Retinal Ganglion Cell-inner Plexiform Layer Research Articles

May ganglion cell complex analysis be a marker for glaucoma susceptibility in unilateral Fuchs' uveitis syndrome?

To compare retinal nerve fiber layer (RNFL) thickness and ganglion cell-inner plexiform layer thickness (GCIPLT) in the affected eyes to fellow unaffected eyes of patients with unilateral Fuchs' uveitis syndrome (FUS) and analyze their change over time. Twenty seven unilateral FUS patients who did not have concomitant systemic or ocular disease were retrospectively enrolled. Central macular thickness (CMT), RNFL thickness, and GCIPLT measurements were evaluated. Data was analyzed using the non-parametric Brunner-Langer model (LD-F2 design) and Wilcoxon signed-rank test. The mean age of the patients was 40.2 ± 10.2years. The median disease duration was 11 (2-62) months. The median best-corrected visual acuity (BCVA) of the affected eyes and the fellow eyes was 0.22 (0.00-2.50) vs. 0.00 (0.0-0.10) logMAR at the initial visit and 0.05 (0.00-2.50) vs. 0.00 (0.0-0.30) logMAR at the final visit. The change in BCVA was found significant in the affected eyes, but not in the fellow eyes (p < 0.001 and p = 0.287, respectively). The median CMT in the affected eyes at the final visit was not statistically different from the value at the initial visit (255 (157-306) vs. 245 (140-310) µm, p = 0.256). The change in RNFL thickness over time in the affected eyes was similar to the fellow unaffected eyes of the patients with unilateral FUS at all quadrants, with non-significant time and group effects (p > 0.05). However, median GCIPLT in all quadrants (except superonasal) in the affected eyes was statistically lower than the fellow eyes at the initial and final visits (p < 0.05). The most affected quadrant of the ganglion cell complex was inferonasal in the involved eyes (79 (42-97) vs. 75 (43-87) µm) at initial and final visits (p = 0.033 for time effect and p < 0.001 for group effect, respectively). Median CMT and RNFL thickness did not change during follow-up in the affected eyes of patients with unilateral FUS. Median GCIPLT in the affected eyes declined over time in all quadrants. Ganglion cell loss was also most prominent in the inferonasal quadrant in the affected eyes. FUS patients should be followed up long-term in terms of ganglion cell loss, especially in the inferonasal quadrant.

Measuring optic nerve head perfusion to monitor glaucoma: a study on structure–function relationships using laser speckle flowgraphy

We aimed to describe the global and localized correlations among visual field (VF) sensitivity, optic nerve head (ONH) perfusion measured by laser speckle flowgraphy (LSFG) and neural structure measured by optical coherence tomography (OCT) in open-angle glaucoma (OAG) and to compare the floor effect for LSFG and OCT. Cross-sectional, multicenter study including one eye each from fifty OAG patients (mean age 69.3 years; average VF mean deviation, MD, -8.5 dB, range -25.17 to 0.85 dB) and fifty-one controls. Patients underwent SITA standard 24-2 automated perimetry and measurement of ONH perfusion, peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell-inner plexiform layer thickness (GCIPLT). We tested the presence of a significant change (breakpoint) in the correlation slope with VF sensitivity to assess floor effect. The correlation between the LSFG parameter Mean All (MA) of the global disc area and MD (r = 0.56, p < 0.001) did not show a breakpoint, in contrast to the correlations between MD and OCT global parameters, which showed breakpoints at -8.53 and -4.05 dB for RNFLT and GCIPLT, respectively. Global and localized correlations with VF sensitivity were stronger for LSFG compared to OCT. In particular, LSFG outperformed OCT in the correlation with the central VF sector (r = 0.50, p < 0.001 and r = 0.06, p = 0.67 for MA and RNFLT, respectively). The global and sectoral correlations with VF sensitivity and the favourable floor effect compared to OCT indicate LSFG as a promising tool to monitor progression particularly in late-stage glaucoma. Further longitudinal studies are warranted.

Association of Retinal Changes With Alzheimer Disease Neuroimaging Biomarkers in Cognitively Normal Individuals

Retinal biomarkers reflecting in vivo brain Alzheimer disease (AD) pathologic abnormalities could be a useful tool for screening cognitively normal (CN) individuals at the preclinical stage of AD. To investigate the association of both functional and structural alterations of the retina with in vivo AD pathologic abnormalities in CN older adults and model a screening tool for detection of preclinical AD. This cross-sectional study included a total of 49 CN individuals, and all assessment was done at the Seoul National University Hospital, Seoul, South Korea. All participants underwent complete ophthalmic examination, including swept-source optical coherence tomography (SS-OCT) and multifocal electroretinogram as well as amyloid-β (Aβ) positron emission tomography and magnetic resonance imaging. Data were collected from January 1, 2016, through October 31, 2017, and analyzed from February 1, 2018, through June 30, 2020. For structural parameters of the retina, the thickness of the macula and layer-specific thicknesses, including peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer measured by SS-OCT, were used for analysis. For functional parameters of the retina, implicit time and amplitude of rings 1 to 6 measured by multifocal electroretinogram were used. Of the 49 participants, 25 were women (51.0%); mean (SD) age was 70.6 (9.4) years. Compared with 33 CN individuals without Aβ deposition (Aβ-CN), the 16 participants with Aβ (Aβ+CN) showed reduced inner nasal macular thickness (mean [SD], 308.9 [18.4] vs 286.1 [22.5] μm; P = .007) and retinal nerve fiber layer thickness, particularly in the inferior quadrant (133.8 [17.9] vs 103.8 [43.5] μm; P = .003). In addition, the Aβ+CN group showed prolonged implicit time compared with the Aβ-CN group, particularly in ring 5 (41.3 [4.0] vs 38.2 [1.3] milliseconds; P = .002). AD-related neurodegeneration was correlated with the thickness of the ganglion cell-inner plexiform layer only (r = 0.41, P = .005). The model to differentiate the Aβ+CN vs Aβ-CN groups derived from the results showed 90% accuracy. The findings of this study showing both functional as well as structural changes of retina measured by multifocal electroretinogram and SS-OCT in preclinical AD suggest the potential use of retinal biomarkers as a tool for early detection of in vivo AD pathologic abnormalities in CN older adults.

Evaluation of Retinal Nerve Fiber Layer, Ganglion Cell-Inner Plexiform Layer, and Optic Nerve Head in Glaucoma Suspects With Varying Myopia.

Myopic glaucoma suspects, particularly with high myopia, experience thinning of nontemporal parameters of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL), without change in optic nerve head (ONH) parameters. The aim was to assess the effect of myopia on RNFL, GCIPL, and ONH parameters in glaucoma suspects. Seventy-six eyes of glaucoma suspects studied with Cirrus high definition optical coherence tomography were divided into low (n=27), moderate (n=25), and high myopia (n=24) groups. Optical coherence tomography parameters were correlated with spherical equivalent (SE) and evaluated with areas under the receiver operating characteristic curve for quantifying diagnostic ability to differentiate high myopia from nonhigh myopia. In high myopia, SE was positively correlated with thinning of average, minimum, and nontemporal GCIPL and thinning of average and nontemporal RNFL (P<0.05 for all), but not for inferior RNFL (P=0.28). In moderate myopia, SE was correlated with thinning of inferonasal and minimum GCIPL as well as superior and inferior RNFL (P<0.05 for all). SE was not correlated with ONH parameters in moderate or high myopia (P>0.05). The largest areas under the receiver operating characteristic curve for RNFL and GCIPL parameters were for superior (0.82) and superonasal (0.80) regions, respectively, with comparable diagnostic ability (P=0.74). High myopia, in particular, is associated with thinning of average RNFL, average and minimum GCIPL, and nontemporal parameters of both RNFL and GCIPL, warranting consideration of refractive status in glaucoma suspects.

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

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). Observational cohort study. 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. 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. Rates of cpRNFL and mGCIPL thinning. 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. 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.

Peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer changes on optical coherence tomography in patients with unilateral hypertensive cytomegalovirus anterior uveitis.

To investigate whether peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thinning are present in patients with unilateral hypertensive Cytomegalovirus anterior uveitis (hCMV AU). We included 19 eyes with unilateral hCMV AU and their unaffected fellow eyes as the control group in this study. Peripapillary RNFL and macular GCIPL changes were determined using spectral-domain (SD) - optical coherence tomography (OCT). The overall calculated mean pRNFL thickness was significantly lower in the effected eyes with hCMV AU than in the uneffected fellow eyes (p = 0.012). The mean macular GCIPL thickness in the affected eyes was also significantly lower than in the normal eyes (p < 0.001). Measurement of pRNFL and macular GCIPL thickness with OCT may detect signs of damage before the visual field changes in patients with hypertensive CMV AU. Early aggressive treatment in these patients may prevent further glaucomatous damage.

Recent advances and future directions on the use of optical coherence tomography in neuro-ophthalmology.

Optical coherence tomography (OCT) is a noninvasive imaging technique used to qualitatively and quantitatively analyze various layers of the retina. OCT of the retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL) is particularly useful in neuro-ophthalmology for the evaluation of patients with optic neuropathies and retrochiasmal visual pathway disorders. OCT allows for an objective quantification of edema and atrophy of the RNFL and GCIPL, which may be evident before obvious clinical signs and visual dysfunction develop. Enhanced depth imaging OCT allows for visualization of deep structures of the optic nerve and has emerged as the gold standard for the detection of optic disc drusen. In the evaluation of compressive optic neuropathies, OCT RNFL and GCIPL thicknesses have been established as the most important visual prognostic factor. There is increasing evidence that inclusion of OCT as part of the diagnostic criteria for multiple sclerosis (MS) increases its sensitivity. Moreover, OCT of the RNFL and GCIPL may be helpful in the early detection and monitoring the treatment of conditions such as MS and Alzheimer's disease. OCT is an important aspect of the neuro-ophthalmologic assessment and its use is likely to increase moving forward.

Analysis of macular microvasculature and thickness after ICL implantation in patients with myopia using optical coherence tomography.

To investigate changes in macular vessels and thickness in myopic eyes after intraocular collamer lens (ICL) implantation using quantitative optical coherence tomography angiography (OCTA). This retrospective included 73 myopic eyes of 73 patients (average age, 27.53±6.16y) who underwent ICL implantation (28 eyes were Toric ICL). Axial length (AL), uncorrected visual acuity (UCVA), refractive dioptre (RD), intraocular pressure (IOP) and OCTA were measured and compared with before and 1wk, 1, and 3mo after surgery. OCTA was used to image vessel density (VD) and skeleton density (SD) in both the superficial (SCP) and deep capillary plexus (DCP). Central retinal thickness (CRT) and ganglion cell-inner plexiform layer thickness (GCT) were also measured. Changes between pre- and postoperative measurements were analysed by repeated measures analysis of variance. Compared with preoperative data, postoperative data on UCVA revealed significant improvements in all patients (P<0.05). However, there was no significant difference in IOP. After the operation, CRT and GCT exhibited significant changes (P<0.05). Among these measures, CRT was significantly higher at one and three months postoperative (all P<0.01). GCT was significantly higher at 1wk, 1, and 3mo postoperative (all P<0.01). Changes in VD and SD were nonsignificant in both the SCP and DCP. There was no difference in postoperative changes between the ICL and Toric ICL groups. ICL and Toric ICL implantation both have good efficacy and safety for myopic eyes, but macular area changes that occur after surgery need attention.

Determinants of Optical Coherence Tomography Parameters in a Population-based Study

To study the effects of age, sex, intraocular pressure (IOP), corneal thickness, axial length (AXL), disc area, and the signal strength of the scan on optical coherence tomography (OCT) parameters of normal subjects in the L V Prasad Eye Institute-Glaucoma Epidemiological and Molecular Genetic Study (LVPEI-GLEAMS), a population-based study. Cross-sectional study. A total of 1,100 eyes (1,100 subjects) of normal adults aged between 40 and 80 years from LVPEI-GLEAMS underwent macular and optic nerve head imaging with spectral-domain OCT (SDOCT). Effect of age, sex, IOP, central corneal thickness (CCT) and AXL, disc area, and signal strength of the OCT scan on retinal nerve fiber layer (RNFL) thickness, rim area, and ganglion cell-inner plexiform layer (GC-IPL) thickness measurements were evaluated using univariate and multivariate regression models. Mean rim area, RNFL, and GC-IPL thickness were 1.31mm2 (standard deviation [SD]= 0.22), 93.7μm (SD= 9.3) and 79.6μm (SD= 8.7), respectively. Age had a negative association with RNFL thickness (coefficient:-0.18, P < .001) and GC-IPL thickness (-0.18, P < .001). GC-IPL thickness was significantly less in women than in men (-1.05, P < .001). AXL had a negative association with rim area (-0.05, P < .001). Disc area was positively associated with RNFL thickness (4.90, P < .001) and rim area (0.15, P < .001). Signal strength of OCT scan was positively associated with RNFL thickness (1.6, P < .001) and negatively associated with rim area (-0.02, P < .001). Age, sex, AXL, disc area, and signal strength of the scan were significantly associated with OCT measurements. These factors may need to be considered while interpreting the OCT parameters in pathologic conditions such as glaucoma.

Advances in ophthalmic structural and functional measures in multiple sclerosis: do the potential ocular biomarkers meet the unmet needs?

Multiple sclerosis is a heterogeneous disorder. Biomarkers to monitor disease activities are highly desirable especially because of the recent shift toward personalized medicine that coincides with the expansion of disease-modifying therapy. The visual system is highly involved in multiple sclerosis, and the rapid advancement of ophthalmic techniques has boosted the development of potential ocular biomarkers for multiple sclerosis management. Recent studies have found that the rapid thinning of the peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer (GCIPL) occurs in the progressive stage. Furthermore, the inter-eye thickness difference of the GCIPL could be used in identifying unilateral optic neuritis to facilitate the early diagnosis of multiple sclerosis. Moreover, the retinal microvascular alterations measured as vessel density were found to be related to the disability and visual function, although a standardized protocol to measure retinal microvascular alterations has not been well established. Additionally, aberrant ocular motility, such as fixation microsaccades, can be used to measure disability objectively. The fast expansion of potential ocular biomarkers measured as retinal microstructural, microvascular, and ocular motility changes may facilitate the diagnosis and management of multiple sclerosis.

Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes

To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. Prospective, longitudinal study. Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P= 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17-1.28; P= 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4-6.1; P= 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P= 0.002), synergistic with thinner CCT (P= 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3-10.5; P= 0.014). Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.

Consistency between optical coherence tomography and humphrey visual field for evaluating glaucomatous defects in high myopic eyes

BackgroundThe study is to investigate the influence of high myopia on the consistency between optical coherence tomography (OCT) and visual field in primary open-angle glaucoma (POAG).MethodsWe enrolled 37 patients with POAG with high myopia (POAG-HM group), 27 patients with POAG without high myopia (POAG group), and 29 controls with high myopia (HM group). All subjects underwent Humphrey perimetry (30–2 and 10–2 algorithms). The peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured using Cirrus HD-OCT. Spearman’s rank correlation analysis was used to determine correlations between OCT and perimetric parameters. Agreement was analyzed by cross-classification and weighted κ statistics.ResultsIn POAG group, the cross-classification analysis showed strong agreement between the inferior temporal GCIPL thickness and the mean sensitivity (MS) of 10–2 algorithms (κ = 0.5447, P = 0.0048), and good agreement between the superior and inferior RNFL thicknesses and 30–2 MS (κ = 0.4407 and 0.4815; P < 0.05). In the POAG-HM group, only the inferior temporal GCIPL thickness showed good agreement with 10–2 MS (κ = 0.3155, P = 0.0289) and none of the RNFL sectors were in good agreement with the corresponding MS.ConclusionsIn POAG patients with high myopia, changes in macular measurements were in accordance with visual field defects, and RNFL thickness did not consistently decline with visual field defects due to the effects of high myopia. This study suggests that during diagnosis and follow-up of glaucoma with high myopia, more attention need to be focused on structure and functional defects in macular areas.

Alcohol consumption is associated with glaucoma severity regardless of ALDH2 polymorphism

The present study investigated the effect of aldehyde dehydrogenase2 (ALDH2) rs671 polymorphism and alcohol consumption on the severity of primary open-angle glaucoma (POAG). The questionnaire for alcohol consumption pattern and targeted genotyping for ALDH2 rs671 polymorphism was performed from 445 Korean POAG patients. Retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured and compared according to alcohol consumption and ALDH2 rs671 genotype. Heavy drinking group eyes had thinner RNFL thickness than did abstinence group eyes (65.0 ± 10.9 vs. 70.9 ± 11.5 µm, P = 0.023). Both mild (65.8 ± 9.6 µm) and heavy (63.8 ± 8.4 µm) drinking group eyes had significantly thinner macular GCIPL thickness than did abstinence group eyes (68.1 ± 8.2 µm, P = 0.003). However, ALDH2 rs671 polymorphism did not show any significant association with RNFL or GCIPL thickness. Alcohol consumption was significantly associated with GCIPL thinning (β = –0.446, P = 0.035) after adjustment for multiple confounding factors. As excessive alcohol consumption was significantly associated with thinner GCIPL thickness while ALDH2 polymorphism had no significant effect on RNFL or GCIPL thickness, glaucoma patients should avoid excessive alcohol consumption regardless of ALDH2 polymorphism.

Effect of medically lowering intraocular pressure in glaucoma suspects with high myopia (GSHM study): study protocol for a randomized controlled trial

BackgroundCurrently, whether and when intraocular pressure (IOP)-lowering medication should be used in glaucoma suspects with high myopia (GSHM) remains unknown. Glaucoma suspects are visual field (VF) defects that cannot be explained by myopic macular changes or other retinal and neurologic conditions. Glaucoma progression is defined by VF deterioration. Here we describe the rationale, design, and methodology of a randomized controlled trial (RCT) designed to evaluate the effects of medically lowering IOP in GSHM (GSHM study).MethodsThe GSHM study is an open-label, single-center, RCT for GSHM. Overall, 264 newly diagnosed participants, aged 35 to 65 years, will be recruited at the Zhongshan Ophthalmic Center, Sun Yat-sen University, between 2020 and 2021. Participants will be randomly divided into two arms at a 1:1 ratio. Participants in the intervention arm will receive IOP-lowering medication, while participants in the control arm will be followed up without treatment for 36 months or until they reach the end point. Only one eye per participant will be eligible for the study. If both eyes are eligible, the eye with the worse VF will be recruited. The primary outcome is the incidence of glaucoma suspect progression by VF testing over 36 months. The secondary outcomes include the incidence of changes in the optic nerve head morphology including the retinal nerve fiber layer, and retinal ganglion cell-inner plexiform layer loss, progression of myopic maculopathy, visual function loss, and change in the quality of life. Statistical analyses will include baseline characteristics comparison between the intervention and control groups using a two-sample t-test and Wilcoxon rank sum test; generalized linear models with Poisson regression for the primary outcome; Kaplan-Meier curve and log-rank test for the incidence of the secondary outcome; and longitudinal analyses to assess trends in outcomes across time.DiscussionTo the best of our knowledge, the GSHM study is the first RCT to investigate the impact of medically lowering IOP in GSHM. The results will have implications for the clinical management of GSHM.Trial registrationClinicalTrials.gov NCT04296916. Registered on 4 March 2020

Dual-input convolutional neural network for glaucoma diagnosis using spectral-domain optical coherence tomography

Background/AimsTo evaluate, with spectral-domain optical coherence tomography (SD-OCT), the glaucoma-diagnostic ability of a deep-learning classifier.MethodsA total of 777 Cirrus high-definition SD-OCT image sets of the retinal nerve fibre layer (RNFL)...

Optical Coherence Tomography Neuro-Toolbox for the Diagnosis and Management of Papilledema, Optic Disc Edema, and Pseudopapilledema.

Distinguishing optic disc edema from pseudopapilledema is a common, sometimes challenging clinical problem. Advances in spectral-domain optical coherence tomography (SD-OCT) of the optic nerve head (ONH) has proven to be a cost effective, noninvasive, outpatient procedure that may help. At its core are tools that quantify the thickness of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL). The SD-OCT also provides a set of tools that may be qualitatively interpreted in the same way that we read an MRI. They include the transverse axial, en face, and circular tomogram. Our goal is to describe a practical office-based set of tools using SD-OCT in the diagnosis and monitoring of papilledema, optic disc edema, and pseudopapilledema. Searches on PubMed were performed using combinations of the following key words: OCT, papilledema, pseudopapilledema, optic disc drusen, retinal folds (RF), and choroidal folds (CF). The principal elements of SD-OCT analysis of the ONH are the RNFL and GC-IPL thickness; however, these metrics have limitations when swelling is severe. Qualitative interpretation of the transverse axial SD-OCT aids in assessing peripapillary shape that may help distinguish papilledema from pseudopapilledema, evaluate atypical optic neuropathies, diagnose shunt failures, and identify outer RF and CF. There is a consensus that the SD-OCT is the most sensitive way of identifying buried optic disc drusen. En face SD-OCT is especially effective at detecting peripapillary wrinkles and outer retinal creases, both of which are common and distinctive signs of optic disc edema that rule out pseudopapilledema. Mechanically stressing the ONH in the adducted eye position, in patients with papilledema, may expose folds and peripapillary deformations that may not be evident in primary position. We also discuss how to optimize the acquisition and registration of SD-OCT images. The SD-OCT is not a substitute for a complete history and a careful examination. It is, however, a convenient ancillary test that aids in the diagnosis and management of papilledema, optic disc edema, and pseudopapilledema. It is particularly helpful in monitoring changes over the course of time and distinguishing low-grade papilledema from buried drusen. The application of the SD-OCT toolbox depends on optimizing the acquisition of images, understanding its limitations, recognizing common artifacts, and accurately interpreting images in the context of both history and clinical findings.

SD-OCT parameters and visual field defect in chiasmal compression and the diagnostic value of neural network model.

To evaluate the peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) measurements using spectral domain optical coherence tomography (SD-OCT) in patients with chiasmal compression and analyze the diagnostic value of a neural network model. Forty-seven patients with chiasmal compressive disorder were recruited and divided into two groups depending on the visual field defect (perimetric; group 1 and preperimetric; group 2). Fifty-seven normal subjects were also recruited (group 3). Peripapillary RNFL and macular GCIPL were analyzed in each group. A multilayer perceptron was trained using a training dataset and derived a neural network model. The diagnostic performances were compared using the area under the receiver operating curve (AUROC) between each parameters and neural network model. All macular GCIPL parameters, except inferotemporal GCIPL thickness, were thinner in group 1 than in group 2 and group 3, with barely any difference between group 2 and group 3 parameter values. The diagnostic power of the neural network model, minimum GCIPL, and inferonasal GCIPL were superior when compared with other parameters; the diagnostic values of these three parameters are not significantly different in discriminating the patients and normal control. However, the neural network exhibited the best diagnostic power in distinguishing group 2 and group 3. Macular GCIPL was reduced in chiasmal compression patients with visual field defect which was not evident in the preperimetric state. Neural network model showed superior diagnostic value in discriminating the preperimetric patients from normal control. The results suggest that neural networks may be helpful in the early diagnosis of chiasmal compression.

Homonymous hemi-macular atrophy of the ganglion cell-inner plexiform layer with preserved visual function

Homonymous hemimacular thinning of the retinal ganglion cell-inner plexiform layer (GCIPL) on optical coherence tomography (OCT) in the absence of significant visual field defects may be identified in the workup of patients with visual complaints, but the causes of this finding remain unknown. We retrospectively reviewed 1425 consecutive patients referred for neuro-ophthalmic assessment who had high quality OCT scans and reliable Humphrey 24–2 SITA-Fast testing. A total of 7 patients, 3 females and 4 males, with a mean age of 39.4 ± 10.5 years that had homonymous thinning of the OCT macular-GCIPL without significant visual field defects were included in the study. Four patients had demyelinating disease and 3 patients had traumatic brain injury. Three patients with demyelinating disease had a documented prior homonymous visual field defect that resolved. The differential diagnosis of homonymous hemimacular thinning of the GCIPL without obvious visual field defects includes previous retrochiasmal demyelination and traumatic brain injury. OCT GCIPL provides a permanent objective way of documenting previous retrochiasmal disease including demyelination and may be helpful in establishing dissemination in time and space in patients being evaluated for multiple sclerosis.

Association of Antihypertensive Medication with Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer Thickness

To evaluate the association between different classes of antihypertensive medication with retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness in a nonglaucomatous multiethnic Asian population. Population-based, cross-sectional study. A total of 9144 eyes for RNFL analysis (2668 Malays, 3554 Indians, and 2922 Chinese) and 8549 eyes for GC-IPL analysis (2460 Malays, 3230 Indians, and 2859 Chinese) aged 44 to 86 years. Participants underwent standardized systemic and ocular examinations and interviewer-administered questionnaires for collection of data on medication and other variables. Intraocular pressure (IOP) readings were obtained by Goldmann applanation tonometry before pupil dilation for fundoscopy and OCT imaging. Blood pressure (BP) was measured with an automatic BP monitor. Mean arterial pressure (MAP) was defined as diastolic BP plus 1/3 (systolic BP - diastolic BP). Regression models were used to investigate the association of antihypertensive medication with OCT measurements of RNFL and GC-IPL. Average and sectoral RNFL and GC-IPL thickness. After adjusting for age, gender, ethnicity, MAP, IOP, body mass index (BMI), and presence of diabetes, we found that participants taking any type of antihypertensive medication (β=-0.83; 95% confidence interval [CI],-1.46 to-0.02; P= 0.01), specifically angiotensin-converting enzyme inhibitors (ACEIs) (β=-1.66; 95% CI,-2.57 to-0.75; P < 0.001) or diuretics (β=-1.38; 95% CI,-2.59 to-0.17; P < 0.05), had thinner average RNFL in comparison with participants who were not receiving antihypertensive treatment. Use of a greater number of antihypertensive medications was significantly associated with thinner average RNFL (P for trend= 0.001). This association was most evident in the inferior RNFL quadrant in participants using ACEIs (β=-2.44; 95% CI,-3.99 to-0.89; P= 0.002) or diuretics (β=-2.76; 95% CI,-4.76 to-0.76; P= 0.007). A similar trend was noted in our analysis of macular GC-IPL thickness. Use of 2 or more antihypertensive medications, ACEI, and diuretics were associated with a loss of structural markers of retinal ganglion cell health in a multiethnic Asian population.

Effect of baseline test selection on glaucoma progression detection by optical coherence tomography-guided progression analysis

PurposeTo evaluate the effect of baseline test selection on progression detection of circumpapillary retinal nerve fibre layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) in glaucomatous eyes by optical...