Peripapillary Retinal Thickness Research Articles

Relationship between peripapillary vessel density and visual function based on Garway-Heath sectorization in open-angle glaucoma.

Purpose:To investigate the relationship between peripapillary vessel density (pVD) and visual field sensitivity (VFS) and between peripapillary retinal nerve fiber layer thickness (pRNFLT) and VFS, based on Garway-Heath sectorization in open-angle glaucoma patients.Methods:Sixty-six eyes of healthy subjects and 84 eyes of glaucoma subjects were included. All subjects underwent several eye examinations, including standard automated perimetry and optical coherence tomography angiography. Sectoral structure-function relationships based on the Garway-Heath sectorization were compared among normal subjects, the ‘mild glaucoma,’ and ‘moderate-to-severe glaucoma’ group. Multivariate analyses were performed for each sector to determine the factors related to VFS. The diagnostic abilities of vessel density parameters and RNFLT were evaluated by calculating the area under the receiver operating characteristic curves (AUROC).Results:The correlation between pVD-VFS and pRNFLT-VFS was statistically significant in the glaucoma group independent of the VFS sector. In the glaucoma group, VFS in the temportal sector was statistically related in a multivariate model to pVD, pRNFLT and age (R2 = 0.721; P = 0.007, < 0.001, .15, respectively). We found pRNFLT and age were significantly associated with VFS in glaucoma. The AUROC values of pVD in the inferotemporal sector of the total, mild, and moderate-to-severe glaucoma (0.843, 0.714, and 0.972, respectively) were comparable to pRNFLT in this sector (0.833, 0.718, 0.948, respectively).Conclusion:Since the relationship between pVD and VFS in the papillomacular area was significant, measuring pVD and RNFLT in the corresponding area will be valuable in expanding our pathophysiologic knowledge of the paracentral field defects in glaucoma.

Comment on “Study of peripapillary retinal nerve fiber layer thickness in patients of type 2 diabetes mellitus and its correlation with glycaemic control”

Comment on “Study of peripapillary retinal nerve fiber layer thickness in patients of type 2 diabetes mellitus and its correlation with glycaemic control”

Peripapillary Retinal Nerve Fiber Layer Thickness by Optical Coherence Tomography in Patients with Unilateral Amblyopia

Peripapillary Retinal Nerve Fiber Layer Thickness by Optical Coherence Tomography in Patients with Unilateral Amblyopia

Ambliyopik ve Sağlam Gözlerde Makuler Ve Retinal Sinir Lifi Tabakası Kalınlığının Karşılaştırılması

Purpose: The purpose of this study is to investigate the relationship between macular and peripapillary retinal nerve fiber layer thickness and amblyopia. Methods: A total of 56 pediatric patients with hyperopic anisometropic amblyopia were evaluated in this study. As the control group, we used the patients’ fellow eyes. A comprehensive eye examination was performed, including best-corrected visual acuity with Snellen charts (converted to logMAR for analysis), slit-lamp examination, fundus examination, cover and, cover-uncover testing, and ocular motility testing. The macular thickness, retinal nerve fiber layer thickness, axial length and optic disc area of both eyes were measured. Results: The mean age was 7.25±1.89 years. For the amblyopic and fellow eyes, the mean best-corrected visual acuity was 0.33± 0.20 logMAR and 0.0± 0.0 logMAR, respectively. Macular center thicknesses were 225,55±18,86 µm and 215,7±12,96 µm in amblyopic and fellow eyes, respectively. Macular 6mm ring thicknesses were 281,32±33,51 µm and 256,07±28,91 µm in amblyopic and fellow eyes, respectively. RNFLT were 108,39±11,59 µm and 104,61±8,43 µm in amblyopic and fellow eyes, respectively There was a statistically significant difference in the macular center thickness, in macular 6-mm ring area thickness and in RNFLT (p&lt;0.05). There was a positive correlation between visual acuity of amblyopic eyes and macular thickness and RNFLT. Conclusions: This study explored objectively measured retinal changes in amblyopia and found a slightly thicker central macular region and 6-mm ring area thicknesses and RNFLT in amblyopic compared with normal eyes.

The Effect of Acute Rises in Intraocular Pressure after Intravitreal Bevacizumab Injection on the Peripapillary Retinal Nerve Fiber Layer Thickness and the Role of Anterior Chamber Paracentesis.

Purpose:To evaluate acute changes in intraocular pressure (IOP) and their short-term effects on the peripapillary retinal nerve fiber layer (RNFL) thickness after intravitreal bevacizumab (IVB) injection.Methods:Fifty-eight eyes of 37 patients with treatment-naïve diabetic macular edema or exudative age-related macular degeneration were included in the study. Patients were divided into two groups, and the participants of each group received 3 monthly injections of IVB. IOP was measured right before the injection, immediately after the injection, and 5 min and 20 min after each injection. Peripapillary, RNFL thickness was measured before the injection and 1 month after the third injection. In the second group, anterior chamber (AC) paracentesis was performed before IVB injection.Results:IOP values after injection in all sessions were significantly higher in the first group (P < 0.001). The peripapillary RNFL thickness changes 1 month after the third injection was not statistically significantly different in each group (P = 0.816 and 0.773 for the first and second groups, respectively).Conclusion:AC paracentesis is an effective modality to reduce the acute rise in IOP. The effect of acute IOP elevation on the peripapillary RNFL thickness was not statistically significant.

Motor Asymmetry and Interocular Retinal Thickness in Parkinson's Disease.

BackgroundTo analyze the relationship between interocular difference of retinal thickness and motor asymmetry in Parkinson's disease (PD).MethodsProspective case-control series analyzed 62 eyes of 31 patients with PD and 62 eyes of 31 age- and sex-matched control. Ophthalmologic examinations including optical coherence tomography (OCT) scans were performed in both groups, and in the patients with PD, motor function was evaluated on the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) to determine the clinically more affected side. Peripapillary retinal nerve fiber layer thickness (pRNFLT) and macular retinal thickness (mRT) were measured in both eyes, after which the interocular asymmetry of the OCT parameters was determined. Additionally, the more and less affected sides of the UPDRS-III were evaluated using Symmetric index.ResultsThe average and quadrant pRNFLT and mRT values between the two groups were not different, but the interocular asymmetry of the average mRT and asymmetry index of retinal thickness (AIRT) of temporal mRT were significantly higher in the PD patients than in the controls (P = 0.026 and 0.044). The sum of UPDRS-III showed a discrepancy between the more and less affected sides (P = 0.002); the calculated Symmetric index was 0.21 ± 0.19, which suggested asymmetric motor symptoms. The Symmetric index of UPDRS-III showed significant relations for interocular asymmetry of superior mRT and AIRT of average mRT (P = 0.001 and 0.008).ConclusionIn the PD patients, the interocular asymmetry of mRT was larger than in the controls, and the motor symptoms were asymmetric. Additionally, the interocular asymmetry of mRT showed a significant correlation with motor-symptom laterality.

OCTA parameters of the peripapillary retina and optic disk in older age group

AbstractPurposeTo investigate the OCTA parameters of the peripapillary retina and optic disk in Caucasian people of an older age groupMethodsThirty‐four patients (68 eyes), 14 male and 20 female, mean age 57.1 ± 9.6 were examine. All patients underwent OCT and OCTA examination (RTVue‐XR, Optovue), by using protocol ‘HD Angio Disk’ 4.5*4.5 mm. OCT and OCTA were used to measure the radial peripapillary capillaries (RPC, %) and retinal nerve fiber layer thickness (RNFL, µm), rim area, disc area, cup volume.ResultsMean value of the RNFL thickness was 109.7 ± 11.1 µm. The lower value of the RNFL thickness was observed in ‘Tempo Inferior’ and ‘Tempo Superior’ segments. Rim area was 1.66 ± 0.33 mm2, disc area—1.87 ± 0.28 mm2. The mean value of RPC density in peripapillary retina was 52.2 ± 2.3%. The lower value of the RPC density was in ‘Nasal Inferior’ and ‘Superior Nasal’ segments, 48.9 ± 3.2% and 49.9 ± 3.1%, respectively.

Study of peripapillary retinal nerve fiber layer thickness in patients of type 2 diabetes mellitus and its correlation with glycemic control

Context: The retina of diabetic patients undergoes neurodegenerative changes, in addition to the vascular changes. Aims: The aim of this study is to evaluate the peripapillary retinal nerve fiber layer (RNFL) thickness in type 2 diabetes mellitus (DM) patients compared to healthy controls, using optical coherence tomography (OCT) and to correlate it with glycemic control. Settings and Design: Prospective study. Subjects and Methods: A total of 90 patients were enrolled in the study. The study group included 120 eyes of 60 type 2 DM patients. Sixty eyes of 30 healthy participants served as the control group. All patients underwent an OCT scan for peripapillary RNFL thickness measurement. Metabolic control of DM was assessed using glycosylated hemoglobin (HbA1c). Statistical Analysis Used: Independent sample t-test was used for normally distributed variables. Pearson's correlation analysis was used to assess the correlation between HbA1c and RNFL thickness. Results: Right eye RNFL thickness was thinner in diabetic patients than controls, with a statistically significant P value (P = 0.002) in the superior quadrant and inferior quadrant (P = 0.019). The average, superior, and inferior RNFL thickness in the left eye was significantly thinner in diabetic patients as compared to controls (P

Characterization of Retinal Microvascular and Choroidal Structural Changes in Parkinson Disease

Noninvasive retinal imaging may detect structural changes associated with Parkinson disease (PD) and may represent a novel biomarker for disease detection. To characterize alterations in the structure and microvasculature of the retina and choroid in eyes of individuals with PD and compare them with eyes of age- and sex-matched cognitively healthy control individuals using optical coherence tomography (OCT) and OCT angiography (OCTA). This cross-sectional study was conducted at the Duke Neurological Disorders Clinic in Durham, North Carolina. Individuals aged 50 years or older with a diagnosis of PD were eligible for inclusion and underwent an evaluation and diagnosis confirmation before enrollment. Control individuals aged 50 years or older and without subjective cognitive dysfunction, a history of tremor, or evidence of motor dysfunction consistent with parkinsonism were solicited from the clinic or the Duke Alzheimer's Disease Prevention Registry. Individuals with diabetes, glaucoma, retinal pathology, other dementias, and corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity worse than 20/40 Snellen were excluded. Data were analyzed between January 1, 2020, and March 30, 2020. All participants underwent OCT and OCTA imaging. Generalized estimating equation analysis was used to characterize the association between imaging parameters and PD diagnosis. Superficial capillary plexus vessel density (VD) and perfusion density (PFD) were assessed within the ETDRS 6 × 6-mm circle, 6 × 6-mm inner ring, and 6 × 6-mm outer ring, as was the foveal avascular zone area. Peripapillary retinal nerve fiber layer thickness, macular ganglion cell-inner plexiform layer thickness, central subfield thickness, subfoveal choroidal thickness, total choroidal area, luminal area, and choroidal vascularity index (CVI) were measured. A total of 124 eyes of 69 participants with PD (39 men [56.5%]; mean [SD] age, 71.7 [7.0] years) and 248 eyes of 137 control participants (77 men [56.2%]; mean [SD] age, 70.9 [6.7] years) were analyzed. In the 6 × 6-mm ETDRS circle, VD (β coefficient = 0.37; 95% CI, 0.04-0.71; P = .03) and PFD (β coefficient = 0.009; 95% CI, 0.0003-0.018; P = .04) were lower in eyes of participants with PD. In the inner ring of the 6 × 6-mm ETDRS circle, VD (β coefficient = 0.61; 95% CI, 0.20-1.02; P = .003) and PFD (β coefficient = 0.015; 95% CI, 0.005-0.026; P = .004) were lower in eyes of participants with PD. Total choroidal area (β coefficient = -1.74 units2; 95% CI, -3.12 to -0.37 units2; P = .01) and luminal area (β coefficient = -1.02 units2; 95% CI, -1.86 to -0.18 units2; P = .02) were greater, but CVI was lower (β coefficient = 0.5%; 95% CI, 0.2%-0.8%; P < .001) in eyes of individuals with PD. This study found that individuals with PD had decreased retinal VD and PFD as well as choroidal structural changes compared with age- and sex-matched control participants. Given the observed population differences in these noninvasive retinal biomarkers, further research into their clinical utility in PD is needed.

Subfoveal choroidal thickness and peripapillary retinal nerve fiber layer thickness in young obese males.

Regarding the effect of obesity on subfoveal choroidal thickness (CT) and peripapillary retinal nerve fiber layer (RNFL) thickness, controversial results have been reported in different patient groups. This study aimed to evaluate the effect of obesity on these parameters among young male subjects in comparison with age-matched non-obese healthy males. This prospective, cross-sectional study included both eyes of 50 obese young males and 50 healthy non-obese young males. The obese and the non-obese groups included subjects with a BMI of ⩾30 and ⩽25 kg/m², respectively. Subfoveal choroidal thickness and RNFL analyses were conducted by spectral domain optical coherence tomography (SD-OCT). Subfoveal choroidal thickness (321.0 ± 46.7 vs 338.4±35.3, p = 0.002) and RNFL thickness at temporal quadrant (73.4 ± 9.9 vs 76.4 ± 9.3, p = 0.008) was significantly lower in the obese group when compared to the non-obese group. The groups did not differ regarding peripapillary RNFL thickness at other quadrants (superior, inferior, or nasal) or regarding mean peripapillary RNFL thickness. Findings of this study demonstrated a negative correlation of obesity with subfoveal choroidal thickness and temporal quadrant peripapillary RNFL thickness. Larger studies on different patient groups with longer-term follow-up are warranted to better elucidate the ophthalmological effects of obesity.

Automated Evaluation of Parapapillary Choroidal Microvasculature in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

To determine whether parapapillary choroidal microvasculature (PPCMv) density as measured by optical coherence tomography angiography differs between pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG). Cross-sectional study. One hundred ninety-two eyes of 120 subjects from 2 academic referral institutions were enrolled. Automated PPCMv density was calculated using custom Matlab software in inner and outer annuli around the optic nerve region in addition to peripapillary superficial vasculature. Linear modeling was used to compare vessel densities among groups. Data from 64 eyes with PXS, 84 eyes with PXG, and 44 eyes healthy control subjects were analyzed. The differences of visual field mean deviation and peripapillary retinal nerve fiber layer thickness among study groups were statistically significant with lower values in PXG eyes compared with the PXS and control groups. Peripapillary superficial retinal vessel densities were significantly reduced in patients with PXG compared with patients with PXS and normal control subjects (all P < .001) without a difference between PXS and control eyes. Customized outer annular PPCMv density in the PXG group with a value of 11.1% (SD 5.1%) was lower than that in PXS with a value of 13.2% (SD 5.3%; P= .001). Similarly, PXS values were lower than those of control eyes with a value of 18.6% (SD 5.1%; P < .001). A progressive decrease in outer PPCMv from the control group to those with PXS without glaucoma to those with PXS and glaucoma (PXG) showed deep peripapillary vasculopathy in pseudoexfoliation syndrome. Choroidal vessel density may be affected early in the course of pseudoexfoliation before glaucoma develops.

Peripapillary retinal nerve fiber layer thickness measured using optical coherence tomography as a marker of Alzheimer's disease

AbstractBackgroundOptical coherence tomography (OCT), is an advanced, noninvasive technology that can provide the images of retinal structure, including peripapillary retinal nerve fiber layer (pRNFL), macular retinal thickness (MRT), as well as macular volume (MV). However, whether the retinal structure varied in Alzheimer's disease (AD) patients was still unclear. This study aims to detect the retinal changes of AD patients and explore their correction with severity of disease and classic biomarker.Method78 AD patients and 188 HC matched with age and sex were enrolled in this study. The pRNFL thickness, MRT and MV were assessed using OCT. In addition, Aβ42, Aβ40 and tau protein in plasma were detected using Simoa technology.ResultThe results showed that the pRNFL thickness of AD patients was significantly thinner than HC (96.76±10.44 vs 101.4±17.74, p=0.023). Compared with HC, MRT and MV were reduced in AD patients, but the differences were not significant(p&gt;0.05). Furthermore, the pRNFL thickness was significantly negatively correlated with MMSE (r=‐0.362, p=0.005) and disease duration (r=‐0.295, p=0.002); In addition, the pRNFL thickness was positively correlated with t‐tau protein in plasma(r=0.409, p=0.002); while negatively correlated with Aβ42/40 in plasma(r=‐0.277, p=0.041). However, there was no significant correction between neither MRT nor MV and MMSE, disease duration, Aβ42, Aβ40 and tau protein in plasma (p&gt;0.05).ConclusionThese results supported that pRNFL thickness measured using OCT may serve as a useful predictor of AD.

Combined Multi-Modal Assessment of Glaucomatous Damage With Electroretinography and Optical Coherence Tomography/Angiography.

PurposeTo compare the diagnostic performance and to evaluate the interrelationship of electroretinographical and structural and vascular measures in glaucoma.MethodsFor 14 eyes of 14 healthy controls and 15 eyes of 12 patients with glaucoma ranging from preperimetric to advanced stages optical coherence tomography (OCT), OCT-angiography (OCT-A), and electrophysiological measures (multifocal photopic negative response ratio [mfPhNR] and steady-state pattern electroretinography [ssPERG]) were applied to assess changes in retinal structure, microvasculature, and function, respectively. The diagnostic performance was assessed via area-under-curve (AUC) measures obtained from receiver operating characteristics analyses. The interrelation of the different measures was assessed with correlation analyses.ResultsThe mfPhNR, ssPERG amplitude, parafoveal (pfVD) and peripapillary vessel density (pVD), macular ganglion cell inner plexiform layer thickness (mGCIPL) and peripapillary retinal nerve fiber layer thickness (pRNFL) were significantly reduced in glaucoma. The AUC for mfPhNR was highest among diagnostic modalities (AUC: 0.88, 95% confidence interval: 0.75–1.0, P < 0.001), albeit not statistically different from that for macular (mGCIPL: 0.76, 0.58–0.94, P < 0.05; pfVD: 0.81, 0.65–0.97, P < 0.01) or peripapillary imaging (pRNFL: 0.85, 0.70–1.0, P < 0.01; pVD: 0.82, 0.68–0.97, P < 0.01). Combined functional/vascular measures yielded the highest AUC (mfPhNR-pfVD: 0.94, 0.85–1.0, P < 0.001). The functional/structural measure correlation (mfPhNR-mGCIPL correlation coefficient [rs]: 0.58, P = 0.001; mfPhNR-pRNFL rs: 0.66, P < 0.001) was stronger than the functional-vascular correlation (mfPhNR-pfVD rs: 0.29, P = 0.13; mfPhNR-pVD rs: 0.54, P = 0.003).ConclusionsThe combination of ERG measures and OCT-A improved diagnostic performance and enhanced understanding of pathophysiology in glaucoma.Translational RelevanceMultimodal assessment of glaucoma damage improves diagnostics and monitoring of disease progression.

Macular and peripapillary vessel density in myopic eyes of young Chinese adults

BackgroundThe aim of this study was to compare the macular and peripapillary vessel densities in eyes of young Chinese adults with different degrees of myopia and to evaluate the association of macular and peripapillary vessel densities with axial length and retinal nerve fibre layer thickness.MethodsA total of 128 eyes (mild myopia, 42; moderate myopia, 45; severe myopia, 41) underwent optical coherence tomography angiography imaging. Parameters assessed were vessel densities in the superficial capillary plexus and deep capillary plexus of the macular area, peripapillary vessel density, retinal nerve fibre layer thickness, foveal thickness and foveal avascular zone area (mm2).ResultsVessel densities in the macular and peripapillary areas as well as peripapillary retinal nerve fibre layer thickness decreased significantly when comparing high myopia to mild myopia. Axial length was significantly associated with vessel density in the macular area (superficial capillary plexus: r = −0.249, p = 0.008; deep capillary plexus: r = −0.398, p < 0.001), peripapillary area (r = −0.204, p = 0.028), foveal avascular zone area (r = −0.309, p < 0.001), and foveal thickness (r = 0.354, p < 0.001). Negative correlations were found between axial length and peripapillary vessel density as well as retinal nerve fibre layer thickness at the nasal superior, nasal inferior and inferior nasal quadrants.ConclusionVarying degrees of myopia affected macular and peripapillary vessel densities as well as retinal nerve fibre layer thickness in young healthy adults. The high myopic group had the lowest vessel density in the superficial capillary plexus, deep capillary plexus of the macular area and the peripapillary area. With increased axial length, macular and peripapillary vessel densities, retinal nerve fibre layer thickness and foveal avascular zone area reduced while foveal thickness increased.

Effect of Systemic Arterial Hypertension on Retinal Nerve Fiber Layer and Macular Thickness.

Purpose: to investigate the changes in peri-papillary retinal nerve fiber layer thickness (RNFL) and macular thickness in patients with systemic arterial hypertension compared to normotensive control eyes. Methods: This study included “40 eyes” of adult hypertensive patients (age 53.75 ± 6.60 years). The control group included “20 eyes” of age-matched participants with normal blood pressure. Peri-papillary (RNFL) and macular thickness were measured with Spectral Domain Optical Coherence Tomography (SD-OCT). Results: The mean duration of systemic hypertension was 7.07 ±1.68 years. Peri-papillary RNFL thickness was thinner at superior, inferior, nasal, temporal quadrants of RNFL and total RNFL thickness at hypertensive patient eyes group (p < 0.001 for all except nasal quadrant: p < 0.007). Macular thickness was thinner at hypertensive patient eyes group (p < 0.001 for all) compared to normotensive control eyes group. Conclusion: This study reported that both peri-papillary RNFL thickness and macular thickness showed significant thinning in patients with systemic arterial hypertension compared with healthy control eyes.

Longitudinal retinal layer changes in preclinical Alzheimer's disease.

PurposeSeveral studies found reduced retinal thickness on optical coherence tomography (OCT) in Alzheimer’s disease (AD), even in preclinical stages, labelling this technique of interest as biomarker. In this study, we examine retinal thickness changes in preclinical AD, as defined by cognitively normal individuals with amyloid‐beta (Aβ) on positron emission tomography (PET).MethodsFor this monocentre study, 145 cognitively healthy monozygotic twins aged ≥ 60 were included from the Netherlands Twin Register taking part in the EMIF‐AD PreclinAD study. At baseline, participants underwent [18F] flutemetamol PET that was visually rated for cortical Aβ. Binding potential was calculated as continuous measure for Aβ. Optical coherence tomography (OCT) was performed at baseline and after 22 months to assess changes in total and individual inner retinal layer thickness in the macular region (ETDRS circles) and peripapillary retinal nerve fibre layer thickness. Differences in rate of change between amyloid‐beta positive and negative individuals and associations between binding potential and change in retinal thickness were evaluated.ResultsSixteen participants (11%) were positive for Aβ. Change in retinal thickness did not differ in any region between Aβ+ and Aβ− individuals. A positive association between binding potential and change in inner plexiform layer thickness was observed in the inner macular ring (beta = 1.708, CI = 0.575 to 2.841, p = 0.003).ConclusionAβ+ individuals did not differ in rate of change of any retinal layer compared to controls, but higher binding potential at baseline was associated with less IPL thinning over time. Optical coherence tomography (OCT) as a longitudinal screening tool for preclinical AD seems limited, but IPL changes offer leads for further research.

Influence of Perfluorocarbon Liquids on Peripapillary Retinal Nerve Fiber-Layer Thickness Following Pars Plana Vitrectomy with Silicone Oil-Based Endotamponade.

BackgroundInner retina–layer modifications after pars plana vitrectomy (PPV) can be objectively assessed through spectral domain optical coherence tomography (SD-OCT).MethodsThis study explored prospectively changes in retinal nerve-fiber layer (RNFL) thickness with SD-OCT in eyes undergoing PPV with silicone oil–based tamponade with and without use of perfluorocarbon liquids (PFCLs) during the early postoperative phase (up to 3 months) at the Research Institute of Ophthalmology, Egypt.ResultsThirty patients were recruited who underwent PPV and silicone oil–based tamponade for either retinal detachment or diabetic retinopathy between April 2019 and September 2019. Mean RNFL thickness showed no significant change during follow-up at the first week (102.90±30.68 mm), 1 month (107.30±32.27), or three months (105.90±36.68; p=0.46, 0.68). There were significant correlations noticed between RNFL thinning and axial length of eyes, intraocular pressure, and use of PFCLs during the follow-up period.ConclusionThe RNFL tends to change postvitrectomy, but not significantly. Careful examination and consistent follow-up is required for postvitrectomy patients with larger axial length and intraoperative PFCL use.

Editors' note: Longitudinal optic neuritis-unrelated visual evoked potential changes in NMO spectrum disorders

In the article “Longitudinal optic neuritis-unrelated visual evoked potential changes in NMO spectrum disorders,” Drs. Ringelstein et al. observed progressive delays in visual evoked potential (VEP) latency, occurring independently of acute optic neuritis, in 167 patients with neuromyelitis optica spectrum disorders (NMOSD) using 548 longitudinally assessed full-field VEP studies over the course of ≥3 months. In response, Dr. Chen seeks clarification about the authors' finding of a reduction in VEP amplitude with ≥3 months of follow-up but not among those with ≥12 months of follow-up. Dr. Chen wonders whether there may be similar correlations between VEP amplitude and disease activity as seen with optical coherence tomography (OCT) measurements of the peripapillary retinal nerve fiber layer thickness—which seem to decrease in NMOSD patients with non-ocular relapses vs those with stable disease—and calls for prospective longitudinal studies with VEP, OCT, and MRI to further explore this topic. Responding to these comments, the authors note that whereas their more restricted analysis of patients with ≥12 months of follow-up was intended to address the potential amplification of measurement variability that may have occurred with their interpolation of shorter-interval data—i.e., for patients with <12 months follow-up—their sample size may have been insufficient to achieve significance for analyses of amplitude changes. Nonetheless, they note that latency findings showed consistent and reliable increases in both the main and sub-analyses. This exchange highlights the ongoing evolution of our understanding about progressive tissue damage in NMOSD, previously thought to occur only in the context of relapses. We agree with Dr. Chen that longitudinal correlation of visual tests of structure, physiology, and function will be necessary to understand how frequently subclinical progressive disease might occur in NMOSD. In the article “Longitudinal optic neuritis-unrelated visual evoked potential changes in NMO spectrum disorders,” Drs. Ringelstein et al. observed progressive delays in visual evoked potential (VEP) latency, occurring independently of acute optic neuritis, in 167 patients with neuromyelitis optica spectrum disorders (NMOSD) using 548 longitudinally assessed full-field VEP studies over the course of ≥3 months. In response, Dr. Chen seeks clarification about the authors' finding of a reduction in VEP amplitude with ≥3 months of follow-up but not among those with ≥12 months of follow-up. Dr. Chen wonders whether there may be similar correlations between VEP amplitude and disease activity as seen with optical coherence tomography (OCT) measurements of the peripapillary retinal nerve fiber layer thickness—which seem to decrease in NMOSD patients with non-ocular relapses vs those with stable disease—and calls for prospective longitudinal studies with VEP, OCT, and MRI to further explore this topic. Responding to these comments, the authors note that whereas their more restricted analysis of patients with ≥12 months of follow-up was intended to address the potential amplification of measurement variability that may have occurred with their interpolation of shorter-interval data—i.e., for patients with <12 months follow-up—their sample size may have been insufficient to achieve significance for analyses of amplitude changes. Nonetheless, they note that latency findings showed consistent and reliable increases in both the main and sub-analyses. This exchange highlights the ongoing evolution of our understanding about progressive tissue damage in NMOSD, previously thought to occur only in the context of relapses. We agree with Dr. Chen that longitudinal correlation of visual tests of structure, physiology, and function will be necessary to understand how frequently subclinical progressive disease might occur in NMOSD.

Peripapillary and Macular Vessel Density Measurement With Optical Coherence Tomography Angiography in Exfoliation Syndrome.

Although peripapillary retinal nerve fiber layer thickness (RNFLTs) and vessel density (VD) values were similar to healthy group, eyes with exfoliation syndrome had significantly lower superficial macular VDs and minimum ganglion cell analysis values. To compare peripapillary and macular perfused capillary densities with optical coherence tomography angiography (OCT-A) between patients with eyes having exfoliation syndrome (XFS) and normal age-matched healthy controls. This cross-sectional study included patients diagnosed with XFS from December 2017 to January 2020 at the Glaucoma Department. Peripapillary and parafoveal superficial VDs were obtained using OCT-A. The RNFLTs and ganglion cell analysis values were compared. Thirty-nine eyes of 39 XFS patients (26 women; mean age, 69.0±8.1 y) and 39 eyes of 39 healthy patients (25 women; mean age, 68.0±8.6 y) were enrolled. There were no statistically significant differences in sex or age distribution, central corneal thickness measurements, refractive errors, or intraocular pressures between both groups (all P>0.05). There were no statistically significant differences in the peripapillary VD or peripapillary RNFLT between XFS eyes and healthy eyes (P>0.05 for all). In the macular region, most superficial VD parameters were significantly reduced in the XFS group (P=0.02 for parafoveal VD, P=0.04 for both hemifields). While the average ganglion cell and internal plexiform layer (GCL+IPL) values were similar between groups (P=0.19), the minimum GCL+IPL value was lower in the XFS group than in the healthy group (P=0.03). Although structural test results, especially peripapillary RNFLT and mean GCL+IPL, were similar between the healthy and XFS groups, macular VD values were lower in XFS eyes. Our findings implicate microvascular damage can be the mechanism underlying XFS-related changes and indicate that it precedes significant structural damage.

Retinal nerve fibre layer thickness measured by spectral domain optical coherence tomography amongst early primary open-angle glaucoma patients at Hospital Melaka

Introduction: Glaucoma is second only to cataract as a cause of blindness worldwide and Asians account for almost half the cases. Retinal nerve fibre layer (RNFL) assessment is an important objective method for diagnosis and monitoring of glaucoma as it develops earlier than the development of visual field defects.&#x0D; Purpose: To estimate the proportion of primary open-angle glaucoma (POAG) patients with normal RNFL thickness (RNFLT) amongst early POAG patients who were under follow-up at the Ophthalmology Department, Hospital Melaka (Melaka, Malaysia).&#x0D; Study design: Observational cross-sectional study.&#x0D; Materials and methods: Consecutive sampling of 64 POAG patients who were diagnosed as early POAG as defined by the Glaucoma Staging System 2 (GSS 2) into stage 1 and 2 on Octopus visual field test were recruited in this study. Data collected included demographic data, refraction, slit-lamp examination, intraocular pressure (IOP), gonioscopy, peripapillary retinal nerve fibre layer thickness (RNFLT) measured by spectral-domain optical coherence tomography (SD-OCT), and fundus photography.&#x0D; Results: Among 64 eyes, 57.8% were found to have normal and 42.2% to have abnormal RNFLT classification. There was no difference in terms of age, gender or ethnicity between those with normal and abnormal RNFLT. Mean IOP at presentation, mean duration of POAG, and mean spherical dioptres were compared between the two groups. Only mean spherical dioptres showed a significant difference between the two groups, p &lt; 0.001. An increase of spherical dioptres also had a moderate positive correlation with RNFLT in most optic disc quadrants except the nasal, temporal, superonasal, and inferonasal quadrants.&#x0D; Conclusion: OCT cannot be used as a diagnostic tool alone, especially in early glaucoma, as it showed a normal RNFLT in almost half the patients. RNFLT in early POAG had significant correlation with spherical dioptres in most quadrants.