Macular Ganglion Cell Layer Thickness Research Articles

Pattern ERGs suggest a possible retinal contribution to the visual acuity loss in acute optic neuritis.

Macular involvement in optic neuritis (ON) is well-recognised but poorly understood and may be of clinical relevance. This study explores macular structure-function correlates in acute ON. This cross-sectional cohort study recruited ON patients within 14days of symptom onset. Subjectsunderwent pattern electroretinography (PERG), pattern visual evoked potentials (PVEP) and optical coherence tomography (OCT) imaging. PERG P50 and N95 components were correlated with OCT data. Twenty-six individuals with ON were recruited, comprising eleven multiple sclerosis (MS-ON), six myelin oligodendrocyte glycoprotein associated (MOG-ON) and nine with isolated ON. These were compared with 28 healthy controls. PVEPs were undetectable in 11 (42%) of individuals with ON. When detectable, PVEP P100 was delayed (median 136ms range 110-173ms) and amplitude reduced (median 6μV, range 3-14μV) in ON compared with controls (both p < 0.001). PERG P50 component amplitudes, largely reflecting macular function, were reduced in affected eyes (median 2.3μV; range 0.8-5.0μV) compared with controls (3.3μV; range 2.8-5.7μV) and compared with fellow eyes (p < 0.001). The N95:P50 ratio was below the reference range in the affected eyes of five patients. Eight cases (32%) had subnormal P50 amplitudes (< 2.0μV), and these patients had poorer visual acuity (p = 0.020). P50 amplitudes were positively correlated with an increase in inner nuclear layer thickness (rs = 0.36; p = 0.009) and macular ganglion cell and inner plexiform layer (mGCIPL) thickness (rs = 0.44, p = 0.022). PERG P50 component reduction reveals dysfunction of inner macular layers in acute ON and correlates with structural alterations on OCT. These early macular pathologic processes are likely to contribute to the visual loss.

Correlation Between Enlargement of Retinal Nerve Fiber Defect Angle in En Face Imaging and Visual Field Progression.

PurposeRetinal nerve fiber layer defects (RNFLDs) become enlarged with glaucoma progression. We measured the RNFLD angle and investigated whether it was correlated with deterioration of the visual field in patients with glaucoma.MethodsThis study included 84 eyes of 84 patients with open-angle glaucoma (mean deviation [MD] = −6.51 ± 5.91 dB, follow-up period = 2.82 ± 0.74 years) with the RNFLDs, who underwent en face swept-source optical coherence tomography (SS-OCT) wide scans (12 × 9 mm) at least 6 times. The RNFLD angle was measured as the intersection between the RNFLD and a circle centered on the disc with a radius half the distance between the disc and the fovea. Slopes for the RNFLD angle, macular ganglion cell layer thickness (GCCT), and circumpapillary RNFL thickness (cpRNFLT) were compared with the MD slope, as measured with the Humphrey field analyzer 24-2 program.ResultsThe correlation coefficients with MD slope were −0.67 for the RNFLD angle slope (P < 0.001), 0.15 for the macular GCCT slope (P = 0.163), and 0.04 for the cpRNFLT slope (P = 0.719). The RNFLD angle tended to increase as the number of disc hemorrhage occurrences increased (rs = 0.31, P = 0.004). The RNFLD angle slope also had good predictive power for glaucoma progression (area under the receiver operating characteristic curve = 0.88, 95% confidence interval = 0.81–0.95).ConclusionsWe found that the RNFLD angle slope was more closely associated with the MD slope than were other OCT parameters. This suggests that measurement of the RNFLD angle with en face OCT images could be effective in evaluating glaucoma progression.Translational RelevanceOur study provides a method for monitoring glaucoma progression with SS-OCT.

Cortical Atrophy Predicts Visual Performance in Long-Term Central Retinal Disease; GCL, pRNFL and Cortical Thickness Are Key Biomarkers.

PurposeThe aim of this study was to assess both retinal and cortical structure in a cohort of patients with long-term acquired central retinal disease in order to identify potential disease biomarkers and to explore the relationship between the anterior and posterior visual pathways.MethodsFourteen participants diagnosed with long-term central retinal disease underwent structural assessments of the retina using spectral-domain optical coherence tomography, including macular ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (pRNFL) thickness. Structural magnetic resonance imaging was used to measure visual cortex, including cortical volume of the entire occipital lobe and cortical thickness of the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively.ResultsMean thickness was significantly reduced in both the macular GCL and the inferior temporal pRNFL across patients. Cortical thickness was significantly reduced in both the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively. Disease duration significantly correlated with GCL thickness with a large effect size, whereas a medium effect size suggests the possibility that cortical thickness in the occipital pole may correlate with visual acuity.ConclusionsLong-term central retinal disease is associated with significant structural changes to both the retina and the brain. Exploratory analysis suggests that monitoring GCL thickness may be a sensitive biomarker of disease progression and reductions in visual cortical thickness may be associated with reduced visual acuity. Although this study is limited by its heterogeneous population, larger cohort studies would be needed to better establish some of the relationships detected between disease dependent structural properties of the anterior and posterior visual pathway given the effect sizes reported in our exploratory analysis.

Normative data and repeatability for macular ganglion cell layer thickness in healthy Swedish children using swept source optical coherence tomography

BackgroundOptical coherent tomography (OCT) technology is evolving with improved resolution and accuracy in segmentation between different cell layers in the retina. The ganglion cell layer in the macula region is a window to see what is happening in the visual pathways and a macula OCT is an examination that most children tolerate. This makes updated normative data necessary since variables may differ between different OCT devices and normative data for children is often not presented.The aim of this study was to develop normative data for macular ganglion cell layer thickness in children, measured with swept source OCT, and investigate the repeatability between measurements.MethodsHealthy Swedish children between 4 and 16 years old, with normal refraction, spherical equivalent mean:1.13 (sd:0.66) dioptre and normal visual acuity Logmar, mean: 0,015 (sd:0,05), were examined with swept source OCT. Macula OCT was performed three times in both eyes and the different retinal layers were evaluated.ResultsFifty-eight children were screened for inclusion. Fifty-five children were included in the study, 24 boys and 31 girls. Mean age was 8.9 years. Results from right eyes was analysed. The mean average thickness of macular ganglion cell layer thickness, retinal nerve fibre layer/ganglion cell layer boundary to inner plexiform layer/inner nuclear layer boundary, was 68.0 μm (sd:4.0, range:58-77). There was no correlation with sex or age. Fifty-three children manage to complete two, and 41 children three acceptable measurement and the mean coefficient of variation was low.ConclusionThe ganglion cell layer thickness differs according to which OCT device that is used, and the population examined. This makes normative data essential to accurately interpret results. Swept source OCT of the macula have excellent repeatability and the examination well tolerated in most children making it an investigation useful for diagnosing and following diseases in the optic pathways.

Impact of Glaucoma Severity on Rates of Neuroretinal Rim, Retinal Nerve Fiber Layer, and Macular Ganglion Cell Layer Thickness Change

To determine the impact of glaucoma severity on rates of change of minimum rim width (MRW), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) thickness. Prospective, cohort study. Glaucoma patients and healthy subjects had optical coherence tomography scans at 6-month intervals. Individual rates of change for MRW, RNFL, and GCL thickness were estimated with ordinary least-squares regression. Linear mixed-effect models were used to estimate the rate of change of each parameter and evaluate the impact of glaucoma severity (expressed by visual field mean deviation, MD) and age on these rates. A total of 132 glaucoma patients and 57 healthy subjects were followed for a median of 4.3 years and 3.7 years, respectively. Healthy subjects had a statistically significant deterioration in MRW (-1.66 µm/year), RNFL (-0.46 µm/year), and GCL thickness (-0.22µm/year). While glaucoma patients had a faster rate of change in each parameter compared with healthy subjects, only GCL thickness showed a statistically significant group difference (mean difference: -0.17 µm/year; P=.03). Older baseline age was associated with faster GCL thickness change (-0.07 µm/year; P=.03), but not other parameters. Baseline MD had no impact on the subsequent rates of change in any of the parameters. The rates of MRW, RNFL, and GCL thickness change were not significantly influenced by glaucoma severity at baseline; however, GCL thickness was able to statistically contrast the rate of change between healthy subjects and glaucoma patients throughout the disease spectrum.

Retinal nerve fibre layer and ganglion cell layer thickness changes following intravitreal aflibercept for age-related macular degeneration

Purpose To evaluate the effect of intravitreal aflibercept (IVA) injections on peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) in neovascular age-related macular degeneration (nAMD) patients during a 1-year follow-up. Methods This is a prospective study including 34 patients who were treated with aflibercept for treatment-naive nAMD. Following a loading phase of 3-monthly aflibercept, re-injections were performed on a pro re nata regimen for 12 months. Best-corrected visual acuity, intraocular pressure, and spectral-domain-optical coherence tomography analysis were performed at baseline and 1 month, 3 months, 6 months, and 12 months following treatment. Peripapillary RNFLT and macular GCLT along with the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) were evaluated at each visit. Results Mean number of aflibercept injections was 6.0 ± 1.8. Significant thinning was observed at the central macular ganglion cell layer and at 1 mm superior, temporal, and nasal ganglion cell layer compared to baseline at 1-year (p < 0.05). No significant change of RNFLT was shown (p > 0.05). Mean CMT and SFCT were significantly reduced after IVA therapy (p < 0.05, for both). No correlation was found between injection number and GCLT change. Conclusions Intravitreal aflibercept caused significant ganglion cell layer thinning during a 1-year follow-up without any changes in RNFLT. Intravitreal aflibercept itself may have a chance to induce decreased GCLT in nAMD patients.

Choroidal thickness changes in post-COVID-19 cases.

The current study aimed to evaluate the effects of the coronavirus disease 2019 (COVID-19) on choroidal thickness using enhanced depth imaging optical coherence tomography. This study evaluated the right eyes from 41 post-COVID-19 cases (Group 1) and 41 healthy subjects (Group 2). Choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Post-COVID-19 cases were evaluated within 1 month after a diagnosis of COVID-19. Two experienced ophthalmologists measured the choroidal thickness at the subfovea, temporal, and nasal quadrants at 500-μm intervals up to 1500 μm from the fovea at seven different points. Moreover, central macular thickness and ganglion cell layer thickness were measured via OCT, after which both two groups were compared. Group 1 showed a significantly thicker choroid compared to Group 2 at the subfovea, 500 μm temporal to the fovea, 500 and 1000 μm nasal to the fovea (p=0.011, p=0.043, p=0.009, and p=0.019, respectively). Although other areas measured were also thicker in Group 1, the difference was not significant (p>0.05). Moreover, no significant difference in the central macular thickness and ganglion cell layer thickness were observed between the groups (p>0.05). Choroidal thickness was increased in post-COVID-19 patients, which might be related to inflammation associated with the pathogenesis of COVID-19.

Diagnostic accuracy of total macular and ganglion cell layer thickness in differentiating different stages of glaucoma: an SD-OCT study

Purpose: To determine the diagnostic accuracy of mean macular retinal thickness (mRT) and macular ganglion cell layer (mGCL) thickness measured by Spectralis spectral-domain optical coherence tomography (SD-OCT) posterior pole thickness map (PPTM) in differentiating between normal and glaucoma eyes of different severity.Study design: Cross-sectional study.Methods: All subjects were divided into normal and glaucoma groups according to the visual fields-based Glaucoma Staging System. They underwent slit-lamp examination, Humphrey visual field test, and SD-OCT (PPTM) imaging. mRT and mGCL thickness measurements were recorded. Analysis of variance with the least significant difference post hoc test was used for pairwise comparison. Ability to discriminate between normal eyes and those with differing severity of glaucoma was assessed using the area under the receiver operating characteristic curve (AUROC).Results: A total of 201 eyes from 201 subjects were enrolled in this study. The mean glaucoma was 290.2 ± 12.1 μm, 270.1 ± 17.0 μm, and 259.1 ± 15.0 μm, respectively. Mean mGCL thickness for the corresponding three groups was 32.3 ± 2.8 μm, 27.6 ± 3.3 μm and 22.2 ± 3.8μm, respectively. AUROC analysis showed excellent diagnostic discrimination between glaucoma and normal subjects for mRT (AUC: 0.90) and mGCL thickness (AUC: 0.92). The cut-off value of mRT was 274.9 μm (90% sensitivity, 75% specificity) and of mGCL thickness was 27.9 μm (93% sensitivity, 74% specificity). The discrimination ability performance of mRT and mGCL thickness deteriorated with increasing severity of glaucoma with mGCL thickness (AUC: 0.67–0.87) performing slightly better than mRT for all grades (AUC: 0.58–0.71).Conclusions: mRT and mGCL thickness measurement on PPTM showed great sensitivity and specificity to discern between normal and glaucomatous subjects. The discrimination ability of mRT and mGCL thickness, however, decreases with increasing grade of glaucoma. We believe SD-OCT PPTM offers an alternative imaging method to detect early glaucoma.

Retinal nerve fibre layer and ganglion cell layer changes in children who recovered from COVID-19: a cohort study

ObjectiveTo investigate the optic nerve and macular parameters of children who recovered from COVID-19 compared with healthy children using optical coherence tomography (OCT).DesignCohort study.SettingHospital Clinico San Carlos, Madrid.PatientsChildren between 6...

Reproducibility of Retinal Nerve Fiber Layer and Macular Ganglion Cell Layer Thickness Measurements by Optical Coherence Tomography in Myopic Eyes.

In myopic eyes, reproducibility of circumpapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer thickness measurement by optical coherence tomography (OCT) showed excellent reproducibility except for the temporal quadrant RNFL thickness measurement. The aim of this study was to evaluate the long-term reproducibility of circumpapillary RNFL and macular ganglion cell-inner plexiform layer (GCIPL) thickness measurements using OCT in myopic eyes. Sixty-five eyes with moderate-to-high myopia (spherical equivalent <-3.0 D, myopia group) and 53 eyes with low-to-no myopia (spherical equivalent ≥-3.0 D, control group) without ocular disorders, such as glaucoma or retinal diseases, were included. Three serial OCT scans recorded at 1-year intervals were analyzed. Reproducibility was evaluated using within-subject SD (Sw), coefficient of variation (CVw), and intraclass correlation coefficient (ICC). Mean±SD refractive error was -0.30±0.80 and -6.26±2.45 D for control and myopia groups, respectively. The myopia group had thinner superior, inferior, and nasal quadrant RNFL, thicker temporal quadrant RNFL, and thinner GCIPL than the control group (P<0.05), except for the minimum and superotemporal GCIPL thicknesses (P>0.05). The myopia group had lower reproducibility in temporal quadrant RNFL thickness (Sw, 2.57 μm; CVw 3.27%; ICC, 0.979) than the control group (Sw, 1.80 μm; CVw 2.59%; ICC, 0.989), whereas in other sectors of RNFL and all GCIPL parameters, comparable reproducibility was observed between the 2 groups. Long-term reproducibility of RNFL and GCIPL thickness measurements in moderate-to-high myopia was comparable to that of low-to-no myopia, except RNFL thickness in the temporal quadrant. These findings should be considered when detecting RNFL and GCIPL changes.

Plasma homocysteine and macular thickness in older adults-the Rugao Longevity and Aging Study.

To determine the association of plasma homocysteine levels with retinal layer thickness in a large community cohort of older adults. The Rugao Longevity and Ageing Study is an observational, prospective and community-based cohort study. A total of 989 older adults who underwent spectral-domain optical coherence tomography (SD-OCT) were included and analyzed. Foveal, macular retinal nerve fibre layer (mRNFL) and ganglion cell layer plus inner plexiform layer (GC-IPL) thicknesses were measured by SD-OCT. Plasma homocysteine levels were measured using chemiluminescence immunoassay. Linear regression analyses were performed to evaluate the relationship between plasma homocysteine and retinal layer thickness while controlling for confounding factors. Of the 989 participants, 500 (50.56%) were men. The mean age was 78.26 (4.58) years, and the mean plasma homocysteine level was 16.38 (8.05) μmol/L. In multivariable analyses, each unit increase in plasma homocysteine was associated with an 8.84 × 10-2 (95% CI: -16.54 × 10-2 to -1.15 × 10-2, p = 0.032) μm decrease in the average inner thickness of the GC-IPL after controlling for confounding factors. The association remained significant even in participants without major cardiovascular disease or diabetes (β = -10.33 × 10-2, 95% CI: -18.49 × 10-2 to -2.18 × 10-2, p = 0.013). No significant associations of plasma homocysteine levels with macular thickness or mRNFL were found in primary and sensitivity analyses (p > 0.05). Increased plasma homocysteine levels are associated with a thinner GC-IPL. Plasma homocysteine may be a risk factor for thinner retinas in older adults.

Correlation of Ocular Biometric Parameters and Macular Ganglion Cell Layer in Normal Eyes

ABSTRACT Purpose To determine the association between ocular biometric parameters and macular ganglion cell layer (MGCL) thickness in normal eyes. Methods This observational cohort study was conducted with 76 eyes of 76 healthy subjects. Keratometry, pachymetry, corneal volume, iridocorneal angle were measured with Sirius (CSO, Florence, Italy); axial length, anterior chamber depth, anterior chamber volume, corneal diameter were measured with IOL Master (Carl Zeiss Meditec, Dublin, California). For all participants, serial horizontal Spectralis Domain Optical Coherence Tomography (SD-OCT, Heidelberg Engineering, GmbH, Dossenheim, Germany) scans of the macula and peripapillary retinal nerve fiber layer (RNFL) analysis were obtained using SD-OCT. The relationship between numerical variables was given by Pearson correlation coefficient. Results The mean age of the subjects was 36.3 ± 11.9 years (between 19 and 70 y). Fifty-one patients were female (67.1%) and twenty-five patients were male (32.9%). MGCL was found to be correlated with anterior chamber depth, anterior chamber volume, iridocorneal angle, axial length and white to white (p = .015 r = 0.594, p = .002 r = 0.365, p = .013 r = 0.299, p = .004 r = 0.335, p = .013 r = 0.289, respectively). In addition, MGCL was correlated positively with the mean global and superotemporal RNFL (p ≤ 0.005). However, neither central corneal thickness nor keratometry values were found to be correlated with MGCL. Conclusion The results of this study showed that MGCL thickness is affected by ocular biometric parameters. Therefore, these parameters should be taken into consideration when interpreting MGCL thickness measurements in the diagnosis of glaucoma.

High-Pass Visual Acuity Loss and Macular Structure-Function Relationship in Patients With Primary Open-Angle Glaucoma.

PurposeThe Logarithm of the Minimum Angle of Resolution (logMAR) chart is the most common clinical test for assessing central visual function in glaucoma. However, based on the use of these charts, visual acuity (VA) often remains normal even when severe macular damage exists. Here, we aim to investigate the potential advantages of high-pass VA in detecting glaucoma compared with conventional VA.MethodsMonocular best-corrected VA measurements were compared for a novel high-pass electronic VA chart (e-chart) and a conventional e-chart in 113 primary open-angle glaucoma (POAG) patients with normal logMAR VA and 65 age-similar healthy controls. One hundred thirty-nine POAG patients underwent spectral-domain optical coherence tomography (SD-OCT) for measurement of macular ganglion cell layer plus inner plexiform layer (GCL+IPL) thickness. Structure-function relationships between OCT measurements and the two VAs were compared. The enrolled eyes were divided into two groups for further analyses according to macular visual field (MVF) defects, specifically two or more adjacent abnormal points within the 12 central sites of 30-2 VF.ResultsThe mean deviation (MD) of 30-2 VF test was −12.77 ± 7.47 dB for glaucoma group and −1.70 ± 1.12 dB for control group. The mean difference of the two VAs was slightly larger in glaucoma group (0.29 logMAR) than in control group (0.22 logMAR). The area under the receiver operating characteristic curve of the high-pass e-chart was larger than that of conventional e-chart (0.917 vs. 0.757, P < 0.001). Significant correlations between high-pass VA and GCL+IPL thickness were found only in the MVF-damaged group. Compared with conventional VA, high-pass VA demonstrates stronger correlations with nasal-side macular GCL+IPL thickness (Fisher's Z-test, two-tailed, P2mm in diameter = 0.033 and P3mm in diameter = 0.005).ConclusionsCompared with conventional VA, high-pass VA displays slightly higher sensitivity to visual loss in glaucoma and has a stronger correlation with the nasal-side macular GCL+IPL thickness.Translational RelevanceThe high-pass acuity test has the potential to be used as an ancillary tool to monitor glaucoma over time.

Impact of ocular dominance on circumpapillary and macular retinal nerve fibre layer thickness and ganglion cell layer thickness in a healthy pediatric population

ObjectiveThis study was designed to evaluate potential differences in circumpapillary retinal nerve fibre layer (cpRNFL) thickness and segmented macular retinal layers between dominant and nondominant eyes on spectral-domain optical coherence tomography in a pediatric population. DesignCross-sectional study. Participants89 healthy children attending a general pediatric clinic. MethodsParticipants underwent sighting dominant testing and macular and cpRNFL spectral-domain optical coherence tomography. Segmented macular layer thicknesses and cpRNFL thickness were compared for individual patients based on their ocular dominance. ResultsOcular dominance occurred particularly in the right eye (64.7%). Dominant and nondominant eyes did not differ significantly in axial length or spherical equivalent refraction; axial length: 22.99 ± 1.17 mm versus 22.98 ± 1.19 mm; p = 0.51 and spherical equivalent refraction: −0.09 ± 2.68 D versus 0.32 ± 2.93 D; p = 0.41. In the comparison of the macular ganglion layer the average thickness in the 1 mm central Early Treatment Diabetic Retinopathy Study area was significantly different between the dominant and nondominant eye (16.56 ± 6.02 μm vs 17.58 ± 8.32 μm; p = 0.02). However, when compensating with Bonferroni, this difference was no longer statistically significant. There were no differences in the analyses of average global and sectorial cpRNFL thickness in dominant and nondominant eyes. ConclusionDominant eyes demonstrated no significantly thicker average macular retinal nerve fiber layer (mRNFL), Ganglion cell layer (GCL) thickness or cpRNFL thickness. No ocular characteristic was found to be associated with the relative dominance of an eye in eyes with low anisometropia.

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) in children.

To analyse structural characteristics and perifoveal/peripapillary vasculature by OCT in children with peripapillary hyperreflective ovoid mass-like structures (PHOMS) and compare the results with those of normal subjects. Forty-five patients (84 eyes) under 18 years old with blurry disc margin were evaluated with spectral domain-OCT and swept course-OCT. Patients were divided into four groups, according to presence of PHOMS and then the size of the existing PHOMS. Eyes with visible optic disc drusen (ODD) were not included. Foveal avascular zone (FAZ) and vessel densities from macula and optic disc area were assessed and potential associations between vessel density and structural parameters, such as peripapillary retinal nerve fibre layer (pRNFL), and macular ganglion cell and inner plexiform layer (mGCIPL) thickness, were analysed. Among 45 patients (eighty-four eyes), coexisting buried ODD were found only in eyes with PHOMS. The scleral canal diameter was significantly smaller in PHOMS positive eyes compared to control eyes. Vessel density measurements from the papillary, peripapillary and optic nerve head (ONH) regions in the large PHOMS group were significantly lower compared to the control group (papillary; P = 0.014, peripapillary; P = 0.001, ONH; P = 0.046). FAZ area and macular vessel densities showed no difference compared to normal eyes in all three PHOMS groups. pRNFL and mGCIPL thickness did not differ among four groups and correlations were also not significant. Children with PHOMS have smaller scleral canal and can entail buried ODD. Vessel densities of optic disc area in large PHOMS eyes are significantly lower than in normal eyes.

Editors' Note: Asymptomatic Optic Nerve Lesions: An Underestimated Cause of Silent Retinal Atrophy in MS

Editors' Note: Asymptomatic Optic Nerve Lesions: An Underestimated Cause of Silent Retinal Atrophy in MS

Pupillary light reflex in ethambutol-induced optic neuropathy

We evaluated changes in the pupillary light reflex (PLR) of ethambutol (EMB)-induced optic neuropathy and analyzed the correlations between PLR parameters and other structural changes in EMB-induced optic neuropathy. This retrospective, observational, case–control study involved thirty-two eyes of 17 patients with EMB-induced optic neuropathy (EON group), sixty eyes of 60 patients without EMB-induced optic neuropathy (non-EON group) while taking ethambutol, and forty-five eyes of 45 normal controls. PLR was measured by digital pupillometry. The clinical characteristics, optical coherence tomography measurements and PLR parameters including pupil diameter, constriction latency, constriction ratio/velocity, and dilation velocity were noted. The differences in PLR measurements were compared among the three groups. Correlations between PLR parameters and other structural parameters in EMB-induced optic neuropathy were evaluated. The pupillary constriction ratio, constriction and dilation velocities were significantly reduced in the EON group compared to the non-EON group and controls (all P < 0.05). In EMB-induced optic neuropathy, average outer macular ganglion cell layer (mGCL) thickness showed a significant correlation with the pupillary constriction ratio (ß = 4.14, P = 0.003) and maximal constriction velocity (ß = 1.08, P < 0.001). This study confirmed that pupillary constriction and dilation velocities were significantly decreased in patients with EMB-induced optic neuropathy, compared to normal controls. Digital pupillometry may be a useful tool in the evaluation of EMB-induced optic neuropathy.

Longitudinal changes in the macula and optic nerve in familial dysautonomia.

Familial Dysautonomia (FD) disease, lacks a useful biomarker for clinical monitoring. In this longitudinal study we characterized the structural changes in the macula, peripapillary and the optic nerve head (ONH) regions in subjects with FD. Data was consecutively collected from subjects attending the FD clinic between 2012 and 2019. All subjects were imaged with spectral-domain Optical Coherence Tomography (OCT). Global and sectoral measurements of mean retinal nerve fiber layer (RNFL) and macular ganglion cell and inner plexiform layer (GCIPL) thickness, and ONH parameters of rim area, average cup-to-disc (C:D) ratio, and cup volume were used for the analysis. The best fit models (linear, quadratic and broken stick linear model) were used to describe the longitudinal change in each of the parameters. 91 subjects (149 eyes) with FD of ages 5-56years were included in the analysis. The rate of change for average RNFL and average GCIPL thicknesses were significant before reaching a plateau at the age of 26.2 for RNFL and 24.8 for GCIPL (- 0.861µm/year (95% CI - 1.026, - 0.693) and - 0.553µm/year (95% CI - 0.645, - 0.461), respectively). Significant linear rate of progression was noted for all ONH parameters, except for a subset of subjects (24%), with no cupping that did not show progression in any of the ONH parameters. The rapidly declining RNFL and GCIPL can explain the progressive visual impairment previously reported in these subjects. Among all structural parameters, ONH parameters might be most suitable for longitudinal follow-up, in eyes with a measurable cup.

Choroidal, macular and ganglion cell layer thickness assessment in Caucasian children measured with spectral domain optical coherence tomography.

To study the subfoveal choroidal thickness (SFCT), macular ganglion cell layer (GCL-IPL) and central macular thickness (CMT) in Caucasian children, and to analyze these optical coherence tomography (OCT) parameters depending on the spherical equivalent (SE). Cross-sectional study of SFCT, GCL-IPL, and CMT in Caucasian children, analyzed with spectral-domain OCT Cirrus 5000 and Enhanced-depth imaging technique. Correlation between these three OCT parameters, age, sex, and spherical equivalent was analyzed. The eyes were classified into three groups: group 1 included eyes with SE < 0, group 2 included eyes with SE between 0 and +2.00, and group 3 eyes with SE > +2.00. Hundred ninety-eight eyes of 121 subjects were studied. The mean age was 9.22 years (range 3-16); 61.1% were female. The mean SFCT was 351.04 ± 84.08 µm, being 310.04 ± 82.84µm in group 1 (n = 62), 373.14 ± 83.16 µm in group 2 (n = 71) and 365.18 ± 73.16 µm in group 3 (n = 65); statistically significant differences were found between groups 2 and 3, compared with group 1. GCL-IPL thickness was significantly thinner (p < 0.001) in group 1, compared with group 3. There were no statistically significant differences between the three groups regarding CMT. Correlation with age, and sex was not found. SFCT and GCL-IPL thickness were significantly thinner (p < 0.001) in myopic children when compared with a non-myopic pediatric population. However, it seems that there is not a correlation among the three OCT parameters studied, age and sex, when they are analyzed depending on refractive error.

Altered visual functions, macular ganglion cell and papillary retinal nerve fiber layer thickness in early-treated adult PKU patients

PurposeRetinal changes are poorly described in early treated phenylketonuria (ETPKU). We aimed to investigate possible visual functional and ocular microstructural changes in adult patients with ETPKU. Optical coherence tomography (OCT) and its angiography (OCTA) data from patients with PKU were compared to healthy controls. MethodsIn this prospective, monocentric, cross-sectional, case-control study 50 patients with ETPKU and 50 healthy subjects were evaluated with OCT and OCTA. Measurements were performed on right eyes. The following visual function parameters were studied: best corrected visual acuity (BCVA), spherical equivalent (SE), contrast sensitivity and near stereoacuity; microstructural parameters: retinal nerve fiber layer thickness (RNFLT), ganglion cell layer (GCC) thickness, focal loss of volume (FLV), global loss of volume (GLV), peripapillary, papillary vessel density (VD), ocular axial length (AL) and intraocular pressure (IOP). ResultsAmong functional tests there were significant differences in contrast sensitivity at 1.5 (p < 0.001), 6 (p < 0.013), 12 (p < 0.001), 18 (p < 0.003) cycles per degree, in near stereoacuity (Titmus Wirt circles, p < 0.001) and in best corrected visual acuity (BCVA, p < 0.001). A statistically significant, moderate positive linear correlation was observed between BCVA and average Phe levels over the last ten years (β = 0.49, p < 0.001). The average (p < 0.001), superior (p < 0.001) inferior GCC (p < 0.001), the FLV (p < 0.003), GLV (p < 0.001) and the average RNFLT (p < 0.004) values of the PKU group were significantly lower than the controls. The serum phenylalanine level (Phe) in the PKU group negatively correlated with inferior (−0.32, p < 0.007), superior (r = −0.26, p < 0.028) and average (−0.29 p < 0.014) RNFL and with AL (−0.32, p < 0.026). In AL we detected a significant difference (p < 0.04) between the good and suboptimal dietary controlled group. There was no significant difference between the ETPKU and control group in the measured vessel density parameters and in IOP. ConclusionsOur results suggest that functional and ocular microstructural defects are present in patients with PKU, and some of them may depend on dietary control. The mechanism is unclear, but the correlation indicates the importance of strict dietary control in terms of preservation of retinal functions.