EFFECT OF ACUTE-PHASE RETINOPATHY OF PREMATURITY ON GRATING ACUITY DEVELOPMENT IN THE VERY-LOW-BIRTH-WEIGHT INFANT

Purpose. To examine the development of grating acuity in four groups o f eyes in the Multicenter Study of Cryotherapy for Retinopathy of Prem aturity (CRYO-ROP): eyes with no ROP; eyes with less-than-prethreshold ROP; eyes with prethreshold ROP; and eyes with threshold ROP that wer e randomized to serve as controls (not treated with cryotherapy). Meth ods. Subjects were 1398 children with birth weights <1251 g whose acut e-phase ROP was documented as part of the CRYO-ROP study. Monocular gr ating acuity was measured using the Teller acuity card procedure when children reached 1, 2, 3 1/2, and 4 1/2 years of age. Results. Eyes in the no-ROP and less-than-prethreshold groups showed nearly identical acuity development. Eyes with prethreshold ROP showed mean acuity simi lar to the no-ROP group at 1 and 2 years, but slightly below the no-RO P group at 3 1/2 and 4 1/2 years. Only 50% of eyes in the threshold un treated ROP group had measurable acuity. These eyes showed mean acuity scores that were approximately 1 octave below those of the no-ROP gro up at all four test ages. When data from eyes with ROP residua or othe r ocular abnormalities, and data from eyes of children who were unable to pass the study developmental screening items, were excluded, acuit y development was similar among groups. Conclusions. Mild (less-than-p rethreshold) ROP has no effect on the development of grating acuity in children between 1 and 4 1/2 years of age. Moderate (prethreshold) RO P is associated with reduced acuity at 3 1/2 and 4 1/2 years. In gener al, severe (threshold untreated) ROP results in moderate to severe red uctions in acuity at all ages between 1 and 4 1/2 years. However, a sm all number of children with severe ROP show normal acuity development.