Abstract
Abstract: :
Purpose: High myopia in childhood has a well-documented association with important ocular and/or systemic conditions. To expedite specialist medical assessment of these conditions, an ongoing study in the UK is investigating high myopia in community health care clinics with the aim of compiling guidelines for subsequent referral to paediatric ophthalmology. This study describes the biometric assessment of two groups of children presenting with high myopia: one with associated ocular and/or systemic conditions (association) and the other without (normal). The specific aim is to examine whether the two groups differ with regard to the principle structural correlate of myopia, axial length. Methods: Community optometry practice data records and orthoptic screening records were searched for children younger than 10 years with myopia ≥5D, spherical equivalent, in one or both eyes. The volunteers (N=28) underwent both an optometric and ophthalmological examination, which included fundoscopy, cycloplegic refraction, slit-lamp assessment and biometric measurements with an IOL Master (Zeiss) and an autokeratometer (Nidek). Results: 57% of the children were classed as normal, 25% were found to have myopia associated with an ocular condition and 18% had an associated systemic condition. Mean refractive errors were -5.59 D (sd ±1.96) for the normal group and -6.35 D (sd ±3.00) for the association group. The mean axial length for the normal group was 25.34mm (sd ±1.22) and for the association group was 23.89mm (sd ±1.82), an independent samples t-test was significant (p=0.029) for axial length. No significant difference in corneal curvature was found (p=0.53): normal mean 7.81mm (sd ±0.40) and association mean 7.70mm (sd ±0.52). Conclusions: Optometric and ophthalmological assessment of children under 10 years with myopia ≥5D is likely to identify evidence of significant ocular or systemic disease, a proportion of which will respond to medical intervention. Axial length measurement suggests that those children whose myopia is associated with an ocular or systemic condition have a shorter axial length than those without. Presumably the lens accounts for the myopia in the association group; unfortunately the IOL Master is unable to measure lens thickness. The study indicates that extending the range and scope of biometric data will provide valuable guidelines for determining the clinical nature of high myopia in children.
Keywords: myopia • clinical (human) or epidemiologic studies: tre • refractive error development