Journal of Pediatric Ophthalmology and Strabismus

Original Article 

The Relationship Between Optic Nerve Cup-to-Disc Ratio and Retinal Nerve Fiber Layer Thickness in Suspected Pediatric Glaucoma

Mehmet C. Mocan, MD; Lindsay Machen, MD; Inae Jang, BS; Dingcai Cao, PhD

Abstract

Purpose:

To evaluate the relationship between optic nerve cup-to-disc ratio and peripapillary retinal nerve fiber layer (RNFL) thickness in suspected pediatric glaucoma with large cup-to-disc ratios.

Methods:

This was a retrospective study undertaken at a single academic institution. Eighty-six eyes of 43 patients who presented with large (≥ 0.5) cup-to-disc ratios in both eyes and without elevated intraocular pressure were evaluated using spectral-domain optical coherence tomography. Global and sectoral peripapillary RNFL thickness measurements, Bruch's membrane opening size, refractive error in spherical equivalents, and intraocular pressure levels were recorded for all patients. Cup-to-disc ratios were manually derived using digital fundus images (D-cup-to-disc ratio). Parameters were compared between gender or race by t tests or analysis of variance. The differences in the relationship among the clinical parameters between two eyes were assessed using generalized estimation equation modeling followed by Pearson's correlation analysis.

Results:

Forty-three patients (25 boys and 18 girls) with a mean age of 9.3 ± 2.7 years (range: 5 to 15 years) were included. The mean global peripapillary RNFL thickness and the D-cup-to-disc ratio of study eyes were 99.0 ± 9.2 µm and 0.66 ± 0.03, respectively. The peripapillary RNFL thickness was found to be correlated with refractive error (r = 0.404; P = .008) and Bruch's membrane opening size (r = 0.410; P = .008) but not with cup-to-disc ratios (r = 0.029; P = .858) or patient age (r = −0.044; P = .797).

Conclusions:

In patients with suspected pediatric glaucoma who present with large cup-to-disc ratios, RNFL thickness does not correlate with the degree of optic nerve cupping. Myopic refractive errors and Bruch's membrane opening size need to be taken into consideration to prevent misinterpretation of peripapillary RNFL measurements.

[J Pediatr Ophthalmol Strabismus. 2020;57(2):90–96.]

Abstract

Purpose:

To evaluate the relationship between optic nerve cup-to-disc ratio and peripapillary retinal nerve fiber layer (RNFL) thickness in suspected pediatric glaucoma with large cup-to-disc ratios.

Methods:

This was a retrospective study undertaken at a single academic institution. Eighty-six eyes of 43 patients who presented with large (≥ 0.5) cup-to-disc ratios in both eyes and without elevated intraocular pressure were evaluated using spectral-domain optical coherence tomography. Global and sectoral peripapillary RNFL thickness measurements, Bruch's membrane opening size, refractive error in spherical equivalents, and intraocular pressure levels were recorded for all patients. Cup-to-disc ratios were manually derived using digital fundus images (D-cup-to-disc ratio). Parameters were compared between gender or race by t tests or analysis of variance. The differences in the relationship among the clinical parameters between two eyes were assessed using generalized estimation equation modeling followed by Pearson's correlation analysis.

Results:

Forty-three patients (25 boys and 18 girls) with a mean age of 9.3 ± 2.7 years (range: 5 to 15 years) were included. The mean global peripapillary RNFL thickness and the D-cup-to-disc ratio of study eyes were 99.0 ± 9.2 µm and 0.66 ± 0.03, respectively. The peripapillary RNFL thickness was found to be correlated with refractive error (r = 0.404; P = .008) and Bruch's membrane opening size (r = 0.410; P = .008) but not with cup-to-disc ratios (r = 0.029; P = .858) or patient age (r = −0.044; P = .797).

Conclusions:

In patients with suspected pediatric glaucoma who present with large cup-to-disc ratios, RNFL thickness does not correlate with the degree of optic nerve cupping. Myopic refractive errors and Bruch's membrane opening size need to be taken into consideration to prevent misinterpretation of peripapillary RNFL measurements.

[J Pediatr Ophthalmol Strabismus. 2020;57(2):90–96.]

Introduction

Glaucoma in pediatric patients is an uncommon and progressive condition that often results in blindness if left untreated.1,2 Recognition of an enlarged optic nerve cup-to-disc ratio raises concern for a glaucomatous process and frequently results in referrals to a pediatric ophthalmologist or a glaucoma specialist.3 The challenge, on referral, is to correctly identify a glaucomatous process in these young patients, especially when intraocular pressures (IOPs) cannot be reliably obtained and when patients do not have any evidence of developmental or secondary causes of glaucoma such as corneal enlargement or predisposing conditions such as Sturge–Weber syndrome.

The hallmark of glaucomatous optic nerve damage is retinal ganglion cell loss with evidence of characteristic visual field losses in the perimetric stage of the disease. However, visual field testing in children is limited due to their shortened attention span and because there is a learning curve necessitating multiple tests to be performed to correctly interpret the visual field findings.4,5 Evaluation of retinal nerve fiber layer (RNFL) loss has become an established diagnostic technique for detecting glaucomatous optic nerve damage, especially at the pre-perimetric and early perimetric stages of glaucoma.6–8 For pediatric patients who are unable to cooperate with visual field testing, this technique may provide the only ancillary diagnostic method to establish or rule out glaucoma. A potential limitation of such an approach is the paucity of age-based normative data for children in the current optical coherence tomography (OCT) devices.9

Bruch's membrane opening defines the boundary of the neural canal and serves as a reference mark to define parameters such as the minimal neuroretinal rim width and area used in differentiating glaucomatous discs from normal discs.10,11 Bruch's membrane opening is a more consistent landmark than the optic nerve margin because the latter does not have a well-defined anatomic correlate.10

Although RNFL thickness measurements of healthy children and those with enlarged cup-to-disc ratios have been determined in previous studies, to the best of our knowledge, correlative analyses of RNFL thickness parameters with cup-to-disc ratios derived from Bruch's membrane opening of suspected pediatric glaucoma have not been previously evaluated.9,12–14 Thus, the purpose of our study was to determine RNFL thickness parameters and assess the relationship between the cup-to-disc ratios and RNFL measurements of pediatric patients who had optic nerve appearances suspicious for glaucoma based on enlarged cup-to-disc ratios.

Patients and Methods

This was a retrospective study undertaken at a single academic center between June 2017 and January 2019. The study was approved by the institutional review board of the University of Illinois at Chicago, adhered to the tenets of the Declaration of Helsinki, and was in compliance with the Health Insurance Portability and Accountability Act of 1996. Patients' records were extracted using the institutional electronic medical record system. Pediatric patients between the ages of 5 and 15 years who were diagnosed as having suspected glaucoma based on an enlarged optic nerve cup-to-disc ratio in one or both eyes but who had no evidence of elevated IOP in either eye were included in the study. IOP measurements were obtained by Goldmann applanation tonometry (Haag-Streit AG, Bern, Switzerland) in children who were old enough to cooperate and with Icare rebound tonometry (Icare, Tiolat Oy, Helsinki, Finland) or the Tonopen (Reichert Inc., Depew, NY) in those who were not able to cooperate for Goldmann applanation tonometry. IOP measurements were obtained at any time during the day when the patients had come in for their appointments.

A lower age limit of 5 years was set to include only patients with good cooperation with OCT testing because it has been our impression that children younger than 5 years cannot sit and fixate reliably for OCT testing. The upper age limit of 15 years was chosen so that all pediatric cases who presented to the pediatric ophthalmology clinic could be included in the study because patients aged 16 years and older are not typically seen in the pediatric ophthalmology service where the study was conducted. The patients had to have a cup-to-disc ratio of 0.5 or greater in both eyes to be included in the study. A cup-to-disc ratio of 0.5 or greater was chosen to parallel the cut-off criteria in similar previously published studies on large optic disc cupping.14,15

Exclusion criteria included an established diagnosis of glaucoma, current or past use of topical glaucoma medications, documented IOP elevation in at least one eye of greater than 24 mm Hg, cup-to-disc ratio asymmetry of greater than 0.2, anomalous appearing optic nerves (ie, optic nerve hypoplasia, colobomatous discs, and megalopapilla), presence of anterior segment dysgenesis, corneal enlargement, Haab striae, past ocular trauma, any form of optic neuropathy, and a history of intraocular surgery including any form of glaucoma surgery. Patients who had abnormal visual field test results with the automated Humphrey visual field device (Carl Zeiss Meditec, Dublin, CA) were excluded. Abnormal visual field findings consisted of presence of abnormal scotoma, a mean deviation of less than −6.0 dB, or an abnormal hemifield test result. Only the visual field results of patients with reliable indices including a fixation loss less than 20%, false-negative result of less than 10%, and false-positive result of less than 10% were taken into evaluation. Patients with a history of prematurity and those with neurodevelopmental disorders were also excluded.16 A cut-off IOP level of 24 mm Hg was chosen in accordance with the Ocular Hypertension Study Group's definition of elevated IOP.17

The clinical parameters for the study included patient age at evaluation, gender, ethnicity, IOP, central corneal thickness, clinical cup-to-disc ratio as measured by indirect ophthalmoscopy, and refractive error in spherical equivalent.

All patients had to have peripapillary RNFL thickness measurements performed by a table-mounted spectral-domain OCT (SD-OCT) device (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany). Only patients who had OCT images with adequate image quality and centration were included in the study. The global, superior, inferior, nasal, and temporal quadrant RNFL thickness measurements were included for analysis. The digital fundus imaging software was used to derive the cup-to-disc ratios (D-cup-to-disc ratio) by averaging the horizontal and vertical D-cup-to-disc ratio. D-cup-to-disc ratios were manually measured by a single observer in a blind manner without knowledge of clinically derived cup-to-disc ratios. The diameter of the Bruch's membrane opening was calculated by averaging the vertical and horizontal Bruch's membrane opening size as measured with the imaging software of the SD-OCT device. Refractive error measurements performed under cycloplegia and recorded at the time of OCT imaging were used for analyses.

The diagnosis of glaucoma was excluded by following the serial IOPs and optic nerve appearances of all patients and their visual fields in whom visual field testing could be performed. Signs of glaucomatous optic nerve changes including presence of optic disc hemorrhages and focal rim notching were specifically looked for in the clinical records of all study patients.

Statistical Analysis

The normal distributions of clinical measures (RNFL thickness, cup-to-disc ratios, and refraction errors) were first confirmed using skewness kurtosis tests. Therefore, the variables were summarized as means and standard deviations. Paired t tests were used first to compare the clinical measures between the right versus left eye and then the Pearson's correlation between the two eye values was calculated for each parameter. The averaged values for each parameter were compared between gender by t tests or among races by analysis of variance. To assess the relationship among cup-to-disc ratio, RNFL thickness, and refraction errors, generalized estimation equation models that could account for correlations between the two eyes were used first to determine whether the relationship differed between the two eyes by including eye, independent variable, and their interaction in the models. If the relationship did not differ between the two eyes (ie, the interaction was not significant), then the values from the two eyes were averaged first for each patient and then Pearson's correlation was computed to assess the associations between the clinical parameters of interest. A P value of less than .05 was considered to be statistically significant. All analyses were conducted in Stata 15.1 software (Stata-Corp, College Station, TX).

Results

Forty-three patients (25 boys and 18 girls) with a mean age of 9.3 ± 2.7 years (range: 5 to 15 years) were included in the study. Of these patients, 22 (51.2%) were Hispanic, 14 (32.6%) were African-American, 3 (7.0%) were white, and 2 (4.7%) were Asian.

The mean IOP and central corneal thickness of the studied eyes were 17.4 ± 3.1 mm Hg and 583 ± 44 µm, respectively. The mean refractive error was −0.48 ± 2.20 diopters (D) (range: −7.00 to +6.00 D). The mean clinically derived cup-to-disc ratio recorded at the time of the dilated fundus examination was 0.66 ± 0.09. The mean D-cup-to-disc ratio was 0.66 ± 0.03. The D-cup-to-disc ratio was shown to correlate to a moderate degree with the clinically derived cup-to-disc ratios (r = 0.408; P = .007). IOP levels were not found to be correlated with either the D-cup-to-disc ratios (r = −0.147; P = .354) or the global RNFL (r = 0.119; P = .446).

The mean global RNFL thickness was 99.0 ± 9.2 µm. The global RNFL parameter was found to be more strongly correlated with superior RNFL (r = 0.838; P < .001) and inferior RNFL (r = 0.867; P < .001) compared to nasal RNFL (r = 0.462; P = .002) and temporal RNFL (r = 0.614; P < .001).

Generalized estimation equation modeling showed that the relationship between cup-to-disc ratio parameters (clinically derived and D-cup-to-disc ratio) and RNFL thickness parameters of pediatric patients with suspected glaucoma did not differ between eyes and therefore Pearson's correlation was used to quantify the strength of the relationship (Table 1). Overall, cup-to-disc ratios were not found to be associated with any of the RNFL parameters studied. In addition, RNFL thickness was not found to be correlated with patient age (r = −0.044; P = .797) (Figure 1).

Correlative Analysis of Optic Nerve Cup-to-Disc Ratios and RNFL Parameters in Pediatric Cases of Suspected Glaucoma as Evaluated With Pearson Correlation Analysis

Table 1:

Correlative Analysis of Optic Nerve Cup-to-Disc Ratios and RNFL Parameters in Pediatric Cases of Suspected Glaucoma as Evaluated With Pearson Correlation Analysis

Relationship between age and retinal nerve fiber layer (RNFL) thickness for the right and the left eyes in suspected pediatric glaucoma. OD = right eye; OS = left eye

Figure 1.

Relationship between age and retinal nerve fiber layer (RNFL) thickness for the right and the left eyes in suspected pediatric glaucoma. OD = right eye; OS = left eye

The relationship between the refractive error of study patients and optic nerve parameters (cup-to-disc ratio and RNFL) did not differ between the two eyes and therefore Pearson's correlations were computed using the averaged values from the two eyes (Table 2). The refractive error was found to be correlated with global, nasal, and inferior RNFL thickness but not with the clinically derived cup-to-disc ratio or the D-cup-to-disc ratio parameters.

Relationship Between Refractive Error and BMO Size and Optic Nerve Cup-to-Disc Ratios and RNFL Thickness in Pediatric Patients With Suspected Glaucoma

Table 2:

Relationship Between Refractive Error and BMO Size and Optic Nerve Cup-to-Disc Ratios and RNFL Thickness in Pediatric Patients With Suspected Glaucoma

The mean Bruch's membrane opening size of study patients was 1,891.7 ± 179.7 µm (range: 1,372 to 2,419 µm). The Bruch's membrane opening size appeared to correlate with both global RNFL (r = 0.410; P = .008) and D-cup-to-disc ratio (r = 0.307; P = .051) (Table 2).

Discussion

A primary concern in pediatric patients who present with large cup-to-disc ratios without any evidence of neuroretinal rim atrophy is the potential presence of a glaucomatous process. This concern may be compounded by factitiously elevated IOPs in a straining or anxious pediatric patient and the inability to obtain reliable visual field tests.4 It would be ideal to rule out a glaucomatous process in these patients at initial presentation by conclusively demonstrating a healthy RNFL layer. In the current study, we were able to show that in pediatric patients with suspected glaucoma who presented with enlarged cup-to-disc ratios (ie, ≥ 0.5) but who did not have elevated IOPs, the cup-to-disc ratios were not related to RNFL thickness (ie, patients with higher cup-to-disc ratios did not have thinner RNFL measurements). Thus, our findings suggest that large cup-to-disc ratios are not indicative of RNFL loss in these patients.

In a previous study by El-Dairi et al.,14 the RNFL thickness parameters of 28 white and black pediatric patients with large (≥ 0.5) cup-to-disc ratios were compared with those of healthy age-matched children with cup-to-disc ratios of less than 0.5. In that study, the average, superior, and inferior RNFL thickness parameters of white but not black patients with large cup-to-disc ratios were found to be thinner when compared to healthy children with small cup-to-disc ratios, suggesting a racial variation for RNFL thickness.14 In our study, a substantial proportion of the patients were of non-white racial background and the number of white patients was insufficient to make RNFL comparisons. Our study sample is more representative of a multi-ethnic patient population treated at the institution in which the study was conducted. Although the average RNFL thickness values in the study by El-Dairi et al. were 100 ± 9 µm in white and 107 ± 10 µm in black patients (vs 99.0 ± 9.2 µm in the current study), a direct comparison cannot be made between the two studies because the current study used a SD-OCT and the study by El-Dairi et al. used the time-domain Stratus OCT (OCT-3; Carl Zeiss Meditec) device.14 There is a good correlation between the RNFL measurements obtained with these two devices, but the RNFL thickness measurements obtained with the Stratus OCT have been shown to be slightly higher as compared to the Spectralis OCT device.18

In a previous study, a negative correlation between severity of optic nerve cupping and RNFL thickness has been reported in pediatric cases with various causes for glaucoma with evidence of a steeper decrease in superior and inferior RNFL thickness values in black versus white patients.19 In that study, patients with suspected glaucoma based on large cup-to-disc ratios were not separately analyzed.19

In the current study, the RNFL parameters correlated with the refractive error in spherical equivalent whereby myopic patients had thinner RNFL values. This finding is in agreement with those of other previous studies and suggests that refractive status of the patients should be taken into consideration in the interpretation of the RNFL measurements when evaluating optic nerves of pediatric patients with large cup-to-disc ratios.13,19,20

A wide range of refractive errors (ie, −7.00 to +6.00 D) were included in the current study to evaluate whether the relationship between refractive error and RNFL thickness held true for otherwise healthy children within this interval. This range is slightly higher than what was previously assessed by Silverstein et al.,15 in which pediatric patients had refractive errors ranging between −5.00 and +5.00 D. On the other hand, an even wider range of refractive errors (−8.00 to +6.30 D) than those evaluated in the current study was investigated in a previous study looking into the RNFL thickness of young adults.21 In the current study, despite the wide range of refractive errors, none of the patients had evidence of pathologic or syndromic myopia (ie, Stickler or Marfan syndrome).

The purpose of this study was to investigate the possible association between cup-to-disc ratios and RNFL thickness in pediatric patients who had undergone OCT RNFL evaluation for workup of suspected glaucoma status; the results should be interpreted as such. To the best of our knowledge, correlation of average and sectorial RNFL thickness measurements with cup-to-disc ratios has not been performed in the pediatric population. Our results suggest that in pediatric patients with suspected glaucoma with large (≥ 0.5) optic disc cups but without otherwise elevated IOPs, the RNFL thickness is not related to cup-to-disc ratio.

One challenge with measuring IOP in younger children is their limited cooperation with Goldmann applanation tonometry. Likewise, patients in the current study were tested with different IOP measuring devices because not all patients were able to cooperate with Goldmann applanation tonometry. The mean IOP obtained in the current study was slightly higher than that reported for healthy children in the literature.22,23 The mean IOP obtained in the current study is likely related to the use of different devices (ie, Goldmann applanation tonometry, rebound tonometry, and Tonopen device) to measure IOP in the study cohort. In previous studies involving children 3 to 17 years of age, rebound Icare tonometry has been shown to overestimate IOP in healthy children and those with known or suspected glaucoma by 2.3 to 2.6 mm Hg compared to Goldmann applanation tonometry.24,25

In the current study, Bruch's membrane opening size was found to be directly correlated with RNFL thickness. This is to be expected because a larger canal opening results in measurement of the RNFL thickness closer to the disc margin where the RNFL is thicker.26 Thus, it is recommended that Bruch's membrane opening size be taken into consideration when interpreting the results of peripapillary RNFL thickness evaluations in pediatric patients who present with large cup-to-disc ratios. In light of previous studies, parameters based on Bruch's membrane opening such as the Bruch's membrane opening minimum rim area appear to have a better diagnostic accuracy than peripapillary RNFL in differentiating glaucomatous from normal discs and may have a value in evaluation of optic nerve health in pediatric patients with suspected glaucoma who are also myopic.11 Bruch's membrane opening size also appeared to be directly correlated with cup-to-disc ratio in our study cohort. Our finding likely represents the effect of a large neural canal opening on the disc area with a resultant large cup in the setting of normal number of axons in these patients. Although patients who had anomalous appearing optic nerves such as megalopapilla or staphylamatous appearing optic nerves were not included in this study, an optic disc area–based exclusion could not be performed because the OCT software used in the current study did not allow for optic disc area calculations.

Our results also showed that the global RNFL thickness was most strongly correlated with superior and inferior RNFL thickness, highlighting the more significant contribution of the vertical sectors to the overall RNFL thickness.

The findings of our study should be interpreted with caution due to certain limitations. This was a retrospective study with a limited sample size. Although we were able to initially identify a greater number of pediatric patients who had suspected glaucoma, a certain number of these had been tested with other OCT imaging devices and were thus excluded at the outset of the study. The limited number of patients with certain racial/ethnic backgrounds (ie, white and Asian patients) prevented us from making robust statistical comparisons involving RNFL or optic nerve cup size between distinct populations. The heterogeneity of the sample population was not due to any selection bias or specific inclusion criteria, but is more reflective of the patient population served by the academic center in which the study was conducted. Axial lengths could not be obtained for the study cohort due to the retrospective nature of the study. Axial length has been shown to correlate significantly with RNFL thickness.27,28 Axial length measurements were not available for analysis in the current study because data collection was done retrospectively. It would have been informative to also include correlative analysis of axial length with RNFL in this patient population. Another limitation is that more than one ophthalmologist analyzed the optic nerve cup-to-disc ratios of these patients and interobserver variability in assessing cup-to-disc ratios is a well-known phenomenon, even among expert glaucoma specialists.29 To overcome this limitation, we determined the cup-to-disc ratios using the built-in software of the digital fundus imaging device (D-cup-to-disc ratio) for all patients in the current study. A control group with smaller cup-to-disc ratios was not included because the study aimed only to correlate the cup-to-disc ratios with RNFL measurements in pediatric patients with suspected glaucoma. RNFL measurements of healthy pediatric patients have been determined using different OCT devices in several prior studies.12,30,31 In addition, a study by Silverstein et al.15 showed no difference in the peripapillary RNFL and macular layers of pediatric patients with physiologic cupping versus those of healthy controls younger than 18 years. Based on the results of the current study, a prospective study with larger sample sizes and looking into the association of RNFLs in pediatric patients with both small and large cup-to-disc ratios is being planned to overcome the limitations of this study.

The results of the current study suggest that in pediatric patients with large optic nerve cup-to-disc ratios, the RNFL thickness parameters do not correlate with the degree of optic nerve cupping. In these patients with suspected glaucoma, myopic refractive errors and Bruch's membrane opening size need to be taken into consideration to prevent misinterpretation of OCT results.

References

  1. Aponte EP, Diehl N, Mohney BG. Incidence and clinical characteristics of childhood glaucoma: a population-based study. Arch Ophthalmol. 2010;128(4):478–482. doi:10.1001/archophthalmol.2010.41 [CrossRef]
  2. Beck AD. Diagnosis and management of pediatric glaucoma. Ophthalmol Clin North Am. 2001;14(3):501–512. doi:10.1016/S0896-1549(05)70248-0 [CrossRef]
  3. Kooner K, Harrison M, Prasla Z, Albdour M, Adams-Huet B. Pediatric glaucoma suspects. Clin Ophthalmol. 2014;8:1139–1145. doi:10.2147/OPTH.S61682 [CrossRef]
  4. Blumenthal EZ, Haddad A, Horani A, Anteby I. The reliability of frequency-doubling perimetry in young children. Ophthalmology. 2004;111(3):435–439. doi:10.1016/j.ophtha.2003.06.018 [CrossRef]
  5. Safran AB, Laffi GL, Bullinger A, et al. Feasibility of automated visual field examination in children between 5 and 8 years of age. Br J Ophthalmol. 1996;80(6):515–518. doi:10.1136/bjo.80.6.515 [CrossRef]
  6. Schuman JS, Hee MR, Puliafito CA, et al. Quantification of nerve fiber layer thickness in normal and glaucomatous eyes using optical coherence tomography. Arch Ophthalmol. 1995;113(5):586–596. doi:10.1001/archopht.1995.01100050054031 [CrossRef]
  7. Fallon M, Valero O, Pazos M, Antón A. Diagnostic accuracy of imaging devices in glaucoma: a meta-analysis. Surv Ophthalmol. 2017;62(4):446–461. doi:10.1016/j.survophthal.2017.01.001 [CrossRef]
  8. Jeoung JW, Kim TW, Weinreb RN, Kim SH, Park KH, Kim DM. Diagnostic ability of spectral-domain versus time-domain optical coherence tomography in preperimetric glaucoma. J Glaucoma. 2014;23(5):299–306. doi:10.1097/IJG.0b013e3182741cc4 [CrossRef]
  9. Turk A, Ceylan OM, Arici C, et al. Evaluation of the nerve fiber layer and macula in the eyes of healthy children using spectral-domain optical coherence tomography. Am J Ophthalmol. 2012;153(3):552–559.e1. doi:10.1016/j.ajo.2011.08.026 [CrossRef]
  10. Reis AS, O'Leary N, Yang H, et al. Influence of clinically invisible, but optical coherence tomography detected, optic disc margin anatomy on neuroretinal rim evaluation. Invest Ophthalmol Vis Sci. 2012;53(4):1852–1860. doi:10.1167/iovs.11-9309 [CrossRef]
  11. Enders P, Adler W, Schaub F, et al. Novel Bruch's membrane opening minimum rim area equalizes disc size dependency and offers high diagnostic power for glaucoma. Invest Ophthalmol Vis Sci. 2016;57(15):6596–6603. doi:10.1167/iovs.16-20561 [CrossRef]
  12. El-Dairi MA, Asrani SG, Enyedi LB, Freedman SF. Optical coherence tomography in the eyes of normal children. Arch Ophthalmol. 2009;127(1):50–58. doi:10.1001/archophthalmol.2008.553 [CrossRef]
  13. Al-Haddad C, Barikian A, Jaroudi M, Massoud V, Tamim H, Noureddin B. Spectral domain optical coherence tomography in children: normative data and biometric correlations. BMC Ophthalmol. 2014;14(1):53. doi:10.1186/1471-2415-14-53 [CrossRef]
  14. El-Dairi M, Holgado S, Asrani S, Freedman SF. Optical coherence tomography (OCT) measurements in black and white children with large cup-to-disc ratios. Exp Eye Res. 2011;93(3):299–307. doi:10.1016/j.exer.2011.05.004 [CrossRef]
  15. Silverstein E, Freedman S, Zéhil GP, Jiramongkolchai K, El-Dairi M. The macula in pediatric glaucoma: quantifying the inner and outer layers via optical coherence tomography automatic segmentation. J AAPOS. 2016;20(4):332–336. doi:10.1016/j.jaapos.2016.05.013 [CrossRef]
  16. Ghate D, Vedanarayanan V, Kamour A, Corbett JJ, Kedar S. Optic nerve morphology as marker for disease severity in cerebral palsy of perinatal origin. J Neurol Sci. 2016;368:25–31. doi:10.1016/j.jns.2016.06.029 [CrossRef]
  17. Gordon MO, Kass MA. The Ocular Hypertension Treatment Study: design and baseline description of the participants. Arch Ophthalmol. 1999;117(5):573–583. doi:10.1001/archopht.117.5.573 [CrossRef]
  18. Arthur SN, Smith SD, Wright MM, et al. Reproducibility and agreement in evaluating retinal nerve fibre layer thickness between Stratus and Spectralis OCT. Eye (Lond). 2011;25(2):192–200. doi:10.1038/eye.2010.178 [CrossRef]
  19. El-Dairi MA, Holgado S, Asrani SG, Enyedi LB, Freedman SF. Correlation between optical coherence tomography and glaucomatous optic nerve head damage in children. Br J Ophthalmol. 2009;93(10):1325–1330. doi:10.1136/bjo.2008.142562 [CrossRef]
  20. Zhu BD, Li SM, Li H, et al. Anyang Childhood Eye Study Group. Retinal nerve fiber layer thickness in a population of 12-year-old children in central China measured by iVue-100 spectral-domain optical coherence tomography: the Anyang Childhood Eye Study. Invest Ophthalmol Vis Sci. 2013;54(13):8104–8111. doi:10.1167/iovs.13-11958 [CrossRef]
  21. Tariq YM, Li H, Burlutsky G, Mitchell P. Retinal nerve fiber layer and optic disc measurements by spectral domain OCT: normative values and associations in young adults. Eye (Lond). 2012;26(12):1563–1570. doi:10.1038/eye.2012.216 [CrossRef]
  22. Lee AJ, Saw SM, Gazzard G, Cheng A, Tan DT. Intraocular pressure associations with refractive error and axial length in children. Br J Ophthalmol. 2004;88(1):5–7. doi:10.1136/bjo.88.1.5 [CrossRef]
  23. Sihota R, Tuli D, Dada T, Gupta V, Sachdeva MM. Distribution and determinants of intraocular pressure in a normal pediatric population. J Pediatr Ophthalmol Strabismus. 2006;43(1):14–18.
  24. Feng CS, Jin KW, Yi K, Choi DG. Comparison of intraocular pressure measurements obtained by rebound, noncontact, and Goldmann applanation tonometry in children. Am J Ophthalmol. 2015;160(5):937–943.e1. doi:10.1016/j.ajo.2015.07.029 [CrossRef]
  25. Flemmons MS, Hsiao YC, Dzau J, Asrani S, Jones S, Freedman SF. Icare rebound tonometry in children with known and suspected glaucoma. J AAPOS. 2011;15(2):153–157. doi:10.1016/j.jaapos.2010.11.022 [CrossRef]
  26. Budenz DL, Anderson DR, Varma R, et al. Determinants of normal retinal nerve fiber layer thickness measured by Stratus OCT. Ophthalmology. 2007;114(6):1046–1052. doi:10.1016/j.ophtha.2006.08.046 [CrossRef]
  27. Wang YX, Pan Z, Zhao L, You QS, Xu L, Jonas JB. Retinal nerve fiber layer thickness. The Beijing Eye Study 2011. PLoS One. 2013;8(6):e66763. doi:10.1371/journal.pone.0066763 [CrossRef].
  28. Yamashita T, Sakamoto T, Yoshihara N, et al. Correlations between retinal nerve fiber layer thickness and axial length, peripapillary retinal tilt, optic disc size, and retinal artery position in healthy eyes. J Glaucoma. 2017;26(1):34–40. doi:10.1097/IJG.0000000000000550 [CrossRef]
  29. Varma R, Steinmann WC, Scott IU. Expert agreement in evaluating the optic disc for glaucoma. Ophthalmology. 1992;99(2):215–221. doi:10.1016/S0161-6420(92)31990-6 [CrossRef]
  30. Salchow DJ, Oleynikov YS, Chiang MF, et al. Retinal nerve fiber layer thickness in normal children measured with optical coherence tomography. Ophthalmology. 2006;113(5):786–791. doi:10.1016/j.ophtha.2006.01.036 [CrossRef]
  31. Huynh SC, Wang XY, Rochtchina E, Crowston JG, Mitchell P. Distribution of optic disc parameters measured by OCT: findings from a population-based study of 6-year-old Australian children. Invest Ophthalmol Vis Sci. 2006;47(8):3276–3285. doi:10.1167/iovs.06-0072 [CrossRef]

Correlative Analysis of Optic Nerve Cup-to-Disc Ratios and RNFL Parameters in Pediatric Cases of Suspected Glaucoma as Evaluated With Pearson Correlation Analysis

ParameterD-CDRMD-CDR


rPrP
Global RNFL0.029.8580.098.531
Superior RNFL−0.083.602−0.028.861
Inferior RNFL0.032.8380.081.607
Nasal RNFL0.205.1940.119.449
Temporal RNFL−0.023.8850.145.353

Relationship Between Refractive Error and BMO Size and Optic Nerve Cup-to-Disc Ratios and RNFL Thickness in Pediatric Patients With Suspected Glaucoma

ParameterRefractive Error (SE)

rP
Refractive error (SE)
  MD-CDR0.091.569
  D-CDR0.182.254
  Global RNFL0.404.008a
  Superior RNFL0.255.103
  Inferior RNFL0.459.002a
  Nasal RNFL0.308.047a
  Temporal RNFL0.120.450
BMO size
  Age0.178.266
  MD-CDR0.169.290
  D-CDR0.307.051
  Refractive error0.049.760
  Global RNFL0.410.008a
  Superior RNFL0.273.084
  Inferior RNFL0.399.010a
  Nasal RNFL0.147.360
  Temporal RNFL0.321.041a
Authors

From the Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois (MCM, LM, DC); and the College of Medicine, University of Illinois at Chicago, Chicago, Illinois (IJ).

The authors have no financial or proprietary interest in the materials presented herein.

Correspondence: Mehmet C. Mocan, MD, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL 60614. E-mail: cmocan@uic.edu

Received: September 30, 2019
Accepted: December 03, 2019

10.3928/01913913-20200117-02

Sign up to receive

Journal E-contents