cpRNFL Thickness Research Articles

Prognostic value of macular ganglion cell layer thickness for visual outcome in parasellar tumors

PurposeOptic nerve compression by mass lesions at the optic chiasm leads to loss of visual function which can be recovered after decompression surgery. In this study, we evaluated the prognostic ability of macular ganglion cell layer (mGCL) thickness measured with spectral-domain optical coherence tomography (SD-OCT) for predicting postoperative visual outcome of compressive optic neuropathy (CON) related to parasellar tumors. MethodsThis observational cohort study used data from the Department of Neurosurgery and Ophthalmology, Seoul National University Bundang Hospital between 2013 and 2018. Seventy-nine eyes from 79 patients with CON due to parasellar tumors who underwent surgery were included. Patients were divided into either a visual recovery group or a non-recovery group according to the degree of postoperative visual field (VF) impairment. SD-OCT scanning with automated segmentation was performed to measure the circumpapillary retinal nerve fiber layer (cpRNFL) and the mGCL thickness in the nine macular subfields as defined by the ETDRS and 8 × 8 posterior pole grid. Correlations between preoperative cpRNFL thickness, mGCL thickness and postoperative VF sensitivity were assessed. The prognostic ability of mGCL thickness for predicting visual recovery after surgical decompression in each ETDRS subfield and posterior pole grid quadrant was evaluated. ResultsThe central inferonasal and superonasal quadrant mGCL thicknesses measured by the 8 × 8 posterior pole grid showed the best predictability of postoperative visual outcome (AUROC = 0.963 and 0.953, respectively), which was superior to the prognostic power of the average cpRNFL. The central inferonasal quadrant mGCL thickness significantly correlated with the superotemporal quadrant VF sensitivity (R2 = 0.589). ConclusionsThe mGCL thickness in the central nasal quadrants measured by SD-OCT is an excellent predictor of visual recovery after chiasmal decompression.

Effect of fundus tracking on structure–function relationship in glaucoma

AimsTo investigate the effect of fundus tracking perimetry on structure–function relationship in glaucoma.MethodsPerimetric data were acquired with the Humphrey Field Analyzer (HFA) and the Compass fundus perimeter (CMP, equipped with...

Diagnostic utility of neuroretinal rim thickness, measured in clock-hour sectors with HD optical coherence tomography, in preperimetric glaucoma

We evaluated the usefulness of neuroretinal rim (NRR) thicknesses, measured in clock-hour sectors with Cirrus HD optical coherence tomography, for diagnosing preperimetric glaucoma (PPG). This prospective study included 39 eyes of 39 patients with PPG and 39 eyes of 39 controls that were matched to patients for age and refractive error. We measured the circumpapillary retinal nerve fiber layer (cpRNFL) thickness, macular ganglion cell-inner plexiform layer (GCIPL) thickness, and optic nerve head (ONH) parameters with optical coherence tomography. The clock-hour NRR thicknesses were derived from a 360° circumferential rim thickness curve. We analyzed the area under the receiver operating characteristics curve (AUROC), cutoff values, and sensitivities at specificities of 90% and 95%. The largest area under the receiver operating characteristics curves were observed for the NRR thickness at 6 o'clock (0.823), the inferior RNFL thickness (0.821), the average RNFL thickness (0.819), and the NRR thickness at 7 o'clock (0.818). The performance of the NRR thickness at 6 o'clock was comparable to the best performances of the cpRNFL, GCIPL, and ONH parameters (all p > 0.05). The ability of the clock-hour NRR thickness assessment to diagnose PPG was comparable to the diagnostic abilities of cpRNFL, GCIPL, and ONH parameters. The best indicator of PPG was the NRR thickness parameter that was at 6 o'clock. This finding could play a role in detecting early structural changes in PPG.

Improving the Structure–Function Relationship in Glaucomatous Visual Fields by Using a Deep Learning–Based Noise Reduction Approach

To investigate whether processing visual field (VF) measurements using a variational autoencoder (VAE) improves the structure-function relationship in glaucoma. Cross-sectional study. The training data consisted of 82 433 VF measurements from 16 836 eyes. The testing dataset consisted of 117 eyes of 75 patients with open-angle glaucoma. A VAE model to reconstruct the threshold of VF was developed using the training dataset. OCT and VF (Humphrey Field Analyzer 24-2, Swedish interactive threshold algorithm standard) measurements were carried out for all eyes in the testing dataset. Visual fields in the testing dataset then were reconstructed using the trained VAE. The structure-function relationship between the circumpapillary retinal nerve fiber layer (cpRNFL) thickness and VF sensitivity was investigated in each of twelve 30° segments of the optic disc (3 nasal sectors were merged). Similarly, the structure-function relationship was investigated using the VAE-reconstructed VF. Structure-function relationship. The corrected Akaike information criterion values with threshold were found to be smaller than the threshold reconstructed with the VAE (thresholdVAE) in 9 of 10 sectors. A significant relationship was found between threshold and cpRNFL thickness in 6 of 10 sectors, whereas it was significant in 9 of 10 sectors with thresholdVAE. Applying VAE to VF data results in an improved structure-function relationship.

Comparisons of photopic negative responses elicited by different conditions from glaucomatous eyes

To compare the clinical significance of the photopic negative response (PhNRs) elicited by different stimuli from glaucomatous eyes. Single-center observational study METHOD: Eighty-four eyes of 84 patients with open angle glaucoma (OAG) and 40 eyes of 40 normal subjects were studied. Cone electroretinograms (ERGs) were elicited by white stimuli on a white background (W/W) or red stimuli on a blue background (R/B). The luminance of the stimuli was 0.5, 1.0, 2.0 or 3.0 cd-s/m2, and of the background light was 10 cd/m2. The first and second troughs of the ERGs that appeared following the b-wave were designated as PhNR1 and PhNR2, respectively. The thickness of the circumpapillary retinal nerve fiber layer (cpRNFL) was measured by spectral-domain optical coherence tomography. The mean deviation (MD) was determined by standard automated perimetry. The area under the receiver operating characteristic curves (AUCs) was created to determine the diagnostic ability of the PhNRs elicited by the different stimulus conditions. The correlation coefficients of the amplitudes of the PhNR1 elicited by W/W stimuli to the MDs and cpRNFL thickness were generally stronger, and the regression lines steeper than for the amplitudes of the PhNR1 elicited by R/B stimuli. In contrast, the correlation coefficients of the amplitudes of the PhNR2 elicited by R/B stimuli to the MDs and cpRNFL thickness were generally stronger, and the regression lines were steeper than the amplitudes of the PhNR2 elicited by W/W stimuli. With both types of stimuli, the slopes of the regression lines became steeper when the ERG recorded with higher stimulus intensities. The AUCs were significantly larger for the PhNR2 elicited by the R/B stimuli at 3.0 cd-s/m2 than for PhNR1 and PhNR2 elicited by W/W stimuli at the same intensity when the PhNRs were used for diagnosing advanced glaucoma. The PhNR1 and PhNR2 elicited by the W/W and R/B stimuli are suitable measures to assess the function of the RGCs in eyes with OAG. The PhNR2 elicited by R/B stimuli at higher stimulus intensities is most effective in detecting functional and structural changes of the RGCs with the highest diagnostic capacity in discriminating advanced glaucoma.

Early Glaucoma Discrimination Index.

ABSTRACTPurposeTo develop a new structural algorithm derived from optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness and asymmetry and validate it as a discriminate among normal, suspect, and early primary open-angle glaucoma (POAG).Study designA case-controlled observational clinical study.Materials and methodsIn total, 150 subjects (299 eyes) were selected, 61 normal, 46 suspect, and 43 early glaucoma, from Al-Azhar University Hospitals. They were in fifth decade and free from any ocular or systemic diseases affecting the retinal nerve fiber layer. They were investigated by two consecutive perimetry (1 month apart), and three scans of circumpapillary retinal nerve fiber layer (cpRNFL) by using Nidek spectral domain (SD)-OCT 3000 Lite. The cpRNFL thickness (cpRNFLT) and inter-eye asymmetry parameters were analyzed among the three groups. Then some selected parameters were selected and analyzed using a binary logistic regression analysis for developing the new algorithm. The new algorithm was tested for the best fitting, accuracy, and diagnostic ability among the three groups and was validated in the suspect group.ResultsThe new algorithm model [early glaucoma discrimination index (EGDI)] works well with only four variables; whole cpRNFLT, inferior quadrant cpRNFLT, inferotemporal clock hour (CH) cpRNFLT, and absolute inter-eye inferior quadrants asymmetry. The highest area under the curve (AUC) obtained from the EGDI among the three groups was 0.854. The validation analysis in the suspect group revealed a higher diagnostic ability in discrimination of early glaucoma with AUC of 0.989 (0.976–1.003).ConclusionThe EGDI showed better diagnostic ability for diagnosis of glaucoma in the pre-perimetric stage. The new OCT algorithm is simple and can be run in any SD-OCT device without dependence on normative data.How to cite this articleSafwat H, Nassar E, Rashwan A. Early Glaucoma Discrimination Index. J Curr Glaucoma Pract 2020;14(1):16–24.

Forecasting Retinal Nerve Fiber Layer Thickness from Multimodal Temporal Data Incorporating OCT Volumes

The purpose of this study was to develop a machine learning model to forecast future circumpapillary retinal nerve fiber layer (cpRNFL) thickness in eyes of healthy, glaucoma suspect, and glaucoma participants from multimodal temporal data. Retrospective analysis of a longitudinal clinical cohort. Longitudinal clinical cohort of healthy, glaucoma suspect, and glaucoma participants. The forecasting models used multimodal patient information including clinical (age and intraocular pressure), structural (cpRNFL thickness derived from scans as well as deep learning-derived OCT image features), and functional (visual field test parameters) data and the intervisit interval for prediction of cpRNFL thickness at the next visit. Four models were developed based on the number of visits used (n = 1 to 4). Longitudinal data from 1089 participants (mean observation period, 3.65±1.73 years) was used with 80% of the cohort for the development of the models. The results of our models were compared with those of a commonly adopted linear regression model, which we refer to here as linear trend-based estimation (LTBE). The mean absolute difference and Pearson's correlation coefficient between the true and forecasted values of the cpRNFL in the healthy, glaucoma suspect, and glaucoma patients. The best forecasting model of cpRNFL was obtained using 3 visits and incorporated deep learning-derived OCT image features. The mean error was 1.10±0.60 μm, 1.79±1.73 μm, and 1.87±1.85 μm in eyes of healthy, glaucoma suspect, and glaucoma participants, respectively. Our method significantly outperformed the LTBE model for glaucoma suspect and glaucoma participants (P < 0.001), which showed a mean error of 1.55±1.16 μm, 2.4±2.67 μm, and 3.02±3.06 μm in the 3 groups, respectively. The Pearson's correlation coefficient between the forecasted value and the measured thickness was ρ = 0.96 (P < 0.01), ρ = 0.95 (P < 0.01), and ρ = 0.96 (P < 0.01) for the 3 groups, respectively. The performance of the proposed forecasting model for cpRNFL is consistent across glaucoma suspect and glaucoma patients, which implies the robustness of the developed model against the disease state. These forecasted values may be useful to personalize patient care by determining the most appropriate intervisit schedule for timely interventions.

Vessel density and retinal nerve fibre layer thickness following acute primary angle closure

BackgroundTo evaluate changes in circumpapillary vessel density (cpVD) and retinal nerve fibre layer (cpRNFL) thickness after a successfully treated episode of acute primary angle closure (APAC) and to identify factors...

The correlation between the thickness of the inner macular layers and the mean deviation of the visual field in children with primary congenital glaucoma

Abstract Purpose To analyse the association between the thickness of the circumpapillary retinal nerve fibre layer (cpRNFL) and the thickness of the inner macular layers with the mean deviation of the visual field (MD) in children with primary congenital glaucoma (PCG). Materials and Methods A total of 41 children with PGC were included in the study. They all had a complete ophthalmological examination, including visual acuity, intraocular pressure, funduscopy, Octopus™ visual field, as well as circumpapillar and macular spectral domain optical coherence tomography (SD-OCT). SD-OCT with automated segmentation was used to measure the thicknesses and volumes of the macular retinal nerve fibre layer (mRNFL), ganglion cell layer (GCL), and inner plexiform layer. Results The mean age was 11.2 ± 3.86 years, and the mean MD was 8.85 ± 6.76 dB. The visual field was classified as normal in 46% of the patients, and 20% of the patients had a concentrical restriction of the visual field. A positive correlation was found between between the cup-to-disc ratio and the MD, r = 0.51 (P = 0.004). The correlation between the MD and the cpRNFL was r = −0.63 (P Conclusions Inner macular layers thickness and cpRNFL thickness show a good correlation with the mean deviation of the visual field in children with primary congenital glaucoma.

Qualitative evaluation of neuroretinal rim and retinal nerve fibre layer on optical coherence tomography to detect glaucomatous damage

PurposeTo understand the added value of Bruch’s membrane opening-minimum rim width (BMO-MRW) measurements to conventional circumpapillary retinal nerve fibre layer (cpRNFL) thickness measurements on optical coherence tomography (OCT) imaging for...

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

AimsTo 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...

Investigating the structure-function relationship using Goldmann V standard automated perimetry where glaucomatous damage is advanced.

To investigate if the structure-function relationship between circumpapillary retinal nerve fibre layer (cpRNFL) thickness and visual field (VF) thresholds is stronger when using the Goldmann V target rather than the Goldman III target where glaucomatous damage is advanced. Optical coherence tomography (OCT) and VF (Humphrey Field Analyzer 24-2 or 30-2) measurements with Goldmann III (SITA standard) and V (full-threshold) targets were carried out in 51 eyes of 51 patients with primary open angle glaucoma. The relationship between cpRNFL thicknesses in supero- and infero-temporal sectors, and VF sensitivity with the Goldmann III or V target was investigated. Visual field sensitivities (dB) both with the Goldmann III target and Goldmann V target showed a floor effect in the structure-function relationship against cpRNFL thickness, at approximately 60μm. There was no significant relationship between visual field sensitivity measured with the Goldmann V target (dB scale: p=0.12, 1/Lambert scale: p=0.40; linear mixed models) and cpRNFL thickness, when corresponding visual field sensitivity, measured with the Goldmann III target, was <20dB. There was no improvement in the structure-function relationship using the Goldmann V target (full-threshold), compared to using the Goldmann III target (SITA standard), where glaucomatous damage was advanced.

Structure-function Relationship in Advanced Glaucoma After Reaching the RNFL Floor

To investigate the relationship between the central visual field (VF) and macular parameters obtained from spectral-domain optical coherence tomography (SD-OCT) in patients with advanced glaucoma that reached the cpRNFL thickness measurement floor and to determine whether the structural changes measured by SD-OCT are useful for estimating the functional status in these patients. A total of 68 eyes from 68 patients with advanced glaucoma were included. Only eyes having an average cpRNFL thickness of ≤57 μm that reached the measurement floor were included. Macular imaging using Cirrus SD-OCT and 10-2 Humphrey VF was performed. The VF mean deviation was converted to a linear scale using unlogged 1/Lambert values. The relationships between the central VF and various macular parameters were determined. Patients had a mean VF mean deviation of -20.69 dB and an average cpRNFL thickness of 51.76±3.61 μm. Correlations between the VF and all cpRNFL thickness parameters were not significant. However, significant correlations were found between the central VF and superonasal macular ganglion cell-inner plexiform layer thickness (r=0.334; P=0.003), inner nasal macular thickness (r=0.301; P=0.013), and outer nasal macular thickness (r=0.331; P=0.007). Even after the cpRNFL had reached the measurement floor, several macular parameters showed a statistically significant relationship with functional status in VF. In particular, the assessment of structural changes in the nasal macular region may be important in determining the central VF in advanced glaucoma.

Circumpapillary and macular vessel density assessment by optical coherence tomography angiography in eyes with temporal hemianopia from chiasmal compression. Correlation with retinal neural and visual field loss.

To compare the circumpapillary and macular vessel density (cpVD/mVD) of eyes with temporal visual field (VF) defect and band atrophy (BA) of the optic nerve and normal controls using OCTA and to verify the association of VD parameters with circumpapillary retinal nerve fibre layer (cpRNFL) thickness, macular ganglion cell complex (mGCC) thickness and VF loss. Thirty-three eyes of 26 patients with BA and 42 eyes of 22 age-matched normal controls underwent OCT + OCTA scanning. cpVD and cpRNFL were expressed as average and sector measurements. mVD and mGCC were calculated as averages and in quadrants and hemiretinas. VF loss was estimated using the 24-2 and the 10-2 protocols. Generalized estimated equation models were used for comparisons and area under the receiver operating characteristics (AROC) were calculated. Compared with controls, BA eyes displayed smaller average cpVD and mVD values (p < 0.001 and AROC = 0.91 for both). Sectorial measurements were also reduced, especially the nasotemporal sector average cpVD (p < 0.001 and AROC = 0.96) and the nasal retina mVD measurements (p < 0.001 and AROC = 0.93). cpVD and mVD correlated strongly with corresponding cpRNFL and mGCC thickness measurements in affected regions (r range: 0.67-0.78 and 0.56-0.76, respectively). Similarly, cpVD and mVD parameters correlated significantly with corresponding VF loss (r range: 0.45-0.68). cpVD and mVD are significantly reduced in BA eyes compared with controls and are strongly correlated with retinal neural and VF loss. cpVD and mVD reduction on OCTA could serve as a surrogate for retinal neural loss in compressive optic neuropathy and might be useful in its management.

Correlación entre el grosor de las capas internas de la retina y el defecto medio del campo visual en pacientes con glaucoma congénito primario

PurposeTo analyse the association between the thickness of the circumpapillary retinal nerve fibre layer (cpRNFL) and the thickness of the inner macular layers with the mean deviation of the visual field (MD) in children with primary congenital glaucoma (PCG). Material and methodsA total of 41 children with PGC were included in the study. They all had a complete ophthalmological examination, including visual acuity, intraocular pressure, funduscopy, Octopus™ visual field, as well as circumpapillar and macular spectral domain optical coherence tomography (SD-OCT). SD-OCT with automated segmentation was used to measure the thicknesses and volumes of the macular retinal nerve fibre layer (mRNFL), ganglion cell layer (GCL), and inner plexiform layer. ResultsThe mean age was 11.2±3.86 years, and the mean MD was 8.85±6.76dB. The visual field was classified as normal in 46% of the patients, and 20% of the patients had a concentrical restriction of the visual field. A positive correlation was found between between the cup-to-disc ratio and the MD, r=0.51 (P=.004). The correlation between the MD and the cpRNFL was r=-0.63 (P<.001), and r=–0.69 (P<.001) with the GCL. ConclusionsInner macular layers thickness and cpRNFL thickness show a good correlation with the mean deviation of the visual field in children with primary congenital glaucoma.

Associations between changes in radial peripapillary capillaries and occurrence of disc hemorrhage in normal-tension glaucoma.

In order to clarify the association between peripapillary vascular changes and disc hemorrhage (DH) occurrences over time, we analyzed the density of radial peripapillary capillary (RPC) and clinical parameters during follow-up periods in patients with normal-tension glaucoma (NTG). Seventy-seven eyes of 77 NTG patients were subjected to analysis. We selected patients who had an initial optical coherence tomography angiography (OCTA) scan in 2015 and who had another OCTA scan in 2018 with both OCTA scans showing good-quality images. We investigated the relationships between DH occurrence and each of the following parameters: RPC density, circumpapillary retinal nerve fiber layer (cpRNFL) thickness slope and total deviation (TD) slope. In the period between the initial and final OCTA, we categorized the patients into 53 sides with DH (DH group) and 101 sides without DH (non-DH group). The ΔRPC density of sides with DH was significantly greater than that of sides without DH (DH, - 4.42 ± 6.43%; without DH, - 2.48 ± 5.29%; p = 0.0469). The cpRNFL thickness slope of sides with DH was significantly faster than that of sides without DH (DH, - 2.85 ± 3.17; without DH, - 0.74 ± 2.46μm/y; p < 0.0001). The TD slope of sides with DH was significantly faster than that of sides without DH (DH, - 0.50 ± 0.77; without DH, - 0.22 ± 0.53dB/y; p = 0.0163). As DH occurrence increased, the RPC density significantly decreased (r = -0.255, p = 0.0014). Stepwise multiple regression analysis to identify factors influencing RPC changes showed that frequency of DH (β = - 0.224, p = 0.008) and central corneal thickness (β = - 0.220, p = 0.009) were significantly associated with RPC changes. DH occurrence may prompt the structural and vascular deterioration of NTG.

Factors Related to Superior and Inferior Hemifield Defects in Primary Open-Angle Glaucoma.

Purpose We aimed to investigate factors related to superior and inferior hemifield defects in primary open-angle glaucoma (POAG). Methods Sixty-seven subjects with newly diagnosed, untreated POAG underwent optical coherence tomography (OCT) of the disc area, macular ganglion cell complex (mGCC), and circumpapillary retinal nerve fiber layer (cpRNFL) thickness within 6 months of the visual field (VF) test. Based on the VF and OCT results, 40 subjects had a superior and 27 an inferior hemifield defect. Clinical data including visual acuity, refractive error, disc hemorrhage, VF indexes, and medical history were recorded. Results Average mGCC thickness corresponding to the defective hemifields was thinner in the superior VF defect group than in the inferior VF defect group (P=0.003). Average total deviation (TD) was comparable between the two groups. However, the superior VF defect group had a higher prevalence of defects (P=0.001) and lower TD (P=0.002) within central 5 degrees of VF than the inferior VF defect group. In multivariate regression analyses, the temporal-lower and inferior-temporal cpRNFL thicknesses were significant contributing factors to the inferior mGCC thickness in the superior VF defect group. In the inferior VF defect group, the disc area, family history of glaucoma, and temporal-upper cpRNFL thickness contributed to the superior mGCC thickness. Conclusion The inferior mGCC thickness corresponding to the superior hemifield defect group was significantly thinner than the superior mGCC thickness corresponding to the inferior hemifield defect group. The factors related to the reduction of the corresponding mGCC thickness may differ between superior VF defect and inferior VF defect groups.

Measurement Floors and Dynamic Ranges of OCT and OCT Angiography in Glaucoma

To determine if OCT angiography (OCTA)-derived vessel density measurements can extend the available dynamic range for detecting glaucoma compared with spectral-domain (SD) OCT-derived thickness measurements. Observational, cross-sectional study. A total of 509 eyes from 38 healthy participants, 63 glaucoma suspects, and 193 glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study. Relative vessel density and tissue thickness measurement floors of perifoveal vessel density (pfVD), circumpapillary capillary density (cpCD), circumpapillary retinal nerve fiber (cpRNFL) thickness, ganglion cell complex (GCC) thickness, and visual field (VF) mean deviation (MD) were investigated and compared with a previously reported linear change point model (CPM) and locally weighted scatterplot smoothing curves. Estimated vessel density and tissue thickness measurement floors and corresponding dynamic ranges. Visual field MD ranged from -30.1 to 2.8 decibels (dB). No measurement floor was found for pfVD, which continued to decrease constantly until very advanced disease. A true floor (i.e., slope of approximately 0 after observed CPM change point) was detected for cpRNFL thickness only. The post-CPM estimated floors were 49.5±2.6 μm for cpRNFL thickness, 70.7±1.0 μm for GCC thickness, and 31.2±1.1% for cpCD. Perifoveal vessel density reached the post-CPM estimated floor later in the disease (VF MD, -25.8±3.8 dB) than cpCD (VF MD, -19.3±2.4 dB), cpRNFL thickness (VF MD, -17.5±3.3 dB), and GCC thickness (VF MD, -13.9±1.8 dB; P<0.001). The number of available measurement steps from normal values to the CPM estimated floor was greatest for cpRNFL thickness (8.9), followed by GCC thickness (7.4), cpCD (4.5), and pfVD (3.8). In late-stage glaucoma, particularly when VF MD is worse than -14 dB, OCTA-measured pfVD is a promising tool for monitoring progression because it does not have a detectable measurement floor. However, the number of steps within the dynamic range of a parameter also needs to be considered. Although thickness parameters reached the floor earlier than OCTA-measured pfVD, there are more such steps with thickness than OCTA parameters.

Inner macular layer thickness by spectral domain optical coherence tomography in children and adults: a hospital-based study

PurposeTo establish the normative ranges of macular ganglion cell layer (mGCL) and macular inner plexiform layer (mIPL) thickness using Spectralis spectral domain optical coherence tomography (SD-OCT) (Heidelberg Engineering, Inc., Heidelberg,...

Diagnostic ability of macular ganglion cell asymmetry in Preperimetric Glaucoma

BackgroundTo evaluate the diagnostic ability of macular ganglion cell asymmetry to diagnose preperimetric glaucoma (PPG), using Cirrus spectral domain optical coherence tomography (OCT).MethodsThis prospective study included 67 eyes of 67 patients with PPG and 67 eyes of 67 age- and refractive error-matched controls. We measured circumpapillary RNFL (cpRNFL) thickness, macular ganglion cell-inner plexiform layer (GCIPL) thickness and optic nerve head (ONH) parameters using OCT. Macular ganglion cell asymmetries were expressed as absolute difference and ratios between inferior hemisphere and superior hemisphere, inferotemporal (IT) and superotemporal (ST), IT and superonasal (SN), IT and inferonasal (IN), ST and IN as well as temporal and nasal. An asymmetry index was assigned by taking the absolute value of log10 of the ratio. The area under the receiver operating characteristics curve (AUROC), partial AUROC (pAUROC) ≥ specificities 90 and 95%, cutoff values and sensitivities at specificities 90 and 95% was analyzed.ResultsParameters with largest AUROCs were IT GCIPL thickness (0.784), average RNFL thickness (0.767), and average C/D (0.746). For macular asymmetry parameters, log IT/SN index had the largest AUROC (0.734), followed by log IT/IN index (0.725), and absolute difference of IT−SN GCIPL thickness (0.715). Performance was comparable between the best measures of asymmetry analysis (log IT/SN index) and those of cpRNFL, GCIPL, and ONH parameters (all P > 0.05). The IT/SN asymmetry index not only had the largest pAUROC based on the pAUROCs ≥90 and 95% specificity (0.044 and 0.019) but also had the highest diagnostic sensitivity at 90 and 95% specificities (52.2 and 46.3%).ConclusionsGCIPL asymmetry measurements have diagnostic ability comparable to cpRNFL, GCIPL, and ONH analysis for PPG. The best macular ganglion cell asymmetry parameter was IT/SN asymmetry index, which could be a new parameter to detect early structural changes in PPG.