Early retinal vessel development and iris vessel dilatation as factors in retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Cooperative Group
J. D. Kivlin, A. W. Biglan, R. A. Gordon, V. Dobson, R. A. Hardy, E. A. Palmer, B. Tung, W. Gilbert, R. Spencer, K. P. Cheng and E. Buckley
Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, USA.
OBJECTIVE: To determine whether the extent of retinal vessel development
present on early screening examinations for retinopathy of prematurity has
prognostic value? DESIGN: The prospectively collected data from the
Multicenter Trial of Cryotherapy for Retinopathy of Prematurity were used
to compare the development of acute retinopathy of prematurity and
long-term structural and visual outcomes for eyes with differing extents of
retinal vessel development. PATIENT: Study patients had eyes with the
following vessel development. In zone I eyes, vessels extended from the
disc less than twice the distance from the disc to the macula. In zone II
eyes, vessels extended beyond zone I but not to the nasal ora serrata.
Transitional eyes had vessels partly in zone I and partly in zone II.
RESULTS: The chance of developing threshold retinopathy of prematurity was
inversely related to the early degree of vessel development: 54% for zone I
eyes, 25% for transitional eyes, and 8% for zone II eyes. The presence of
prominent iris vessels at 34 to 35 weeks of postmenstrual age was
associated with increased risk for all three groups; zone I eyes almost
always needed treatment (94%). The chance of having an unfavorable anatomic
alteration of the posterior fundus, or poor vision at the ages of 1 year
and 3 1/2 years, was also inversely related to the degree of early vessel
development. Vessel development was an independently important factor even
when birth weight, gestational age, and race were considered. CONCLUSIONS:
The degree of early retinal vessel development is a significant predictor
of outcome from retinopathy of prematurity. Iris vessel dilatation is an
important indication for greater vigilance in following these infants.
