Anatomical and Refractive Characterstics of an Eyeball in Children with Myopia

Aleksandrova J. L.
MD, PhD, ophthalmologist¹

Shefer K. K.
MD, PhD, Head, Department for Children¹; Ophthalmologist, Assistant Professor, Chair for Ophthalmology²

1 - The Saint-Petersburg Branch of the S.N. Fyodorov Eye Microsurgery Federal State Institution, Saint-Petersburg, Russia
2 - North-Western State Medical University named after I.I. Mechnikov, Ophthalmology Department. Saint-Petersburg, Russia

Shefer Kristina; e-mail: kristinashefer@yahoo.com

None declared.

The study had no sponsorship.

Purpose: Myopia is the main cause of visual impairment in the world. The analysis of its causes and anatomical characteristics of an eyeball is a challenging task for prognosis of ametropia progression especially in children. The aim of our study is an assessment and analysis of anatomical and refractive characteristics of an eyeball in children with myopic refraction. Material and methods: We observed 248 (496 eye) children with myopia dividing them into two age groups: younger school age 7-12 years (168 eyes) and older school age 13-18 years (244 eyes)). Control group – 21 emmetropic children: 11 (n=22) 7-12 years of age and 10 children (n=20) 13-18 years of age. We performed standard ophthalmological investigation: sciascopy with medical cycloplegia, ophthalmometry, measurement of the eye size (optical biometry). We calculated theoretical refraction for each child and compared it with his (her) actual refraction. Results: In the group of younger children we found prevalence of slight and moderate myopia. We found axial type of myopia (increase of an eye size) in 70% of cases and mixed type (increase of an eye size as to corneal refraction) in 20,5% and in 9,5% refractive type of myopia (eye size is normal but corneal refraction is increased). We found extreme increase of an eyeball in 29% of children from the group of axial myopia. Also, we found in them the theoretical (calculated) refraction is much higher than the real one (due to the lower corneal refraction compared to control group and other myopic children). In the older children we found double increase of high myopia compared to younger. The incidence of myopia in girls was higher compared to boys in the older children. In older group we found axial type of myopia in 64% of cases and mixed type in 36%. As well we see decrease of number of older children with pathological increase of an eyeball (20%). Conclusion: In children we see age-related increase of myopic refraction in connection with the eyeball size increase. In schoolchildren we see prevalence of axial myopia (70% in yonger age and 64% in older) but with the age one can see increase of mixed type of myopia (up to 36% compared to 20 in younger children)

myopia, axial size of an eyeball, corneal refraction, eyeball characteristics

10.29234/2308-9113-2020-8-1-74-81

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