Tomographie par cohérence optique (OCT) en neuro-ophtalmologie

Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO), Fort Lauderdale, Florida, May 5-10, 2002.

To study the significance of optic disc tomography and retinal nerve fiber layer (RNFL) thickness measurement by spectral-domain optical coherence tomography (OCT) in the diagnosis of glaucoma. It was a noninterventional, observational study. The optic disc topographic parameters and total and regional RNFL thickness were measured by RTVue OCT in 60 normal eyes and 97 glaucomatous eyes. One-way analysis of variance was used to compare the parameters above mentioned between normal and glaucomatous groups. The area under the receiver operating characteristic curve (AUC) and the sensitivity at 80% specificity were used to assess the ability of each testing parameter in the differentiation between normal and glaucoma eyes. There were statistically significant differences in all RTVue OCT measurement parameters (F = 1.024, P = 0.596;F = 36.519, 54.464, 27.659, 36.176, 20.562, 63.833, 30.031, 54.652, 98.146, 78.705, 99.839, 43.728, 75.720, 45.709, 39.380, 33.590, 66.887, 78.335, 45.485;P = 0.000) except disc area. The average RNFL thickness in normal, early, moderate and advanced glaucomatous eyes was 109.950, 93.313, 80.374 and 65.570 µm, respectively. Among the eight regions around the optic disc, the thickest RNFL was located at the inferotemporal (150.066 µm) and superotemporal (146.285 µm) regions in normal eyes, and the superotemporal (108.569, 103.420 and 88.708 µm in early, moderate and advanced glaucomatous eyes, respectively) and inferotemporal (108.201, 102.830 and 86.369 µm in early, moderate and advanced glaucomatous eyes, respectively) regions in glaucomatous eyes. Both in normal and glaucomatous eyes, the thinnest RNFL was located at the nasal and temporal regions, respectively. For optic disc topographic parameters, the highest AUC was vertical cup/disc ratio (AUC = 0.762, 0.946 and 0.988 in early, moderate and advanced glaucomatous eyes, respectively), and the sensitivity at 80% specificity was 62.2%, 76.5% and 99.2% in early, moderate and advanced glaucomatous eyes, respectively. For RNFL thickness, the highest AUC was superotemporal region RNFL thickness (AUC = 0.915) and the sensitivity at 80% specificity was 89.5% in early glaucomatous eyes. The highest AUC was inferior average RNFL thickness (AUC = 0.967) and the sensitivity at 80% specificity was 94.1% in moderate glaucomatous eyes. The highest AUC was average RNFL thickness (AUC = 0.985) and the sensitivity at 80% specificity was 99.2% in advanced glaucomatous eyes. Among the eight regions around the optic disc, RNFL thickness of region ST (AUC = 0.915, 0.926 and 0.966 in early, moderate and advanced glaucomatous eyes, respectively) achieved the highest AUC. RNFL thicknesses of the nasal and temporal regions showed the lowest AUCs. RTVue OCT shows fair discriminating ability in distinguishing normal from glaucomatous eyes. RTVue OCT is a useful equipment for the diagnosis of glaucoma.

BackgroundMultiple sclerosis (MS) is an autoimmune disease that attacks the central nervous system, with optic neuritis (ON) being a common early manifestation. Retinal nerve fiber layer (RNFL) thickness may be a biomarker of neuroaxonal damage in MS patients. We sought to evaluate changes in RNFL thickness over 4 years in Omani MS patients with or without ON in comparison to a healthy control group.MethodsThis retrospective case-control study involved 27 MS patients and 25 healthy controls. Optical coherence tomography was performed upon first diagnosis and at a four-year follow-up. Differences in mean RNFL thickness were calculated.ResultsA total of 51 eyes from the MS group and 50 eyes from the control group were evaluated. There was a significant reduction in mean RNFL thickness among MS patients with ON at follow-up (81.21 versus 72.14 μm; P = .003), whereas no significant RNFL thinning was observed among MS patients without ON. However, there was a significant reduction in RNFL thickness among MS patients compared to healthy controls (76.79 versus 93.72 μm; P = .009), regardless of ON presence/absence.ConclusionsAxonal damage was seen in the optic nerves of Omani MS patients. Moreover, there was a significant reduction in RNFL thickness among MS patients with ON as the disease progressed; however, while there was evidence of RNFL thinning in MS patients without ON, this difference lacked statistical significance. Evaluation of RNFL thickness may represent a useful biomarker for monitoring disease progression in MS and its association with ON.

Objective To measure RNFL thickness by Frequency-domain optical coherence tomography (OCT) in patients with different stages of primary glaucoma (CACG and POAG),to evaluate the correlation between RNFL thickness and visual field mean defect (MD),to detect RNFL thickness change of early stage primary glaucoma,and to discuss the clinical significance in the early diagnosis of primary glaucoma objectively. Methods Ninety-two subjects of 40 normal and 52 with different stages of primary glaucoma were enrolled in this study.RNFL thickness was measured by Zeiss Cirru HD-OCT,and visual field was tested by Zeiss Humphrey-750.The association between visual field MD and RNFL thickness was evaluated with Pearson correlation coefficients. Results In the normal group,mean RNFL thickness was 112.91±9.36μm; the early period glaucoma group 94.43±7.67μm; the middle period glaucoma group 80.82±10.36μm; the later period glaucoma group 67.86±8.01μm.Visual field MD in each group was-0.88±1.53dB,-4.26±1.83dB,-7.43±2.64dB and -17.06±5.85dB.The differences in mean RNFL thickness and visual field MD between normal and each stage glaucoma group were significant (P ＜0.05) by independent sample t-test.In each stages of glaucoma group,mean RNFL thickness and visual field MD (early period:r =-0.537,middle period:r =-0.615,later period:r=-0.804) correlated significantly (P ＜0.05).In the early period glaucoma group,superior RNFL thickness was 116.32±11.65μm,inferior RNFL thickness 105.58±9.73μm,nasal RNFL thickness 75.40±10.91μm,and temporal RNFL thickness 70.28±13.08μm.In group B,superior RNFL thickness was 140.15±8.79μm,inferior RNFL thickness 137.29±10.07μm,nasal RNFL thickness 90.20±14.19μm,and temporal RNFL thickness 88.43±10.85μm.The difference of superior and inferior RNFL thickness between group A1 and group B had statistical significance tested by independent sample t-test,P ＜0.05; nasal and temporal RNFL thickness between group A1 and group B was tested by independent sample t-test,P ＞0.05,there was no statistical significance difference. Conclusions Frequency-domain OCT detected that the average of RNFL thickness become thinning with the progression of disease in the primary glaucoma patients,have negative correlation with vision MD,it is able to objectively reflect the degree of glaucomatous optic nerve damage.Frequency-domain OCT can show significantly decreased superior and inferior RNFL thickness of the early period primary glaucoma,which shows good ability in distinguishing normal from early period primary glaucomatous eyes. Key words: Optical coherence tomography (OCT); Retinal nerve fiber layer (RNFL); Mean defect (MD); Early diagnosis primary glaucoma

Background Both functional and morphological changes in amblyopic development are known to occur at various levels in the central visual pathway.However,whether the retina is involved or not during amblyopic progression remains controversial.Objective This study was designed to compare the thicknesses of the fovea and retinal nerve fiber layer (RNFL) of the normal fellow eye of amblyopic eye using optical coherence tomography (OCT) in children with myopic anisometropia.Methods Twenty-two patients with unilateral myopic anisometropic amblyopia were included as the anisometropia amblyopia group.Ten unilateral myopic anisometropic amblyopia subjects received treatment and recovered were used as the amblyopic cure group,and 11 individuals with simple myopic anisometropia without amblyopia were enrolled as the control group.OCT was performed on both eyes of all the subjects with informed consent.Fovea retinal thickness and RNFL thickness from the superior,inferior,nasal and temporal quadrants in the peripapillary region were evaluated.The measurement parameters were bilaterally compared in all the individuals by paired t test.The multiple regression model was used to analyze the correlation of retinal thickness with amblyopia patients.This study was approved by the Ethic Committee of this hospital.Written informed consent was obtain from each subject prior to the eye examination.Results Fovea retinal thickness increased in the amblyopic eyes compared with the fellow eyes,showing a statistically significant difference between them (P =0.001).However,no significant differences were found in the fovea retinal thickness between both eyes in the amblyopic cure group and simple myopic anisometropia without amblyopia group (P =0.778,0.943).Among the anisometropia amblyopia group,amblyopia cure group and simple myopic anisometropia without amblyopia group,the RNFL thicknesses of the temporal quadrant was significantly thicker in the higher myopic lateral eyes than those of the fellow eyes (P＜0.001,P =0.003,P =0.046).However,the differences in the superior,inferior,nasal and the average RNFL thickness were not statistically significant between the two eyes (P＞0.05).A negative correlation was found between the inferior retinal thickness with age (r=-0.559,P=0.016).Conclusions The fovea may be affected in unilateral myopic anisometropic amblyopia.There is no significant difference in the RNFL thickness between simple myopic eye and unilateral myopic anisometropia amblyopic eye.Improvement in amblyopia is coming along with the reduction of the thickness of the fovea. Key words: Refractive error/myopia; Anisometropia; Amblyopia; Optical coherence tomography; Foveal thickness; Retinal nerve fiber layer thickness

Purpose:The current study aimed to evaluate changes in peripapillary retinal nerve fiber layer (RNFL) thickness in diabetic patients with bilateral proliferative diabetic retinopathy (PDR) after receiving panretinal photocoagulation (PRP) or intravitreal bevacizumab (IVB) with PRP.Methods:Ocular examination and peripapillary optical coherent tomography (OCT) were performed for each patient at baseline, 1, 3, 6, and 10 months after treatment. Both eyes of each patient were randomized into either PRP or PRP + IVB group.Results:Sixty-four eyes (32 patients) were enrolled in this randomized clinical trial. In the PRP group, global RNFL thickness initially increased and reached statistical significance in the third month (from 105.9 ± 21.4μm at baseline to 119 ± 41.6μm at 3 months, P = 0.03). Subsequent decline was observed with no significant difference from baseline at 10 months (106 ± 19.3μm, P = 0.914). There were no statistically significant changes in the PRP + IVB group (from 101.7 ± 22.2μm at baseline to 109.3 ± 26.9μm at 3 months, P = 0.996 and 101.9 ± 16.5μm at 10 months, P = 0.999). In the latter group, slight increase in RNFL thickness was observed in the first month (107.7 ± 21.1μm). RNFL thickness was similar to baseline in the two groups at month 10, with the exception of significant increase in superior-temporal sector in the PRP group (145.3 ± 13.4μm vs. 127.2 ± 17.3μm, P = 0.045).Conclusion:Compared to eyes treated with PRP, eyes treated with adjunctive IVB showed less significant post-treatment changes in RNFL thickness.

Natural History of Leber's Hereditary Optic Neuropathy: Longitudinal Analysis of the Retinal Nerve Fiber Layer by Optical Coherence Tomography

Diagnosing pseudo-papilloedema (PPO) in children presents challenges and may lead to invasive investigations, with optic disc drusen (ODD) being the most common etiology. Other specific causes include tilted disc, optic neuritis, tumoral infiltration, vitreo-papillary traction, and Leber hereditary optic neuropathy. Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are frequently observed in these cases, yet their pathophysiology remains unexplained, particularly their relation to ODD, which is still debated. Here, we explored whether patients with PPO associated with ODD, or seemingly isolated cases, could exhibit PHOMS without ODD or ODD without PHOMS, and how this might affect retinal nerve fiber layer (RNFL) thickness. In this two-centre retrospective observational study, we included patients under 20years old presenting with PPO without specific causes, with a subgroup followed for at least one year. Enhanced depth imaging optical coherence tomography was used to assess the presence and evolution of PHOMS and ODD, as well as RNFL thickness. We included twenty-seven patients, with thirteen followed for at least one year. In all eyes, we observed concomitant PHOMS and either deep or superficial ODD. RNFL thickness was increased in patients with deep ODD and decreased in those with superficial ODD, which was observed during follow-up. ODD and PHOMS are concomitant features present in patients with PPO. PHOMS sometimes serve as indicators, as buried ODD are challenging to identify in young children. However, ODD tend to become more superficial over time, while RNFL thickness decreases. WHAT IS KNOWN : Diagnosing the cause of pseudo-papilledema (PPO) in children is challenging and often requires invasive investigations. The relationship between optic disc drusen (ODD) and peripapillary hyperreflective ovoid mass-like structures (PHOMS) in the context of PPO remains poorly understood. PHOMS and ODD seem to consistently co-occur in pediatric PPO cases where no other specific causes are identified. Retinal nerve fiber layer (RNFL) thickness increases in the presence of deep ODD and decreases as ODD become more superficial with age. RNFL thinning progresses in correlation with the patient's age.

The aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression. A total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearman's correlation coefficients and with linear regression analysis. Macular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (rho=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (rho=0.60; P<0.001). Although FD-OCT RNFL and macular thickness measurements were both correlated with VF loss, the correlation was stronger with quadrantic macular than with RNFL thickness measurements in patients with temporal hemianopia. Such measurements could potentially be used to quantify neuronal loss in patients with chiasmal compression.

Optical coherence tomography as a tool for monitoring pediatric pseudotumor cerebri

To investigate the difference of retinal nerve fiber layer (RNFL) thickness and macular fovea thickness/volume between multiple sclerosis (MS) patients and healthy normal individuals using optical coherence tomography (OCT) and assess its association with visual field parameters. Thirty consecutive MS patients and 28 healthy controls were recruited in this prospective study. Comprehensive standardized ophthalmic examinations included visual acuity, cycloplegic refraction, intraocular pressure, gonioscopy, visual field, and RNFL thickness and macular fovea thickness/volume detection using Humphrey OCT. Mean values for the thickness of the peripapillary RNFL and macular volume were calculated. Associations between visual field parameters and RNFL thickness/macular volume were analyzed by Pearson correlation analysis. The RNFL thicknesses in each quadrant, the average macular thickness, and the average macular volume in MS patients were all less than those in healthy controls, with statistically significant differences. The RNFL thickness and macular fovea thickness/volume were greater in eyes without optic neuritis than in eyes with optic neuritis. The average visual field parameters had positive correlations with the RNFL thickness and negative correlations with macular parameters in MS patients. OCT measurements can effectively identify the nerve changes of MS patients, which provide more data for the diagnosis of MS.

Objective: This study aimed to evaluate retinal nerve fiber layer (RNFL) thickness in healthy individuals with myopic and hypermetropic eyes, using optical coherence tomography (OCT).Study Design: A cross-sectional study. Place and Duration of Study: The study was carried out at the Department of Ophthalmology, Dr. Akil bin Abdul Qadir Institute of Ophthalmology, Karachi, Pakistan from January 2015 to June 2015.Methods: In this study, 300 eyes were included were examined using standard protocols by a single examiner. Subjects with a history of diabetic or hypertensive retinopathy, raised intraocular pressure (&gt; 21mmHg), and previous intraocular or laser surgery were excluded from the study. The mean retinal nerve fiber layer thickness was calculated in both myopic and hypermetropic eyes. Results: The mean global retinal nerve fiber layer thickness (RNFLT) in myopic eyes was found to be 93.98 ± 8.57 μm. In hypermetropic eyes, it was found to be 101.00 ± 6.58. This variation was found to be statistically significant with p-value of 0.001.Conclusion: We concluded that individuals with myopic eyes had significantly reduced retinal nerve fiber layer thickness whereas those with hypermetropic eyes showed an insignificant increase in RNFLT compared to emmetropic eyes.How to cite this: Mukhtar S, Hassan N, Lakhani M, Fatima U, Shaheen S, Raza I. Retinal Nerve Fiber Layer Thickness (RNFLT) in Myopic &amp; Hypermetropic Eyes in a Subset of Pakistani Population. Life and Science. 2024; 5(1): 54-60. doi: http://doi.org/10.37185/LnS.1.1.480

Objective To investigate the relationship between retinal nerve fibre layer (RNFL) thickness and peripheral neuropathy in patients with type 2 diabetes. Methods Ninety-eight cases diagnosed with type 2 diabetes in the Department of Endocrinology in Beijing Hospital from March 2014 to June 2015 were enrolled in this study. Global and sectoral RNFL thicknesses were measured at 3.45 mm diameter around the optic nerve head using optical coherence tomography(OCT), and conduction velocity of peripheral nerve was measured in all cases. According to the diagnosis of diabetic neuropathies, participants were divided into 3 groups: non-diabetic peripheral neuropathy group(NDPN, n=36), subclinical diabetic peripheral neuropathy group(SDPN, n=37) and define diabetic peripheral neuropathy group(DDPN, n=25). RNFL thickness in different group was compared by analysis of variance and least-significant difference pairwise comparison. Results All sectoral RNFL thickness was thinning from NDPN group, SDPN group to DDPN group, specially inferior quadrant RNFL thickness, and there was significant difference among the three groups((132±19), (124±18) vs (116±17)μm, F=5.848, P=0.004). And significant difference was found in inferior quadrant RNFL thickness between NDPN and SDPN group(mean difference=8.67 μm, t=1.975, P=0.048), NDPN and DDPN group (mean differenc=16.59 μm, t=3.412, P=0.001). No significant difference was found in inferior quadrant RNFL thickness between SDPN and DDPN group(mean difference=7.93 μm, t=1.661, P=0.104). Covariance analysis showed that age and diabetes duration had no significant influence on RNFL thickness. Conclusions RNFL thickness maybe associated with diabetic peripheral neuropathy in patients with type 2 diabetes, especially in serious cases. Key words: Diabetes mellitus, type 2; Retinal nerve fibre layer; Diabetic peripheral neuropathy

PurposeThe purpose of this study was to evaluate optic disk perfusion and neural retinal structure in patients with subacute Leber's hereditary optic neuropathy (LHON) and LHON carriers, as compared with healthy controls.MethodsThis study included 8 patients with LHON in the subacute stage, 10 asymptomatic carriers of a LHON-associated mitochondrial DNA mutation, and 40 controls. All subjects underwent measurement of the retinal nerve fiber layer (RNFL) thickness, the ganglion cell-inner plexiform layer (GCIPL) thickness using optical coherence tomography and optic disk microvascular perfusion (Mean Tissue [MT]) using laser speckle flowgraphy (LSFG). Patients were re-examined after a median interval of 3 months from the baseline visit.ResultsLHON carriers had higher values of RNFL thickness, GCIPL thickness, and disk area than controls (P < 0.05), whereas MT was not different between the two groups (P = 0.936). Median MT and RNFL thickness were 32% and 15% higher in the early subacute stage of the disease than in controls (P < 0.001 and P = 0.001). MT declined below the values of controls during the late subacute stage (P = 0.024), whereas RNFL thickness declined later during the dynamic stage (P < 0.001). GCIPL thickness was lower in patients with LHON than in controls independently of the stage of the disease (P < 0.001).ConclusionsThe high blood flow at the optic disk during the early subacute stage may be the consequence of vasodilation due to nitric oxide release as compensation to mitochondrial impairment. Optic disk perfusion as measured by LSFG is a promising biomarker for LHON diagnosis and monitoring as well as an objective outcome measure for assessing response to therapies.

Background: The aim was to compare the retinal nerve fibre layer (RNFL) thickness and visual evoked potentials (VEP) among eyes with multiple sclerosis (MS)‐associated optic neuritis, unaffected eyes of the same patients and eyes of disease‐free controls. Changes in RNFL thickness, visual acuity (VA) and VEP over time are evaluated in MS‐associated optic neuritis.Methods: Forty‐six eyes of 23 patients (six male and 17 female), who suffer from MS and were diagnosed with unilateral or bilateral optic neuritis, participated in the study. Forty eyes of 20 age‐ and gender‐matched controls were tested. VA measurement, optical coherence tomography and VEP were performed in all patients at presentation and at one, three and six months thereafter.Results: There was a statistically significant difference in VA between MS eyes with optic neuritis and controls (p < 0.0001), as well as between MS eyes with and without optic neuritis (p < 0.005). VA improved over time. Average RNFL thickness was reduced in MS eyes with or without optic neuritis in comparison to control eyes. This reduction in RNFL thickness was more marked over time. The amplitude of P100 was significantly decreased in MS eyes with optic neuritis in comparison to controls (p < 0.0001) and there was a statistically significant delay in peak time of P100 in MS eyes with optic neuritis versus the eyes of normal subjects (p < 0.0001), which improved over time.Conclusion: The present study suggests that there is a progressive decrease in RNFL over time in eyes with optic neuritis associated with MS. The amplitude and latency of P100 in VEP examination returned to normal ranges over time.