Optical coherence tomography analysis of the inner retinal layers in children

Optical coherence tomography in the diagnosis and monitoring of congenital and juvenile glaucoma

Optical coherence tomography (OCT) in everyday routine practice is the method of choice for the instrumental diagnosis of glaucoma in adults. As a non-invasive and safe method of visualizing structural changes in the retina and the optic nerve, the method is of particular value in pediatric practice. At the same time, OCT diagnostics in children is associated with certain difficulties, both during the study and when interpreting the scan results.

This review summarizes the data from the literature and our own research in the diagnosis and monitoring of congenital and juvenile glaucoma from the standpoint of our own long-term clinical experience in using optical coherence tomography. We consider the physiological changes of the retina and optic nerve, attention is focused on the need to create a pediatric regulatory database of retinal thickness, the factors that determine the normal range of the data obtained and allow distinguishing physiological processes from pathological ones are identified. Clinical cases confirming the value of OCT in combined pathology are presented as examples.

The Paediatric Glaucoma Diagnostic Ability of Optical Coherence Tomography: A Comparison of Macular Segmentation and Peripapillary Retinal Nerve Fibre Layer Thickness

Simple Summary

Optical coherence tomography (OCT) is an established ophthalmologic diagnostic tool to visualise vital retinal structures. In glaucoma, it is used to quantify the thickness decrease in the peripapillary retinal nerve fibre layer (pRNFL) and in the macula. While glaucoma management in adults incorporates traditional clinical parameters as well as instrumental methods such as OCT, guidelines for paediatric glaucoma focus on conventional methods. Even though some reports encouraging a broader use of OCT in children are present, its diagnostic potential in this particular population has still not been sufficiently analysed. To address this, the present study compares the glaucoma discriminative ability of OCT measurements of the pRNFL and macular layers in a paediatric population. The results indicate a reduction of the pRNFL and of inner macular layer thickness in glaucoma eyes, as well as a high correlation with the presence of glaucoma. The glaucoma discriminative ability can be maximised combining either all pRNFL sectors or the thickness results of the three innermost macular layers, even though sensitivity remains moderate. In conclusion, the OCT measurements of the pRNFL and macular thickness have a strong ability to diagnose paediatric glaucoma. However, OCT should be used in addition to conventional diagnostic tools rather than as a standalone method.

Abstract

Paediatric glaucoma leads to a decreased thickness of the peripapillary retinal nerve fibre layer (pRNFL) and of the macula. These changes can be precisely quantified using spectral domain-optical coherence tomography (SD-OCT). Despite abundant reports in adults, studies on the diagnostic capacity of macular SD-OCT in paediatric glaucoma are rare. The aim of this study was to compare the glaucoma discriminative ability of pRNFL and macular segment thickness in paediatric glaucoma patients and healthy children. Data of 72 children aged 5–17 years (glaucoma: 19 (26.4%), healthy: 53 (73.6%)) examined with SD-OCT (SPECTRALIS^®, Heidelberg Engineering) were analysed retrospectively. The thickness of pRNFL sectors and of macular segment subfields were compared between diseased and healthy participants. Areas under the receiver-operating characteristic curves (AUC), sensitivity, and specificity from logistic regression were used to evaluate the glaucoma discriminative capacity of single and combined pRNFL and macular segments’ thickness. The results revealed a reduced thickness of the pRNFL and of the three inner macular layers in glaucoma patients, which correlates highly with the presence of glaucoma. The highest glaucoma discriminative ability was observed for the combination of pRNFL sectors or inner macular segments (AUC: 0.83 and 0.85, respectively), although sensitivity remained moderate (both 63% at 95% specificity). In conclusion, while confirmation from investigations in larger cohorts is required, SD-OCT-derived pRNFL and macular thickness measurements seem highly valuable for the diagnosis of paediatric glaucoma.

Normative data for optical coherence tomography in children: a systematic review

The purpose of this study is to systematically review the reported data of normal optical coherence tomography (OCT) results in the paediatric population. A systematic literature search was performed using the PubMed, Embase, and Web of Science databases, using the keywords "optical coherence tomography"; "normative data" or "healthy eyes"; "children" or "paediatric population". Studies with at least 50 participants were included, irrespective of the OCT equipment employed. We excluded the OCT angiography studies or the studies investigating the choroidal thickness. Seventy-four studies were included in the final analysis and information on study design, number of participants, demographic characteristics, type of OCT equipment, OCT parameters and results was collected. Due to the high variability of OCT instruments and parameters used, a meta-analysis was not feasible. We report the normative values for the peripapillary retinal nerve fibre layer thickness and the macular retinal thickness for each ETDRS quadrant, as provided by the studies included in the present analysis. We also report the influence of ethnicity, age, gender, eye laterality, ISNT rule, spherical equivalent, and axial length on OCT results.

Choroidal, macular and ganglion cell layer thickness assessment in Caucasian children measured with spectral domain optical coherence tomography

PURPOSE

To study the subfoveal choroidal thickness (SFCT), macular ganglion cell layer (GCL-IPL) and central macular thickness (CMT) in Caucasian children, and to analyze these optical coherence tomography (OCT) parameters depending on the spherical equivalent (SE).

METHODS

Cross-sectional study of SFCT, GCL-IPL, and CMT in Caucasian children, analyzed with spectral-domain OCT Cirrus 5000 and Enhanced-depth imaging technique. Correlation between these three OCT parameters, age, sex, and spherical equivalent was analyzed. The eyes were classified into three groups: group 1 included eyes with SE < 0, group 2 included eyes with SE between 0 and +2.00, and group 3 eyes with SE > +2.00.

RESULTS

Hundred ninety-eight eyes of 121 subjects were studied. The mean age was 9.22 years (range 3-16); 61.1% were female. The mean SFCT was 351.04 ± 84.08 µm, being 310.04 ± 82.84µm in group 1 (n = 62), 373.14 ± 83.16 µm in group 2 (n = 71) and 365.18 ± 73.16 µm in group 3 (n = 65); statistically significant differences were found between groups 2 and 3, compared with group 1. GCL-IPL thickness was significantly thinner (p < 0.001) in group 1, compared with group 3. There were no statistically significant differences between the three groups regarding CMT. Correlation with age, and sex was not found.

CONCLUSIONS

SFCT and GCL-IPL thickness were significantly thinner (p < 0.001) in myopic children when compared with a non-myopic pediatric population. However, it seems that there is not a correlation among the three OCT parameters studied, age and sex, when they are analyzed depending on refractive error.

Profile of macular ganglion cell-inner plexiform layer thickness in healthy 6.5 year- old Swedish children

Background

The purpose was to study the macular ganglion cell- inner plexiform layer (GC-IPL) thickness in healthy 6.5 year- old Swedish children using Optical Coherence Tomography (OCT) and to study topography symmetry within eyes and between eye pairs.

Methods

A total of 181 eyes of 92 healthy children (39 girls, 53 boys) aged 6.5 and serving as a term-born control group in the Extremely Preterm Infants in Sweden Study (EXPRESS), were examined with Cirrus HD-OCT. Main outcome measures were average and minimum values of GC-IPL thickness of the device’s predefined macular sectors. Single sectors, combined sectors defined as superior and inferior hemispheres and temporal and nasal sectors were evaluated. Intra-individual GC-IPL thickness between eye pairs was analyzed. Visual acuity, refraction and general cognition were assessed and correlated to GC-IPL outcome.

Results

Eighty-five children completed the OCT examination and 155 out of 181 scans (86%) were analyzed. The mean average GC-IPL thickness was 85.9 μm (± 5.3; 5th and 95th percentiles were 76.0 and 94.6 μm). The mean minimum GC-IPL thickness was 83.6 μm (± 4.9; 5th and 95th percentiles were 75.4 and 92.3 μm). The difference in thickness between nasal and temporal sectors and between superior and inferior hemisphere sectors were less than 2 μm. The difference between average GC-IPL thickness and minimum GC-IPL thickness was 2.3 μm (± 1.9; 5th and 95th percentiles were 0.0 and 6.0 μm). The difference between the thickest and thinnest sector within eye was 6.4 μm (± 2.2; 5th and 95th percentiles were 3.0 and 10.0 μm). There was a moderate correlation in the difference between the nasal combined and the temporal combined sectors within eye pairs (p < 0.0001, Spearman’s ρ 0.58). The average GC-IPL thickness was weakly positively correlated with SE (spherical equivalent; combined sphere and ½ cylinder) (p = 0.031, Spearman’s ρ 0.23).

Conclusions

This study provides normative GC-IPL thickness values for healthy 6.5 year- old Swedish children. The GC-IPL thickness variations within eyes and within eye pairs are generally small. It could therefore be assumed that larger variations are sensitive markers of focal GC-IPL thinning due to damage to the primary visual pathways in children.

The optic nerve head, lamina cribrosa, and nerve fiber layer in non-myopic and myopic children

The purpose of this study was to evaluate the optic nerve head, lamina cribrosa, retina, and choroid in school age children using spectral domain optical coherence tomography (SD-OCT) and to assess these structural parameters in relation to age, axial length, and refractive error. Healthy children, ages 11.15 ± 2.62 years (range 6-15 years, n = 53), underwent cycloplegic autorefraction, biometry, and SD-OCT imaging in both eyes. Images were analyzed using custom written programs in MATLAB, after adjustment for lateral magnification. Peripapillary retinal nerve fiber layer (RNFL) thickness, retinal and choroidal thicknesses, Bruch's membrane opening (BMO) area, minimum rim width (MRW), and anterior lamina cribrosa surface depth (ALCSD) were determined and analyzed with age, axial length, and refraction. Results show that axial length increased and refractive error became more myopic with increasing age (R2 = 0.25, β = 0.18, P < 0.0001 and R2 = 0.27, β = -0.37, P < 0.0001, respectively). Minimum foveal thickness and central 1 mm retinal thickness increased with increasing age (R2 = 0.15, β = 2.38, P < 0.01 and R2 = 0.11, β = 3.16, P < 0.05, respectively). Age-adjusted raw values for peripapillary RNFL thickness decreased with increasing axial length (R2 = 0.11, β = -3.18, P < 0.05); however, this relationship was not present when image magnification was corrected (R2 = 0.07, β = 2.72, P = 0.09). BMO area increased with myopic refractive error (R2 = 0.16, β = -0.10, P < 0.01). Age-adjusted vertical cup-to-disc ratio decreased with increasing axial length and myopic refractive error (R2 = 0.12, β = -0.05, P < 0.05 and R2 = 0.11, β = 0.03, P = 0.05, respectively). Mean MRW, mean ALCSD, and peripapillary choroidal thickness were not associated with age, axial length, or refraction. Mean MRW was significantly thinner in eyes with deeper ALCS (R2 = 0.41, β = -0.83, P < 0.0001). These findings provide normal values for retinal and optic nerve head parameters in school age children, and also suggest that ocular remodeling occurs in some structures in school age children with normal eye growth and during early stages of myopia development.

Agreement in retinal nerve fiber layer values and comparison in children using two optical coherence tomography devices

OBJECTIVE

To assess absolute agreement and differences in peripapillary retinal nerve fiber layer (pRNFL) values according to sex, age, laterality, origin and optical coherence tomography (OCT) type in normal pediatric patients undergoing OCT scans using both Cirrus and Spectralis.

MATERIAL AND METHODS

Prospective, cross-sectional, and comparative study. We used Spectralis OCT and Cirrus OCT to measure optic disc values of both eyes in one hundred pediatric patients (age 5 to 15years), with no previous ocular pathology or systemic disease that could affect the eye. Due to the similarity between eyes, only right eyes were considered (n=100).

RESULTS

The average peripapillary retinal nerve fiber layer (pRNFL) values were 99.6μm with Cirrus and 106.7μm with the Spectralis system. The four quadrants followed the ISNT rule (inferior-superior-nasal-temporal). The average pRNFL measures correlated negatively with the AL (P<.01) in both OCTs, and the degree of agreement between OCTs for pRNFL and inferior RNFL was moderate (CCI: 0.67 and 0.61, respectively), and low in the rest of the sectors. The average pRNFL values of both OCTs were higher in women than in men (P>.05) and there were also no statistical differences in the pRNFL according to age or laterality (P>.05). All RNFL values were significantly different between both types of OCTs (P<.05) and average pRNFL values were significantly thicker (P<.05) in Latin American than in European children in both eyes.

CONCLUSIONS

We suggest that the respective peripapillary RNFL values obtained using these two OCTs should not be considered interchangeable in pediatric patients.

Differences of megalopapilla and normal sized disk with age-an optical coherence tomography analysis

PURPOSE

To compare the optic disks of children and adults with megalopapilla using optical coherence tomography (OCT).

SUBJECTS AND METHODS

We conducted a case-control study of subjects with megalopapilla and normal sized disks seen between February 2013 and July 2015 at the Hospital da Luz, Lisbon. All subjects and controls were imaged with spectral domain OCT, and optic nerve head (ONH) parameters were evaluated. The main outcome measures were rim area, cup:disk ratio, and cup volume.

RESULTS

A total of 168 eyes of 168 subjects were included: 78 with megalopapilla (39 children/39 adults) and 90 (45/45) with normal sized disks. For the same ONH area, children had a higher rim area (P = 0.000), a smaller cup:disk ratio (P = 0.001), and a smaller cup volume (P = 0.001) than adults. For the same age group, megalopapilla had a larger cup:disk ratio (P = 0.000) and a larger cup volume (P = 0.000) than normal-sized disks.

CONCLUSIONS

In this study cohort, compared to adults with the same disk size, children (with megalopapilla or normal-sized disks) had a larger rim area and smaller cup. These findings suggest that enlargement of the cup of the optic disk and reduction of the rim area can occur through life.