Inferior Retinal Nerve Fiber Layer Thickness Research Articles

A Deep Learning Approach to Improve Retinal Structural Predictions and Aid Glaucoma Neuroprotective Clinical Trial Design

To investigate the efficacy of a deep learning regression method to predict macula ganglion cell-inner plexiform layer (GCIPL) and optic nerve head (ONH) retinal nerve fiber layer (RNFL) thickness for use in glaucoma neuroprotection clinical trials. Cross-sectional study. Glaucoma patients with good quality macula and ONH scans enrolled in 2 longitudinal studies, the African Descent and Glaucoma Evaluation Study and the Diagnostic Innovations in Glaucoma Study. Spectralis macula posterior pole scans and ONH circle scans on 3327 pairs of GCIPL/RNFL scans from 1096 eyes (550 patients) were included. Participants were randomly distributed into a training and validation dataset (90%) and a test dataset (10%) by participant. Networks had access to GCIPL and RNFL data from one hemiretina of the probe eye and all data of the fellow eye. The models were then trained to predict the GCIPL or RNFL thickness of the remaining probe eye hemiretina. Mean absolute error (MAE) and squared Pearson correlation coefficient (r2) were used to evaluate model performance. The deep learning model was able to predict superior and inferior GCIPL thicknesses with a global r2 value of 0.90 and 0.86, r2 of mean of 0.90 and 0.86, and mean MAE of 3.72 μm and 4.2 μm, respectively. For superior and inferior RNFL thickness predictions, model performance was slightly lower, with a global r2 of 0.75 and 0.84, r2 of mean of 0.81 and 0.82, and MAE of 9.31 μm and 8.57 μm, respectively. There was only a modest decrease in model performance when predicting GCIPL and RNFL in more severe disease. Using individualized hemiretinal predictions to account for variability across patients, we estimate that a clinical trial can detect a difference equivalent to a 25% treatment effect over 24 months with an 11-fold reduction in the number of patients compared to a conventional trial. Our deep learning models were able to accurately estimate both macula GCIPL and ONH RNFL hemiretinal thickness. Using an internal control based on these model predictions may help reduce clinical trial sample size requirements and facilitate investigation of new glaucoma neuroprotection therapies. Proprietary or commercial disclosure may be found after the references.

Ganglion Cell-inner Plexiform Layer Thickness Measured by Cirrus High-definition Optical Coherence Tomography Enhances Glaucoma Diagnosis in Patients with Moderate or High Myopia

Objective: To assess the diagnostic ability of Cirrus high-definition optical coherence tomography (HD-OCT) parameters in patients with moderate or high myopia for detecting glaucoma, and to compare the thickness of the macular ganglion cell-inner plexiform layer (GC-IPL) in glaucomatous and normal eyes in both types of myopia.Materials and Methods: This prospective study enrolled moderately (spherical equivalent -3.00 to -6.00 diopters) and highly (spherical equivalent ≤ -6.00 diopters) myopic patients without (controls) and with (study) glaucoma. Cirrus HD-OCT was used to determine the thickness of the peripapillary retinal nerve fiber layer (RNFL) and the GC-IPL. The area under the receiver operating characteristic curve was analyzed to evaluate the glaucoma detection capability of each Cirrus HD-OCT parameter.Results: Seventy eyes (31 moderate myopia, 39 high myopia) were included. The parameters with the best diagnostic ability were minimum GC-IPL, inferior RNFL and average RNFL thickness in moderately myopic eyes, and average RNFL, inferior RNFL and inferotemporal GC-IPL thickness in highly myopic eyes. All parameters were thinner in glaucomatous than in normal eyes in both groups.Conclusion: Although macular GC-IPL thickness demonstrated high ability to detect glaucoma in patients with moderate or high myopia, it should be used in combination with other structural imaging and functional assessments for diagnosing glaucoma.

Associated Factors and Distribution of Peripapillary Retinal Nerve Fiber Layer Thickness in Children by Optical Coherence Tomography: A Population-based Study

To determine the distribution of peripapillary retinal nerve fiber layer (RNFL) thickness and its association with different demographic and ocular parameters in adolescents. The present study is part of the second phase of the Shahroud Schoolchildren Eye cohort study, which was conducted in 2018 by reinviting the participants in the first phase. First, preliminary ocular examinations were performed, including measurement of uncorrected and best-corrected visual acuity, autorefraction, and subjective refraction.All study participants underwent corneal imaging using Pentacam to measure central corneal thickness and corneal radius of curvature (keratometry), ocular biometry using Allegro Biograph to measure anterior chamber depth, crystalline lens thickness, and axial length (AL), and finally optical coherence tomography imaging to measure RNFL thickness as well as macular thickness and volume. The data of 4963 right eyes were analyzed after applying the exclusion criteria. The mean age of the study participants was 12.41±1.72 (9 to 15) years. The mean total, superior, inferior, temporal, and nasal RNFL thicknesses were 98.93 [95% confidence interval (CI): 98.61-99.25], 122.84 (95% CI: 122.31-123.37), 129.17 (95% CI: 128.63-129.7), 68.02 (95% CI: 67.65-68.38), and 75.69 (95% CI: 75.3-76.07), respectively. According to the results of the multivariable regression model, macular volume (β=9.81, P =0.001) had a significant direct association, and macular thickness (β=-0.01, P =0.046) had a significant inverse association with the average RNFL thickness. In addition, AL (β=-3.14, P <0.001), mean keratometry (β=-1.38, P <0.001), and central corneal thickness (β=-0.01, P =0.011) were significantly inversely related to the average RNFL thickness. We report the distribution of peripapillary RNFL thickness using spectral-domain optical coherence tomography and identify macular volume, AL, and mean keratometry as significantly associated factors in children. Our findings may serve as a database to interpret RNFL thickness results in children aged 9 to 15 years with suspected ocular disease.

Effect of oral citicoline therapy on retinal nerve fiber layer and ganglion cell-inner plexiform layer in patients with primary open angle glaucoma

To evaluate the short-term effects of oral citicoline therapy on the retinal nerve fiber layer (RNFL) and the macular ganglion cell-inner plexiform layer (mGCIPL) in patients with primary open angle glaucoma (POAG). Fifty-four eyes of 54 patients with POAG glaucoma included in the study. In addition to a topical hypotensive, 250-mg oral citicoline was administered to 27 patients, while 27 patients were assigned as the control group. RNFL and mGCIPL values were measured using optical coherence tomography (OCT) at 1d before treatment and 3mo after the initiation of treatment. At the third month visit, citicoline treatment was discontinued and drug-free control (wash-out) measurements were obtained at the fourth month in citicoline group. The average RNFL thickness was significantly higher at month 3 than the baseline (P=0.038) in citicoline group. However, this improvement partially regressed after a 1-month wash-out period. No statistically significant changes in RNFL were observed in the superior, nasal, temporal and inferior quadrants at months 3 and 4 (P>0.05). The change in the average and inferior quadrant RNFL thickness in the citicoline group at 3mo was significantly greater than the control group (P=0.006 and P=0.014, respectively). There were no significant differences between the groups according to the change in mGCIPL thickness and the superior, nasal and temporal quadrant RNFL thickness (P>0.05). With oral citicoline treatment, the loss in the average RNFL is prevented in POAG patients in the short-term. Study data show that citicoline may have a significant impact on slowing glaucoma progression, which could have a potential neuroprotective effect.

Management of Patients with Thyroid-Associated Ophthalmopathy: Role of Spectral Domain Optical Coherence Tomography

AIM: To demonstrate the changes in optic nerve head (ONH), retinal nerve fiber layer (RNFL) and macula in patients with thyroid-associated ophthalmopathy (TAO) by spectral domain optical coherence tomography (SD-OCT). &#x0D; METHODS: We included forty-one eyes of 41 patients with a diagnosis of TAO and forty-eight eyes of 48 age- and sex-matched healthy subjects (control group) from June 2016 to July 2018. The ONH parameters, RNFL and macular thicknesses in the nine macular quadrants according to ETDRS were measured with SD-OCT. Proptosis level was determined by Hertel exophthalmometer. Clinical activity score (CAS) according to the European Group of Graves' Orbitopathy (EUGOGO) guidelines was determined in all patients. &#x0D; RESULTS: Superior, inferior and average RNFL thicknesses were significantly lower in the TAO group compared to the control group (p &lt; 0.05). Optic disc area was significantly larger in the TAO group. Outer quadrant macular thicknesses and average macular thickness were significantly lower in the TAO group (p &lt; 0.05). CAS had a weak correlation with RNFL thickness and average macular thickness. &#x0D; CONCLUSION: Alterations in RNFL thicknesses and macular thicknesses according to ETDRS template can be detected before the development of ocular symptoms in patients with TAO. OCT is a convenient, non-invasive tool for the evaluation and follow-up of macular structural changes. Patients can be diagnosed at an early stage prior to the development of functional damage. However, the low number of studies investigating this subject and the conflicting findings of existing studies necessitate further studies.

Optical Coherence Tomography Findings of Nonarteritic Ischemic Optic Neuropathy

Objective: To evaluate the optical coherence tomography (OCT) parameters in patients with nonartheritic ischemic optic neuropathy (NAION) and glaucomatous optic atrophy. Material-Method: Datas of patients diagnosed with glaucomatous optic atrophy (Group 1) and NAION (Group 2) and followed-up at the the glaucoma department between 2017-2020 were retrospectively analyzed. Detailed ophthalmologic examination including demographic data, best corrected visual acuity (BCVA), intraocular pressure (IOP), central corneal thickness (CCT) obtained by ultrasonic pachymetry, retinal nerve fiber layer (RNFL) and ganglion cell complex thickness obtained by OCT (Carl Zeiss Meditec, Dublin, CA, USA). The mean and regional (superior, superotemporal, inferior, inferotemporal, temporal, nasal, superonasal, and inferonasal) RNFL and ganglion cell complex thicknesses were compared between the groups. Results: The mean age of 30 patients (14 female and 16 male) in Group 1 was 66.2 ± 12 and the mean age of 36 patients (20 male, 16 female) in Group 2 was 61.6 ± 13.05 years. Age and gender were similar between the groups (p=0.25). The mean BCVA was 0.43 ± 0.3 and 0.16 ± 0.1 in groups, respectively (p <0.01). The mean RNFL was 50.8 ± 10 µ in Group 1 and 59.05 ± 11 µ in Group 2 (p:021). The mean ganglion cell thickness was 50.2 ± 10.4 and 48 ± 15 µ in Group 1 and Group 2, respectively. It was found to be significantly thinner in Group 2 (p:0.04). The mean inferior quadrant RNFL thickness was 53.96 ± 13 and 74.18 ± 23 µ, in Group 1 and Group 2, respectively and it was significantly thinner in Group 1 (p: 0.02). There was no significant difference between the two groups in the other quadrants’ RNFL thickness. The mean inferotemporal quadrant ganglion cell thickness was significantly thinner in Group 1 and the mean superoquadrant ganglion cell thickness was significantly thinner in Group 2 (p1 <0.01, p2:0.09). Discussion: The mean ganglion cell complex thickness was found to be thinner in the NAION group. This may indicate that the ganglion cell complex is more susceptible to ischemia-related damage.

Effect of Inconsistent Optical Coherence Tomography Scan Location on Glaucoma Progression Analysis.

Circumpapillary retinal nerve fiber layer (RNFL) thickness change induced by optical coherence tomography (OCT) scan circle location displacement was not completely compensated despite the use of Guided Progression Analysis (GPA), especially when the "R1" registration method was applied. The purpose of this study was to evaluate the effect of inconsistent OCT scan location on glaucoma progression detection using GPA. Eighty-four glaucomatous eyes with at least 4 serial OCT tests were included. To evaluate the ability of OCT GPA to adjust the OCT scan location, an analysis was performed without manipulation (control set), and after the OCT scan of the latest test was intentionally moved inferotemporally (test set). The eyes were classified into the adjustment and nonadjustment groups based on the superior or inferior quadrant RNFL thickness agreement between the control and test sets. When the OCT GPA parameters between the control and test sets were compared, the test set showed a greater superior RNFL thickness and lesser inferior RNFL thickness compared with the control set (P<0.05). The eyes in the nonadjustment group (n=21, 25%) had a lower chance of applying the eye-tracking function (P=0.003) and a higher frequency of the "R1" registration method of OCT GPA (P<0.001) than the adjustment group (n=63, 75%); all eyes with the "R1" method were in the nonadjustment group and all eyes with the "R2" method were in the adjustment group. Inconsistent OCT scan location induced changes in RNFL thickness that were not completely compensated despite the use of OCT GPA, especially when the "R1" registration method was applied. These findings indicates a potential for misidentified glaucoma progression.

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

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

Retinal Nerve Fiber Layer Thickness and Associations With Cognitive Impairment in Parkinson's Disease.

ObjectiveThis study intended to investigate whether retinal nerve fiber layer (RNFL) thickness could become a potential marker in patients with Parkinson’s disease with cognitive impairment (PD-CI).MethodsFifty-seven PD patients and 45 age-matched healthy controls (HCs) were recruited in our cross-sectional study and completed optical coherence tomography (OCT) evaluations. PD with normal cognition (PD-NC) and cognitive impairment (PD-CI) patients were divided following the 2015 Movement Disorder Society criteria. RNFL thickness was quantified in subfields of the 3.0-mm circle surrounding the optic disk; while a battery of neuropsychiatric assessments was conducted to estimate the Parkinsonism severity. General linear models and one-way ANOVA were adopted to assess RNFL thickness between subgroups with different cognitive statuses; logistic regression analyses were applied to determine the relation between RNFL and PD-CI cases.ResultsCompared with HCs, more thinning of the RNFL was observed in the inferior and temporal sectors in PD patients, especially in the PD-CI group. Inferior RNFL thickness was reduced in PD-CI compared with PD-NC patients. Logistic regression analysis found that inferior RNFL thickness was independently associated with PD-CI cases (odds ratio = 0.923, p = 0.014). Receiver operating characteristic analysis showed that the RNFL-involved combined model provided a high accuracy in screening cognitive deficiency in PD cases (area under the curve = 0.85, p < 0.001).ConclusionReduced RNFL thickness especially in the inferior sector is independently associated with PD-CI patients. Our study present new perspectives into verifying possible indicators for neuropathological processes or disease severity in Parkinsonians with cognitive dysfunction.

Retinal nerve fiber layer thickness evaluation in iron deficiency anemia patients using optical coherence tomography

Background Anemia is a widespread public health problem. Iron deficiency is the most common cause of anemia. Hemoglobin (Hb) concentration was supposed to affect the retinal nerve fiber layer thickness (RNFLT).Objective The aim of this study was to evaluate the influence of iron deficiency anemia (IDA) on the peripapillary RNFLT using optical coherence tomography (OCT).Patients and methods A total of 30 patients with IDA with Hb less than 12 g/dl were enrolled in the study. Optic disk and RNFL parameters obtained by Topcon OCT in these patients were compared with those of age-matched and sex-matched nonanemic 30 individuals. The anemia group was also divided according to the Hb concentration into three groups: mild, moderate, and severe.Results The average age of the IDA cases and the controls was 23.38±9.06 years (range=15–30 years), and 25.37±7.64 years (range=15–30 years), respectively (P=0.09). The average right eye RNFLT in IDA patients was 98.20±10.98 µm compared with 106.30±14.05 µm in the control group (P=0.001), while in the left eye, it was 98.87±12.24 µm in the IDA group, and 105.30±6.59 µm in the control group (P=0.015). The average nasal and inferior RNFLT of the IDA group were thinner than the control group in the right eye (P=0.003 and 0.045, respectively) and in the left eye (P=0.016 and 0.038, respectively). There was a positive association between average RNFLT and Hb concentration in the right eye (r=0.554) and in the left eye (r=0.561), which was statistically significant (P=0.001). In addition, there was a positive correlation between nasal and inferior RNFLT and Hb concentration in the right eye (P=0.002 and 0.001, respectively) and in the left eye (P=0.001 and 0.002, respectively). The degree of thinning was related to the severity of anemia as the RNFL thinning was significantly more in severe anemia cases than in mild and moderate ones.Conclusions The peripapillary RNFLT measured by OCT was significantly thinner in the IDA patients in the average, inferior, and nasal quadrants, with more thinning in the severe than in mild and moderate groups. This finding may have a significant effect, as these pseudoglaucomatous changes could be misdiagnosed as glaucoma or other neuro-ophthalmological disorders.

Relationships Among Retinal Nerve Fiber Layer Thickness, Vascular Endothelial Growth Factor, and Cognitive Impairment in Patients with Schizophrenia.

BackgroundStudies have suggested retinal nerve fiber layer (RNFL) involvement in the pathogenesis of schizophrenia. Additionally, research has shown that vascular endothelial growth factor (VEGF) potentially contributes to the pathophysiology of psychiatric disorders. Therefore, this study aimed to investigate VEGF, RNFL, and correlations with cognitive impairments in schizophrenia patients.MethodsPatients with schizophrenia (n = 138) were compared to healthy controls (n = 160). RNFLs were measured with optical coherence tomography (OCT). The Stroop color and word test (SCWT) was used to evaluate neurocognition. Blood samples were collected to measure VEGF. SPSS 20.0 was used to perform analysis of covariance, t-tests, partial correlation analysis, and linear regression.ResultsThinner RNFLs were found in schizophrenia patients (p < 0.001). RNFL showed a significant correlation with SCWT scores (all p < 0.05). Serum level of VEGF was lower in patients with schizophrenia (p = 0.010). Total and inferior RNFL thicknesses of right eyes were positively correlated to VEGF level (RNFL total thickness p = 0.032, inferior thickness p = 0.014).Total RNFL thicknesses were shown to be reduced following a prolonged duration of illness (both p < 0.01).ConclusionThese findings suggest that patients with schizophrenia have degeneration with RNFL thickness following illness duration, which may contribute to neurocognitive impairments observed in schizophrenia. VEGF is speculated to play some important role on RNFL degeneration with schizophrenia patients.

Retinal Nerve Fibre Layer Thickness Change Following Femtosecond Laser-Assisted in situ Keratomileusis

Purpose: To evaluate the effect of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness.Methods: Thirty-seven eyes (37 patients) undergoing FS-LASIK were included in this prospective study. Optical coherence tomography (OCT) was performed 1 day before, 1 h and 1 day after FS-LASIK surgery.Result: Eighteen male and nineteen females were enrolled. Mean patient age was 22.94 ± 4.22 years. One hour postoperatively, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, macula perifovea thickness, macula perifove volume, temporal RNFL thickness, and superior RNFL thickness measures showed significant decrease (t = 6.171, 6.032, and 9.837, 9.700, 2.532, 4.393, 4.926, 2.265; p = 0.000, 0.000, 0.000, 0.000, 0.016, 0.000, 0.000, and 0.011). Day 1 post-operation, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, and inferior RNFL thickness measures showed significant change compared to preoperative measures (t = 3.620, 3.220, 2.901, 2.910, 3.632; p = 0.001, 0.003, 0.006, 0.006, and 0.001).Conclusion: Our data suggest there are alterations in retinal foveal and RNFL measurements by OCT 1 h and 1 day after FS-LASIK surgery.

Peripapillary changes after vitrectomy and silicone oil tamponade for rhegmatogenous retinal detachment.

Purpose:To evaluate the peripapillary changes after vitrectomy and silicone oil (SO) tamponade in eyes with rhegmatogenous retinal detachment (RRD).Methods:In this study, 25-gauge vitrectomy with SO tamponade was performed in 22 eyes with RRD. The radial peripapillary capillary (RPC) vessel density (VD) and retinal nerve fiber layer thickness (RNFLT) were assessed by optical coherence tomography angiography at 2, 4, 8, and 12 weeks postoperatively. The values of healthy fellow eyes were used as controls.Results:The global RPC VDs were significantly lower in the eyes with RRD than in fellow healthy eyes at 2 weeks (P < 0.001), and increased at 4 weeks, then decreased over time after surgery (F = 1.046, P = 0.377). The RPC VDs in the superior-hemifield were lower than those in the inferior-hemifield at 12 weeks postoperatively (t = −2.844, P = 0.010). The global RNFLTs decreased gradually after vitrectomy in the eyes with RRD (F = 1.312, P = 0.276). The RNFLTs in the superior-hemifield were thinner than those in the inferior-hemifield at 12 weeks postoperatively (t = −2.222, P = 0.037). The global, superior, and inferior RNFLTs were correlated with corresponding RPC VDs in the eyes with RRD at all time-points postoperatively (P < 0.05).Conclusion:RRD resulted in the decrease of RPC VDs. The RPC VDs recovered in the early postoperative period but were still lower than the normal level. Long-term application of SO tamponade resulted in the reduction of peripapillary VDs secondary to loss of RNFLTs.

Structural abnormalities associated with glaucoma using swept-source optical coherence tomography in patients with systemic sclerosis.

Vasospasm represents an early event in systemic sclerosis (SSc). Ocular vasospasm may induce optic nerve head (ONH) damage and has been involved in the pathogenesis of glaucoma, especially normal-tension glaucoma (NTG). We aimed to investigate the presence of structural abnormalities associated with NTG using swept-source optical coherence tomography (SS-OCT) and to correlate the OCT parameters with clinical, capillaroscopy and digital blood flow measures in patients with SSc. In this cross-sectional study, 40 patients with SSc and 23 age-matched controls were included. The following parameters were measured using SS-OCT: mean and sectoral retinal nerve fibre layer (RNFL) thickness, macular ganglion cell layer complex (GCC) thickness and ONH morphology. Nailfold capillaroscopy (NFC) and digital blood flow measurements using laser Doppler imaging (LDI) were performed in all subjects. Patients with SSc showed a thinner temporal RNFL than the controls (69.23 ± 11.74 versus 83.35 ± 20.19µm, p = 0.001). The other parameters were similar between the two groups. In SSc patients, there was an inverse correlation between the disease duration and the average, superior and inferior RNFL thickness and the GCC thickness and between Raynaud's phenomenon duration and the average RNFL and GCC thickness (p < 0.05). NFC and LDI measurements did not show correlations with OCT parameters. A thinner temporal RNFL and the correlation between Raynaud's phenomenon and disease duration and structural abnormalities on OCT suggest the presence of early ganglion cell damage in patients with SSc. Although mild, these findings indicate the need to monitor ocular abnormalities in SSc.

Retinal Nerve Fibre Layer Analysis in Non-Glaucomatous Pseudoexfoliation Syndrome Patients

Abstract Background Pseudoexfoliation syndrome (PXS) is a disorder characterized by the progressive accumulation of fibrillary extracellular deposits in several ocular tissues. It is an independent risk factor for glaucomatous optic nerve damage. Retinal nerve fiber layer (RNFL) thickness analysis using optical coherence tomography is a documented investigative tool to detect glaucoma at an early stage. Objective The aim was to evaluate and compare RNFL thickness in PXS patients without glaucoma with their age- and sex-matched healthy controls and detect the possibility of early glaucomatous damage in patients with RNFL thinning. Study Design This was a cross sectional case–control study. Materials and Methods A total of 100 patients were included, of which 50 were cases (Group A) and 50 were controls (Group B). RNFL thickness of cases and controls were compared using Zeiss Cirrus HD-OCT 500 (ZEISS Medical Technology, United States). Results There were no significant differences between the two groups with respect to mean RFNL thickness in nasal (p = 0.129) and temporal quadrants (p = 0.832). The mean inferior RNFL thickness values were 112.9 ± 21.72 μm in Group A and 120.6 ± 10.35 μm in Group B (p = 0.002). The mean thickness of the retinal nerve fiber layer in superior quadrant in Group A was 101.6 ± 23.16 μm, whereas it was 113.5 ± 13.47 μm in group B (p &lt; 0.001). The average RFNL thickness in Group A was 85.1 ± 13.99 μm and it was 88.9 ± 7.01 μm in Group B (p = 0.017). Conclusion There was statistically significant difference in RNFL thickness between cases and controls in inferior and superior quadrants and in global average thickness.

Effect of vitamin B12 deficiency anemia on peripapillary retinal nerve fiber layer.

To evaluate the effect of vitamin B12 deficiency anemia (BDA) on peripapillary retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT), and to determine any correlation arising thereof. In this cross-sectional observational study, 99 eyes of 50 BDA patients of age 18-65y were compared with 100 eyes of 50 healthy control subjects. All subjects underwent comprehensive clinical, ophthalmic, and hematological evaluation, followed by peripapillary RNFLT assessment using SD-OCT. The mean total, inferior, nasal, and temporal RNFLT were significantly lower in BDA group as compared to control group (P<0.05). The mean total, inferior and nasal RNFLT correlated significantly (P<0.05) with serum Hb%, B12 and mean corpuscular volume (MCV) level (r=0.310, 0.435, -0.386 for total; r=0.932, 0.481, -0.513 for inferior; r=0.344, 0.254, -0.233 for nasal; respectively), while temporal and superior RNFLT quadrant did not show any correlation with any of the hematological parameters (r=0.144, 0.167, -0.096; r=0.111, 0.070, -0.099; respectively). The mean total RNFLT showed progressive thinning at par with the progression of anemia, except in very severe BDA, where an inverse relationship was documented. The mean total, inferior, nasal, and temporal peripapillary RNFLT was significantly thinner in BDA patients. Peripapillary RNFLT thinning seemed to proceed at par with the progression of severity of anemia, except in very sever grade. Early assessment of peripapillary RNFLT may be crucial in BDA patients to prevent potential blinding sequelae. Peripapillary RNFLT thinning in BDA patients should be considered in the differential diagnosis of other non-glaucomatous optic neuropathies, as well.

Is retinal nerve fibre layer thickness correlated with visual function in individuals having optic neuritis?

ABSTRACT Clinical relevance The existence of a correlation between the results of paraclinical retinal imaging and clinical tests such as contrast sensitivity can reduce time and cost in diagnosing optic neuritis (ON). Background To demonstrate whether changes of peripapillary retinal nerve fibre layer (RNFL) thickness are correlated with the results of visual acuity, contrast sensitivity and colour vision in eyes with acute ON. Methods Thirty patients with acute ON, 23 females and seven males, who had no previous history of ON in neither eye, were examined. Inclusion criteria were: subjects had spherical refraction of less than ±5D, no prior ON or optic disc swelling, no history of amblyopia or colour blindness, and no history or ophthalmoscopic evidence of glaucoma, diabetic retinopathy, or maculopathies. Visual acuity, contrast sensitivity and colour vision were tested and optical coherence tomography was performed for all patients after complete ophthalmologic examinations including refraction, biomicroscopy, and funduscopy with a 90D lens by a neuro-ophthalmologist. Results Thirty patients who were 18–45 years old entered the study. There was an inverse correlation between contrast sensitivity and nasal (r = −0.430, p = 0.018), inferior (r = −0.503, p = 0.005) and mean (r = −0.510, p = 0.004) RNFL thickness. The multiple linear regression model, after adjustment for age and sex, showed a significant association between visual acuity and nasal RNFL thickness (coefficient = 0.025, p = 0.032). There was also a significant inverse correlation between contrast sensitivity and nasal (coefficient = −0.003, p = 0.036), inferior (coefficient = −0.006, p = 0.010) and mean (coefficient = −0.007, p = 0.012) RNFL thickness. No significant correlation was found between colour vision and RNFL thickness. Conclusion Contrast sensitivity is more correlated with changes in RNFL thickness in comparison with visual acuity and colour vision. Contrast sensitivity measurement therefore can be used as one of the first assessments in patients with ON.

Retinal Nerve Fiber Layer and Macular Thickness in Parkinson's Disease Patients.

Objective: This study aimed to evaluate the retinal nerve fiber layer (RNFL) thickness and macular thickness in Parkinson’s disease (PD) patients.Methods: The present study is a comparative cross-sectional, hospital-based study. A total number of 64 PD patients and 64 controls were recruited. Candidates that fulfilled the criteria with normal ocular examinations were undergone optical coherent tomography (OCT) examinations of the right eye. RNFL and macular thickness were evaluated.Results: There was a statistically significant reduction in RNFL thickness in average (adjusted mean 84.32 vs 95.93, p ≤ 0.001), superior (adjusted mean 105.15 vs 118.13, p ≤ 0.010), and inferior (adjusted mean 104.95 vs 126.55, p ≤ 0.001) PD group compared to the control group. The macula thickness also was significantly reduced in average (adjusted mean 266.51 vs 281.34, p = 0.015), central (adjusted mean 236.37 vs 255.55, p = 0.001), outer superior (adjusted mean 269.16 vs 278.19, p = 0.014), outer inferior (adjusted mean 256.34 vs 272.24, p ≤ 0.001), and outer nasal (adjusted mean 287.64 vs 302.84, p = 0.001) PD group compared to the control group. There was a significant positive correlation between RNFL thickness and visual acuity among PD patients in the inferior segment with p = 0.020 and nasal segment with p ≤ 0.001. There was also a significant positive correlation between macular thickness and visual acuity among PD patients in the inner temporal segment with p = 0.006, outer superior segment with p = 0.003, and outer temporal segment with p ≤ 0.001.Conclusion: The mean of the average, superior, and inferior RNFL thickness was significantly lower in the PD group compared to the control. The mean of the average, central, outer superior, outer inferior, and outer nasal macular thickness was significantly lower in the PD group compared to the control.

THE EFFECT OF CORNEAL ASTIGMATISM ON RETINAL NERVE FIBER LAYER THICKNESS AND OPTIC NERVE HEAD MEASUREMENTS BY OPTICAL COHERENCE TOMOGRAPHY

ABSTRACT Background: Optical Coherence Tomography (OCT) is a non-invasive investigative technique that functions as a type of optical biopsy. It has been an important diagnostic tool in evaluation of optic nerve head (ONH) and macula. Evaluation of OCT ONH is essential, since the thickness of the RNFL and ONH parameters can be affected in various optic neuropathies like glaucoma, optic atrophy and optic disc edema. Objective: To evaluate the effect of corneal astigmatism on retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) parameters measured with spectral-domain optical coherence tomography (OCT). Methods: Forty eyes of 32 patients were included in this study.Group I; 20 non/low astigmatic eyes to be compared with Group II; 20 astigmatic eyes (10 eyes have with the rule corneal astigmatism WTR and 10 eyes have against the rule corneal astigmatism ATR). The average corneal astigmatism in group I was -0.33±0.17 D (range -0.5-0 D), in group II it was -3.18±0.87 D (range -4.5- -2 D) in eyes of with the rule corneal astigmatism, and -3.13±0.84 D (range -4.5- -2.25 D) in eyes of against the rule corneal astigmatism. All forty eyes underwent full ophthalmic examination and performed OCT ONH imaging by SD-OCT Angio Vuein Ophthalmology Department, Faculty of Medicine, Al-Azhar University, Cairo, from January to November 2019. Results: No significant difference was noted in the disc area, rim area, vertical C/D ratio and cup volume (all P values > 0.05). There were no significant differences between the two groups in global average RNFL thickness, as well as superior, inferior, nasal and temporal quadrant RNFL thickness (P values > 0.05). Conclusions: corneal astigmatism had statistically insignificant effect on optic nerve head parameters and retinal nerve fiber layer thickness measured with spectral domain optical coherence tomography.

Evaluation of Macular and Retinal Nerve Fiber Layer Thickness in Children with Type 1 Diabetes Mellitus without Retinopathy.

PurposeThere are limited data from Asian countries regarding retinal thickness in children with type 1 diabetes mellitus (T1DM). This study aimed to compare the macular and retinal nerve fiber layer (RNFL) parameters between diabetic children without retinopathy and non-diabetic healthy children. We also evaluated the factors associated with RNFL thickness in children with T1DM.MethodsA comparative cross-sectional study was conducted among children with T1DM and healthy children aged 7 to 17 years old in Hospital Universiti Sains Malaysia from 2017 to 2019. Children with retinal disease or glaucoma were excluded. Macular and RNFL thicknesses were measured using spectral-domain optical coherence tomography. Demographic information, duration of diabetes, blood pressure, body mass index, visual acuity, and retinal examination findings were documented. Glycosylated hemoglobin levels, renal function, and blood lipid levels were also collected.ResultsForty-one children with T1DM and 80 age- and sex-matched children were enrolled. Both sexes were affected. Mean duration of diabetes mellitus was 3.66 years. The mean glycated hemoglobin levels in the T1DM group was 9.99%. The mean macular and RNFL thicknesses in children with T1DM were 277.56 (15.82) μm and 98.85 (12.05) μm, respectively. Children with T1DM had a significantly thinner average macula, superior outer macula, nasal outer macula, mean RNFL, and inferior RNFL thickness compared to controls (p < 0.05). There was a significant association between nephropathy and the mean RNFL thickness.ConclusionsChildren with T1DM had significantly decreased mean macular and RNFL thicknesses. Nephropathy is associated with an increased RNFL thickness.