward the periphery, and Zone 3 is crossed as the vessels reach the ora serrata. Table 1 summarizes the zones of development.
The stages reported when screening an infant for ROP indicate the severity of the disease process. Stage 1 is defined as a distinct line between the vascularized and avascularized regions of the retina. On examination, it usually appears white or yellow. Stage 2 occurs when the line noted in Stage 1 gains both depth and height. When the blood vessels extend into the vitreous, it is classified as Stage 3. Stage 4 is defined as partial retinal detachment; Stage 5 is total retinal detachment.[3,6] Table 2 shows a summary of the stages of ROP.
Numerous rates of progression have been observed. Some infants progress slowly, whereas others may progress very rapidly.
The presence of plus disease is documented with screening examinations. Because plus disease is highly associated with retinal detachment, its presence contributes to the decision to surgically intervene. Because of this risk, infants with plus disease require more frequent retinal examinations.
Threshold is another term used in classifying the severity of ROP. This is based on dividing the eye into 12 continuous clock hours. The area of involved retina is described in clock hours. To use the threshold term in reporting ophthalmic findings, the infant must have Stage 3 disease in either Zone I or Zone II, with a minimum of five continuous clock hours, or eight total clock hours with plus disease. Untreated threshold ROP will progress to Stage 4 with retinal detachment in about 50% of the cases. Prethreshold is used to describe those infants who require more vigilant screening for the development of threshold.
Rush disease is defined as a rapid progression through the three stages of ROP, with plus disease and retinal detachment occurring within a few weeks.[6,7] Rush disease requires rapid surgical intervention.
NAINR. 2003;3(3) © 2003 W.B. Saunders
Cite this: Does My Child Really Need to Wear These Glasses? A Review of Retinopathy of Prematurity and Long-Term Outcomes - Medscape - Sep 01, 2003.