Abstract
Purpose: :
To evaluate the relationship between choroidal thickness and ocular maturity in young infants, and to determine if there is a correlation between swelling of choroid and macular edema in premature infants at risk for retinopathy of prematurity (ROP).
Methods: :
Images were obtained in 62 preterm infants and 60 term infants using an 840nm wavelength portable SD-OCT system (Bioptigen Inc., Research Triangle Park, NC). Of the 62 preterm infants, 42 who were imaged prior to 37 weeks were assessed for relationship between choroidal thickness and pre-laser ROP status, maximum stage of ROP, plus disease, and macular pathology on SD-OCT. Eight out of 60 term infants were excluded from the study due to bilateral subretinal fluid. The images of all eligible infants were scored to determine if the choroidal-scleral junction (CSJ) was visible. Subfoveal choroidal thickness and central foveal thickness were measured using Image J (NIH) in subjects with a visible subfoveal choroid.
Results: :
Choroidal thickness was measured in 39/42 premature infants and in 38/52 term infants. Six out of 14 African American and 9/21 Hispanic term infants were not measured due to the inability to visualize the subfoveal CSJ. Choroidal thickness was measured in all Caucasian term infants (16/16). Mean choroidal thickness was greater in term infants than preterm infants (term infants, 321.5+70.2µm and preterm infants, 188.8+59.5µm, p-value<0.001). Choroidal thickness ranged from 113µm-332µm in premature infants and 197µm-492µm in term infants. There was no correlation between subfoveal choroidal thickness and central retinal foveal thickness in either group (R2=0.16 in term, R2=0.0028 in preterm). Choroidal thickness was weakly correlated to the postmenstrual age when both term and preterm infants were combined (R2=0.43). Choroidal thickness was not different between preterm infants with and without plus disease (p=0.11).
Conclusions: :
The thickness of subfoveal choroid is greater in term infants than preterm infants, and there is a large range of subfoveal choroidal thickness values within both groups. In preterm infants, greater choroidal thickness does not appear to be associated with severity of ROP, as it is not associated with height of macular edema, maximum ROP stage, or presence of plus disease.
Keywords: choroid • retinopathy of prematurity • imaging/image analysis: clinical