Prevalence of myopia between 3 months and 5 1/2 years in preterm infants with and without retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group.
OBJECTIVE
The purpose of the study was to examine spherical equivalent refractive errors, especially myopia, at six ages between 3 months and 5 1/2 years post-term in preterm children with birth weights of less than 1251 g.


METHODS
A cohort study.


METHODS
There were a total of 827 participants in the multicenter study of cryotherapy for retinopathy of prematurity (ROP). Approximately one third of the eyes did not develop ROP, whereas two thirds developed mild-to-severe ROP. None of the eyes underwent cryotherapy.


METHODS
Refractive error was measured at 3 months, 1 year, and 5 1/2 years term due date at the five long-term follow-up centers. In most eyes, refractive error also was measured at 2, 3 1/2, and 4 1/2 years.


METHODS
Myopia was defined as 0.25 diopter (D) or greater with high myopia as 5 D or greater.


RESULTS
The proportion of eyes with myopia in this preterm population was increased compared to published data on full-term children and was related to severity of both acute-phase and cicatricial-phase ROP. The percentage of eyes with myopia varied little across ages, ranging from 21.2% at 1 year to 15.7% at 4 1/2 years. The percentage of eyes with high myopia doubled from 1.8% to 3.9% between 3 months and 1 year and remained stable thereafter. The distribution of refractive errors in eyes with mild acute-phase ROP was similar to that of eyes with no ROP. In contrast, eyes with moderate or severe acute-phase ROP showed an increased prevalence of high myopia. The distribution of refractive errors changed between 3 months and 1 year with little change after 1 year. This pattern of refractive development differs from that of full-term infants. Birth weight, severity of ROP, and degree of myopia at 3 months predicted the presence of myopia and high myopia at 5 1/2 years of age.


CONCLUSIONS
The distribution of refractive errors in preterm infants from age 3 months to 5 1/2 years varies with severity of acute-phase ROP and cicatricial disease. Changes in refractive error distribution occur primarily between 3 months and 1 year and involve a decrease in the proportion of eyes with hyperopia and an increase in the proportion with high degrees of myopia.
Quinn
G E
GE
Division of Pediatric Ophthalmology, Children's Hospital of Philadelphia, PA 19104, USA.
Dobson
V
V
Kivlin
J
J
Kaufman
L M
LM
Repka
M X
MX
Reynolds
J D
JD
Gordon
R A
RA
Hardy
R J
RJ
Tung
B
B
Stone
R A
RA
D000208:Acute Disease; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017679:Cryotherapy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D009216:Myopia / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000150:complications* / Q000601:surgery; D014481:United States / Q000453:epidemiology