Analysis of Optic Nerve Head Parameters in Different Refractive States Pediatrics Using Spectral Domain Optical Coherence Tomography

Purpose: Normative values of optic disc cup size in pediatric age group using spectral domain OCT with correlations to refractive error and axial length.
Methods: An observational cross-sectional study recruiting 174healthy children from Nile delta region aged6 to 16years with no ocular comorbidity except refractive error. A thorough examination of the eyes was conducted, and the Cirrus OCT device was used to quantify axial length, RNFL,and macular thickness. Main outcome parameters were macular volume, macular thickness and RNFL thickness values as well as their correlations with age, refractive error and axial length. Right eyes of all subjects were selected for analysis.
Results: One hundred and seventy-four children were included in the study,74females and 100males. They were divided into3groups according to their refractive error.Group1(80)emmetrope, group2(62)Myopes and group3(32)hypermetropes.Average spherical equivalent refraction (SE) was-0.20 ±0.77diopters in group1,-3.17±1.27in group2and1.77±0.57diopters in group 3.And average axial length was22.97±.738mm in group1, 23.86±0.925in group2and22.97±0.67mm in group3.According to those results, there were statistically significant differences among the studied groups as regards the mean values of disc area, and H disc diameter(p<0.05),but no statistically significant differences were found among the studied groups as regards the mean rim area(p>0.05).Regarding disc area, statistically significant differences were found when comparing group(1)with group(2),and group(2)with group(3).
Conclusions:The axial length is an important factor in defining disc size, which is a crucial component in determining cup to disc ratio, when it comes to spectral domain OCT optic disc properties. Normal children with significant cupping should be evaluated for axial length, myopic refractive defects, and disc size.