Three-dimensional mapping of peripapillary retinal layers using a spectral domain optical coherence tomography

Figures & data

Figure 1 The ETDRS sectors around the optic nerve head.

Note: The center is 1 mm, the inner circle is 1–3 mm away, and the outer circle is 3–6 mm away.
Abbreviation: ETDRS, Early Treatment Diabetic Retinopathy Study.

Figure 2 The retinal layers that were measured are shown.

Note: The ONL spans from the OPL to the ELM (not displayed).
Abbreviations: ELM, external limiting membrane; ONL, outer nuclear layer; OPL, outer plexiform layer.

Table 1 General characteristics

Age group (Y)	Patients (N)	Gender (M/F)	Refractive error (D)	IOP (mmHg)	Axial length (mm)
20–29	55	27/28	−0.6±1.5	14.3±2.5	23.4±1.0
30–39	64	21/43	−0.5±1.2	15.1±3.2	23.7±1.7
40–49	41	24/17	−0.0±1.3	15.5±2.7	23.5±0.9
50–59	42	24/18	1.2±1.0	13.8±3.8	23.1±0.7
60+	40	30/10	0.9±1.1	15.4±3.1	23.2±0.8
Total	242	126/116	−0.0±1.5	14.8±3.1	23.5±1.2

Note: The values are mean ± SD.

Abbreviations: D, diopters; F, female; IOP, intraocular pressure; M, male; N, number; Y, years.

Table 2 Retinal thickness by layer

Layer (µm)	Inner circle				Outer circle
	Superior	Inferior	Nasal	Temporal	Superior	Inferior	Nasal	Temporal	Mean
Single layers
RNFL	130.4±31.6	135.2±37.7	71.9±18.9	92.0±35.0	95.5±16.1	97.1±15.8	54.4±10.9	56.6±10.4	91.6±22.0
GCL	28.1±6.1	28.1±5.5	28.2±4.7	28.8±5.5	21.5±2.1	21.6±1.8	33.8±5.7	22.7±4.2	26.6±4.4
IPL	27.9±6.1	27.7±6.2	29.3±6.7	32.8±7.4	17.2±3.0	16.9±2.0	27.4±4.7	19.0±3.7	24.7±4.9
INL	33.9±6.5	33.5±6.7	33.0±6.0	34.6±7.3	26.0±2.8	25.5±2.5	33.9±4.2	27.0±4.1	30.9±5.1
OPL	25.7±4.3	24.6±4.0	27.2±4.0	24.4±3.5	23.0±1.6	23.1±1.6	31.5±4.7	23.5±3.5	25.3±3.4
ONL	43.5±7.0	40.4±6.2	40.2±6.7	43.7±7.6	47.2±5.5	42.7±5.3	49.4±7.4	45.9±5.8	44.1±6.4
RPE	14.4±5.6	14.1±4.2	15.4±7.0	15.5±5.3	12.3±2.3	12.0±2.0	14.7±7.9	14.4±4.3	14.1±4.8
Combined layers
IRL	285.1±30.0	288.9±43.8	222.9±30.7	250.1±41.7	230.9±22.1	227.5±24.1	228.0±19.4	193.6±18.7	240.8±28.8
PL	78.6±4.7	78.9±8.3	79.7±4.9	80.3±4.4	75.9±2.8	74.6±2.9	78.0±3.1	77.8±3.6	77.9±4.3
TRT	361.3±45.6	365.0±50.2	302.9±34.9	331.5±50.4	305.3±26.6	300.6±28.9	307.0±21.6	270.5±25.2	318.0±35.4

Notes: The values are in mean ± SD. Center, ONH, inner circle 1–3 mm from ONH; outer circle 3–6 mm from ONH.

Abbreviations: GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; IRL, inner retinal layer; ONH, optic nerve head; ONL, outer nuclear layer; OPL, outer plexiform layer; PL, photoreceptor layer; RNFL, retinal nerve fiber layer; RPE, retinal pigment epithelium; TRT, total retinal thickness.

Table 3 Retinal thickness by gender

Layer (µm)	Total (n=242)	Male (n=126)	Female (n=116)	p-value
Single layers
Retinal nerve fiber layer
Whole	91.6±37.2	90.2±35.0	93.0±39.4	0.128
Inner circle	107.3±40.9	104.7±38.1	110.0±43.8	0.065
Outer circle	75.8±24.5	75.7±24.2	76.0±24.8	0.856
Ganglion cell layer
Whole	26.6±6.2	26.5±6.1	26.7±6.3	0.704
Inner circle	28.3±5.5	28.1±5.4	28.5±5.6	0.256
Outer circle	24.9±6.4	25.0±6.3	24.8±6.5	0.648
Inner plexiform layer
Whole	25.6±8.3	25.4±8.2	25.8±8.4	0.402
Inner circle	29.4±6.7	29.1±6.5	29.7±6.9	0.182
Outer circle	21.7±7.7	21.7±7.6	21.8±7.9	0.940
Inner nuclear layer
Whole	30.9±6.4	30.7±6.2	31.2±6.7	0.128
Inner circle	33.7±6.6	33.2±6.4	34.2±6.8	0.111
Outer circle	28.1±4.8	28.1±4.8	28.1±4.9	0.970
Outer plexiform layer
Whole	25.4±4.5	25.5±4.7	25.3±4.2	0.394
Inner circle	25.5±4.1	25.5±4.4	25.5±3.9	0.926
Outer circle	25.3±4.7	25.5±5.0	25.1±4.5	0.226
Outer nuclear layer
Whole	43.0±7.7	42.9±7.7	43.1±7.8	0.593
Inner circle	39.7±7.5	39.3±7.3	40.1±7.7	0.137
Outer circle	46.3±6.5	46.5±6.3	46.1±6.7	0.417
Retinal pigment epithelium
Whole	14.7±5.2	14.7±5.9	13.5±4.6	<0.001*
Inner circle	14.8±11.1	15.6±6.3	14.1±4.8	<0.001*
Outer circle	13.3±4.8	13.9±5.4	12.8±4.3	0.002*
Combined layers
Inner retinal layer
Whole	240.8±43.3	238.2±40.7	243.4±45.9	0.015*
Inner circle	261.7±47.0	257.0±44.6	266.4±49.4	0.004*
Outer circle	220.0±26.1	219.5±25.1	220.5±27.1	0.561
Photoreceptor layer
Whole	78.0±9.7	78.9±4.5	77.1±5.2	<0.001*
Inner circle	79.4±5.6	80.3±5.0	78.5±6.3	<0.001*
Outer circle	76.5±3.3	77.4±3.4	75.7±3.2	<0.001*
Total retinal thickness
Whole	319.3±44.0	317.8±41.1	320.8±47.0	0.162
Inner circle	340.6±47.2	337.3±44.1	342.0±50.3	0.121
Outer circle	446.0±25.3	298.2±25.8	295.6±24.8	0.136

Notes: The values are in mean ± SD. Center, ONH, inner circle 1–3 mm from ONH; outer circle 3–6 mm from ONH.

* Statistically significant.

Abbreviation: ONH, optic nerve head.

Table 4 Correlation of retinal thickness with age

Layer (µm)	Regression equation	R-value	p-value	Adjusted p-value**
Single layers
Retinal nerve fiber layer
Whole	107.9−0.41× age	0.139	<0.001*	<0.001*
Inner circle	130.4−0.59× age	0.180	<0.001*	<0.001*
Outer circle	85.1−0.23× age	0.122	<0.001*	<0.001*
Ganglion cell layer
Whole	28.8−0.05× age	0.116	<0.001*	<0.001*
Inner circle	31.5−0.08× age	0.190	<0.001*	<0.001*
Outer circle	26.1−0.03× age	0.062	0.073	0.067
Inner plexiform layer
Whole	27.1−0.03× age	0.059	0.016*	0.006*
Inner circle	31.7−0.05× age	0.103	0.003*	0.001*
Outer circle	22.6−0.02× age	0.034	0.326	0.308
Inner nuclear layer
Whole	33.0−0.05× age	0.104	<0.001*	<0.001*
Inner circle	36.3−0.06× age	0.124	<0.001*	<0.001*
Outer circle	29.7−0.04× age	0.106	0.002*	0.002*
Outer plexiform layer
Whole	26.3−0.02× age	0.064	0.009*	0.027*
Inner circle	26.6−0.02× age	0.084	0.016*	0.017*
Outer circle	26.0−0.01× age	0.047	0.174	0.174
Outer nuclear layer
Whole	46.8−0.09× age	0.157	<0.001*	<0.001*
Inner circle	43.6−0.10× age	0.170	<0.001*	<0.001*
Outer circle	49.9−0.09× age	0.179	<0.001*	<0.001*
Retinal pigment epithelium
Whole	15.4−0.03× age	0.079	0.001*	0.021*
Inner circle	16.3−0.03× age	0.082	0.018*	0.022*
Outer circle	14.5−0.03× age	0.077	0.026*	0.028*
Combined layers
Inner retinal layer
Whole	266.6−0.66× age	0.190	<0.001*	<0.001*
Inner circle	294.6−0.84× age	0.224	<0.001*	<0.001*
Outer circle	238.6−0.48× age	0.230	<0.001*	<0.001*
Photoreceptor layer
Whole	78.8−0.02× age	0.053	0.030*	0.271
Inner circle	80.0−0.01× age	0.036	0.306	0.346
Outer circle	77.6−0.02× age	0.094	0.007*	0.008*
Total retinal thickness
Whole	345.5−0.67× age	0.191	<0.001*	<0.001*
Inner circle	374.8−0.85× age	0.225	<0.001*	<0.001*
Outer circle	316.1−0.49× age	0.245	<0.001*	<0.001*

Notes: The values are in mean ± SD. Center, ONH, inner circle 1–3 mm from ONH; outer circle 3–6 mm from ONH.

* Statistically significant;

** Adjusted for axial length.

Abbreviation: ONH, optic nerve head.

Table 5 Correlation of retinal thickness with axial length

Layer (µm)	Regression equation	R-value	p-value	Adjusted p-value**
Single layers
RNFL	140.0−1.07× axial length	0.036	0.244	0.118
GCL	36.8−0.41× axial length	0.093	0.003*	0.001*
IPL	37.7−0.45× axial length	0.072	0.020*	0.013*
INL	41.5−0.39× axial length	0.073	0.018*	0.009*
OPL	23.1+0.08× axial length	0.026	0.407	0.489
ONL	57.1−0.67× axial length	0.110	<0.001*	<0.001*
RPE	10.6+0.16× axial length	0.038	0.215	0.272
Combined layers
IRL	332.9−3.28× axial length	0.092	0.003*	<0.001*
PL	74.4+0.18× axial length	0.042	0.180	0.204
TRT	414.7−3.37× axial length	0.094	0.003*	<0.001*

Notes:

* Statistically significant;

** Adjusted for age.

Abbreviations: GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; IRL, inner retinal layer; ONL, outer nuclear layer; OPL, outer plexiform layer; PL, photoreceptor layer; RNFL, retinal nerve fiber layer; RPE, retinal pigment epithelium; TRT, total retinal thickness.

Table 6 Reproducibility of measurements

Layer (µm)	CV			ICC
	Inner	Outer	Whole	Inner	Outer	Whole
Single layers
RNFL	0.092	0.041	0.067	0.940	0.982	0.964
GCL	0.097	0.037	0.184	0.682	0.965	0.884
IPL	0.128	0.050	0.089	0.614	0.962	0.866
INL	0.128	0.056	0.092	0.352	0.902	0.733
OPL	0.001	0.039	0.063	0.476	0.898	0.759
ONL	0.086	0.028	0.057	0.661	0.931	0.840
RPE	0.101	0.034	0.068	0.468	0.881	0.641
Combined layers
IRL	0.028	0.017	0.023	0.961	0.925	0.968
PL	0.025	0.009	0.017	0.595	0.924	0.784
TRT	0.019	0.008	0.014	0.972	0.986	0.984

Abbreviations: CV, coefficient of variation; GCL, ganglion cell layer; ICC, intraclass correlation coefficient; INL, inner nuclear layer; IPL, inner plexiform layer; IRL, inner retinal layer; ONL, outer nuclear layer; OPL, outer plexiform layer; PL, photoreceptor layer; RNFL, retinal nerve fiber layer; RPE, retinal pigment epithelium; TRT, total retinal thickness.