Normative magnetic resonance imaging measurements of orbital structures in pediatric population of North-Eastern India: A retrospective cross-sectional study

Abstract

Purpose: The people of Northeast India comprise mostly of Mongoloid descent with characteristic craniofacial features. The purpose of this study was to evaluate the normal orbital structures with MRI and determine normative data in the Northeast Indian pediatric population. Methods: MRI images of the 302 orbits of 151 pediatric patients below 16 years of age were retrospectively evaluated to measure the various orbital structures. Both axial and coronal MRI images were utilized for various orbital measurements. An independent sample t -test was done to compare various orbital data according to the sex and side. Linear regression was also done. Results: The mean age of the pediatric population was 9.64 ± 1.47 years with a male: Female ratio of 1.13:1. The mean interzygomatic line was 88.4 ± 9.09 mm and the interorbital line was 22.18 ± 3.62 mm. The mean thicknesses of medial, lateral, superior, and inferior recti muscles were 2.58 ± 0.46, 2.34 ± 0.42, 2.16 ± 0.40, and 2.53 ± 0.49 mm in males and 2.41 ± 0.41, 2.08 ± 0.34, 2.08 ± 0.46, and 2.46 ± 0.49 mm in females. The mean horizontal orbital, vertical orbital diameters, orbital index, mean volume of eyeball, and orbital cavity were 30.27 ± 2.97,3 7.06 ± 3.57, 122.58 ± 7.39, 4.63 ± 0.84, and 15.29 ± 3.52 in males, while 29.16 ± 3.23, 34.96 ± 3.99,119.96 ± 7.31, 4.49 ± 0.87, and 14.65 ± 3.47 in females, respectively. With an increase in age, the interzygomatic line ( r = 0.883, r 2 = 0.780; P < 0.0005), anterior medial interorbital line ( r = 0.808, r 2 = 0.652; P < 0.0005), mean volume of eyeball ( r = 0.915, r 2 = 0.838; P < 0.0005), orbital cavity ( r = 0.924, r 2 = 0.854; P < 0.0005), and distance between the optic nerve entry site ( r = 0.829, r 2 = 0.687; P < 0.0005) were increased. Conclusion: This study provides normative data of various orbital structures in a pediatric population and these data likely to be useful for diagnosing various pediatric orbital disorders and helps in the planning of various surgical procedures of orbits.

Evaluation of the Anatomical and Radiological Morphometry of Optic Nerve and Cranium in Healthy Individuals

“…Moreover, the same measurement was found as 21.90 mm (1.51) in females and 22.82 mm (1.43) in males, respectively. A statistically significant difference was found between sexes in eyeball transverse measurement ( P < 0.01) 20 …”

“…A statistically significant difference was found between sexes in eyeball transverse measurement (P < 0.01). 20 In another study that examined age-related orbital morphometry in the pediatric population of North Carolina (USA), the transverse diameter of the eyeball showed a very rapid increase in the first 12 months, followed by a slower increase between the 12th and 35th months. The transverse diameter of the eyeball increases slowly until the age of 8 years and then reaches 96% of the average adult length at this point.…”

Cribra orbitalia is correlated with the meningo‐orbital foramen and is vascular and developmental in nature

“…The higher prevalence reported in children relative to adults and among females relative to males, may be explained by both anatomical ontogeny and allometry. For example, in the early postnatal years, orbit size increases significantly with age, and with particularly rapid growth in the first few years of life, until the teenage years (Boruah et al, 2021; Chau et al, 2004; Ye et al, 2021). Also, female adults tend to have smaller orbit size compared to males, regardless of age (Ugradar & Lambros, 2019).…”

Normal diameter of the optic nerve using magnetic resonance imaging: A retrospective Nigerian study

“…The stalk contains an inner layer with axons of ganglion cells and an outer layer of neuroglial cells. [ 2 ] Myelination of the ON occurs at 8 weeks of gestation following the proliferation of oligodendrocytes. [ 3 ] The ON is 25 mm long with a small cross-sectional area (2.8–4.27 mm 2 ) at birth.…”