
































Original Article PeriPaPillary and Macular nerve fiber layer thickness in GlaucoMa

J Nepal Paediatr Soc | VOL 42 | ISSUE 02 |MAY-AUG,  202230

*Pragati Adhikari Gautam1, Hira  Nath Dahal2, Jyoti Baba Shrestha3

1Lecturer, Department of Ophthalmology, B P Koirala Lions Center for Ophthalmic Studies, Maharajgunj Medical Campus, Tribhuvan 
University, Kathmandu, Nepal
2Optomtery Instructor, Department of Ophthalmology, B P Koirala Lions Center for Ophthalmic Studies, Maharajgunj Medical 
Campus, Tribhuvan University, Kathmandu, Nepal
3Associate Professor, Department of Ophthalmology, B P Koirala Lions Center for Ophthalmic Studies, Maharajgunj Medical 
Campus, Tribhuvan University, Kathmandu, Nepal

Evaluation of Peripapillary and Macular Nerve Fiber Layer 
Thickness in Paediatric Glaucoma Suspects

Introduction: Glaucoma patients are known to have optic disc cupping, 
leading to loss of retinal ganglion cell axons. This peripapillary nerve thinness is 
known to be associated with glaucoma in adult patients. Hence, we intended to 
evaluate the peripapillary and macular nerve fiber thickness in eyes of pediatric 
glaucoma suspects using spectral domain optical coherence tomography (OCT).

Methods: This cross-sectional analytical study included 44 eyes of 22 paediatric 
glaucoma suspects, who were compared with 40 eyes of 20 normal paediatric 
eyes. Pearson correlation coefficients were calculated to assess the relations 
between the peripapillary retinal nerve fiber layer (RNFL) thickness and ganglion 
cell complex (GCC). Receiver Operating Characteristics (ROC) curve was plotted 
for OCT parameters in both the groups along with area under the curve (AUC) 
calculation. P values < 0.05 were considered as statistically significant. 

Results: We found the RNFL to be thickest in the superior, inferior, nasal and 
temporal quadrants in both glaucoma suspects and normal group. When 
compared among quadrants in RNFL, all the values in different quadrants were 
statistically significant from each other and in between groups with p < 0.01. 
The RNFL thickness was statistically different in glaucoma when compared with 
normal in superior, temporal, and nasal quadrants however, no statistically 
significant difference was found in inferior quadrant RNFL. The largest AUC for 
discrimination of glaucoma suspect eyes from normal in peripapillary RNFL in 
was nasal quadrant in right eye, followed by temporal quadrant whereas it was 
largest in superior followed by nasal quadrants then average in left eye. However, 
AUC for discrimination of glaucoma suspects from normal in GCC was poor.

Conclusions: Glaucoma suspect paediatric eyes showed significant thinning in 
peripapillary nerve fiber layer thickness compared to normal subjects.

Abstract

*Corresponding Author
Pragati Gautam Adhikari 
Lecturer, 
Department of Ophthalmology, 
B P Koirala Lions Center for Ophthalmic 
Studies, Maharajgunj Medical Campus, 
Maharajgunj, Kathmandu, Nepal.
E-mail: pragatigautam@hotmail.com

Article History 
Received On : 18 Jan, 2022
Accepted On : 09 Dec, 2022

Funding sources:  None

Conflicts of interest: None

Keywords: Ganglion cell complex; 
Pediatric glaucoma; Retinal nerve fiber 
layer; Spectral domain OCT

Online Access

DOI: 
https://doi.org/10.3126/jnps.v42i2.42495 

Introduction
Glaucomatous optic disc cupping is associated with the loss of retinal ganglion cell 
axons.1 Normal optic disc usually has the inferior neuroretinal rim as the thickest 
portion of the rim, followed by the superior rim, and then the nasal rim, with the 
temporal rim being the thinnest portion.2 Violation of this ISNT rule has shown to have 
predictive value in diagnosing glaucoma in adults.3,4 

Original Article

DOI: 103126/JNPS.V4113

Copyrights & Licensing © 2022 by author(s). This is an Open Access article distribut-
ed under Creative Commons Attribution License (CC BY NC )



J Nepal Paediatr Soc | VOL 42 | ISSUE 02 |MAY-AUG,  2022 31

Original ArticlePeriPaPillary and Macular nerve fiber layer thickness in GlaucoMa

The faster image acquisition with spectral-domain OCT (SD - OCT) 
like RTVue has made OCT even more feasible in children.5-9 OCT 
has been used in eyes of normal children but published reports of 
the use of OCT in paediatric glaucoma suspects are sparse.

This study tries to explore and correlate the measurements of 
peripapillary RNFL thickness and macular thickness in paediatric 
glaucoma suspects with that of normal using SD - OCT. To the 
best of our knowledge, this is one of the first studies using the 
OCT machine to investigate the correlation between the macular 
thickness and the peripapillary RNFL thickness in pediatric 
glaucoma and suspects. 

Methods

This was a hospital-based cross-sectional comparative study. 
Written informed consent was obtained from all parents or 
guardians. Approval from the Institutional Review Committee of 
Institute of Medicine was taken. The study duration was from 
15th June 2021 to 15th December 2021. From a prevalence 
of childhood glaucoma from previous study done in Nepal,9 a 
sample size of 22 was calculated for glaucoma suspects and 20 
cases were taken in for control. The non-probability purposive 
sampling method was applied. Children aged between five to 17 
years with glaucoma suspect were included in study. Children less 
than five years, those with hypermetropia more than + 3D, myopia 
more than – 5D, or astigmatism more than 2D, pseudophakia and 
prematurity at birth, corneal lesions, chronic uveitis, secondary 
glaucoma, optic neuropathy other than glaucoma, retinal 
pathology, maculopathy and previous ocular trauma history were 
excluded from this study. The peripapillary retinal nerve fiber 
layer (RNFL) and macular thickness mainly ganglion cell complex 
(GCC) was compared amongst two groups: normal eyes, eyes 
with glaucoma suspects. Glaucoma suspects were defined as eyes 
with (cup disc ratio < 0.4 and < 0.7, IOP < 21), with or without 
family history of glaucoma, vertical cup-to-disc ratio asymmetry < 
0.2 between the two eyes without focal notching or generalized 
loss of the neuroretinal rim, excavation of the optic disc was taken 
as glaucoma suspects. The normal subjects were from patients 
coming for routine ophthalmic examination, with no clinical 
suspicion of glaucoma, who also had optic nerves and retinas 
that were considered clinically normal. Family history in these 
individuals was negative for glaucoma. All subjects underwent 
a complete ophthalmological examination. The intraocular 
pressure (IOP) was measured with Keeler, UK pulse air desktop 
non-contact applanation tonometry and any high reading < = 
21 were be reconfirmed with Goldman applanation tonometry. 
For peripapillary RNFL and Ganglion cell complex in macular 
thickness measurements the RTVue -100 software was used. 
Peripapillary RNFL thickness measurements were performed by 
the same investigator using RTVue OCT (Optovue, Fremont, CA). 
The RNFL thickness was measured by averaging the results of 
three sequential circular scans. Images with signal strength index 
≥ 50 were included in the study. Both eyes from each individual 
were included in the analyses. The statistical package for social 
sciences (SPSS) version 22.0 was used in the analysis. Pearson 
correlation coefficients were calculated to assess the relations 
between the peripapillary RNFL thickness and GCC. Interocular 
OCT parameters difference among gender was calculate with 

paired t test. Interocular OCT parameters difference was calculated 
with paired t test among glaucoma suspects and control. The OCT 
parameters were compared among the two groups by one-way 
ANOVA test. Receiver Operating Characteristics (ROC) curve 
was plotted for OCT parameters in both control and glaucoma 
suspect along with area under the curve (AUC) calculation. The 
diagnostic specificity and sensitivity of the main parameters 
(AUC < 0.7) for distinguishing fellow eyes from normal eyes were 
evaluated, and cut-off points were presented. A probability value 
(P value) less than 0.05 was considered as significant at 95% 
confidence level. 

Results

The mean age of the subjects in the study was 14.59 ± 1.89 
years (11 years - 17 years). Of the total 22 subjects in the study, 
54.5% (n = 12) were males and 45.5% (n = 10) were females. 
The mean cup disc ratio was 0.56 ± 0.078 in right eyes and 0.55 
± 0.071 in left eyes. Twenty age and gender matched normal 
children were also included in the study. The mean age of normal 
group was 13.80 ± 2.14 years (11 - 17 years). Male to female 
ratio was 1:1 in control group. All subjects had best corrected 
visual acuities of 0.0 logMAR or better. None of subjects had 
glaucoma, ocular hypertension. There was no effect of age on 
RNFL thickness in glaucoma suspects and normal as presented in 
Table 1. Average OCT parameters were not statistically significant 
in relation to gender (RE, p = 0.630, LE p = 0.178, independent 
t - test) in glaucoma suspect group.



Original Article PeriPaPillary and Macular nerve fiber layer thickness in GlaucoMa

J Nepal Paediatr Soc | VOL 42 | ISSUE 02 |MAY-AUG,  202232

 Table 1.  OCT parameters in relation to gender

OCT Parameters (µm)  Male  Female P value (Independent t-test)

  Right Eye Superior 22.77 ± 130 16.15 ± 129.60 0.876

Inferior 24.05 ± 127.83 14.54 ± 121.00 0.422

Temporal 12.39 ± 75.75 7.43 ± 72.70 0.485

Nasal 12.50 ± 74.66 12.77 ± 82.10 0.186

Average 17.48 ± 104.37 11.26 ± 101.35 0.630

  Left Eye Superior 13.36 ± 133.33 12.73 ± 124.10 0.114

Inferior 18.77 ± 128.91 15.74 ± 120.00 0.240

Temporal 8.14 ± 77.50 8.52 ± 71.30 0.099

Nasal 8.80 ± 76.66 11.00 ± 79.20 0.564

Average 9.24 ± 104.10 9.02 ± 98.65 0.178

In this study, we found RNFL to be thickest in the superior, inferior, 
nasal and temporal quadrants, in that order in both glaucoma 
suspects and control group. When compared among quadrants 
in RNFL, all the values in different quadrant were statistically sig-
nificant from each other and in between groups with p < 0.01 

when tested with ANOVA test. This means, there was statistically 
significant difference in RNFL thickness quadrant wise and in be-
tween groups. RNFL thickness was statistically different in glauco-
ma suspects when compared with control in superior, temporal, 
and nasal quadrants as presented in Table 2.

 
Table 2. Intraocular differences in peri papillary nerve fiber thickness along different quadrant

OCT characteristics (µm)  Right Eye P value 
(ANOVA)

 Left Eye P value 
(ANOVA)Glaucoma Suspects Normal Glaucoma Suspects Normal

Superior 19.59 ± 130.31 142.31±7.10 0.005 13.60 ± 129.13 6.22 ± 144.60 0.000

 Inferior 20.14 ± 124.72 9.73 ± 124.72 0.680 17.65 ± 124.86 8.60 ± 126.10 0.744

Temporal 22.79 ± 78.90 4.75 ± 82.80 0.002 8.70 ± 74.68 5.77 ± 82.40 0.005

Nasal 12.89 ± 78.04 9.73 ± 93.20 0.000 9.70 ± 77.81 10.22 ± 90.30 0.000

Average 14.72 ± 103.00 6.14 ± 110.85 0.019 9.34 ± 101.62 6.44 ± 110.85 0.001

The macular ganglion cell complex thickness was similar in both 
groups with no statically significant difference quadrant wise in 

both right eye and left eye respectively. (Table 3)

Table 3. Distribution of macular ganglion cell thickness  

Ganglion cell thickness 
(µm)

 Right Eye P value 
(ANOVA)

Left Eye P value (ANOVA)

Glaucoma Suspects Normal Glaucoma Suspects Normal

Superior quadrant 12.20 ± 94.50 2.68 ± 95.10 0.648 7.08 ± 94.59 3.78 ± 93.10 0.458

Inferior quadrant 10.45 ± 93.68 3.22 ± 95.20 0.296 6.83 ± 94.90 3.52 ± 92.70 0.291

Average 10.98 ± 94.09 2.92 ± 95.15 0.460 6.69 ± 94.75 3.58 ± 92.9 0.349

 However, there was no statistically significant interocular difference quadrant wise in right eye and left eye respectively. 
(Table 4)



J Nepal Paediatr Soc | VOL 42 | ISSUE 02 |MAY-AUG,  2022 33

Original ArticlePeriPaPillary and Macular nerve fiber layer thickness in GlaucoMa

Table 4. Comparison between mean peri-papillary nerve fiber thickness between right eye and left eye in glaucoma suspect group

Quadrant  Right Eye Left Eye P value (t-test)

 Superior 19.59 ± 130.31 13.60 ± 129.13 0.765

Inferior 20.14 ± 124.72 17.65 ± 124.86 0.972

Temporal 22.79 ± 78.90 8.70 ± 74.68 0.887

Nasal 12.89 ± 78.04 9.70 ± 77.81 0.926

Average 14.72 ± 103.00 9.34 ± 101.62 0.584

The peri-papillary RNFL in all quadrants showed a positive 
correlation with GCC in right eyes whereas no such correlation 
was found in left eyes and in both eyes of control group. Pearson 
correlation coefficients among the different quadrants to that of 

GCC displayed significant correlation with that of all quadrants 
and average parameters in right eye and only superior quadrant 
in left eye in glaucoma suspect group. (Table 5)

Table 5. Correlation between peri papillary nerve fiber thickness and average macular ganglion cell thickness (Pearson Correlation)

Glaucoma Suspect Control

 Quadrant (GCC (RE (GCC (LE (GCC (RE (GCC (LE

 Superior (r = 0.755, p = 0.000) (r = 0.410, p = 0.058) (r = 0.343, p = 0.331) (r = 0.371, p = 0.291)

Inferior (r = 0.587, p = 0.004) (r = 0.077, p = 0.734) (r = -0.177, p=0.625) (r = -0.066, p = 0.856)

 Temporal (r = 0.785, p = 0.000) (r = 0.252, p = 0.257) (r = 0.314, p = 0.377) (r = -0.100, p = 0.784)

Nasal (r = 551, p = 0.008) (r = 0.392, p = 0.071) (r = -0.256, p = 0.475) (r = -0.228, p = 0.527)

Average (r = 0.658, p = 0.001) (r = 0.346, p = 0.115) (r = -0.007, p = 0.984) (r = -0.045, p = 0.901)

ROC curves were plotted and AUC calculated for right eye and 
left eye for RNFL thickness and GCC thickness respectively. The 
largest AUC for discrimination of glaucoma suspect eyes from 
normal in peripapillary RNFL in was nasal quadrant (0.84) in 
right eye, followed by temporal quadrant (0.78) whereas it was 
largest in superior (0.85) followed by nasal quadrants (0.83) 
then average (0.80) in left eye. This was statistically significant 
to diagnose glaucoma suspects from normal eye. However, AUC 
for discrimination of glaucoma suspects from normal in GCC was 
poor in right eye (0.54) and had no discrimination in left eye 
(0.38).

Discussion

The present study showed that average peripapillary RNFL and 
peripapillary RNFL of all sectors except for inferior was significantly 
thinner in glaucoma suspects compared to normal children. Since 
glaucomatous optic neuropathy has been documented to develop 
locally rather than globally3

The normal group of participants had thicker RNFL using SD-OCT 
as compared to earlier studies,3,4 with maximum thickness in the 
superior quadrant, contradicting the ISNT rule. Some researchers 
have reported the thinning of average RNFL thickness in all sectors 
between paediatric glaucoma and controls. However, other 
researchers have found that children with glaucoma and normal 
participants have comparable RNFL thickness in some regions 
such as the temporal, nasal, and inferior nasal quadrants.

The average peripaillary thickness was 110.85 ± 6.14 in right 

eyes and 110.85 ± 6.44 in left eyes in normal group which is 
slightly higher than reported in various studies11-14 but almost 
similar to reported in others.15-17 This may be attributed to ethnic 
differences and differences in the OCT version used in earlier 
studies. 

 Studies of the sensitivity and specificity of OCT for the diagnosis
 of glaucoma have primarily focused on glaucoma patients who
 already have visual field defects.18,19 However, in our study, the
 largest AUC for discrimination of glaucoma suspect eyes from
 normal in peripapillary RNFL in was nasal quadrant in right eye,
 followed by temporal quadrant whereas it was largest in superior
 followed by nasal quadrants then average in left eye. Budenz and
 associates found higher AUC values for mean RNFL thickness,
 superior quadrant and inferior quadrant.8 Similarly, in a study
 comparing SD-OCT to stratus OCT, the RNFL parameters with
 the highest AUCs were in similar locations as those in the Stratus
 OCT.20 The ability to discriminate normal from glaucomatous
 results is directly proportional to the magnitude of disease
 severity as suggested in previous studies.19,21,22 The changes of
 pRNFL thickness are meaningful in these children with less severe
 glaucomatous optic nerve damage, where the damage of visual
 function may be difficult to measure. Age-related decrease in
 RNFL has been reported in adults11,23 using OCT however it was
 not found in our study of paediatric age group. Similar to our
 finding, Rao et al also showed that peripapillary RNFL thickness
 was independent of age in children.24 Alamouti and Funk have
 suggested that the rate of decrease in RNFL thickness is slower in
 the younger age.23 However, it is still unclear as to the exact age
 at which the thinning starts. More so, it is possible that such an
 age-related process starts in adult life, which may explain the lack



Original Article PeriPaPillary and Macular nerve fiber layer thickness in GlaucoMa

J Nepal Paediatr Soc | VOL 42 | ISSUE 02 |MAY-AUG,  202234

of correlation of age with RNFL thickness in the paediatric group.24

Gender also did not contribute to the variability in RNFL thickness in 
our study. Similarly, such gender related difference in the pediatric 
age group was not found in other studies too.25,26 In our study, 
we did not find significant differences between the two eyes with 
symmetric RNFL and macular parameters. Similarly, no significant 
difference in mean RNFL thickness of the four quadrants was 
seen between the two eye in other studies.7,24 However, eye side 
had significant influence on RNFL thickness in some studies.8,10,13 
The mechanism underlying interocular differences is unclear in 
normal children, it may be physiological however in children 
with glaucoma suspects or glaucoma it could be attributed to the 
asymmetrical nature of the disease itself.

 In addition to peripapillary RNFL thickness, macular thickness
 especially GCC has been shown as an important parameter
 for the early detection of glaucoma in adults, with significant
 differences reported by some between glaucomatous and normal
 eyes. In the study by Hess et al, significant differences were found
 in the OCT scans obtained from glaucoma patients compared
 with those of normal children, using both the RNFL map protocol
 and the fast macular map.27 However, another study has showed
 that macular thickness had lower diagnostic capability compared
 with peripapillary RNFL thickness in early glaucoma.19 Similarly,
 no much difference was found in our study too. Since diagnostic
 accuracy of GCC is significantly influenced by disease severity.
 Moreso, this difference may not be pronounced in early disease
 state. Our group of glaucoma suspect eyes based on optic nerve
 cupping. Even though we did not correlate RNFL and cupping,
 a study had correlated RNFL and cupping and found that the
 degree of optic nerve cupping does not correlate with the RNFL
 thickness.10 The glaucoma suspects patients may represent a
 mild or early stage of glaucomatous damage. This provides us
 with a standard comparison for glaucoma screening since any
 deviation from the normative database would be definite along
 with other factors. Inclusion of eyes with glaucoma in the group
 would probably have made the differences between the glaucoma
 and normal groups even larger. The axial length was not taken
 into account in our study and our measurements were obtained
 in children without ocular disease and significant refractive error
 as previous studies showed that they did not affect the RNFL and
GCC parameters significantly.13,15

The strength of the study is that it included a heterogeneous mixture 
of Nepalese ethnic group visiting a tertiary eye care center in 
Kathmandu, Nepal. The major limitation of the present study is 
related to the characteristics of the subjects enrolled ranging mainly 
in age group 11 - 17 years, so results may not be applicable to 
younger age groups. More so, a larger sample size will help to 
differentiate better predictive value of each parameter. Longitudinal 
follow-up of eyes with paediatric glaucoma suspects, and serial 
OCT measurements in these same eyes, will assess the use of this 
technology in monitoring glaucoma progression and evaluate 
outcomes in more detail along with identification of additional risk 
factors in the development of glaucoma in paediatric glaucoma 
suspects.

Conclusions

This study demonstrated that spectral domain OCT of RNFL 
can quantitatively measure structural changes that are known 
to occur with glaucoma, in glaucoma suspects. In our study, 
paediatric glaucoma suspects had significantly reduced average 
quadrants RNFL thickness compared with healthy controls along 
with largest AUC for discrimination of glaucoma suspect eyes from 
normal in nasal quadrant and temporal quadrant in right eye, 
and superior, nasal quadrants and average RNFL in left eye. We 
would like to highlight SD-OCT has potential clinical value in early 
diagnosis in pediatric glaucoma suspects.

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