Values of peripapillary retinal nerve fibre layer thickness are different in children and adults.

CLINICAL RELEVANCE: The detection of abnormal values of peripapillary nerve fibre layer (pRNFL) thickness measured with optical coherence tomography (OCT) is important for detecting optic nerve disease in children. BACKGROUND: To evaluate the level of agreement between the adult reference database supplied with an OCT device and the present paediatric study database for the measurement of pRNFL thickness in children. This study also aimed to provide reference values for pRNFL thickness according to the spherical equivalent in the paediatric population. METHODS: This was a cross-sectional study. One hundred and twenty-six healthy children were included, who had undergone a full ophthalmological examination including cycloplegic refraction and examination of pRNFL thickness using the Topcon 3D OCT 2000 device (Topcon Corporation, Tokyo, Japan). Values equal to or below the fifth percentile (≤p5) and above the 95th percentile (>p95) were considered abnormal. Observed agreement and specific agreement were investigated between OCT measurements classified with paediatric and adult reference values for normality. RESULTS: Values ≤ p5 in the adult database were recorded for 2 of the 30 values (6.6%) of the pRNFL values by quadrants ≤p5 in the paediatric database and 17 of the 88 (19.3%) values by sectors ≤p5. For values >p95 in the adult database, 88% by quadrants and 72% by sectors would have been classified as being within the normal range using the paediatric database. CONCLUSION: The use of adult reference values currently available in OCT devices can lead to classification errors concerning the normal range of pRNFL thickness in a large proportion of paediatric patients. The use of normative paediatric databases, such as the one discussed in this study, should be taken into consideration.

Optic disc morphology and interocular symmetry in children.

PURPOSE: The purpose of the study was to obtain a pediatric reference database for optic disc parameters and interocular symmetry. To ascertain factors that modify these parameters (age, spherical equivalent [SE], and sex). METHODS: This was a cross-sectional study. 90 patients aged 5-17 years fulfilled all the inclusion criteria. After a full examination including cycloplegic refraction, all patients underwent optical coherence tomography (OCT) of the papilla using the three-dimensional (3D) scan protocol of the Topcon 3D 2000 OCT device. We provide reference values for optic disc parameters in the pediatric population. We also retrieved interocular symmetry reference values for these parameters. RESULTS: The multivariate regression analysis did not reveal variations in any of the optic disc parameters associated with age, sex, or SE (all P ≥ 0.126). The 95th percentile limit for absolute interocular differences for the cup-to-disc area ratio was 0.24. The multivariate regression analysis revealed the absence of a correlation between asymmetry of the optic disc parameters and age, sex, and the interocular difference in SE (all P ≥ 0.105). CONCLUSION: Pediatric reference databases for optic disc parameters and ranges of normality for interocular symmetry provide key diagnostic support in diseases that affect the optic nerve.

Measurement of macular thickness with optical coherence tomography: impact of using a paediatric reference database and analysis of interocular symmetry.

PURPOSE: Optical coherence tomography (OCT) software is used to classify abnormality of macular thickness by colour category based on reference data from adult series. We assessed the impact of using paediatric reference thickness values for macular thickness instead of adult reference values. METHODS: Cross-sectional study. Primary and tertiary healthcare setting. Out of 140 healthy participants aged 5 to 18 years, 126 were eligible, 83% from European origin. Following a dilated eye examination and cycloplegic refraction, participants underwent macular scanning with OCT (Topcon 3D OCT-2000). Macular thickness paediatric reference values were recorded by spherical equivalent (SE) and sex, and the specific agreement between paediatric and adult reference values below or equal to percentile 5 and above percentile 95 was estimated. The absolute interocular differences for all macular parameters were determined. RESULTS: Multivariate regression analysis confirmed statistically independent positive associations between SE and average thickness, total volume, and temporal and inferior outer quadrants (all p values ≤ 0.003). The analysis also revealed higher values in males for average thickness, central thickness, and all inner macula quadrants (all p values ≤ 0.039). The use of the adult database only detected 49% of the extreme values (≤ p5 and > p95) in our paediatric sample. The 95th percentile limits for absolute interocular differences for all macular parameters ranged from 12 to 17 µm. CONCLUSIONS: OCT-based macular reference values for paediatric SE and sex improve detection of children with abnormal macular thicknesses. Interocular differences exceeding standard references for macular parameters should be considered for further examinations.

Interobserver reproducibility and interocular symmetry of the macular ganglion cell complex: assessment in healthy children using optical coherence tomography.

BACKGROUND: Assessment of interobserver reproducibility and interocular symmetry using optical coherence tomography (OCT)-based measurements of the macular ganglion cell complex (GCC) in healthy children facilitates interpretation of OCT data. We assessed the interobserver reproducibility and interocular symmetry of GCC and evaluated candidate determinants. METHODS: This was a cross-sectional study performed in a primary and tertiary health-care setting. A total of 126 healthy participants aged 5 to 18 years were eligible. GCC scans were performed by 4 operators using the Topcon 3D OCT-2000 device. Intraclass correlation coefficients (ICCs) were used to estimate reproducibility and symmetry. Cut-off points for symmetry were defined as the 95th percentile of the absolute interocular difference for 6 GCC parameters. Percentile distributions of interocular difference were generated based on age and difference in absolute interocular spherical equivalent (SE). RESULTS: The reproducibility ICC ranged from 0.96 to 0.98 for all 6 GCC parameters. Cut-off points for interocular symmetry of the superior and inferior quadrants and total macular retinal nerve fibre layer thickness (mRNFL) and macular ganglion cell layer-inner plexiform layer thickness were 3.5, 4.5, 3.0, 3.0, 2.5, and 2.5 µm respectively. A positive association was observed between the absolute interocular difference of SE and superior and total mRNFL symmetry values (p = 0.047 and p = 0.040, respectively). CONCLUSIONS: OCT measurements of GCC in healthy children show excellent reproducibility. Interocular differences in SE should be assessed when mRNFL differences exceed the 95% cut-off. These findings can contribute to establish reference values for interocular symmetry in paediatric GCC parameters.

Assessment of macular ganglion cell complex using optical coherence tomography: Impact of a paediatric reference database in clinical practice.

IMPORTANCE: Optical coherence tomography software classifies abnormality of macular ganglion cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness based on adult series. BACKGROUND: We assessed the impact of using paediatric reference macular ganglion cell complex values instead of adult reference values. DESIGN: Cross-sectional study. Primary and tertiary health-care setting. PARTICIPANTS: Out of 140 healthy participants aged 5 to 18 years, 90% were eligible. METHODS: Following a dilated eye examination and cycloplegic refraction, participants underwent optical coherence tomography ganglion cell scans (Topcon 3D OCT-2000; Topcon Corporation, Tokyo, Japan). Right eye measurements for superior, inferior, and total layer thickness and spherical equivalent were reported, together with age, sex and origin. MAIN OUTCOME MEASURES: Paediatric reference values by age and spherical equivalent were produced, and the specific agreement between paediatric and adult ganglion cell complex reference values below or equal to percentile 5 was estimated. RESULTS: The multivariate analysis confirmed a positive association between spherical equivalent and macular ganglion cell-inner plexiform layer thickness, and between age and macular retinal nerve fibre layer (five out of six regression coefficients P values were ≤ 0.03). Specific agreement was 25% for ganglion cell-inner plexiform layer thickness and > 80% for macular retinal nerve fibre layer. Adult-based software identified low ganglion cell values in one in seven children compared to paediatric reference values (0.8% vs 5.5%, P = 0.031). CONCLUSIONS AND RELEVANCE: The availability of optical coherence tomography ganglion cell complex reference values for paediatric age and spherical equivalent groups can be used to improve detection of children with low cell layer thickness.