Axial Length, Subfoveal Choroidal Thickness Changes Accompany Precocious Puberty

Increased axial length (AL) and thicker central subfoveal choroidal thickness (ChT) are associated with precocious puberty, according to a study published in the Journal of American Association for Pediatric Ophthalmology and Strabismus. 

Researchers enrolled 38 children with precocious puberty (100% girls; mean age, 92.2  months) and 34 healthy control children (100% girls, mean age 94.6 months) in a cross-sectional study to compare ocular findings between the groups. Patients underwent refractive error, axial length (AL), keratometry, corneal volume, anterior chamber depth, anterior chamber volume, and iridocorneal angle measurements. Central macular thickness (CMT), retinal nerve fiber layer (RNFL) thickness and central subfoveal choroidal thickness were also obtained for each participant.

Weight, height, body mass index (BMI) and standard deviation scores (SDS) were calculated using a comprehensive online calculation program and evaluated according to the Center for Disease Control’s (CDC) growth references. Puberty grade was determined by Tanner staging according to breast sizes. Blood samples were obtained for hormonal measurements in the early morning after 8 hours of overnight fasting. Serum follicle-stimulating hormone (FSH), LH, and estradiol were measured using the electrochemiluminescence immunological method (ECLIA).

Spherical refraction was less hyperopic (P =.017) and AL was significantly longer in individuals with precocious puberty compared with control individuals (22.90 vs 22.24 mm; P =.001). Both spherical values and AL were significantly associated with the Tanner stage. 

No differences were noted in anterior segment parameters between the two groups. The CMT and RNFL thicknesses were comparable between the two groups with the exception of sub foveal ChT — which was significantly higher among children with precocious puberty, regardless of Tanner stage (349.90 vs 293.25 µm; P < .001).

“The presence of sex-based differences in many ocular conditions and alterations seen in ocular conditions during puberty and pregnancy suggest the possibility that sex hormones affect ocular tissues,” according to researchers.

Study limitations include an inability to measure changes in ocular parameters over time due to the cross-sectional nature and failure to consider known variables for AL progression including family history, education, and near work time.