[Biometry in the growth of the high myopic eye in childhood].

Purpose: To determine if the growth of the axial length measured by optical and ultrasound biometry in a pediatric population of high myopes is significant, as well as significant variation of lens thickness, anterior chamber depth, corneal curvature and ophthalmoscopic findings during follow-up.

Methods: A pediatric population (mean age: 8.7 years old) of 11 high myopic eyes (mean initial refractive error: -11.28 D) was submitted to serial evaluation over a 9-months period including optical (IOLMaster, Zeiss) and ultrasound biometry (Ultrascan, Alcon, contact technique), cycloplegic refraction, indirect ophthalmoscopy and fundus photography.

Results: During a 9-months period, eye growth was significant in 64% (7 eyes) and did not occur in 36% (3 eyes), with change in the mean axial length (pre=26.76 mm; final=26.98 mm). During this period, refractive spherical equivalent increased in 45% (5 eyes), did not show variation in 27% (3 eyes), with a change in mean refraction (pre=-11.28 D; final=-11.69 D). There was no statistically significant variation of lens thickness, anterior chamber depth, corneal curvature and ophthalmoscopic findings.

Conclusion: Ocular globe growth (axial length) measured by optic and ultrasound biometry was significant in the high myopic pediatric population examined. The findings suggest that axial length variation preceded variation of other structures in the sample examined. In a group of children with high myopia followed during a 9-months period, ocular growth was demonstrated with variation of axial length either with optical or ultrasound biometry techniques, and change in mean refraction. Other parameters studied as lens thickness, anterior chamber depth and corneal curvature did not demonstrate variation during the time of the study.