Retinal Nerve Fiber Layer Parameters Research Articles

Evaluation of optical coherence tomography findings in patients with multiple sclerosis and glaucoma.

Glaucoma and multiple sclerosis (MS) can cause optic disc pathology and, in this way, affect optical coherence tomography (OCT) data. In this context, the objective of this study is to investigate the changes in the mean, quadrant, and sector data measured by OCT in glaucoma and MS patients. The sample of this prospective cohort study consisted of 42 MS patients (84 eyes), 34 Primary open-angle glaucomas patients (67 eyes), and 24 healthy control subjects (48 eyes). The MS group was divided into two groups according to the presence of a history of optic neuritis. Accordingly, those with a history of optic neuritis were included in the MS ON group, and those without a history of optic neuritis were included in the MS NON group. The differences between these groups in the mean, quadrant, and sector data related to the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) were evaluated. Superior nasal (SN), superior temporal (ST), inferior nasal (IN), and superior quadrant (SUP) values were significantly lower in the glaucoma group than in the MS group (p < 0.05). The mean superior GCC (GCC SUP) value was significantly lower in the MS ON group than in the glaucoma group (p < 0.05). On the other hand, SN, ST, inferior temporal (IT), IN, average RNFL (AVE RNFL), semi-average superior RNFL (SUP AVE RNFL), semi-average inferior RNFL (INF AVE RNFL), SUP, and inferior quadrant RNFL (INF) values were significantly lower in the glaucoma group than in the MS NON group (p < 0.05). RNFL and GCC parameters get thinner in MS and glaucoma patients. While the inferior and superior RNFL quadrants are more frequently affected in glaucoma patients, the affected quadrants vary according to the presence of a history of optic neuritis in MS patients. It is noteworthy that the GCC superior quadrant was thin in MS ON patients. The findings of this study indicate that OCT data may be valuable in the differential diagnosis of glaucoma and MS.

Racial-ethnic disparities in concurrent rates of peripapillary & macular OCT parameters among a large glaucomatous clinical population.

To compare rates of change in peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) parameters among different race-ethnicities from a large electronic health record database of subjects with or suspected of glaucoma. In this retrospective cohort study, rates of change were obtained using joint longitudinal linear mixed models for eyes with ≥3 visits and ≥1 year of follow-up, adjusting for age, sex, intraocular pressure, central corneal thickness, and baseline pRNFL and mGCIPL thickness. Best linear unbiased predictor estimates of various parameters were stratified by baseline glaucoma severity and analysed by racial-ethnic group. A total of 21,472 spectral domain optical coherence tomography (OCT) pRNFL scans and 14,431 mGCIPL scans from 2002 eyes were evaluated. A total of 200 (15.6%) and 601 (46.8%) subjects identified as non-Hispanic Black (NHB) and Hispanic, respectively. NHB eyes exhibited faster rates of change in pRNFL among glaucoma suspect (global pRNFL -0.57 ± 0.55 µm/year vs. -0.37 ± 0.62 µm/year among Hispanics, p < 0.001), mild glaucoma (superior pRNFL quadrant -1.20 ± 1.06 µm/year vs. -0.75 ± 1.51 µm/year among non-Hispanic Whites (NHW), p = 0.043), and moderate glaucoma eyes (superior pRNFL quadrant -1.31 ± 1.49 µm/year vs. -0.52 ± 1.26 µm/year among Hispanics, p = 0.003). NHB eyes exhibited faster rates of mGCIPL loss corresponding to pRNFL rates. Global pRNFL and mGCIPL rates were strongly correlated (R2 = 0.70). Adjusted rates of pRNFL and mGCIPL loss significantly differed between racial-ethnic groups when stratified by glaucoma severity, with faster rates among NHB patients. These differences highlight key racial-ethnic disparities in adjusted rates of glaucoma OCT parameters.

Optic nerve head neurovascular assessments in patients with schizophrenia: A cross‐sectional study

AbstractObjectiveThe retina is a protrusion of the brain, so researchers have recently proposed retinal changes as a new marker for studying central nervous system diseases. To investigate optic nerve head neurovascular structure assessed by optical coherence tomography angiography (OCTA) in schizophrenia compared to healthy subjects.MethodsThe study was conducted from 2019 to 2021 at the Ibn Sina Psychiatric Hospital in Mashhad, Iran. We enrolled 22 hospitalized known cases of schizophrenia, treated with risperidone as an antipsychotic drug, and 22 healthy subjects. The two groups were matched in age and gender. In the schizophrenic group, the positive and negative syndrome scale test was used to assess the illness severity. All subjects underwent complete ophthalmic evaluations and OCTA imaging.ResultsWe found that the cup/disc area ratio, vertical cup/disc ratio, and horizontal cup/disc ratio are significantly higher in patients with schizophrenia than in healthy subjects (with p‐values of 0.019, 0.015, and 0.022, respectively). No statistically significant difference in the peripapillary retinal nerve fiber layer and vascular parameters of the optic nerve head was observed between schizophrenia and healthy groups.ConclusionWe found evidence regarding the difference in the optic nerve head tomographic properties in schizophrenia compared to healthy subjects. However, ONH vascular parameters showed no significant difference. More studies are needed for a definite conclusion.

Connecting the Dots: Exploring the Relationship between Optical Coherence Tomography and 99mTc-TRODAT-1 SPECT Parameters in Parkinson's Disease.

While optical coherence tomography (OCT) is explored as a potential biomarker in Parkinson's disease (PD), technetium-99m-labeled tropane derivative (99mTc-TRODAT-1) single-photon emission computed tomography (SPECT) imaging has a proven role in diagnosing PD. Our objective was to compare the OCT parameters in PD patients and healthy controls (HCs) and correlate them with 99mTc-TRODAT-1 parameters in PD patients. This cross-sectional study included 30 PD patients and 30 age- and gender-matched HCs. Demographic data, PD details including Movement Disorders Society Unified Parkinson's Disease Rating Scale-III (MDS-UPDRS-III) and Hoehn-Yahr (HY) staging, and OCT parameters including macular and peripapillary retinal nerve fiber layer (RNFL) thickness in bilateral eyes were recorded. PD patients underwent 99mTc-TRODAT-1 SPECT imaging. The terms "ipsilateral" and "contralateral" were used with reference to more severely affected body side in PD patients and compared with corresponding sides in HCs. PD patients showed significant ipsilateral superior parafoveal quadrant (mean ± standard deviation [SD] = 311.10 ± 15.90 vs. 297.57 ± 26.55, P = 0.02) and contralateral average perifoveal (mean ± SD = 278.75 ± 18.97 vs. 269.08 ± 16.91, P = 0.04) thinning compared to HCs. Peripapillary RNFL parameters were comparable between PD patients and HCs. MDS-UPDRS-III score and HY stage were inversely correlated to both ipsilateral (Spearman rho = -0.52, P = 0.003; Spearman rho = -0.47, P = 0.008) and contralateral (Spearman rho = -0.53, P = 0.002; Spearman rho = -0.58, P < 0.001) macular volumes, respectively. PD duration was inversely correlated with ipsilateral temporal parafoveal thickness (ρ = -0.41, P = 0.02). No correlation was observed between OCT and 99mTc-TRODAT-1 SPECT parameters in PD patients. Compared to HCs, a significant thinning was observed in the ipsilateral superior parafoveal quadrant and the contralateral average perifoveal region in PD patients. Macular volume and ipsilateral temporal parafoveal thickness were inversely correlated with disease severity and duration, respectively. OCT and 99mTc-TRODAT-1 SPECT parameters failed to correlate in PD patients.

The effect of systemic sclerosis and its subtypes on ocular anterior and posterior segment parameters.

To evaluate anterior and posterior segment parameters in the eyes of patients with systemic sclerosis (SSc) and examine the effect of disease and disease subtypes on these parameters. This cross-sectional study included 54 eyes of 27 SSc patients and 54 eyes of 27 age- and sex-matched healthy controls. In addition to a complete ophthalmologic examination, all patients were examined using a Scheimpflug camera, specular microscopy, and spectral domain optical coherence tomography. The mean age of the patients was 52.5 ± 11.4years and 19 patients were female. Anterior chamber volume, central corneal thickness, and central macular thickness (CMT) were significantly lower in the eyes of SSc patients compared to healthy controls (p = 0.01, p = 0.03, and p = 0.006, respectively). When evaluated according to SSc subtype, CMT was lower in diffuse SSc patients (p = 0.001), while mean retinal nerve fiber layer (RNFL) and inferior quadrant RNFL values were lower in limited SSc (p = 0.003 and p = 0.005, respectively). In the eyes of patients with SSc, some ocular parameters may show decreases compared to healthy individuals, presumably secondary to disease-related vasculopathy and fibrosis. CMT and RNFL parameters may be affected differently according to disease subtype.

Comparison of diagnostic capability of macular ganglion cell complex vs retinal fiber layer thickness in primary open angle glaucoma patients of Indian origin.

Comparison of diagnostic capability of macular ganglion cell complex thickness vs. retinal nerve fiber layer (RNFL) thickness in patients of primary open-angle glaucoma (POAG). This cross-sectional observational study was carried out between June 2021 and October 2022 at a tertiary care hospital in North India. A total of 118 eyes were included in the study with 30 control and the rest 88 eyes with POAG were divided into three groups based on visual field loss Group 1 (30 eyes): early field loss with mean deviation (MD) < -6 dB; Group 2 (30 eyes): moderate field loss with MD -6 to -12 dB; and Group 3 (28 eyes): severe field loss with MD > -12 dB. Optical coherence tomography (OCT) scans to measure RNFL loss and ganglion cell inferior plexiform layer (GCIPL) loss were taken for each patient. Categorical variables were analyzed using either the Chi-square test or Fisher's exact test. A receiver operating characteristics analysis was calculated to determine optimal cut-off values of superior, inferior, and average GCIPL and RNFL for determining the severity of field loss as compared to controls (30 normal eyes). In the mild field loss group the sensitivity of superior, inferior, and average GCIPL was 86.7, 96.7, and 96.7%, respectively. Similarly, the specificity was 96.7, 93.3, and 100%, respectively. In the same group, the sensitivity of superior, inferior, and average RNFL was 70, 93, and 66%, respectively. Similarly, the specificity was 46.7, 83.3, and 70%, respectively. In the moderate and severe groups, the results were comparable. The sensitivity and specificity of GCIPL loss are significantly better than that of RNFL parameters in the mild field loss group.

Optic Nerve Head and Retinal Nerve Fiber Layer Analysis in Emmetropic Malay Children.

The study aims to investigate the normal reference values for optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters in emmetropic Malay children, utilizing measurements obtained through Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA). A cross-sectional study was conducted on 95 Malay children, aged between seven and 17 years, with no ocular abnormalities. It was held at Hospital Universiti Sains Malaysia, Malaysia, from January 2014 to December 2015. All children underwent a full ocular examination, including refraction and calculation of axial length. ONH and retinal nerve fiber layer thickness (RNFLT) parameters were measured using the Cirrus SD-OCT machine. One eye of each subject was selected randomly for study. The associations between the parameters and the effect of age, gender,axial length, and spherical equivalent (SE) on the measurements were statistically validated. Ninety-five children were involved in the study, with 65 females (68.4%) and 30 males (31.6%). The mean age was 10.6 (2.82) years, the mean intraocular pressure (IOP) was 14.8 (2.81) mmHg, the mean SE-refraction was 0.12 (0.28) diopters, and the mean axial length was 23.03 (0.76) mm. The mean disc area, rim area, and cup volume were 2.32 (0.40) mm2, 1.53 (0.33) mm2, and 0.204 (0.16) mm3, respectively. The average cup-to-disc ratio (SD) (CDR) and the vertical CDR were 0.55 (0.13) and 0.50(0.14). Mean (SD) RNFLT was 102.08 (11.08) μm for all patients. There was a strong positive correlation between the average, superior, and inferior RNFLT with the optical disc area. The rim area and the average, superior, inferior, and nasal RNFLT alsoshowed a significant correlation. The inferiorRNFLT was negatively correlated with the average CDR. There was also a major influence of gender on the disc area. There were no major age, axial length, and SE influences on the measurements. This study provided normative information for ONH and RNFLT parameters in emmetropic Malay children. It was observed that emmetropic Malay males exhibited a significantly larger optical disc area. The increase in RNFLT is correlated with a significant increase in disc and rim areas.

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.

Structure-function relationship and diagnostic value of macular ganglion cell complex measurement using Fourier-domain OCT in glaucoma.

To evaluate the relationship between visual function and macular ganglion cell complex (GCC) thickness measured by Fourier-domain optical coherence tomography (OCT) and evaluate the diagnostic value of GCC measurement compared to retinal nerve fiber layer (RNFL) thickness and macular thickness in detecting early, moderate, and severe glaucomas. Subjects underwent standard automated perimetry (SAP), OCT imaging with optic nerve head mode and GCC mode. The relationship between OCT parameters (mean GCC thickness, mean RNFL thickness, and macular thickness) and perimetry global indices (mean deviation [MD] and pattern standard deviation [PSD]) was evaluated by regression analysis. Diagnostic values of mean RNFL thickness, GCC parameters, and macular thickness were compared with the area under the receiver operating characteristic curves (AUC). A total of 84 eyes, 42 of each normal and primary open-angle glaucoma patients were included in the study. Compared with linear models, second-order polynomial models better described relationships between GCC thickness and MD ( P < 0.001), and between GCC thickness and PSD ( P = 0.00). RNFL parameter, inferior RNFL thickness had the highest AUC for detecting early glaucoma. The AUC of mean GCC thickness for early glaucoma was higher than that of mean RNFL; however, the difference was not significant ( P = 0.09), which was higher than that of macular thickness. The relationship between visual field (VF) sensitivity and GCC thickness is best expressed by the curvilinear function. Macular GCC thickness and RNFL thickness showed similar diagnostic values but were better than macular thickness for detecting early glaucoma but inferior to macular thickness and RNFL thickness for detecting moderate glaucoma.

Effect of Bergmeister papilla on disc parameters in spectral domain optical coherence tomography

ObjectivesTo investigate the morphological characteristics of Bergmeister papilla (BMP), a persistent hyaloid remnant tissue, and its effects on the measurements and repeatability of spectral-domain optical coherence tomography (OCT).Subjects/MethodsThe subjects of this prospective cross-sectional study including 83 patients with BMP and 76 unaffected individuals, all had open-angle structures. Images, including a 5-line raster and three consecutive optic disc cube scans centred on the optic disc, were acquired using the Cirrus high-definition OCT. BMP’s structural characteristics were classified based on the raster scan images, and repeatability of acquiring optic nerve head and retinal nerve fibre layer parameters acquisition was analysed by calculating the test-retest standard deviation (Sw), coefficient of variance (CV), and intraclass correlation coefficient.ResultsBMPs (n = 83) were categorised into lifting edge (LE) type (63.9%, n = 53), which partially covers the edge of the optic nerve head, and covering disc (CD) type (36.1%, n = 30), which completely covers the cupping area like a cap. The average cup-to-disc ratio (0.58 ± 0.21), vertical cup-to-disc ratio (0.55 ± 0.21), and cup volume (0.22 ± 0.22) of the CD type were lower than those of the LE type (0.66 ± 0.13, 0.64 ± 0.13, and 0.4 ± 0.27, respectively; all P < 0.05). Tolerability indices for repeatability of cup volume (Sw = 0.40 and CV = 0.36) and inferonasal (4 o’clock) retinal nerve fibre layer (Sw = 0.27 and CV = 0.25) in LE-type BMPs exceeded the cut-off value (0.22) and demonstrated stronger correlation with BMP location than that of the controls.ConclusionCaution should be exercised when interpreting OCT findings in eyes with BMP, as BMP can introduce a pitfall in OCT imaging.

Optical Coherence Tomography Angiography (OCTA) Differences in Vessel Perfusion Density and Flux Index of the Optic Nerve and Peri-Papillary Area in Healthy, Glaucoma Suspect and Glaucomatous Eyes.

To assess the ability of vascular perfusion parameters determined by optical coherence tomography angiography (OCTA) to detect and monitor glaucoma. This prospective study included healthy, glaucoma suspect and glaucomatous eyes. All eyes underwent comprehensive glaucoma examination, including visual field tests and ocular imaging scans by OCTA. Parameters measured included retinal nerve fiber layer (RNFL) thickness, ganglion cell analysis (GCA), vascular perfusion density (VPD) and flux index (FI) of the optic nerve and peri-papillary area. Ocular parameters in healthy, glaucoma suspect, and glaucomatous eyes were compared by generalized estimating equations (GEE) with adjustments for age, with their relationships analyzed by Pearson's correlation coefficient. Rates of change per year were compared in glaucomatous eyes with and without glaucoma progression. This study enrolled 238 eyes, including 56 healthy, 79 glaucoma suspect, and 103 glaucomatous eyes. After adjustments for age, the average VPD (45.40 ± 0.19% vs 45.05 ± 0.22% vs 42.89 ± 0.32%, p < 0.001) and FI (0.4210 ± 0.0055 vs 0.4105 ± 0.0039 vs 0.3801 ± 0.0048, p < 0.001) in these three groups differed significantly. Average VPD in the glaucoma group was inversely associated with the severity of glaucoma, being 43.99 ± 0.32%, 42.63 ± 0.43% and 39.27 ± 0.48% in eyes with early, moderate and severe glaucoma, respectively (p < 0.001). Average VPD, as well as VPD in the superior and inferior quadrants correlated well with both OCT determined RNFL and visual field parameters. The decreases per year in both superior (-0.012 vs -0.001, p = 0.002) and inferior (-0.008 vs -0.003, p = 0.007) FI were significantly greater in glaucomatous eyes with than without glaucoma progression. Both VPD and FI as measured by OCTA are promising ocular parameters that can distinguish between normal and glaucomatous eyes. VPD is sensitive in comparing eyes at different glaucoma stages, whereas FI can detect rates of glaucoma progression. Thai Clinical Trial Registry, TCTR20181031002.

Anatomical and Functional Evaluation of RNFL Parameters and Choroidal Thickness Changes in Patients with Chronic Renal Failure Undergoing Hemodialysis Using Spectral-Domain Optical Coherence Tomography and Visual Field

Background There is a structural analogy between the glomerular vascular network and the choroidal circulation. With hemodialysis (HD), lots of alterations occur in patients' homeostasis and metabolic parameters. These alterations affect the eye and may cause neuro-ophthalmologic complications. Aim To evaluate anatomical and functional changes of retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL), and changes in subfoveal choroidal thickness (SFCT) in patients with chronic renal failure (CRF) on HD. Methods This case control study was carried on 20 eyes of 20 CRF patients (HD group) and 20 eyes of 20 healthy individuals. 10 of the HD group were non-diabetic (NDM subgroup) and 10 were diabetic (DM subgroup). For all eyes, the thickness of peripapillary RNFL, GCL, and SFCT were measured by optical coherence tomography (OCT) (RS-3000; NIDEK, Japan) and visual field (VF) analysis using Humphrey field analyzer (Carl Zeiss, USA). Results A statistically significant decrease in peripapillary RNFL thickness in HD group when compared to the control group in most analyses, but did not amount to statistical significance in the temporal quadrant and in 5 of the studied clock hour sectors. There was also a statistically significant decrease in the macular GCL thickness of HD group when compared to the control group in both hemifields, and in all of the 8 subfields. The results of the SFCT reported in HD group were also significantly less than that reported in the control group. Analysis of results from VF demonstrated a highly significant depression in both MD and PSD of the HD group when compared to the control group. The difference between the NDM and DM subgroups was not significant in any of the studied parameters. Conclusion Our results demonstrate highly significant retinal and choroidal changes in CRF patients on HD. Thus, we recommend that CRF patients undergo regular ocular examination by OCT to prevent early ocular damage.

Agreement between Two Swept-source Optical Coherence Tomography: Optic Nerve Head, Retinal Nerve Fiber Layer and Ganglion Cell Layers in Healthy Eyes.

Precision of optical coherence tomography (OCT) measurements of the optic nerve head (ONH), retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) is essential for the diagnosis and monitoring of glaucoma. The purpose of this research was to evaluate the repeatability and reproducibility of retinal and ONH parameters measured with two identical swept-source optical coherence devices. A cross-sectional study was conducted. A total of 30 eyes of 15 healthy subjects were included. Two technicians performed four OCT-wide protocol scans in the same visit using two identical Triton swept-source OCT (DRI-OCT) instruments. The interdevice and interobserver reproducibility and the repeatability of both instruments for all ONH, RNFL, and macular GCL parameters were evaluated by the intraclass correlation coefficient (ICC). Additionally, Bland-Altman test analysis was used for repeatability and reproducibility measurements. Intraclass correlation coefficient (ICCs) of the ONH, RNFL, and GCL measurements were excellent for repeatability and interdevice reproducibility (>0.9). Interobserver reproducibility was good for all parameters except for RNFL clock hour 11 (ICC = 0.72). The variability of the average RNFL was from -4.103 to 4.97 µm, with a mean percentage of the difference (PD) of 0.37 ± 2.03%. Among GCL parameters, the greatest variability was found in the inferior sector (PD = -0.88 ± 5.39%, limits of agreement (LoA) = -8.345-7.078 μm). Using two identical swept-source OCT instruments for the evaluation of the structural parameters of the ONH, RNFL, and macular GCL showed high repeatability and reproducibility. This allows the clinician to make a therapeutic decision based on OCT findings coupled with the clinical evaluation of the patient. When evaluating RNFL clock hours measurements, interobserver reproducibility might decrease. The understanding of measurement variability while using different devices and the impact of the observer capturing the images, is clinically relevant. Prada AM, Tello A, Rangel CM, et al. Agreement between Two Swept-source Optical Coherence Tomography: Optic Nerve Head, Retinal Nerve Fiber Layer and Ganglion Cell Layers in Healthy Eyes. J Curr Glaucoma Pract 2023;17(2):85-90.

Effects of COVID-19 on Retinal and Choroidal Thickness by Optical Coherence Tomography.

The aim of our study was to evaluate the subclinical changes in the macula, retinal nerve fiber layer (RNFL), and choroidal thickness after coronavirus disease 2019 (COVID-19) infection using spectral domain optical coherence tomography. Our study was prospectively designed and involved 170 eyes of 85 patients. Patients with polymerase chain reaction (PCR)-positive COVID-19 infection were examined in the ophthalmology clinic before and after infection were included. All included patients had mild COVID-19 with no hospitalization and no need for intubation. Control ophthalmic examination was repeated at least 6 months after PCR positivity. Macular and choroidal thickness and RNFL parameters were compared before and at least 6 months after PCR-positive COVID-19 infection using optical coherence tomography. When the mean macular thickness data were evaluated, a significant decrease was detected in the inner (mean difference, -3.37 µm; 95% CI: -6.09 to -0.65, P = 0.021) and outer (mean difference, -6.56 µm; 95% CI: -9.26 to -3.86, P < 0.001) temporal segments and the inner (mean difference, -3.39 µm; 95% CI: -5.46 to -1.32, P = 0.002) and outer (mean difference, -2.01 µm; 95% CI, -3.70 to -0.31, P = 0.018) su p erior segments in the post-COVID-19 measurements compared with pre-COVID-19 measurements. Similarly, on RNFL evaluation, some thinning was evident in the temporal superior (mean = 1.14 µm, P = 0.004) and temporal inferior (mean = 1.30 µm, P = 0.032) regions. All choroidal regions, including central, nasal 500 µm and 1500 µm and temporal 500 µm and 1500 µm, exhibited significant thinning ( P < 0.001). At least 6 months after mild COVID-19 infection, significant thinning was seen in the temporal and superior quadrants of the macula, the temporal superior and temporal inferior regions of the RNFL, and all measured areas of choroidal regions.

The Discriminatory Ability of Ganglion Cell Inner Plexiform Layer Complex Thickness in Patients with Preperimetric Glaucoma.

To evaluate diagnostic performance of ganglion cell inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) parameters measured with Cirrus high-definition optical coherence tomography (OCT) in patients with preperimetric glaucoma. In this multicenter cross-sectional study, 150 eyes of 83 patients with preperimetric glaucoma were compared with 200 eyes of age and sex matched healthy subjects. All patients had visual field testing and OCT scanning of GCIPL and RNFL in all quadrants. The independent Samples t-test was used to determine if a difference exists between the means of two independent groups on a continuous dependent variable. The area under the receiver operating characteristic (ROC) curve (AUC) of each parameter was calculated for discriminatory ability between normal controls and preperimetric glaucoma. The sensitivity and specificity were estimated by point coordinates on ROC curve. The best parameters for distinguishing preperimetric glaucoma from healthy eyes were the combined average GCIPL + average RNFL, followed by average RNFL + GCIPL (inferotemporal), and average RNFL + GCIPL (minimum). The GCIPL parameters with the highest to lowest AUC (in decreasing order) were inferotemporal, followed by average, minimum, superior, inferior, superonasal, inferonasal, superotemporal, and quadrants. The RNFL parameters with the highest to lowest AUC (in decreasing order) were average, followed by nasal, temporal, superior, and inferior quadrants. The sensitivity of combined GCIPL + RNFL parameters ranged 85%-88% and the specificity ranged 76%-88%. The sensitivity for RNFL parameters ranged 80%-90% and the specificity ranged 64%-88%. GCIPL and RNFL have good discriminatory ability; the sensitivity and specificity increase when both parameters are combined for early detection of glaucoma.

Diagnostic performance of optical coherence tomography macular ganglion cell inner plexiform layer and retinal nerve fiber layer thickness in glaucoma suspect and early glaucoma patients at St. Paul's hospital millennium medical college, Addis Ababa, Ethiopia.

To evaluate glaucoma diagnostic performance of ganglion cell inner plexiform layer and retinal nerve fiber layer parameters measured with cirrus HD optical coherence tomography (OCT). Total of 188 eyes were included in our study. 49 eyes of healthy controls, 70 glaucoma suspect eyes and 69 early glaucomatous eyes. Complete ophthalmic examination was done including visual field test (with Humphrey field analyzer) and OCT scanning of ganglion cell inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) in different quadrants. Sensitivity, specificity and area under the receiver operating characteristic curve (AUROC) of each parameter was calculated to provide diagnostic ability between normal controls, glaucoma suspects or early glaucoma. GCIPL and RNFL parameters had strong power in discriminating early glaucoma from healthy controls with all having AUROC of above 0.76. Of all the GCIPL and RNFL parameters, the only variable that could discriminate between glaucoma suspect and healthy controls was the combined parameter by OR-logic approach. Of all the parameters, the average and nasal RNFL parameters had the strongest power in discriminating between the two with AUROC of 0.81. All parameters had an overall good diagnostic performance with excellent sensitivity but the specificity was relatively poor. The combined parameter had the best specificity (62.2%) with excellent sensitivity (93.5%). Nasal RNFL parameters had the strongest power in discriminating between glaucoma suspect and healthy controls and the OR-logic combination of RNFL and GCIPL provides better diagnostic performance than single GCIPL, RNFL or ONH parameter.

Longitudinal evaluation of RTVue optical coherence tomography in patients with glaucoma and suspected glaucoma and stable visual fields.

To longitudinally compare isolated structural parameters obtained using RTVue optical coherence tomography in patients with glaucoma and suspected glaucoma with stable visual fields. All patients were required to have a reliable SITA Standard 24-2 Humphrey Visual Field test. Visual field stability was defined as having <5 points with p<5% and/or having no points with p<1% and/or p<0.05% in the glaucoma progression analysis comparison graph. Furthermore, the glaucoma assessment strategy was used in optical coherence tomography. The study included 75 eyes from 75 patients, 43 of which had glaucoma and 32 had suspected glaucoma. The mean visual field intervals were 29.57 ± 9.65 months between the first and third tests. No visual field parameter variations (mean deviation, pattern standard deviation, and visual field index) and no retinal nerve fiber layer or optic disk parameter variations between the first and third tests were observed (p>0.05 for all), and no retinal nerve fiber layer parameter variations throughout the study were observed, except for optic disk parameters presenting with cup volume changes (p=0.004). However, ganglion complex cells presented a progressively decreased average ganglion cell complex parameter, with a variability of -0.98% ± 3.71% (p=0.04) between the first and third tests. By contrast, the global loss volume progressively increased throughout the study, with a variability of 14.71% ± 44.52% (p=0.04) between the first and third tests. The inferior ganglion cell complex parameter was significantly decreased between the first and third tests (p=0.02). The present findings suggest that patients with glaucoma or suspected glaucoma with stable visual fields may present structural ganglion complex cell progression as assessed using RTVue optical coherence tomography.

Obsructive sleep apnea syndrome: is it a risk factor for ocular surface disease and ocular comorbidities?

To investigate the accompanying ocular findings in patients with obstructive sleep apnea syndrome (OSAS) and evaluate the susceptibility to ophthalmological diseases. In this cross-sectional study, qualifying study subjects were patients who had been diagnosed with severe OSAS (apnea/hypopnea index (AHI > 30/h), n = 31), and control subjects (n = 30) who had an AHI index of < 5 (as normal). General ophthalmological examination, eyelid laxity measurements, corneal topography, visual field, retinal nerve fiber layer parameters, dry eye tests were performed on the patients. It was observed that the two groups had similar characteristics in terms of gender, age, presence of hypertension, diabetes, and body mass index. According to eyelid laxity measurements, the incidence of loose eyelids was higher in the OSAS patient group. Choroidal thickness was thinner in the study group than in the control group. Schirmer test and tear break-up time were significantly lower in the study group than in the control group. The percentage of meibomian gland loss in meibography and the ocular surface disease index score for symptoms was significantly higher in the study group than in the control group. In this study, we found significant changes in ocular surface parameters, eyelid laxity, choroidal thickness, and visual field indices in OSAS patients. Dry eye syndrome might be related eyelid laxity and inflammation in OSAS patients. Early diagnosis and follow-up of ocular diseases in OSAS, which affect the quality of life and visual prognosis in advanced ages, are important.

Assessment of changes in optic disc parameters and peripapillary retinal nerve fiber layer thickness in myopic patients and its correlation with axial length and degree of myopia.

The present study aimed to assess the changes in optic disc and peripapillary retinal nerve fiber layer (RNFL) parameters in myopic patients and its correlation with axial length (AL) and spherical equivalent (SE) using optical coherence tomography (OCT). This was a cross-sectional study carried out from August 2019 to September 2021 in the ophthalmology department of a tertiary care hospital in eastern India. Myopic patients in the age group of 20-40 years and SE between - 0.5 to - 10 Diopters (D) were included in the study. Patients were divided into two groups on the basis of degree of myopia and AL. Appropriate statistical analysis was done at the end of the study period. The study included 307 eyes of 307 myopic patients. There were 181 females (58.96%) and 126 males (41.04%). The mean age of the patients enrolled for the study was 28.78 ± 5.76 years. Statistically significant difference (P < 0.001) was found between SE and AL in between the subgroups of A and B. With every 1 D increase in SE, the average peripapillary RNFL thickness decreased by 0.61 μ while with every 1 mm increase in AL, the average peripapillary RNFL thickness was found to reduce by 1.03 μ. Analysis of optic nerve head parameters and RNFL thickness by OCT for the diagnosis should be compared with a normative control group that has been matched for refractive error and AL instead of comparison with a normative database that has only been age matched.

Diagnostic evaluation of optical coherence tomography parameters in normal, preperimetric and perimetric glaucoma patients.

To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography (OCT) in normal, preperimetric glaucoma (PPG) and perimetric glaucoma (PG) patients. This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG (51 eyes), PG (46 eyes), and normal controls (30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) to assess the optic nerve head and ganglion cell layer (GCL) thickness in the macula. RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity (>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves (AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW (AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively). While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.