Superior Retinal Nerve Fiber Layer Thickness Research Articles

Correlation between glycemic control and retinal nerve fiber layer parameters in type 2 diabetics without retinopathy: a case control study

Background Retinal neurodegenerative changes were found to develop in patients with diabetes mellitus (DM) before the onset of microvascular changes of diabetic retinopathy (DR). Such changes usually affect inner retinal layers in the form of retinal nerve fiber layer (RNFL) thinning. Aim To correlate the degree of glycemic control [in the form of hemoglobin A1c (HBA1c) levels] with changes in peripapillary RNFL thickness in patients with type 2 DM without DR using optical coherence tomography (OCT). Patients and methods Participants are divided into three groups each including 28 eyes: group 1: uncontrolled type 2 DM without DR (HBA1c≥7%), group 2: controlled type 2 DM without DR (HBA1c<7%), group 3: healthy age and sex-matched controls. Peripapillary RNFL and macular ganglion cell complex (GCC) thickness were evaluated in all participants using RTVue spectral domain OCT device (Optovue, Fremont, USA). Results Peripapillary RNFL and macular GCC were significantly thinner in the uncontrolled type 2 DM group in comparison to both the controlled type 2 DM group and the healthy control group. No significant difference in OCT parameters between the controlled type 2 DM group and the healthy control group. HBA1c shows a statistically significant negative correlation with average, superior and inferior RNFL thickness as well as average, superior, and inferior GCC thickness. Conclusion Early and adequate glycemic control, indicated by HBA1c less than 7%, is of critical importance in delaying and reducing early neurodegenerative changes in the form of RNFL and GCC thinning in patients with type 2 DM without DR.

Optical Coherence Tomography Angiography Analysis of Peripapillary Choroidal Microvascular Density in normal-tension Glaucoma and Primary open-angle Glaucoma.

Glaucoma patients had a reduction in the inner annulus peripapillary choroidal microvascular density (PCMD) that became worse as the glaucoma severity progressed, which might provide new evidence supporting the vascular theory. To compare PCMD among normal-tension glaucoma (NTG), primary open-angle glaucoma (POAG), and healthy controls using optical coherence tomography (OCT) angiography (OCTA). The study included 40 POAG, 25 NTG, and 33 healthy controls. All subjects underwent OCT and OCTA testing. Inner annulus and outer annulus PCMD, as well as peripapillary vessel density (VD), was calculated. One-way analysis of variance was used to compare the vascular parameters of the three groups. Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between PCMD and glaucomatous severity factors. The spatial positional relationship between PCMD and corresponding peripapillary retinal nerve fiber layer (RNFL) thickness and visual field (VF) mean deviation (MD) was also assessed. The average and four quadrants of the inner annulus PCMD and peripapillary VD in the two glaucomatous groups were significantly lower than in normal eyes (P<0.05). Strong correlations were found between inner annulus PCMD and VF MD, peripapillary VD, and RNFL in POAG patients. Similarly, the inner annulus PCMD in NTG patients was strongly correlated with peripapillary VD and RNFL (all r>0.5). Strong positional correlations were found between inner superior quadrantal PCMD and RNFL thickness in both POAG and NTG patients (r=0.566, r=0.731, respectively). Likewise, inner inferior quadrantal PCMD exhibited a strong correlation with RNFL thickness in POAG patients (r=0.608). Strong positional correlations were also found between inner superior PCMD and VF MD in both POAG and NTG patients (r=0.589, r=0.622, respectively). Inner inferior PCMD exhibited a moderate correlation with VF MD in both POAG and NTG patients (r=0.487, r=0.440, respectively). The study found that the inner annulus PCMD decreased to varying degrees in NTG and POAG patients. The inner annulus PCMD was closely related to the structural and visual function parameters of glaucoma in both NTG and POAG. Furthermore, inner PCMD demonstrated a spatial correlation with corresponding RNFL thickness and VF MD.

Visual Field Defects and Retinal Nerve Fiber Layer Thickness in Migraine Patients: A Study From a Tertiary Care Center in India.

Background This study aimed to analyze the visual field changes and retinal nerve fiber layer (RNFL) thickness during the headache phase of migraine attacks among migraine patients compared with controls. Methodology A prospective, case-control study was conducted at a tertiary care center in Palakkad, Kerala from January 2022 to August 2023. This study included 50 migraine patients and 50 age/gender-matched controls. Adults aged 20-40 years with a more than three-year history of migraine were included in this study and those who had systemic or ocular pathologies were excluded. All 100 subjects underwent complete ocular examination, including full threshold 24-2 automated perimetry for visual field analysis and optical coherence tomography for analyzing RNFL thickness. Statistical analysis was done using SPSS Statistics Version 25 (IBM Corp., Armonk, NY, USA). Results In this study, the average age for cases was 29.24 ± 5.10 years, and for controls was 30.12 ± 6.20 years. Gender distribution was identical between cases and controls with 29 (58%) females and 21 (42%) males. Among the 50 migraine patients, 22 (44%) had generalized, while 28 (56%) had localized field defects during the headache phase of migraine attacks. There was a statistically significant (p < 0.001) difference in superior quadrant RNFL thickness between cases (114.08 ± 12.25) and controls. Conclusions We found that RNFL thinning in the superior quadrant and non-specific localized visual field changes occur during migraine attacks. We conducted this study in a tertiary care center as very few studies in our country have revealed visual field changes during migraine headache attacks.

Ocular dominance and its association with retinal thickness profile - A cross-sectional study.

The retinal thickness profile is essential for detecting ocular diseases like glaucoma and other optic neuropathies. The retinal nerve fiber layer (RNFL) thickness is affected by age, ethnicity, axial length, optic disc area, and inter-eye differences. Ocular dominance has a strong functional correlation with cerebral cortical activity. However, its relationship with RNFL thickness profile is yet to be fully established. A cross-sectional study was conducted in 136 healthy adults to study the association between ocular dominance and RNFL parameters measured by Spectral domain optical coherence tomography (SD-OCT) and to study the association of ocular dominance with other parameters such as handedness, intraocular pressure, average axial length, average keratometry, and refractive error. Sighting ocular dominance was detected using the Miles test, and sensory ocular dominance was detected using the fogging test. Visual acuity and refraction assessment were done, and the patients underwent ocular biometry using the Lenstar 900 machine to measure the axial length and keratometry. The RNFL thickness was measured using the Cirrus HD optical coherence tomographer. One hundred and thirty-two (97.06%) individuals were right-handed, four (2.94%) were left-handed, 108 (79.41%) participants were right eye dominant, and 28 (20.59%) were left eye dominant. There was 100% agreement between sighting and sensory ocular dominance. The average RNFL thickness and other measured ocular parameters were comparable in the dominant and nondominant eyes. Regardless of dominance, the left eyes in the study cohort had a greater statistically significant difference in superior RNFL thickness (P < 0.05), which correlated with increased central macular thickness. Ocular dominance occurred mostly in the right eye. The RNFL thickness profile is not associated with ocular dominance in emmetropic and mild myopic individuals with normal best corrected visual acuity.

The effect of trifocal and extended-depth-of-focus intraocular lenses on optical coherence tomography parameters.

Optical properties of commonly used multifocal and extended-depth-of-focus (EDOF) intraocular lenses (IOLs) can induce artifacts or changes in optical coherence tomography (OCT) measurements. Our purpose was to investigate the possible effects of different IOLs on peripapillary and macular OCT parameters. The preoperative and postoperative third-month peripapillary OCT and ganglion cell analysis (GCA) parameters of patients having monofocal (Alcon IQ), multifocal (PanOptix), or EDOF (Vivity) IOL implanted during cataract surgery were compared. Sixty-four eyes of 64 patients were included (21 monofocal, 24 multifocal, and 19 EDOF). Although all OCT image qualities increased postoperatively, only GCA image quality changes in the monofocal and multifocal groups reached statistical significance. Most peripapillary retinal nerve fiber layer (RNFL) and GCA parameters were similar preoperatively and postoperatively. The superior RNFL thickness in the monofocal group and the temporal RNFL thickness in the EDOF group were higher postoperatively ( P = 0.04 and P = 0.02, respectively). Most GCA and RNFL value changes between preoperative and postoperative measurements were similar between groups. In the parameters that changed, postoperative values were higher in the monofocal group ( P = 0.02 for minimum ganglion cell layer and inner plexiform layer, P = 0.04 for average RNFL). Trifocal and EDOF IOLs do not seem to have a negative effect on OCT parameters.

Retinal Nerve Fiber Layer Thickness in Patients with Schizophrenia and Its Relation with Cognitive Impairment.

Schizophrenia is a chronic severe mental illness with heterogeneous clinical presentation, course, and outcome. Cognitive impairment is one of its core features. Retinal nerve fiber layer (RNFL) imaging using OCT (optical coherence tomography) could provide easy access for in vivo imaging of the retina, rendering it as a "window to the brain." Studies done on schizophrenia have shown RNFL thinning. This study attempts to look into the association between cognitive impairment, disease duration, and RNFL abnormality in patients with schizophrenia using OCT. Patients diagnosed with schizophrenia meeting DSM 5 (Diagnostic and Statistical Manual of Mental Disorders) criteria and who were confirmed to be in remission for at least six months clinically and scoring less than three on PANSS-8 (positive and negative symptom scale-8) remission scale were included. They were administered the Montreal Cognitive Assessment Scale (MoCA) for cognitive assessment. RNFL measures were taken using spectral domain-OCT. Variables were compared using Pearson's correlation test, one-way ANOVA test, and independent t-test as appropriate. A total of 36 patients were studied. MoCA scores and RNFL thickness showed a positive correlation. Patients with schizophrenia had reduced average RNFL thickness and reduced RNFL thickness in superior, inferior, and temporal quadrants. Average RNFL thickness, Superior and inferior quadrant RNFL thickness showed a positive correlation with MoCA scores. No correlation was obtained between macular volume, macular thickness, duration of illness, and MoCA scores. Patients with schizophrenia have reduced average RNFL thickness. Patients with low MoCA scores have RNFL thinning.

Dyslipidemia and reduced retinal layer thicknesses in mild to moderate non-proliferative diabetic retinopathy.

To investigate the changes in ganglion cell layer-inner plexiform layer (GCL-IPL) thickness and its association with peripheral blood indices in non-proliferative diabetic retinopathy (NPDR). In this cross-sectional study, 132 participants were categorized into three groups: 30 healthy volunteers (control group), 50 diabetic patients with non-diabetic retinopathy (NDR group), and 52 patients with NPDR. Optical coherence tomography (OCT) was used to measure the retinal nerve fiber layer (RNFL) and GCL-IPL thicknesses in the macula. The associations between RNFL loss and systemic risk factors for DR, such as diabetes duration, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and hemoglobin A1c (HbA1c) were evaluated. The average, superior, and nasal thicknesses in the NDR and NPDR groups were significantly thinner compared to the control group (P=0.002, 0.020, 0.090, respectively). Similarly, GCL-IPL thicknesses in the 3 mm and 6 mm zones of the NDR and NPDR groups were thinner than those in the control group (P=0.040, 0.022, 0.037, respectively). Temporal thicknesses in the 3 mm range of the NDR and NPDR groups were also thinner than in the control group (P=0.010). Superior RNFL thickness was positively correlated with HbA1c (r=0.200, P=0.044), and negatively correlated with HDL (r=-0.198, P=0.047). The average inferior and nasal GCL-IPL thicknesses were negatively correlated with TC across the 3 mm zone (r=-0.211, P=0.033; r=-0.224, P=0.023; r=-0.227, P=0.022). Additionally, the average thickness of GCL-IPL in the 6-mm range were positively correlated with the duration of diabetes (r=0.196, P=0.048). This study demonstrates that dyslipidemia in diabetic patients correlates with reductions in RNFL and GCL-IPL thicknesses, suggesting a role in the pathogenesis of diabetic retinopathy.

OPTIC DISK PIT STUFFING-TO DO OR NOT TO DO.

Optic disk pit (ODP) is a subset of spectrum of congenital cavitary anomalies. Optic disk pit maculopathy causes progressive visual deterioration and is addressed with pars plana vitrectomy (PPV) with or without ODP stuffing. We report a case of progressive ODP maculopathy who was taken up for 23-G 3-port PPV, with complete vitreous removal and stuffing of the ODP with autologous sclera and sequential analysis of change in the retinal nerve fiber layer (RNFL) thickness. Spectral-domain optical coherence tomography RNFL analysis at 1 and 12 months follow-up postoperatively showed total RNFL thickness decrease from 130 µm to 103 µm respectively. Hemiquadrant analysis showed slight reduction of superior RNFL thickness from 142 µm to 139 µm. However, in the inferior hemiquadrant, the reduction in mean RNFL thickness seems to be significant from 133 µm to 100 µm at 1 and 12 months respectively. Sector-wise analysis of the RNFL thickness showed maximum reduction in the inferotemporal quadrant and other sectors seemed to be relatively preserved corresponding to the area of scleral stuffing. Retrospective or prospective analysis of RNFL health of patients undergoing surgery for ODP-M with stuffing needs to evaluated.

Retinal nerve fiber layer and ganglion cell complex thickness in diabetic smokers without diabetic retinopathy

Purpose To compare the thickness of the retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC-IPL) in smoker and nonsmoker diabetics without diabetic retinopathy. Materials and Methods Patients with diabetes were divided into two groups according to their smoking status: Group 1 consisted of 38 smoker diabetics who had chronically smoked more than 20 cigarettes per day for more than five years; Group 2 consisted of 38 nonsmoker diabetics. After a detailed ophthalmologic examination, the mean and regional (superior, supratemporal, inferior, inferotemporal, temporal, nasal, superonasal, and inferonasal) RNFL and GC-IPL thicknesses were measured with spectral-domain optic coherence tomography (SD-OCT) and compared between groups. Results The mean age was 54.7 ± 10.5 and 51.2 ± 9.7 years in the smoker and nonsmoker groups, respectively (p = 0.14). Gender, duration of diabetes, and the mean axial length were similar between groups (p:0.43, p:0.54, p: 0.52, respectively). Mean RNFL thickness was 89.1 ± 8.0 µm in the smoker group and 93.4 ± 7.0 µm in the nonsmoker group, and it was significantly thinner in the smoker group (p = 0.01). The temporal RNFL thickness in the smoker group was thinner than in the nonsmoker group (p = 0.02). There was no difference in superior, inferior, and nasal RNFL thicknesses between the groups (p = 0.31, p = 0.12, p = 0.39, respectively). The mean macular GC-IPL thickness of the smoker and nonsmoker groups was 78.53 ± 15.74 µm and 83.08 ± 5.85 µm, respectively (p = 0.09). Superior, superonasal, inferonasal, inferior, inferotemporal, and superotemporal quadrant GC-IPL thicknesses were similar between the groups (p = 0.07, p = 0.60, p = 0.55, p = 0.77, p = 0.71, p = 0.08, respectively). The groups showed no difference in minimum GC-IPL thickness (p = 0.43). There was a significant negative correlation between smoking exposure and mean, inferior quadrant RNFL thicknesses in the smoker group (p = 0.04, r= −0.32, and p = 0.01, r= −0.39, respectively). Conclusion Mean RNFL thickness was significantly thinner in smoker diabetics. Although not statistically significant, especially mean, superior, and superotemporal GC-IPL was thinner in smoker diabetics. The results suggest a potential association between the coexistence of diabetes and smoking with alterations in RNFL and GC-IPL thickness.

Evaluation of optical coherence tomography parameters before and after parenteral iron treatment of patients with iron deficiency anemia

PurposeThe aim of our study is to evaluate the relationship between iron deficiency anemia (IDA), which is a common and often chronic condition in young women, and the optical coherence tomography (OCT) findings, which have become an indispensable part of ophthalmology practice. We aim to identify a new biomarker for anemia evaluation by demonstrating the morphological changes in the eye before and after iron replacement treatment through OCT findings. Methods70 eyes of 35 patients diagnosed with IDA and planned to have parenteral iron replacement were included in the study. Patients were evaluated before treatment and between 4–6 weeks and 12–16 weeks after treatment. During visits, peripapillary and macular choroidal thicknesses and retinal nerve fiber layer (RNFL) thicknesses were evaluated with OCT along with serum hemoglobin(Hb) values. ResultsThe mean age of the patients was 36.80 ± 7.25. All 35 patients (100%) were female. The mean baseline Hb values of the patients increased statistically significantly both after 4–6 weeks and after 12–16 weeks (p < 0.05). A statistically significant difference was found between baseline and third visit in OCT findings in subfoveal, temporal, nasal, peripapillary temporal and peripapillary nasal choroidal thicknesses and total, inferior, nasal and temporal RNFL thicknes (p < 0.05). There was no statistically significant difference between the baseline and the third visit in the central macular thickness and superior RNFL thickness. ConclusionSignificant increases in choroidal and RNFL thickness were detected after parenteral iron replacement in patients diagnosed with IDA. Our results demonstrate that the changes induced by IDA on the retina can be reversed with treatment.

Optic Nerve Head Parameters in Saudi Male Young Adults Using Swept-source Optical Coherence Tomography.

To assess the optic nerve head (ONH) parameters in normal male Saudi eyes using swept-source optical coherence tomography (SS-OCT). The study included 86 healthy men with a mean age of 23.6 ± 4.82 years. The metrics collected using SS-OCT from each individual was disk area (DA), rim area (RA), cup volume (CV), linear cup-disk ratio (LCDR), vertical cup-disk ratio (VCDR), and total retinal nerve fiber layer (RNFL) thickness, superior RNFL thickness, and inferior RNFL thickness. All the metrics were correlated with the DA. The right eye data were used for the correlation analysis. The mean DA in OD was 1.78 mm2 (range 1.09-2.70 mm2). The mean RA was 1.28 mm2 (range 0.72-2.47 mm2). The DA showed a significant positive correlation (p < 0.05) with RA, cup area (CA), CV, VCDR, LCDR, and total RNFL thickness. For the first time, using sweeping source OCT (DRI OCT Triton, Topcon Corporation), a normative database of ONH parameters was made accessible to the Saudi male population. While assessing the optic disk for progressive optic neuropathies like glaucoma, disk size should be taken into consideration since the optic DA affects ONH topography, especially in Saudi eyes. Challa NK. Optic Nerve Head Parameters in Saudi Male Young Adults Using Swept-source Optical Coherence Tomography. J Curr Glaucoma Pract 2023;17(2):58-62.

Correlation between visual field and retinal nerve fiber layer thickness in adult north Indian population from Gurugram region with glaucoma suspect

: To find the correlation between visual field and retinal nerve layer thickness in adult North Indian population from Gurugram region with glaucoma suspect. Correlative and quantitative study was carried between the visual field and retinal nerve fiber layer (RNFL) thickness of 400 adult eyes. The age of subjects participating in the study ranged between 18 to 80 years with mean age 45 ± 14years. The standard automated perimetry was acquired by Humphrey visual field analyser using 24-2 SITA standard strategy. Retinal nerve fiber layer thickness was measured by Spectral Domain OCT (3D OCT2000FA). Visual field was performed on the same day or within ± three months of OCT acquisition. Statistical analysis was performed using MS Excel, SPSS (ver.20) and other descriptive statistical tools.: The mean MD and PSD were -2.79 dB ±2.21 and 2.52 dB ±1.49, respectively. The average thickness of RNFL of the four quadrants calculated was 98.40 µm±10.70. RNFL thickness in an inferior and superior quadrant was 122.49µm ± 16.71 and 118.86 µm ±15.21 respectively. The mean cup to disc area ratio (CDAR) in the glaucoma suspect subject was 0.60± 0.10, and the vertical cup to disc ratio (VCDR) was 0.74± 0.074. Correlation of the average RNFL thickness, Inferior RNFL thickness and superior RNFL thickness with GHT was 0.245(P=0.011), 0.19 (P=0.094) and 0.27, (P=0.004), respectively. Superior RNFL thickness showed a more significant Correlation (r= 0.193, P&amp;#60;0.01) with mean deviation (MD) of the visual field. Retinal nerve fiber layer thickness demonstrated a weak to mild and statistically significant correlation with the visual field. The correlation of average RNFL thickness with Visual field global indices and parameters were significant but weaker. Correlation between superior RNFL thicknesses was highest with GHT in adult North India Gurugram subjects with glaucoma suspect. Superior RNFL thickness showed a higher Correlation with Mean deviation (MD) and VFI of the visual field

Optical coherence tomography angiography evaluation of retinal and optic disc microvascular morphological characteristics in retinal vein occlusion.

To evaluate microvascular morphological characteristics of the retina and optic disc (OD) in retinal vein occlusion (RVO) patients using optical coherence tomography angiography (OCTA), compare the results to age- and gender-matched healthy subjects, and determine correlations between OCTA parameters and best-corrected visual acuity (BCVA) and age. In this retrospective study, right eyes of 53 RVO patients and 51 healthy subjects were compared regarding BCVA, as well as superficial and deep capillary plexus (SCP and DCP) vessel densities (VDs), foveal avascular zone (FAZ) parameters, outer retinal and choriocapillaris flow areas, OD whole and peripapillary VDs, and retinal nerve fiber layer thickness (RNFLT). Retinal vein occlusion patients were further divided into subgroups based on therapy and risk factors, and OCTA parameters were compared. Retinal vein occlusion rate or OCTA parameters did not differ significantly by gender (p>0.05). Retinal vein occlusion patients had significantly decreased BCVA, whole, parafoveal and perifoveal SCP and DCP VDs, as well as VDs 300µm area around FAZ (FD-300) than healthy subjects (p<0.001). Their choriocapillaris flow area, RNFLT, whole and peripapillary VDs were also affected. However, FAZ area did not differ significantly between groups. Superior RNFLT (p=0.016) and whole peripapillary VD (p<0.001) differed significantly between laser photocoagulation-treated and non-treated patients. The remaining OCTA parameters revealed no significant differences CONCLUSIONS: The RVO and its therapeutic alternatives may affect both OD and retinal VDs. Given its numerous benefits, it seems that OCTA will be used more frequently in clinics for RVO diagnosis, monitoring, and therapeutic response evaluation.

Evaluation of Retinal Nerve Fibre Layer Thickness and Choroidal Thickness in Parkinson Disease Patients

To evaluate the retinal nerve fibre layer (RNFL) thickness and choroidal thickness (CT) in Parkinson disease (PD) patients. A comparative cross-sectional, hospital-based study. 39 PD and 39 controls were recruited, who were gender and age matched. Subjects that fulfilled the inclusion criteria underwent optical coherence tomography for evaluation of RNFL thickness and choroidal thickness (CT). There was significant reduction of RNFL thickness in average (adjusted mean 88.87 µm vs. 94.82 µm, P=0.001), superior (adjusted mean 110.08 µm vs. 119.10 µm, P=0.002) and temporal (adjusted mean 63.77 µm vs. 70.36 µm, P=0.004) in PD compared to controls. The central subfoveal CT was significantly thinner in PD compared to controls (adjusted mean 271.13 µm vs. 285.10 µm, P=0.003). In PD group, there was significant weak negative correlation between the duration of PD with average RNFL thickness (r=–0.354, P=0.027), moderate negative correlation between the duration of PD with central subfoveal CT (r=–0.493, P=0.001), and weak negative correlation between the stage of PD with central subfoveal CT (r=–0.380, P=0.017). PD group had significant thinner average, superior and temporal RNFL thickness and CT compared to controls.

Retinal thickness changes in different subfields reflect the volume change of cerebral white matter hyperintensity

To investigate the relationship between the retinal thickness in different subfields and the volume of white matter hyperintensity (WMH), with the hope to provide new evidence for the potential association between the retina and the brain. A total of 185 participants aged over 40 years were included in our study. Magnetic resonance imaging (MRI) was used to image the WMH, and WMH volume was quantitatively measured by a specific toolbox. The thickness of the total retina, the retinal nerve fiber layer (RNFL), and the ganglion cell and inner plexiform layer (GCIP) was measured by optical coherence tomography (OCT) in nine subfields. The association between retinal thickness and WMH volume was demonstrated using binary logistic regression and Pearson correlation analysis. Participants were divided into two groups by the WMH volume (‰, standardized WMH volume) median. In the quartile-stratified binary logistic regression analysis, we found that the risk of higher WMH volume showed a positive linear trend correlation with the thickness of total retina (95% CI: 0.848 to 7.034; P for trend = 0.044)/ GCIP (95% CI: 1.263 to 10.549; P for trend = 0.038) at the central fovea, and a negative linear trend correlation with the thickness of nasal inner RNFL (95% CI: 0.086 to 0.787; P for trend = 0.012), nasal outer RNFL (95% CI: 0.058 to 0.561; P for trend = 0.004), and inferior outer RNFL (95% CI: 0.081 to 0.667; P for trend = 0.004), after adjusting for possible confounders. Correlation analysis results showed that WMH volume had a significant negative correlation with superior outer RNFL thickness (r = -0.171, P = 0.02) and nasal outer RNFL thickness (r = -0.208, P = 0.004). It is suggested that central fovea and outer retina thickness are respectively associated with WMH volume. OCT may be a biological marker for early detection and longitudinal monitoring of WMH.

Evaluation of retinal nerve fiber layer thickness in children with autism spectrum disorders

BackgroundThe study compared retinal nerve fiber layer (RNFL) thickness, macular thickness, and macular volume of children with autism spectrum disorder (ASD) to those of healthy control group and correlated the RNFL thickness with symptom severity in children with ASD. MethodForty children between the ages of 7 and 12 with normal intelligence levels and who were diagnosed with ASD as per DSM-5 were included in the ASD group. The control group consisted of healthy children, who were matched with subjects in the ASD group in terms of age and gender. The Autism Behavior Checklist (ABC) and Childhood Autism Rating Scale (CARS) were used to evaluate the severity of the disease in the cases diagnosed with ASD. The RNFL, macular thickness, and macular volume of all participants were measured optical coherence tomography (OCT). ResultsThe temporal, temporal superior, nasal superior, temporal inferior, and global RNFL thicknesses were significantly lower in the ASD group than in the control group. There was no correlation between the RNFL thickness and ASD symptom severity. The macular thickness and volume were not significantly different between the groups. ConclusionOur data suggest that lower RNFL thickness may relate to atypical brain development in the ASD, and this can be measured in the retina.

Corneal endothelium, retinal nerve fiber layer, ganglion cell complex, and perimetry measurements in normal eyes and those with primary open-angle glaucoma.

Corneal endothelial cell (CEC) loss in glaucoma can be attributed to the direct compressive effect of elevated intraocular pressure. Herein, we aimed to evaluate specular microscopic changes in CEC count and morphology in correlation to retinal nerve fiber layer (RNFL) changes detected by spectral-domain optical coherence tomography (SD-OCT) in early and advanced primary open-angle glaucoma (POAG). This descriptive-analytical study involved patients with medically controlled POAG versus non-glaucomatous patients of the same age group. Specular microscopy, visual field testing, and SD-OCT of the RNFL and macular ganglion cell complex (GCC) were performed. Eyes with POAG were further subcategorized into early and advanced stages. The study included 130 eyes of 130 participants; 70 were eyes with POAG (40 eyes with early-stage POAG, 30 eyes with advanced-stage POAG), and 60 were healthy eyes. The groups were comparable regarding mean age and sex. No significant difference was found in corneal parameters between healthy eyes, eyes with early POAG, and eyes with advanced POAG (all P > 0.05). In eyes with early-stage POAG, a significant negative correlation was found between the coefficient of variation (CV) and superior RNFL thickness (r = - 0.5; P = 0.018), and between the percentage of hexagonal cells (hexagonality) and vertical cup-to-disc ratio (r = - 0.43; P = 0.035). A significant positive correlation was found between hexagonality and superior as well as inferior RNFL thickness (r = + 0.53; P = 0.008 and r = + 0.50; P = 0.015, respectively). However, in the advanced glaucomatous eyes, no significant correlation was found between RNFL thickness and CEC parameters. CEC parameters were not affected in eyes with early or advanced POAG compared with healthy eyes, despite a significant thinning of RNFL and macular GCC. In eyes with early-stage POAG, a significant correlation was found between morphological characteristics of CECs, such as CV and hexagonality, with superior and inferior RNFL thickness in the optic nerve head on SD-OCT images. Future longitudinal studies with larger sample sizes are needed to verify our results.

Difference between before and after Compensating for Cyclotorsion by Optical Coherence Tomography Guided Progression Analysis

Purpose: This study evaluated the difference in parameters before and after the application of optical coherence tomography (OCT) Guided Progression Analysis (GPA) to compensate for cyclotorsion during image acquisition.Methods: Among glaucomatous eyes with ≥4 OCT tests, eyes with correction for cyclotorsion in GPA printouts defined as rotated OCT fundus images were included. The degree of cyclotorsion (i.e., the degree of fundus image rotation), direction of cyclotorsion (incyclotorsion or excyclotorsion), difference in optic nerve head (ONH) parameters, and retinal nerve fiber layer (RNFL) thickness before and after correction were analyzed.Results: Correction for cyclotorsion was seen in 33 of the 401 eyes (12.2%). Incyclotorsion was observed in 16 eyes (48.5%) and excyclotorsion in 17 (51.5%). The mean degree of cyclotorsion was 5.5 ± 2.3 degrees. The ONH parameters were unchanged after correcting for cyclotorsion. The mean overall, inferior, and superior quadrant RNFL thicknesses were 73.6 ± 14.8, 79.3 ± 26.3, and 90.1 ± 24.7 μm before correction and 73.6 ± 14.9, 79.6 ± 26.6, 89.7 ± 24.8 μm afterwards (p &gt; 0.05). The difference in RNFL thickness after correction ranged from 0 to 6 μm.Conclusions: The difference in RNFL thickness before and after cyclotorsion correction by GPA was not large. GPA did not correct the ONH parameters induced by cyclotorsion. Regarding this, GPA algorithm improvements may be needed.

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.

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.