Abstract
Purpose: :
To determine the incidence of refractive amblyopia and strabismus in very low birth weight infants with and without a history of retinopathy of prematurity (ROP).
Methods: :
This is a prospective study based on a previous retrospective study presented at ARVO in 2005.
Results: :
The previous study examined the incidence and severity of ROP in preterm infants with a birth weight less than 1500 grams between 2003 and 2004. 64% of the babies born with a birth weight less than 1500 grams developed ROP. There was a high correlation between low birth weight and young gestational age. The group with any form of ROP had a mean gestational age of 26.98 weeks and mean birth weight of 913.31g. The group without any ROP had a mean gestational age of 28.34 weeks and a mean birth weight of 1061.39g. The group with threshold ROP had a mean gestational age of 25.80 weeks and mean birth weight of 774.20g. The group without threshold ROP had a mean gestational age of 27.60 weeks and mean birth weight of 979.92g.In our study, we attempt to determine the long term visual outcome of the patients in the original study who would now be between 2 and 4 years old. Of the original 96 patients, 15 patients have been evaluated to date. Attempts to reach the remainder of the patients have been made without success. Of the 15 patients, 2 (13.3%) had a history of threshold ROP requiring laser treatment. 1 developed exotropia by age 6 months and underwent strabismus surgery and has been orthophoric on follow-up. The other has been orthophoric to age 4. Both are mild hyperopes.Of the remaining 13 patients, 6 (40%) had a history of non-threshold ROP. 4 have central, steady, and maintained vision; 1 sees 20/20 OU; 1 patient’s vision was not recorded. 4 of the 6 are mild hyperopes. 1 is myopic with anisometropia, and 1 refraction was not recorded. 5 of the 6 (83%) patients were orthophoric, and one patient had an esotropia of 30 prism diopters. Only 2 patients cooperated for stereoacuity testing, both of whom had gross stereopsis (+fly).The remaining 7 patients had no history of developing any ROP. 6 have central, steady, and maintained vision; 1 is 20/20 OU. 5 are mild hyperopes, 1 is plano, and 1 did not have a recorded refraction. 6 out of 7 are orthophoric and 1 has an esotropia of 50 prism diopters. 2 patients cooperated for stereo testing, having 200 and 100 seconds of arc, respectively.
Conclusions: :
Our study sample is too small to make any long-term conclusions. However, our results seem to be consistent with previous studies in that there is an increased incidence of strabismus and refractive amblyopia in very low birth weight infants, especially if there is a history of ROP.
Keywords: retinopathy of prematurity • refractive error development • strabismus