Aging-associated changes of optical coherence tomography-measured ganglion cell-related retinal layer thickness and visual sensitivity in normal Japanese.

PURPOSE: To report aging-associated change rates in circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and macular ganglion cell-inner plexiform layer and complex thickness (MGCIPLT, MGCCT) in normal Japanese eyes and to compare the data in linear scaled visual field (VF) sensitivity of central 4 points of Humphrey Field Analyzer (HFA) 24-2 test (VF4TestPoints) to that in MGCIPLT in four 0.6-mm-diameter circles corresponding to the four central points of HFA 24-2 adjusted for retinal ganglion cell displacement (GCIPLT4TestPoints). STUDY DESIGN: Prospective observational study METHODS: HFA 24-2 tests and spectral-domain optical coherence tomography (SD-OCT) measurements of cpRNFLT, MGCIPLT, MGCCT and GCIPLT4TestPoints were performed every 3 months for 3 years in 73 eyes of 37 healthy Japanese with mean age of 50.4 years. The time changes of SD-OCT-measured parameters and VF4TestPoints were analyzed using a linear mixed model. RESULTS: The aging-associated change rates were -0.064 µm/year for MGCIPLT and and -0.095 for MGCCT (P=0.020 and 0.017), but could not be detected for cpRNFLT. They accelerated with aging at -0.009µm/year/year of age for MGCIPLT (P<0.001), at 0.011 for MGCCT (P<0.001) and at 0.013 for cpRNFLT(0.031). The aging-associated decline of -82.1 [1/Lambert]/year of VF4TestPoints corresponded to -0.095 µm/year of GCIPLT4TestPoints. CONCLUSION: We report that aging-associated change rates of cpRNFLT, MGCIPLT and MGCCT in normal Japanese eyes were found to be significantly accelerated along with aging. Relationship between VF sensitivity decline rates and SD-OCT measured GCIPLT decline rates during physiological aging in the corresponding parafoveal retinal areas are also documented.

Evaluation of preoperative visual pathway impairment in patients with non-functioning pituitary adenoma using diffusion tensor imaging coupled with optical coherence tomography.

Objective: Optic chiasma compression and associated visual impairment induced by a non-functioning pituitary adenoma (NFPA) is commonly assessed by the optic disk and retina but is inadequate to understand the entire visual pathway impairment. We aim to evaluate the use of optical coherence tomography (OCT) coupled with diffusion tensor imaging (DTI) for the preoperative evaluation of visual pathway impairment. Methods: Fifty-three patients with NFPA (categorized into mild and heavy compression subgroups) were subjected to OCT to calculate the thickness of the circumpapillary retinal nerve fiber layer (CP-RNFL), macular ganglion cell complex (GCC), macular ganglion cell layer (GCL), and macular inner plexus layer (IPL), as well as to DTI to calculate the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values. Results: Compared to mild compression, heavy compression caused decreased FA value, increased ADC value of several segments of the visual pathway, thin temporal CP-RNFL, and quadrant macular GCC, IPL, and GCL. Average CP-RNFL thickness, inferior-macular inner-ring IPL and GCC thicknesses, inferior CP-RNFL thickness, and superior CP-RNFL thickness were the best indicators of the impairment of the optic nerve, optic chiasma, optic tract, and optic radiation, respectively. Conclusion: DTI and OCT parameters can effectively evaluate visual pathway impairment and are beneficial for the objective preoperative evaluation of visual pathway impairment in patients with NFPA.

Structure-Function Relationships and Glaucoma Detection with Magnification Correction of OCT Angiography.

Purpose: To investigate the effects of adjusting the ocular magnification during OCT-based angiography imaging on structure-function relationships and glaucoma detection. Design: Cross-sectional study. Participants: A total of 96 healthy control participants and 90 patients with open-angle glaucoma were included. Methods: One eye of each patient in the control group and the patient group was evaluated. The layers comprising the macula vascular density (VD) and circumpapillary VD were derived from swept-source OCT angiography imaging. The mean sensitivity (MS) of the standard automated perimetry was measured using the Humphrey 24-2 test. Structure-function relationships were evaluated with simple and partial correlation coefficients. A receiver operating characteristic analysis was performed to evaluate the diagnostic accuracy for glaucoma using the area under the receiver operating characteristic curve (AUC). Ocular magnification was adjusted using Littmann's formula modified by Bennett. Main Outcome Measures: The association between the axial length and VD, structure-function relationships, and glaucoma detection with and without magnification correction. Results: The superficial layer of the macular region was not significantly correlated to the axial length without magnification correction (r = 0.0011; P = 0.99); however, it was negatively correlated to the axial length with magnification correction (r = -0.22; P = 0.028). Regarding the nerve head layer in the circumpapillary region, a negative correlation to the axial length without magnification correction was observed (r = -0.22; P = 0.031); however, this significant correlation disappeared with magnification correction. The superficial layer of the macula and the nerve head layer of the circumpapillary region were significantly correlated to Humphrey 24-2 MS values without magnification correction (r = 0.22 and r = 0.32, respectively); however, these correlations did not improve after magnification correction (r = 0.20 and r = 0.33, respectively). Glaucoma diagnostic accuracy in the superficial layer (AUC, 0.63) and nerve head layer (AUC, 0.70) without magnification correction did not improve after magnification correction (AUC, 0.62 and 0.69, respectively). Conclusions: Adjustment of the ocular magnification is important for accurate VD measurements; however, it may not significantly impact structure-function relationships and glaucoma detection.

Progressive Thinning of Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer in Glaucoma Eyes with Disc Hemorrhage.

PURPOSE: To evaluate the thinning of the circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) in primary open-angle glaucoma eyes with and without a history of disc hemorrhage (DH). DESIGN: Observational cohort study. PARTICIPANTS: Thirty-nine 39 eyes (34 participants) with DH and 117 eyes (104 participants) without DH from the Diagnostic Innovations in Glaucoma Study and the African Decent and Glaucoma Evaluation Study. METHODS: Participants had at least 1.5 years of follow-up, with a minimum of 3 visits with biannual spectral-domain OCT cpRNFL and mGCIPL thickness measurements and visual fields (VFs). The rates of cpRNFL and mGCIPL thinning were calculated using mixed-effects models. The dynamic range-based normalized rates of cpRNFL and mGCIPL thinning were calculated and compared between the DH and non-DH groups. MAIN OUTCOME MEASURES: Rates of cpRNFL and mGCIPL thinning. RESULTS: The rate of mGCIPL thinning was significantly faster in the DH group compared with the non-DH group (-0.62 µm/year vs. -0.38 µm/year; P = 0.024). The rate of cpRNFL thinning in the DH quadrant and rate of mGCIPL thinning in the inferotemporal sector in the DH group were faster than the corresponding regions in the non-DH group after adjusting for intraocular pressure (-1.33 µm/year vs. -0.58 µm/year; P = 0.053) and race (-0.82 µm/year vs. -0.44 µm/year; P = 0.048). In the DH group, percent rate of loss was significantly faster for the mGCIPL than the cpRNFL (-1.59 %/year vs. -1.31 %/year; P = 0.046). Rates of mGCIPL thinning were associated weakly with mean deviation slope, VF index slope, and guided progression analysis (GPA). The areas under the receiver operating characteristic curve for VF progression were 0.75 for mGCIPL and 0.56 for cpRNFL in the DH group. CONCLUSIONS: The rate of mGCIPL and cpRNFL thinning was faster in DH eyes than non-DH eyes. Compared with cpRNFL, mGCIPL showed higher proportional rates of thinning and greater association with functional progression. In addition to cpRNFL, clinicians should consider incorporating mGCIPL imaging to monitor glaucoma progression, especially in glaucoma eyes with DH.

Thinning rates of retinal nerve layer and ganglion cell-inner plexiform layer in various stages of normal tension glaucoma.

AIMS: To compare the changes in the macular retinal nerve fibre layer (mRNFL), macular ganglion cell layer and inner plexiform layer (mGCIPL), and circumpapillary retinal nerve fibre layer (cpRNFL) in various stages of normal tension glaucoma (NTG) using spectral domain optical coherence tomography. METHODS: Eyes with NTG (n=218) were assigned into three groups based on initial mean deviation (MD) as follows: mild (MD>-6 dB), moderate (-6 dB≥MD≥-12 dB) and severe (-12 dB>MD>-20 dB). Annual rates of change in mRNFL, mGCIPL and cpRNFL thickness were calculated by linear regression analysis. RESULTS: Age, gender, spherical equivalent, and average intraocular pressure during follow-up were not significantly different among the three groups. There were significant differences in the mRNFL, mGCIPL and cpRNFL among the three groups at baseline (p<0.0001 in all sectors except for the mRNFL in the superonasal sector). The average thinning rates of the mRNFL, mGCIPL and cpRNFL were -0.38±0.32 µm/year, -0.62±0.46 µm/year and -0.86±0.83 µm/year, respectively. No significant difference in the rates of change in the mRNFL and mGCIPL were found among the groups in any sector. However, there was a significant difference in the rate of change in the cpRNFL among the groups (in all sectors: p<0.0001). CONCLUSIONS: Changes in the mRNFL and mGCIPL can reflect the progression of NTG even in its advanced stage. However, careful interpretation of changes in the cpRNFL in the advanced stage of glaucoma is warranted due to a potential floor effect.

Circumpapillary structure-function relationships with microperimetry and spectral domain optical coherence tomography in glaucoma: a pilot study.

PURPOSE: To compare the relationships between circumpapillary microperimetry (MP)-sensitivity measurements and various circumpapillary retinal thickness parameters in healthy and primary open-angle glaucoma (POAG) eyes. METHODS: In 14 eyes of 14 healthy subjects and 22 early-moderate POAG eyes of 22 patients, circumpapillary optical coherence tomography thickness measurements (RS-3000 Advance OCT, NIDEK) of the retinal nerve fiber layer (cpRNFL), total retina (cpTR), and ganglion cell complex (cpGCC) and outer retina (cpOR) and circumpapillary MP-sensitivity measurements (MP-3 microperimeter, NIDEK) were made in 12 sectors of identical circumpapillary circles. The structure-function relationship was investigated in each sector. RESULTS: Statistically significant correlations with circumpapillary MP-sensitivity values were found for cpRNFL in five sectors, cpTR in nine sectors, cpGCC in nine sectors, and cpOR in three sectors. The structure-function relationship was strong (r=0.4-0.69) in three sectors for cpRNFL, in six for cpTR, in four for cpGCC, and in one for cpOR. The relationship was very strong (r>0.7) in one sector for cpRNFL, cpTR, and cpGCC, and in no sectors for cpOR. The very strong relationships all occurred in sector 5 (inferotemporal sector). CONCLUSION: In our pilot study, the circumpapillary structure-function relationship was more extensive for cpTR thickness and cpGCC thickness than for cpRNFL thickness, which suggests that the former parameters may require greater attention in structure-function research into glaucoma.

The development of a reference database with the Topcon 3D OCT-1 Maestro.

IMPORTANCE: The paper presents the range for measurements taken with a new spectral domain optical coherence tomography (OCT) device to establish a reference database for discrimination purposes. OBJECTIVE: To report the range of thickness values for the new Topcon Maestro 3D OCT device with 2 scan size settings: the 12×9 mm wide field and 6×6 mm scans. DESIGN: Prospective, multicenter cohort study conducted at 7 clinical sites across the USA. SETTING: Primary eyecare clinics within academic, hospital, and private practice locations. PARTICIPANTS: Healthy volunteers; all enrolled participants underwent a complete ophthalmological examination to confirm healthy ocular status prior to being enrolled in the study. MAIN OUTCOME MEASURE: Average and 1st, 5th, 95th, and 99th percentile ranges for OCT parameters Early Treatment Diabetic Retinopathy Study macula full retinal thickness, ganglion cell + inner plexiform layer thickness (GCL + IPL), ganglion cell complex (GCC) thickness, circumpapillary retinal nerve fiber layer (cpRNFL) thickness. RESULTS: Three hundred and ninety-nine eyes of 399 subjects were included in the analysis. Mean (SD) age was 46.3 (16.3) years (range 18-88 years). Forty-three percent of the subjects were male. Mean (SD) measurements (in µm) for the 12×9 mm wide scan were as follows: foveal thickness=237.079 (20.899), GCL + IPL=71.363 (5.924), GCC=105.949 (8.533), cpRNFL=104.720 (11.829); measurements for the 6×6 mm scans were as follows: foveal thickness=234.000 (20.657), GCL + IPL=71.726 (5.880), GCC=106.698 (9.094), cpRNFL=104.036 (11.341). CONCLUSION: The overall normal thickness values reported with Topcon 3D OCT-1 Maestro were like those studies with OCT from different manufactures. The reference limits at the 1st, 5th, 95th, and 99th percentile points establish the thresholds for the quantitative comparison of the cpRNFL and the macula in the human retina to a database of known healthy subjects.

Comparison of longitudinal changes in circumpapillary retinal nerve fiber layer and ganglion cell complex thickness after acute primary angle closure: a 12-month prospective study.

PURPOSE: To compare longitudinal changes in circumpapillary retinal nerve fiber layer (cpRNFL) and ganglion cell complex (GCC) thicknesses and factors that are related to changes in cpRNFL and GCC thicknesses after acute primary angle closure (APAC). STUDY DESIGN: A prospective consecutive case series. METHODS: This study was a prospective, consecutive case series study including 64 eyes of 64 subjects with APAC. cpRNFL and GCC thicknesses were measured by RTVue-100 OCT. To measure cpRNFL and GCC thicknesses, the "three-dimensional (3D) optic disc scan and ONH scan" and "GCC" scan mode were used. Differences in cpRNFL and GCC thicknesses between the affected eye and fellow eye were compared, and logistic regression analysis was performed to investigate the factors associated with longitudinal changes in cpRNFL and GCC thicknesses. RESULTS: The average, superior and inferior cpRNFL, and GCC thicknesses were thicker in the affected eye than in the fellow eye within 1 week after remission and gradually decreased up to 12 months after remission. Compared with the cpRNFL and GCC thicknesses at 1 week after remission, the cpRNFL and GCC thicknesses at 1 month, 3 months, 6 months, and 12 months after remission were significantly thinner. Logistic regression analysis revealed that a longer duration from the onset of symptoms to adjustment of treatment (cpRNFL: odds ratio = 0.865, p = 0.003) (GCC: odds ratio = 0.824, p = 0.001) was associated with abnormal cpRNFL and GCC thicknesses. CONCLUSION: A week after APAC both cpRNFL and GCC thicknesses were thicker in the affected eye than in the fellow eye and further decreased up to 12 months post APAC. A longer duration from the onset of symptoms to adjustment of treatment was associated with cpRNFL and GCC loss after APAC.

Influence of corneal power on circumpapillary retinal nerve fiber layer and optic nerve head measurements by spectral-domain optical coherence tomography.

AIM: To evaluate the influence of corneal power on circumpapillary retinal nerve fiber layer (cpRNFL) and optic nerve head (ONH) measurements by spectral-domain optical coherence tomography (SD-OCT). METHODS: Twenty-five eyes of 25 healthy participants (mean age 23.6±3.6y) were imaged by SD-OCT using horizontal raster scans. Disposable soft contact lenses of different powers (from -11 to +5 diopters including 0 diopter) were worn to induce 2-diopter changes in corneal power. Differences in the cpRNFL and ONH measurements per diopter of change in corneal power were analyzed. RESULTS: As corneal power increased by 1 diopter, total and quadrant cpRNFL thicknesses, except for the nasal sector, decreased by --0.19 to -0.32 µm (P<0.01). Furthermore, the disc, cup, and rim areas decreased by -0.017, -0.007, and -0.015 mm2, respectively (P<0.001); the cup and rim volumes decreased by -0.0013 and -0.006 mm3, respectively (P<0.01); and the vertical and horizontal disc diameters decreased by -0.006 and -0.007 mm, respectively (P<0.001). CONCLUSION: For more precise OCT imaging, the ocular magnification should be corrected by considering both the axial length and corneal power. However, the effect of corneal power changes on cpRNFL thickness and ONH topography are small when compare with those of the axial length.

[Disc-fovea angle adjustment for peripallary retinal nerve fiber layer analysis by a spectral domain optical coherence tomography. Preliminary study]. / Analyse des fibres nerveuses rétiniennes péripapillaires ajustée selon l'angle papillo-maculaire en tomographie par cohérence optique en domaine spectral. Étude préliminaire.

INTRODUCTION: Circumpapillary retinal nerve fiber layer (cpRNFL) analysis by spectral domain optical coherence tomography (SD-OCT) has become essential for the assessment of glaucoma patients. The foveal projection is conventionally below the disc plane, creating an angle with the horizontal meridian, the disc-fovea angle. The purpose of this study is to evaluate the role of adjustment of cpRNFL analysis based on this angle. MATERIALS AND METHODS: This study concerns 40 control eyes and 55 eyes affected with and followed for primary open angle glaucoma (POAG). After precise localization of the optic disc center and the axis connecting it to the center of the fovea, a circular peripapillary scan is performed with Spectralis OCT (Heidelberg Engineering, Germany). The mean thickness in each of six papillary sectors and the global mean thickness of the cpRNFL were evaluated. The ROC (receiver operating characteristic) analysis evaluated the diagnostic capabilities of the various sectors before and after adjustment of the analysis for the disc-fovea angle. RESULTS: The disc-fovea angle was not different between the two groups (-7.0 ± 1.2° for controls vs. -6.6 ± 1.2° for POAG, P=0.70). There is a significant variance of this angle in both groups (the angle varies in the control group between -22.5° to +1.8° and in the POAG group between -18° to +2.4°). The global mean and inferior temporal (IT) thickness of the cpRNFL show the best diagnostic performance. Adjustment for disc-fovea angle does not increase the diagnostic accuracy of the various sectors analyzed. Although there is an increase in the area under the curve for the IT sector after adjustment, it is not statistically significant (0.910 ± 0.056 vs. 0.936 ± 0.045, P=0.06). CONCLUSIONS: There is a significant variation in disc-fovea angle. In this study, accounting for it does not significantly improve the diagnostic capabilities of cpRNFL in patients with POAG.

Sectoral analysis of the retinal nerve fiber layer thinning and its association with visual field loss in homonymous hemianopia caused by post-geniculate lesions using spectral-domain optical coherence tomography.

PURPOSE: To report a sectoral analysis of circumpapillary retinal nerve fiber layer (cpRNFL) thinning and its association with visual field loss using spectral-domain optical coherence tomography (SD-OCT) in patients with homonymous hemianopia following acquired post-geniculate visual pathway damage. PATIENTS AND METHODS: Seven patients with homonymous hemianopia due to unilateral acquired post-geniculate visual pathway lesions were studied. The average duration from the onset of brain lesions to the initial visit was 49.8 months. Forty-nine normal control subjects without visual field defects, as confirmed using a Humphrey visual field analyzer, were also enrolled. Measurement of the cpRNFL thickness was performed at the initial visit and 24 months using SD-OCT (RTVue-100® OCT). The cpRNFL thickness was divided into eight sectors (superior temporal: ST, temporal upper: TU, temporal lower: TI, inferior temporal: IT, inferior nasal: IN, nasal lower: NL, nasal upper: NU, superior nasal: SN). The eye on the same side as the occipital lobe lesions was defined as the ipsilateral eye, and the eye on the opposite side was defined as the contralateral eye. RESULTS: The average cpRNFL thickness in the homonymous hemianopic eyes was significantly reduced as compared with that seen in the normal controls, except for the ipsilateral eyes at the initial visit. Four of the eight sectors of the cpRNFL thickness in the homonymous hemianopic eyes were significantly reduced compared with that noted in the normal controls. In the ipsilateral eyes, the cpRNFL thickness in the ST, TU, TL, and IT sectors was significantly reduced at both the initial visit and 24 months. In the contralateral eyes, the cpRNFL thickness in the TU, TL, IT, and SN sectors was significantly reduced at both the initial visit and 24 months. The reduction of the quadrantic cpRNFL thickness significantly correlated with some of the visual field parameters, in accordance with the structure-function relationship. In the contralateral eyes, the T and I quadrant cpRNFL thickness correlated with the mean deviation and hemianopic field total deviation at 24 months. In the ipsilateral eyes, the S, T, and I quadrant cpRNFL thickness correlated with mean deviation. However, there were no correlations between the cpRNFL thickness and visual field parameters at the initial visit. CONCLUSIONS: A reduction of the cpRNFL thickness corresponding to the hemianopic visual field loss due to acquired post-geniculate visual pathway lesions was detected using SD-OCT, and the change was more evident at 24 months than at the initial visit. The latter finding suggests that this change is, at least partially, caused by transsynaptic retrograde degeneration.

Association between a relative afferent pupillary defect using pupillography and inner retinal atrophy in optic nerve disease.

PURPOSE: The aim of this study was to compare the asymmetrical light reflex of the control subjects and patients with optic nerve disease and to evaluate the relationships among the relative afferent pupillary defect (RAPD), visual acuity (VA), central critical fusion frequency (CFF), ganglion cell complex thickness (GCCT), and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) using spectral-domain optical coherence tomography. MATERIALS AND METHODS: Using a pupillography device, the RAPD scores from 15 patients with unilateral optic nerve disease and 35 control subjects were compared. The diagnostic accuracy of the RAPD amplitude and latency scores was compared using the area under the receiver operating characteristic curve. Thereafter, we assessed the relationships among the RAPD scores, VA, central CFF, GCCT, and cpRNFLT. RESULTS: The average RAPD amplitude score in patients with optic nerve disease was significantly higher than that of the control subjects (P<0.001). The average RAPD latency score in patients with optic nerve disease was significantly higher than that of the control subjects (P=0.001). The area under the receiver operating characteristic curve for the RAPD amplitude score was significantly higher than that for the latency score (P=0.010). The correlation coefficients for the RAPD amplitude and latency scores were 0.847 (P<0.001) and 0.874 (P<0.001) for VA, -0.868 (P<0.001) and -0.896 (P<0.001) for central CFF, -0.593 (P=0.020) and -0.540 (P=0.038) for GCCT, and -0.267 (P=0.337) and -0.228 (P=0.413) for cpRNFLT, respectively. CONCLUSION: Our results suggest that pupillography is useful for detecting optic nerve disease.

Topographical correlation between macular layer thickness and clockwise circumpapillary retinal nerve fiber layer sectors in patients with normal tension glaucoma.

PURPOSE: To define topographical areas of the macula in optical coherence tomography (OCT) scans by identifying regions in which macular retinal nerve fiber layer (mRNFL) and ganglion cell-inner plexiform layer (mGCL + IPL) thickness was highly correlated with clockwise circumpapillary RNFL (cpRNFL) thickness in patients with normal tension glaucoma (NTG). METHODS: This study included 101 eyes of 101 patients with mild or moderate NTG. CpRNFL, mRNFL, and mGCL + IPL thickness were assessed with spectral-domain OCT (3D OCT-2000). The region of interest (6 × 6 mm square) was centered on the fovea and layer thickness was measured at each point on a 10 × 10 grid. Spearman's rank correlation coefficient was determined between each temporal clockwise sector (7, 8, 9, 10, 11 o'clock) of the cpRNFL and each grid point in the mRNFL and mGCL + IPL. Grid points were defined as correlated to specific clockwise sectors when the correlation coefficient was more than 0.4. To validate the areas comprised by these points, they were superimposed on a swept-source OCT image (12 × 9 mm, EnView software, Topcon) showing the anatomical trajectory of nerve fiber defects. RESULTS: Macular areas with a high correlation coefficient (r ≥ 0.4, p < 0.05) to clockwise cpRNFL were identified. The number of grid points in the mRNFL and mGCL + IPL correlated to specific clockwise cpRNFL sectors was, respectively, 40 and 18 (7 o'clock), 41 and 22 (8), 33 and 44 (9), 39 and 39 (10), and 18 and 19 (11) (r = 0.40-0.79). Interestingly, the distribution of mRNFL sectors closely matched the RNFL defects in the OCT image, although the mGCL + IPL sectors differed and were closer to the fovea than the mRNFL sectors. CONCLUSION: The identification of these topographical macular areas, and the different layouts in the mRNFL and the mGCL + IPL, may increase the accuracy of clinical research on NTG.

Comparison of Kang's and Littmann's methods of correction for ocular magnification in circumpapillary retinal nerve fiber layer measurement.

PURPOSE: To assess and compare the accuracy of Kang's method for ocular magnification correction in circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurement with that of the currently used Littmann's method. METHODS: A total of 148 eyes of 148 healthy participants underwent cpRNFL measurement without correction and with correction by Littmann's method using spectral-domain optical coherence tomography. Correction of ocular magnification by Kang's method is based on the observed uncorrected cpRNFL thickness. The accuracy of Kang's method was compared with that of Littmann's method for magnification correction by using the Pearson product-moment correlation coefficient (r) and Bland-Altman analysis. RESULTS: A total of 132 eyes were assessed. The two methods used to correct the global cpRNFL thickness were strongly correlated (r = 0.940, P < 0.01), and the mean difference between the two methods was -0.4 µm, with 95% limits of agreement (LoA) of ±6 µm without systemic bias (P > 0.05). Although the cpRNFL thicknesses corrected with the two methods at quadrant and 12-o'clock sectors showed a strong correlation (r > 0.731, P < 0.01), high LoAs ranging from ±13.3 to ±27.9 and systemic biases were observed at nasal and inferior sectors. CONCLUSION: No difference was found between Kang's and Littmann's methods for correction of ocular magnification in global cpRNFL thickness measurement. However, with regard to magnification correction for sectoral cpRNFL thickness, further scrutiny of Kang's method is warranted, even in healthy participants, because of the high variability between Littmann's and Kang's methods.