Membrane Opening Minimum Rim Width Research Articles

Analysis of retinal nerve layers in idiopathic, LRRK2-associated Parkinson's disease and unaffected carriers of G2019S mutation

IntroductionIn both prodromal and early symptomatic stages of idiopathic PD (iPD) peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell layer (mGCL) thinning have been identified. Here we assessed whether these alterations can also be detected in symptomatic and presymptomatic stages of LRRK2-PD. Methods218 eyes belonging to 20 iPD, 19 LRRK2-PD (L2PD), 24 LRRK2 non-manifesting carriers (L2NMC), and 46 controls (HCs). pRNFL, mGCL thickness (squares), and Bruch's membrane opening minimum rim width were evaluated by SD-OCT. In L2NMC, 123I-ioflupane SPECT (DaT-SPECT) with semi-quantitative analysis was carried out. ResultsCompared to HCs, iPD patients showed significant thinning of the temporal (BMO-MRW and pRNFL), superior-temporal (BMO-MRW), inferior-temporal (BMO-MRW), superior-nasal (BMO-MRW) and central sectors (BMO-MRW) (p < 0.05), as well as in five mGCL sectors (p < 0.05). No significant differences were found between the L2PD or L2NMC and HCs. BMO-MRW thickness in its temporal-superior, superior-nasal and middle sectors was influenced by disease duration (p < 0.05) and mGCL thickness in sectors TS1, TS2, TS3, NS1 and NS3 was influenced by UPDRSIII and age (p < 0.05). ConclusionLRRK2-PD is distinguished from iPD by absent or less retinal nerve involvement, both in clinical and preclinical stages.

Early Detection of Primary Open Angle, Angle Closure, and Normal Tension Glaucoma in an Asian Population Using Optical Coherence Tomography.

Spectral-domain optical coherence tomography (SD-OCT) facilitates early glaucoma detection in the Chinese population in Taiwan. The best parameters for primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG), normal tension glaucoma (NTG), and suspected glaucoma (GS) detection are temporal inferior Bruch's membrane opening-minimum rim width (BMO-MRW), inner temporal macular ganglion cell layer (mGCL), temporal superior Circumpapillary retinal nerve fiber layer (cpRNFL), and mean global BMO-MRW, respectively. We investigated the diagnostic capability of SD-OCT for different types of early glaucoma among the Chinese population in Taiwan. One eye each was assessed from 113 individuals with healthy eyes, 125 individuals with suspected glaucoma (GS), and 156 patients with early glaucoma (POAG, 87; PACG, 50; and NTG, 19). Circumpapillary (cp) RNFL thickness (global and sectoral), BMO-MRW, and macular parameters, including the macular RNFL (mRNFL), mGCL, and macular inner plexiform layer (mIPL), were assessed using SD-OCT. The areas under receiver operator characteristic curves (AUCs) were calculated to evaluate the diagnostic capacity of the parameters to differentiate between healthy and early glaucomatous eyes. The parameters most suitable for detecting early POAG, PACG, NTG, and GS were temporal inferior BMO-MRW (AUC, 0.847), inner temporal mGCL (AUC, 0.770), temporal superior cpRNFL (AUC, 0.861), and mean global BMO-MRW (AUC, 0.768), respectively. Among the macular parameters, the mGCL exhibited the highest diagnostic capacity. The diagnostic capacity of the mGCL was lower than that of cpRNFL and BMO-MRW for POAG and NTG but not PACG. After adjusting for confounding variables in multivariable analysis, the AUC was determined to be 0.935 for POAG and 0.787 for GS. SD-OCT facilitates the detection of early POAG, PACG, and NTG. Using a combination of cpRNFL, BMO-MRW, and macular parameters may enhance their diagnostic capacities. Further studies are necessary to validate these findings.

Diagnostic evaluation of optical coherence tomography parameters in normal, preperimetric and perimetric glaucoma patients.

To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography (OCT) in normal, preperimetric glaucoma (PPG) and perimetric glaucoma (PG) patients. This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG (51 eyes), PG (46 eyes), and normal controls (30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) to assess the optic nerve head and ganglion cell layer (GCL) thickness in the macula. RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity (>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves (AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW (AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively). While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.

Racial Differences in Detection of Glaucoma Using Retinal Nerve Fiber Layer Thickness and Bruch Membrane Opening Minimum Rim Width

To compare the sensitivities and specificities of the retinal nerve fiber layer thickness (RNFLT) and Bruch membrane opening minimum rim width (BMO-MRW) reference database-based criteria for detection of glaucoma in individuals of European descent (ED) and individuals of African descent (AD). Comparative diagnostic analysis by race METHODS: 382 eyes of 255 glaucoma patients (ED=170, AD=85) and 94 eyes of 50 healthy individuals (ED=30, AD=20) with global and sectoral RNFLT and BMO-MRW measured with Spectralis optical coherence tomography (OCT) were included. Six diagnostic criteria were evaluated: global measurement below the 5th or 1st percentile, ≥1 of the 6 sector measurements below the 5th or 1st percentile, and superotemporal (ST) and/or inferotemporal (IT) measurement below the 5th or 1st percentile. The sensitivities and specificities of these measurements for detection of glaucoma were compared using bootstrapping methods. ST and/or IT RNFLT below the 5th percentile has the best performance for detection of glaucoma among RNFLT classifications with a sensitivity (95% CI) of 89.5% (86.1, 92.5) and specificity of 87.2% (77.8, 95.1). In AD individuals, sensitivities of ST and IT RNFLT and BMO-MRW measurements below the 5th percentile criteria were lower than in ED individuals (RNFLT: 83.7% vs 92.5%, and BMO-MRW: 72.1% vs 88.5%, respectively), as well as specificities (AD RNFLT: 73.7% and BMO-MRW: 89.5% vs ED RNFLT: 96.4% and BMO-MRW: 98.2%, respectively). RNFLT and BMO-MRW had consistently lower diagnostic performance in AD individuals compared with ED individuals. BMO-MRW criteria might fail to detect as many as one-third of eyes with glaucoma, specifically in AD individuals. With the current reference database, RNFLT, and especially BMO-MRW, criteria are not adequate for diagnosing glaucoma in AD individuals.

Changes of Optical Coherence Tomography Parameters after Cataract Surgery in Primary Open-Angle Glaucoma Eyes.

To investigate the impact of uncomplicated cataract surgery on the measurement of Bruch's membrane opening-minimum rim width (BMO-MRW) and retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT) in primary open-angle glaucoma (POAG) patients. This retrospective study included 63 eyes of 63 patients, including 32 POAG eyes and 31 normal eyes who underwent uneventful cataract surgery and follow-up for at least 6 months. Using SD-OCT, BMO-MRW and RNFLT were measured preoperatively and postoperatively at 6 months. Paired t-test was used to compare intraocular pressure (IOP), BMO-MRW, RNFLT, and image quality before and after surgery. These parameters and their changes were compared between POAG and normal groups. Univariate and multivariate linear regression analyses were performed to determine the factors associated with the postoperative change (Δ) in RNFLT and BMO-MRW. BMO-MRW and RNFLT were significantly increased and IOP was decreased after phacoemulsification in both groups (p < 0.001, respectively). The ΔRNFLT was significantly greater in POAG eyes compared with the normal eyes (p < 0.001). The ΔRNFLT was associated with the postoperative IOP reduction and glaucoma diagnosis (p < 0.001 and p = 0.001, respectively). In the normal group, only the ΔIOP had a significant influence on the ΔRNFLT (p = 0.003), but in the POAG group, not only the ΔIOP (p = 0.044) but also preoperative visual field mean deviation (p = 0.029) showed a significant influence. The ΔBMO-MRW showed no difference between POAG and normal eyes. The postoperative increase of RNFLT was significantly greater in the POAG group, and the postoperative increase of RNFLT was associated with the preoperative visual field mean deviation and ΔIOP in POAG eyes and with the ΔIOP in normal eyes. Our results imply that RNFLT is more affected than BMO-MRW in POAG eyes compared to normal eyes by cataract surgery.

Combined Model of OCT Angiography and Structural OCT Parameters to Predict Paracentral Visual Field Loss in Primary Open-Angle Glaucoma

To assess a model combining OCT angiography (OCTA) and OCT parameters to predict the severity of paracentral visual field (VF) loss in primary open-angle glaucoma (POAG). Cross-sectional study. Forty-four patients with POAG and 42 control subjects underwent OCTA and OCT imaging with a swept-source OCT device. The circumpapillary microvasculature was quantified for vessel density (cpVD) and flow (cpFlow) after delineation of Bruch's membrane opening and removal of large vessels. Retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured from structural OCT. Paracentral total deviation (PaTD) was defined as the average of the total deviation values within the central 10 degrees on Humphrey VF testing (24-2) for upper and lower hemifields. The OCT and OCTA parameters were measured in the affected hemisphere corresponding to the hemifield with lower PaTD for POAG patients. Models were created to predict affected PaTD based on RNFLT alone; RNFLT and BMO-MRW; OCTA alone; or RNFLT, BMO-MRW and OCTA parameters. The models were compared using coefficient of determination (r2) and Bayesian information criterion (BIC) score. Bayesian information criterion decrease of ≥6 indicates strong evidence for model improvement. Performance of models containing OCT and OCTA parameters in predicting PaTD. Patients with POAG and controls were similar in age and sex (65.9 ± 9.5 years and 38.4% male overall, P ≥ 0.56 for both). Average RNFLT, minimum RNFLT, average BMO-MRW, minimum BMO-MRW, cpVD, and cpFlow were all significantly lower (all P < 0.001) in the affected hemisphere in patients with POAG than in controls. In patients with POAG, the average mean deviation was -4.33 ± 3.25 dB; the PaTD of the affected hemifield averaged -4.55 ± 5.26 dB and correlated significantly with both OCTA and structural OCT parameters (r ≥ 0.43, P ≤ 0.004 for all). The model containing RNFLT, BMO-MRW, and OCTA parameters was superior in predicting affected PaTD (r2= 0.47, BIC= 290.7), with higher r2 and lower BIC compared with all 3 other models. A combined model of OCTA and structural OCT parameters can predict the severity of paracentral VF loss of the affected hemifield, supporting clinical utility of OCTA in patients with POAG with paracentral VF loss. Proprietary or commercial disclosure may be found after the references.

Comparison of retinal nerve fiber layer thickness and Bruch’s membrane opening minimum rim width thinning rate in open-angle glaucoma

This study aimed to compare the rate of thinning between retinal nerve fiber layer thickness (RNFLT) and Bruch’s membrane opening minimum rim width (BMO-MRW) in open-angle glaucoma (OAG) according to glaucoma severity. We retrospectively reviewed subjects with a total of 111 eyes with OAG that had undergone optical coherence tomography more than four times during more than 3 years of follow-up. The subjects were divided into three groups based on the mean deviation (MD) of the baseline visual field test: high MD (MD > − 2 dB), medium MD (− 2 dB ≥ MD > − 6 dB), and low MD (− 6 dB ≥ MD > − 12 dB) groups. A linear mixed model was employed to compare the rate of thinning between RNFLT and BMO-MRW among the three groups. The rate of RNFLT thinning was fastest in the inferotemporal sector in all three groups. The rate of BMO-MRW thinning was fastest in the inferotemporal sector of the high MD group and the superotemporal sector of the other two groups. Among the three groups, the rate of RNFLT thinning was not significantly different in the global sector and all sectors except the nasal sector. The rate of BMO-MRW thinning in the inferotemporal sector showed no significant difference, but that in the superotemporal sector was faster in the medium MD and low MD groups than in the high MD group. The fastest rate of RNFLT thinning was consistently observed in the inferotemporal sector, but BMO-MRW showed a change in the fastest thinning sector from inferotemporal to superotemporal, with increasing severity in early to moderate OAG. The difference in the changes in the two parameters may help understand the pathogenesis of glaucoma and predict its progression.

Comparison of Vascular Density and Structural Patterns Between Primary Open Angle Glaucoma and Primary Angle Closure Glaucoma.

To compare the pattern of vascular density and structural damage in primary open angle glaucoma (POAG) with primary angle closure glaucoma (PACG) using optical coherence tomography (OCT) and OCT angiography (OCTA) in the optic nerve head, circumpapillary, and macular regions, respectively. One hundred thirty-one eyes of 82 patients (53 eyes with PACG and 78 eyes with POAG) were enrolled in this study. The patients underwent complete ophthalmic examination, Bruch membrane opening minimum rim width, circumpapillay retinal nerve fiber layer (cpRNFL), and macular ganglion cell complex (GCC) measurements and vascular density determination of the peripapillary and macular area with OCT and OCTA. A linear mixed model was used for the statistical analysis. There was no significant difference between the 2 groups in terms of age ( P =0.94) and visual field mean deviation ( P =0.78). Female-to-male ratio was higher in PACG patients than the POAG group ( P =0.02), and AL was shorter in PACG eyes ( P <0.001). cpRNFL and GCC were not different between the 2 groups (all P values>0.05, except for nasal segment cpRNFL). Vessel densities in the peripapillary and macular areas were comparable between the 2 groups (all P values>0.05). Although Bruch membrane opening minimum rim width was thicker in PACG eyes on univariate analysis, the multivariable analysis showed no significant difference between the 2 groups ( P >0.05). PACG and POAG eyes with similar visual field damages have comparable structural damage patterns in the peripapillary and inner macular thickness and vessel density measurements.

Increase in Bruch’s membrane opening minimum rim width with age in healthy children: the Hong Kong Children Eye Study

Background/aimsTo identify normative values and determinants for Bruch’s membrane opening (BMO) and the minimum rim width of BMO (BMO-MRW) among healthy children.MethodsA population-based cross-sectional study from the Hong Kong Children...

Diagnostic Performance of Optical Coherence Tomography for Pseudoexfoliation Glaucoma.

Lamina cribrosa (LC) thickness and LC curvature index (LCCI) had comparable diagnostic performances with retinal nerve fiber layer (RNFL) thickness in distinguishing eyes with pseudoexfoliation glaucoma (PXG) from those with pseudoexfoliation syndrome (PXS). Bruch's membrane opening-minimum rim width (BMO-MRW) showed the lowest diagnostic performance among all geometric parameters derived from optical coherence tomography (OCT) scans we evaluated. The aim was to compare the diagnostic performance of different geometric parameters derived from OCT scans (RNFL thickness, LC thickness, LCCI, and BMO-MRW) for distinguishing eyes with PXG from PXS and healthy eyes. Fifty-five eyes of 55 patients with PXG, 55 eyes of 55 patients with PXS, and 50 healthy subjects were enrolled in this cross-sectional study. The areas under the receiver operating characteristic curves (AUCs) of RNFL thickness, LC thickness, LCCI and BMO-MRW were calculated and compared. In discriminating between eyes with PXG from those with PXS, LC thickness [0.930; 95% confidence interval (CI): 0.883-0.978] and global RNFL thickness (0.974; 95% CI: 0.947-0.992) presented comparable AUCs ( P =0.244). In distinguishing subjects with PXG from healthy controls, both LC thickness (0.972; 95% CI: 0.948-0.997) and LCCI (0.983; 95% CI: 0.968-0.998) had comparable AUCs with global RNFL thickness (0.988; 95% CI: 0.974-1.000) ( P =0.094 and 0.239, respectively). Global BMO-MRW had lower AUCs than RNFL thickness (0.839; 95% CI: 0.759-0.920 and 0.897; 95% CI: 0.836-0.958, respectively) in distinguishing PXG from both PXS and healthy controls ( P =0.001 and 0.002, respectively). BMO-MRW also had significantly lower AUCs than both LC thickness and LCCI in distinguishing PXG from healthy controls ( P =0.034 and 0.001, respectively). LC thickness and LCCI had better diagnostic performance than BMO-MRW in distinguishing PXG from PXS and healthy controls, which were comparable to RNFL thickness.

The retinal ganglion cell layer reflects neurodegenerative changes in cognitively unimpaired individuals

BackgroundTo evaluate a wide range of optical coherence tomography (OCT) parameters for possible application as a screening tool for cognitively healthy individuals at risk of Alzheimer’s disease (AD), assessing the potential relationship with established cerebrospinal fluid (CSF) core AD biomarkers and magnetic resonance imaging (MRI).MethodsWe studied 99 participants from the Valdecilla Study for Memory and Brain Aging. This is a prospective cohort for multimodal biomarker discovery and validation that includes participants older than 55 years without dementia. Participants received a comprehensive neuropsychological battery and underwent structural 3-T brain MRI, lumbar puncture for CSF biomarkers (phosphorylated-181-Tau (pTau), total Tau (tTau), beta-amyloid 1–42 (Aβ 1–42), and beta-amyloid 1–40 (Aβ 1–40)). All individuals underwent OCT to measure the retinal ganglion cell layer (GCL), the retinal nerve fiber layer (RFNL), the Bruch’s membrane opening-minimum rim width (BMO-MRW), and choroidal thickness (CT). In the first stage, we performed a univariate analysis, using Student’s t-test. In the second stage, we performed a multivariate analysis including only those OCT parameters that discriminated at a nominal level, between positive/negative biomarkers in stage 1.ResultsWe found significant differences between the OCT measurements of pTau- and tTau-positive individuals compared with those who were negative for these markers, most notably that the GCL and the RNFL were thinner in the former. In stage 2, our dependent variables were the quantitative values of CSF markers and the hippocampal volume. The Aβ 1–42/40 ratio did not show a significant correlation with OCT measurements while the associations between pTau and tTau with GCL were statistically significant, especially in the temporal region of the macula. Besides, the multivariate analysis showed a significant correlation between hippocampal volume with GCL and RNFL. However, after false discovery rate correction, only the associations with hippocampal volume remained significant.ConclusionsWe found a significant correlation between Tau (pTau) and neurodegeneration biomarkers (tTau and hippocampus volume) with GCL degeneration and, to a lesser degree, with damage in RFNL. OCT analysis constitutes a non-invasive and unexpensive biomarker that allows the detection of neurodegeneration in cognitively asymptomatic individuals.

Short-term changes in Bruch’s membrane opening-based morphometrics during the first week after trabeculectomy

PurposeTo evaluate the dynamics of Bruch’s membrane opening-based morphometrics of the optic nerve head (ONH) using spectral-domain optical coherence tomography (SD-OCT) during the first week after glaucoma surgery by trabeculectomy with mitomycin C.MethodsProspective, longitudinal analysis of 25 eyes of 25 patients treated by trabeculectomy. Twenty-four eyes had evaluable postoperative SD-OCT examinations. Bruch’s membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (RNFL) thickness were analyzed at baseline before surgery, 1 day, 2 to 3 days, and 1 week after surgery. Changes compared to baseline were correlated to intraocular pressure (IOP).ResultsOne day after surgery, the mean BMO-MRW changed by + 26.17 µm, p = 0.001 (mean IOP reduction by 17.01 mmHg). This increase persisted on day 2–3 with a mean increase of BMO-MRW of + 25.33 µm, p = 0.001 (mean IOP reduction by 20.46 mmHg) and by week 1 with a mean BMO-MRW increase of + 33.17 µm, p < 0.001 (mean IOP reduction by 22.55 mmHg). The increase in BMO-MRW correlated significantly with the reduction of IOP on day 1 (Spearman’s rho ρ = 0.656, p = 0.003) and d2–3 (Spearman’s rho ρ = 0.479, p = 0.038). There was no statistically significant correlation found between the IOP and the increase in BMO-MRW in week 1.RNFL thickness showed no significant changes at day 1 as well as days 2–3 (p ≥ 0.078, respectively). It showed a small but significant increase in week 1 by 3.94 µm, p = 0.015.ConclusionsStructural reversal of disc cupping in BMO-MRW occurs as early as 1 day after trabeculectomy and correlates to the extent of the IOP reduction. During the whole first week after surgery, a strong increase in BMO-MRW can be noted. The changes in BMO-based parameters need to be considered when evaluating patients’ longitudinal follow-up.

Corneal Hysteresis and Rates of Neuroretinal Rim Change in Glaucoma

To evaluate the impact of corneal hysteresis (CH) as a risk factor for progressive neuroretinal rim loss in glaucoma, as measured by spectral-domain OCT of the Bruch's membrane opening minimum rim width (MRW). Prospective, observational cohort study. The study group included 118 eyes of 70 subjects with glaucoma. The average follow-up time for the cohort was 3.9 ± 1.3 years, with an average of 6.4 ± 2.0 spectral-domain OCT tests, ranging from 4 to12. Corneal hysteresis measurements were acquired at baseline using the Ocular Response Analyzer (Reichert Instruments). Linear mixed models were used to investigate the relationship between the rates of MRW loss and baseline CH. Multivariable analyses adjusted for other putative predictive factors for progression, including mean intraocular pressure (IOP), central corneal thickness (CCT), age, race, and baseline disease severity. Effects of CH on the rate of MRW change over time. Corneal hysteresis had a significant effect on rates of MRW progression over time. Each 1-mmHg lower CH was associated with-0.38 μm/year faster MRW loss (95% confidence interval [CI],-0.70 to-0.06; P=0.019), after adjustment for other predictive factors. The mean IOP was also significantly associated with progression, with-0.35 μm/year (95% CI,-0.47 to-0.23 μm/year) faster MRW change for each 1-mmHg higher pressure (P < 0.001). In the analysis of predictive strength, the mean IOP was the strongest predictive factor (R2=23%), followed by CH (R2= 14%) and baseline disease severity (R2= 6%). Central corneal thickness explained only 3% of the variability in slopes of change in global MRW. Lower CH measurements were associated with faster loss of the neuroretinal rim in glaucoma, as measured by MRW. The predictive ability of CH was superior to that of CCT. These findings suggest that CH is an important parameter to be considered in assessing the risk of glaucoma progression.

Retinal Nerve Fiber Layer-to-Disc Ratio Distinguishing Glaucoma from Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose: To evaluate the diagnostic value of retinal nerve fiber layer-to-disc ratio (RDR) compared to established parameters including retinal nerve fiber layer thickness (RNFLT), Bruch membrane opening-minimum rim width (BMO-MRW), and Bruch membrane opening-minimum rim area (BMO-MRA) for differentiating between open angle glaucoma (OAG) and nonarteritic anterior ischemic optic neuropathy (NAION).Methods: This retrospective study included 23 optic disc size-matched normal control eyes and 23 OAG and NAION eyes matched according to global RNFLT. The RDR, RNFLT, BMO-MRW, and BMO-MRA were analyzed; the diagnostic capabilities of these parameters were compared using the area under the receiver operating characteristic curve (AUC).Results: The global BMO-MRW and total BMO-MRA were lower in the OAG group than in the other two groups (all &lt;i&gt;p&lt;/i&gt; &lt; 0.001). RDR was greatest in the OAG group, followed by the healthy and NAION groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). Between the OAG and NAION groups, the AUCs for temporal inferior BMO-MRW, total BMO-MRA, and RDR were 0.987, 0.996, and 1.000, respectively; these were greater than the temporal inferior RNFLT (0.811; &lt;i&gt;p&lt;/i&gt; = 0.005, &lt;i&gt;p&lt;/i&gt; = 0.006, and &lt;i&gt;p&lt;/i&gt; = 0.006, respectively).Conclusions: RDR could be one of the useful parameters for differential diagnosis in OAG and NAION.

A comprehensive enhanced depth imaging spectral-domain optical coherence tomography analysis of pseudoexfoliation spectrum from non-glaucomatous to advanced stage glaucoma in the aspect of Bruch's membrane opening-minimum rim width.

To compare the correlations between lamina cribrosa (LC) and related structures with Bruch's membrane opening-minimum rim width (BMO-MRW) and retinal nerve fiber layer (RNFL) thickness in pseudoexfoliation syndrome (PXS) and different stages of pseudoexfoliation glaucoma (PXG). This prospective cross-sectional study included 32 PXS eyes of 24 patients and 94 PXG eyes (early-stage (n: 55) and advanced-stage glaucoma (n: 39) of 78 patients. Global and six sectors of RNFL thicknesses and BMO-MRW parameters were measured with enhanced depth imaging (EDI) mode of SD-OCT. Structural parameters; lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), prelaminar tissue thickness (PLTT), four quadrants of peripapillary choroidal thicknesses (PPCT), and subfoveal choroidal thickness (SFCT) were measured and statistical relationships between the structural parameters have been laid out. We apply the generalized estimating equations method to take into account dependency of right and left eyes. From PXS to mild and advanced PXG groups LCT and PLTT decrease from 147.29 ± 33.10, 145.62 ± 30.64, 126.30 ± 29.14 and 260.93 ± 185.07, 247.27 ± 142.58, 159.89 ± 86.84, respectively, and LCD varies as 159.89 ± 86.84, 420.88 ± 117.80, and 505.64 ± 183.25. The correlations between LCD, LCT, and PLTT and the stage of the disease are significant. BMO-MRW shows slightly stronger correlations than the RNFL with LC related parameters. SFCT does not exhibit any significant relationship with the stage of the disease. However, PPCT in only the interior quadrant does. The significant correlations between LCD and all quadrants of PPCT is the sign of important anatomic relationship. These findings show that the BMO-MRW parameter may be more sensitive than RNFL and can safely be used in the diagnosis and follow-up in PXS and PXG, but this result should be supported with longer and larger series.

Decoding glaucoma module premium edition.

Traditional methods for neuroretinal rim width measurement in spectral domain optical coherence tomography (SD-OCT) employs the Bruch's membrane opening (BMO) as the anatomical border of the rim, referenced to a BMO horizontal reference plane, termed as "Bruch's Membrane Opening-Horizontal Rim Width" (BMO-HRW). BMO-HRW is defined as the distance between BMO and internal limiting membrane (ILM) on the horizontal plane. In contrast, the Spectralis OCT (Heidelberg Engineering, Germany) employs a new parameter called "Bruch's Membrane Opening-Minimum Rim Width" (BMO-MRW) with Glaucoma Module Premium Edition (GMPE). GMPE provides a novel objective method of optic nerve head (ONH) analysis using BMO, but the neuroretinal rim assessment is performed from the BMO to the nearest point on the ILM, rather than on the horizontal reference plane. It is the BMO-MRW and is defined as the minimum distance between the BMO and ILM in the ONH. In this video, anatomy of the ONH and GMPE is decoded from a neophyte user's point of view, as to why BMO-MRW is more important than the traditional BMO-HRW for glaucoma evaluation. The GMPE concepts are depicted in a novel dynamic (Clinical vs OCT Vs Histology) screenplay, detailing the below focal points with 2D & 3D animations: True Margin of ONH, Bruch's Membrane (BM), Histology Vs OCT, BMO, Bruch's Membrane Opening-Minimum Rim Width, Bruch's Membrane Opening-Minimum Rim Width Versus Bruch's Membrane Opening-Horizontal Rim Width, Alpha, Beta, Gamma Zone of ONH in OCT, Anatomic Positioning System, Impact of Fovea Bruch's Membrane Opening Centre Axis. This video also highlights, how with the advent of Anatomic Positioning System, scans were able to align relative to the individual's Fovea-to-BMO-center (FoBMOC) axis at every follow-up, for accurately detecting changes, as small as 1 micron in BMO-MRW, thus creating a new world in diagnosing glaucoma and detecting glaucomatous progression with precision. https://youtu.be/6RqF5guAziw.

Impact of Epiretinal Membrane on Optical Coherence Tomography Tools Used for Monitoring Glaucoma.

Background: Retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) measurements can be influenced by many factors including the presence of concomitant retinal diseases. The aim of this study it to assess the impact of epiretinal membrane (ERM) on RNFL and GCL assessment using optical coherence tomography (OCT). Methods: GCL, peripapillary RNFL (pRNFL), and Bruch’s Membrane Opening Minimum Rim Width (BMO-MRW) thicknesses were analysed using an SD-OCT (Spectralis OCT) in eyes with idiopathic ERM and compared with a control group. Results: 161 eyes were included, 73 eyes in the control group and 88 eyes with idiopathic ERM. The pRNFL analysis revealed a statistically significant difference between the two groups in overall and temporal sector thicknesses. For GCL thickness report, the percentage of scans in which the GCL was erroneously segmented by automatic segmentation was assessed for each eye. A statistically significant difference was found in all sectors (p < 0.001), with the exception of external nasal sector. A statistically significant difference (p < 0.001) in the GCL total volume report was found in ERM group compared to the control group. For MRW at BMO analysis, there was no statistically significant difference in MRW thickness in any sector. Conclusion: In eyes with ERM, the GCL and pRNFL analysis seemed affected by the morphological retinal layers’ modification. MRW-BMO did not appear to be directly affected by the presence of ERM.

Repeatability of Bruch’s Membrane Opening-minimum Rim Width in Age-related Macular Degeneration and Diabetic Macular Edema

Purpose: To evaluate the repeatability of retinal nerve fiber layer (RNFL) thickness and Bruch’s membrane opening-minimum rim width (BMO-MRW) measurements by spectral-domain optical coherence tomography (SD-OCT) in wet age-related macular degeneration (wAMD) and diabetic macular edema (DME).Methods: This was a prospective study. The RNFL thickness and BMO-MRW parameters for each sector and global average were measured twice by SD-OCT. Repeatability was evaluated using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). If the optic disc membrane was confirmed, it was analyzed by dividing it into three groups based on severity.Results: A total of 99 eyes (48 with wAMD, 51 with DME) were included in the analysis. The ICCs of the global RNFL thickness and global BMO-MRW measurements were 0.996 and 0.997, respectively, in wAMD and 0.994 and 0.996, respectively, in DME eyes. The CV values of global RNFL thickness and BMO-MRW were 0.60% and 0.73%, respectively, in wAMD eyes and 1.10% and 1.21%, respectively, in DME eyes. The disc membrane on the optic nerve head significantly affected global BMO-MRW repeatability (B = 0.814, &lt;i&gt;p&lt;/i&gt; &lt; 0.001).Conclusions: Both RNFL thickness and BMO-MRW measurements showed good repeatability in eyes with wAMD and DME. The severity of the optic disc membrane significantly affected the repeatability of BMO-MRW measurements in eyes with wAMD and DME. Therefore, physicians should examine the BMO-MRW in eyes with severe optic disc membrane.

Pattern Electroretinogram Parameters Are Associated with Optic Nerve Morphology in Preperimetric Glaucoma after Adjusting for Disc Area.

Purpose We examined the relationships between pattern electroretinogram and optical coherence tomography derived optic nerve head measurements, after controlling for disc area. Methods Thirty-two eyes from 20 subjects with preperimetric glaucoma underwent pattern electroretinogram and optical coherence tomography. Pattern electroretinogram parameters (Magnitude, MagnitudeD, and MagnitudeD/Magnitude ratio) and optic nerve head measurements (rim area, average cup to disc ratio, vertical cup to disc ratio, cup volume, retinal nerve fiber layer thickness sectors, and Bruch's membrane opening-minimum rim width thickness sectors) were analyzed after controlling for disc area. Results Magnitude and MagnitudeD were significantly associated with rim area (r ≥ 0.503, p ≤ 0.004). All pattern electroretinogram parameters significantly correlated with Bruch's membrane opening-minimum rim width sectors—temporal superior and nasal inferior (r = 0.400, p=0.039)—and retinal nerve fiber layer sectors—superior, nasal superior, and inferior (r ≥ 0.428, p ≤ 0.026). Magnitude and MagnitudeD explained an additional 26.8% and 25.2% of variance in rim area (B = 0.174 (95% CI: 0.065, 0.283), p=0.003, and B = 0.160 (95% CI: 0.056, 0.265), p=0.004), respectively. MagnitudeD and MagnitudeD/Magnitude ratio explained an additional 13.4% and 12.8% of the variance in Bruch's membrane opening-minimum rim width global (B = 38.921 [95% CI: 3.872, 73.970], p=0.031, and B = 129.024 (95% CI: 9.589, 248.460), p=0.035), respectively. All Bruch's membrane opening-minimum rim width sectors and retinal nerve fiber layer sectors (nasal superior, nasal inferior, and inferior) were significantly correlated with rim area (r ≥ 0.389, p ≤ 0.045). Conclusion PERG abnormalities can predict rim area loss in preperimetric glaucoma after controlling for disc area. We recommend controlling for disc area to increase diagnostic accuracy in early glaucoma.

Comparison of Different Machine Learning Classifiers for Glaucoma Diagnosis Based on Spectralis OCT.

Early detection is important in glaucoma management. By using optical coherence tomography (OCT), the subtle structural changes caused by glaucoma can be detected. Though OCT provided abundant parameters for comprehensive information, clinicians may be confused once the results conflict. Machine learning classifiers (MLCs) are good tools for considering numerous parameters and generating reliable diagnoses in glaucoma practice. Here we aim to compare different MLCs based on Spectralis OCT parameters, including circumpapillary retinal nerve fiber layer (cRNFL) thickness, Bruch’s membrane opening-minimum rim width (BMO-MRW), Early Treatment Diabetes Retinopathy Study (ETDRS) macular thickness, and posterior pole asymmetry analysis (PPAA), in discriminating normal from glaucomatous eyes. Five MLCs were proposed, namely conditional inference trees (CIT), logistic model tree (LMT), C5.0 decision tree, random forest (RF), and extreme gradient boosting (XGBoost). Logistic regression (LGR) was used as a benchmark for comparison. RF was shown to be the best model. Ganglion cell layer measurements were the most important predictors in early glaucoma detection and cRNFL measurements were more important as the glaucoma severity increased. The global, temporal, inferior, superotemporal, and inferotemporal sites were relatively influential locations among all parameters. Clinicians should cautiously integrate the Spectralis OCT results into the entire clinical picture when diagnosing glaucoma.