Peripapillary Retinal Nerve Fiber Layer Thickness Research Articles

Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer Thicknesses in Hydroxychloroquine Retinopathy

To investigate macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thicknesses in patients with hydroxychloroquine retinopathy of differing severity. Cross-sectional, case-control comparison study. From patients screened for hydroxychloroquine retinopathy between January 2016 and October 2021 using swept-source optical coherence tomography (SS-OCT), fundus autofluorescence (FAF), and standard automated perimetry, 66 patients with retinopathy and 66 without retinopathy were included by 1:1 propensity score matching based on age, sex, systemic diseases, history of tamoxifen and pentosan use, and kidney disease. Eyes with hydroxychloroquine retinopathy were divided into early, moderate, and severe stages. Inner-retinal thickness parameters, including macular GCC (RNFL + ganglion cell layer + inner plexiform layer) and peripapillary RNFL thicknesses, were automatically obtained using SS-OCT (DRI-OCT Triton, Topcon Inc., Japan) and compared between patients with and without retinopathy and between severity subgroups. The structure-function relationships between GCC or peripapillary RNFL thicknesses and perimetric parameters including mean deviation (MD) and visual field index (VFI) of Humphrey 30-2 test were evaluated. Macular GCC and peripapillary RNFL thickness parameters. The average macular GCC and peripapillary RNFL thicknesses were significantly decreased in patients with hydroxychloroquine retinopathy relative to those without retinopathy. Macular GCC thicknesses in 4 of 6 macular sectors and peripapillary RNFL thicknesses in 9 of 12 clock-hour sectors were significantly different between the groups. The differences in the average and sectoral macular GCC parameters were statistically significant among the severity subgroups, particularly between severe and earlier stages. Average macular GCC and peripapillary RNFL thicknesses significantly correlated with MD and VFI in all patients (all P < .001). Macular GCC and peripapillary RNFL thinning was more prominent in eyes with severe hydroxychloroquine retinopathy, as indicative of inner-retinal thinning in eyes with advanced-stage disease. Further, as inner-retinal thinning showed a significant correlation with worse perimetric function, cautious evaluation of the inner retina may be required for eyes with advanced hydroxychloroquine retinopathy.

A STUDY TO COMPARE THE RETINAL NERVE FIBER LAYER (RNFL) MEASUREMENTS USING THE TD OCT 'STRATUS' AND THE SD OCT 'RTVUE' IN HEALTHY PARTICIPANTS AND GLAUCOMA PATIENTS

Background: To compare the RNFL measurements using the conventional Time Domain Optical Coherence Tomography (TD-OCT) 'Stratus' and the Spectral Domain Optical Coherence Tomography (SD OCT) 'RTVue' in healthy participants and glaucoma patients. ThisMethods: prospective cross-sectional study included 50 eyes in each of the two study groups as, healthy eyes and eyes of established glaucoma patients. Peripapillary RNFL thickness was measured by both machines in random order by the same operator on the same day with pupils uniformly dilated to over 5.0 mm. Three separate fast RNFL Scans were acquired with Stratus OCT, from which the most reliable scan was chosen for comparison. For RTVue, “RNFL3.45” scan protocol was used, which consists of four sets of 1024 “A-scans” along a 3.45 mm-diameter circle centered on the optic disc. There was a signicant difference in RNFL measurements between the two methods ,which was maximum in the superiorResults: quadrant and minimum in the nasal quadrant in both the groups In both the groups, RTVue RNFL measurements are thicker as. Conclusion: compared to that of Stratus with maximum quadrant mean RNFL measurement in the inferior quadrant and minimum in the nasal quadrant. Maximum difference in RNFL measurement between the two machines was at superior quadrant in both the groups.

Morphometric parameters of the optic nerve in patients with symptomatic ophthalmohypertension and secondary glaucoma associated with endocrine ophthalmopathy

Objective. To analyze the morphometric parameters of the optic disc (OD) in patients with symptomatic ophthalmohypertension and secondary glaucoma associated with endocrine ophthalmopathy (EOP) according to the data of optical coherence tomography (OCT).Materials and methods. The morphometric parameters of OD and retinal nerve fiber layer (RNFL) thickness were assessed according to OCT data of 175 patients (350 eyes and orbits) with different forms and activity of EOP. 30 patients (60 eyes and orbits) were diagnosed with symptomatic ophthalmohypertension in active EOP stage. 30 patients (58 eyes and orbits) were diagnosed for the first time with secondary open-angle glaucoma associated with inactive EOP course. The control group comprised 30 somatically healthy individuals comparable in terms of age and sex without clinical EOP symptoms with normal ophthalmic tonus.Results. The patients with symptomatic ophthalmohypertension have revealed increased peripapillary RNFL thickness up to Me 95.5 [90; 101] μm (Mann-Whitney U=1107, p=0.0002), and increased neuro-retinal rim (NRR) area up to Me 1.65 [1.5; 1.9] mm² (Mann-Whitney test U=1425; p=0.04). The patients with secondary glaucoma associated with EOP have found a statistically significant decrease of the average RNFL thickness to Me 85[80;89] μm (by 8%) compared to the control group (Mann-Whitney U=553, p=0.00). The NRR area was statistically significantly reduced to Me 1.15 [1.0; 1.2] mm² (Mann-Whitney U=255.5; p=0.00).Conclusion. Patients with symptomatic ophthalmohypertension and active course of the processs detect signs of increased RNFL and NRR area thickness, which is related to retrobulbar fiber swelling and development of compressive ischemic optic neuropathy. Patients with secondary glaucoma are characterized by remodeling of OD parameters at the expense of decreased average peripapillary RNFL thickness, reduced NRR area and extended excavation, which is typical for glaucomatous optic neuropathy.

One-Year Changes in Optic Nerve Head Parameters in Recovered COVID-19 Patients.

The main purpose was to evaluate the changes in peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) in post-COVID-19 patients during 12-month follow-up. In this prospective study, patients with COVID-19 who were attended in the Hospital Clinico San Carlos (Madrid, Spain) were included. All patients underwent a complete ophthalmological examination, optic nerve head optical coherence tomography (OCT), and OCT angiography (OCTA) using the Cirrus HD-OCT 5,000 with AngioPlex OCTA 1, 3, and 12 months after laboratory-confirmed diagnosis. Sociodemographic data, medical history, disease severity, and laboratory workup were registered. A total of 180 eyes of 90 patients with SARS-CoV-2 infection were included; the mean age was 55.5 ± 8.9 years, and 46 patients (51%) were females. The mean visual acuity was 0.76 ± 0.16, and no abnormalities attributable to SARS-CoV-2 were detected in the ocular or fundus examination. No differences in the OCT and OCTA data were found between severity groups in each visit (all P > 0.05). Overall, there was a decrease in RNFL global thickness ( P < 0.001) from the first to the last visit, and an increase in VD and flux index was noted in some sectors at the 12-month examination. A significant correlation was detected at 12 months between vascularization parameters and RNFL thickness. One year after SARS-CoV-2 infection, changes in peripapillary RNFL thickness and vascularization occur, possibly indicating a recovery in such parameters.

Two-year longitudinal study on changes in thickness of the retinal nerve fiber layer and ganglion cell layer in children with type 1 diabetes mellitus without visual impairment or diabetic retinopathy

Purpose To study changes in the thickness of the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) in children with type 1 diabetes mellitus (T1DM) without visual impairment or diabetic retinopathy (DR) after 2 years of follow-up and analyze the associated factors. Methods Thirty-seven children with T1DM were enrolled in this study. All children underwent a complete ophthalmologic evaluation that included swept-source optical coherence tomography at baseline and follow-up. Changes in RNFL and GCL thickness were compared among the children at baseline and follow-up. Results The peripapillary RNFL thickness was greater in the temporal (inner, p = 0.015; outer, p = 0.004) and inner superior (p = 0.043) sectors in the follow-up group than in the baseline group. The macular RNFL thickness in the fovea, inner nasal sector, inner inferior sector, and outer ring and the average thickness (all p < 0.05) were greater in the follow-up group than in the baseline group. The peripapillary GCL thickness decreased in the temporal sector (inner, p = 0.049; outer, p = 0.041) and increased in the inner nasal sector (p = 0.006) in the follow-up group compared with the baseline group, and the thickness of the inner temporal, inner superior, inner inferior, outer nasal, and outer inferior sectors and average thickness in the macula were lower in the follow-up group than in the baseline group (all p < 0.05). The total retinal thickness around optic disc in the follow-up group increased in the inner superior sectors (p = 0.006). The total retinal thickness of the macula decreased in inner temporal sector, inner superior sector and outer nasal sector, and increased in outer superior sector (all p < 0.05). Conclusions Retinal neurodegenerative changes preceded microvascular changes in children with T1DM in the early stage. Peripapillary RNFL thickness in the nasal sector may be lower in children with T1DM without visual impairment or other ocular pathologies.

Brain Gray Matter Atrophy and Functional Connectivity Remodeling in Patients With Chronic LHON.

PurposeThe aim of this study was to investigate the brain gray matter volume (GMV) and spontaneous functional connectivity (FC) changes in patients with chronic Leber's hereditary optic neuropathy (LHON), and their relations with clinical measures.MethodsA total of 32 patients with chronic LHON and matched sighted healthy controls (HC) underwent neuro-ophthalmologic examinations and multimodel magnetic resonance imaging (MRI) scans. Voxel-based morphometry (VBM) was used to detect the GMV differences between the LHON and HC. Furthermore, resting-state FC analysis using the VBM-identified clusters as seeds was carried out to detect potential functional reorganization in the LHON. Finally, the associations between the neuroimaging and clinical measures were performed.ResultsThe average peripapillary retinal nerve fiber layer (RNFL) thickness of the chronic LHON was significantly thinner (T = −16.421, p < 0.001), and the mean defect of the visual field was significantly higher (T = 11.28, p < 0.001) than the HC. VBM analysis demonstrated a significantly lower GMV of bilateral calcarine gyri (CGs) in the LHON than in the HC (p < 0.05). Moreover, in comparison with the HC, the LHON had significantly lower FC between the centroid of the identified left CG and ipsilateral superior occipital gyrus (SOG) and higher FC between this cluster and the ipsilateral posterior cingulate gyrus (p < 0.05, corrected). Finally, the GMV of the left CG was negatively correlated with the LHON duration (r = −0.535, p = 0.002), and the FC between the left CG and the ipsilateral posterior cingulate gyrus of the LHON was negatively correlated with the average peripapillary RNFL thickness (r = −0.522, p = 0.003).ConclusionThe atrophied primary visual cortex of the chronic LHON may be caused by transneuronal degeneration following the retinal damage. Moreover, our findings suggest that the functional organization of the atrophied primary visual cortex has been reshaped in the chronic LHON.

Evaluation of retinal microvasculature according to stable chronic obstructive pulmonary disease severity and the correlation of pulmonary parameters with optical coherence tomography angiography findings.

Purpose:To evaluate the retinal and optic disc microvascular changes according to disease severity in patients with stable chronic obstructive pulmonary disease (COPD), and the correlation of pulmonary parameters with optical coherence tomography angiography (OCTA) findings.Methods:Forty patients with COPD and 30 age- and sex-matched subjects (control group) were included in this cross-sectional prospective study. The COPD group was then divided into two subgroups according to GOLD classification and disease severity as mild-to-moderate COPD group (group 1) and severe COPD group (group 2). OCTA was performed with 6 mm × 6 mm sections for the macula and 4.5 mm × 4.5 mm sections for the optic disc. Foveal retinal thickness (FRT), peripapillary retinal nerve fiber layer (RNFL) thickness, and vessel density in different sections of the retina and optic disc were analyzed.Results:The mean ages, gender, intraocular pressures, peripapillary RNFL thickness, FRT, and optic disc vessel densities were similar among the groups. Compared to the control group and group 1, group 2 showed significantly lower mean foveal vessel density measurements in superficial and deep capillary plexus (P = 0.014 and P = 0.007, respectively). Cigarette packets/year, exacerbation per year, and Modified Medical Research Council showed significant negative correlations, whereas forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity showed significant positive correlations with foveal vessel densities.Conclusion:COPD severity seems to have a negative effect on OCTA measurements. OCTA may reflect the severity of inflammation and hypoxia in COPD and may provide useful detailed information on the role of retinal vascular changes in the follow-up and progression of patients with COPD.

Evaluation of Progressive Retinal Degeneration in Bipolar Disorder Patients over a Period of 5 Years

Purpose To quantify visual and retinal changes in patients with bipolar disorder (BD) over 5 years, compared with controls. Methods Thirty-eight patients with BD and 122 healthy subjects underwent visual acuity (VA) evaluation, contrast sensitivity vision testing (CSV) with the Pelli Robson and CSV 1000E tests, and retinal thicknesses measurement [ganglion cell layer (GCL) and retinal nerve fiber layer (RNFL)] using Spectralis Optical Coherence Tomography (OCT). All subjects were re-evaluated after 5 years. The relationship between progressive structural changes and disease duration was analyzed. Results Visual function parameters in BD patients remained unchanged during the follow-up period. A progressive decrease affecting macular and peripapillary RNFL thickness (p < 0.050) was observed in patients. Progressive changes in BD were more pronounced when compared with healthy controls (p < 0.050). A significant correlation between GCL thickness changes and disease duration was found (GCL outer temporal, r = −0.680, p = 0.016; GCL central, r = −0.540, p = 0.038). Conclusions Progressive axonal loss was detected in BD patients. Visual function parameters were not affected after the 5-year follow-up. Despite observed changes in the neuroretina of patients with BD, axonal degeneration in these patients seemed to be mild and might be slowed down by other factors, such as BD treatments.

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.

Retinal nerve fibre layer thickness measured with SD-OCT in a population-based study: the Handan Eye Study

PurposeTo examine the normative profile of retinal nerve fibre layer (RNFL) thickness and ocular parameters based on spectral-domain optical coherence tomography (SD-OCT) and its associations with related parameters among the...

Change of peripapillary retinal nerve fiber layer and choroidal thickness during 4-year myopic progress: Boramae Myopia Cohort Study Report 4

AimsTo investigate the longitudinal changes of peripapillary retinal nerve fibre layer (RNFL) and choroidal thickness during myopic axial elongation.MethodsPeripapillary RNFL and choroidal thickness were prospectively evaluated by spectral-domain optical coherence...

Change of Peripapillary Vessel Density after Ahmed Valve Implantation

Purpose: To investigate the changes of peripapillary vessel density after Ahmed valve implantation.Methods: This is a retrospective review of 42 glaucomatous eyes that Ahmed valve implantation. Preoperative and postoperative intraocular pressure (IOP), peripapillary retinal nerve fiber layer (RNFL) thickness, peripapillary vessel density were analyzed.Results: The mean IOP was 37.49 ± 12.85 mmHg preoperatively, 13.72 ± 4.39 mmHg at 1 month postoperatively, and 12.48 ± 3.54 mmHg at postoperative 6 months which were significantly decreased after surgery (p &lt; 0.001). Peripapillary RNFL thickness and peripapillary vessel density increased significantly at 6 months postoperatively (p = 0.013, p = 0.002, respectively). The improvement in peripapillary vessel density was associated with a greater reduction in the IOP (p &lt; 0.001), and the lower preoperative peripapillary vessel density value (p = 0.001).Conclusions: The improvement in peripapillary vessel density was associated with a greater reduction in the IOP after Ahmed valve implantation. Measurement of peripapillary vessel density may be useful to monitor the progression of glaucoma after Ahmed valve implantation.

Peripapillary Microvascular and Structural Parameters in Atrophic Nonarteritic Anterior Ischemic Optic Neuropathy and Their Unaffected Fellow Eyes.

This cross-sectional study aimed to evaluate the peripapillary vessel density (VD), peripapillary retinal nerve fiber layer (RNFL) thickness values of eyes with atrophic nonarteritic anterior ischemic optic neuropathy (NAION), and unaffected fellow eyes. Peripapillary VDs and RNFL thicknesses in the peripapillary region and 4 sectors (superior, inferior, nasal, and temporal) were evaluated using optical coherence tomography angiography among 19 atrophic NAION eyes, 19 unaffected fellow eyes, and 22 age-matched and sex-matched healthy controls. The NAION eyes had lower peripapillary VD and RNFL thickness values in all areas compared with both the fellow and the healthy control eyes ( P < 0.001 for all). The fellow eyes also demonstrated lower peripapillary VD values ( P = 0.02) despite similar RNFL thickness values ( P = 0.99) in the peripapillary region compared with the age-matched and sex-matched healthy controls. The peripapillary RNFL thickness values significantly correlated with peripapillary VD values in both NAION and fellow eyes. Diminished RNFL thickness and peripapillary VD values were observed in atrophic NAION eyes. In addition, a tendency for a lower peripapillary VD despite similar RNFL thickness values in the fellow eyes may indicate the potential vascular risk factors for NAION.

Comparison of the clinical and genetic features of autosomal dominant optic atrophy and normal tension glaucoma in young Chinese adults.

To compare the clinical and optical coherence tomography (OCT) characteristics of autosomal dominant optic atrophy (ADOA) and normal tension glaucoma (NTG) in Chinese patients. Twenty-four unrelated patients with ADOA and 21 unrelated patients with NTG, younger than 30 years, were enrolled in this study. Data regarding the demographic and clinical characteristics of the patients were collected, and their peripapillary retinal nerve fibre layer (RNFL) and macular ganglion cell complex (GCC) thicknesses were evaluated using OCT. Sequencing of genes associated with neuro-ophthalmic disorders was performed for all patients. The average age at onset of the ADOA group (13.92 ± 10.73 years) was significantly younger than that of the NTG group (23.67 ± 4.98 years, P = 0.002). Best-corrected visual acuity was significantly poorer in the ADOA group (0.75 ± 0.32) than in the NTG group (0.16 ± 0.19, P < 0.001). The average peripapillary RNFL thickness and the RNFL thicknesses in the temporal upper, temporal lower, and nasal lower sectors were significantly thinner in the ADOA group than in the NTG group (all P < 0.05). Moreover, the macular GCC thickness of the ADOA group was significantly thinner than that of the NTG group (P < 0.001). Twenty-three OPA1 variants (11 novel OPA1 variants) and one OPA3 variant were detected in 24 patients with ADOA. Our study revealed a distinct difference between the patterns of RNFL and GCC loss in ADOA and NTG, which will help to differentiate ADOA from NTG in young patients. Additionally, this study expanded the genetic spectrum of ADOA.

Study of central macular and nerve fiber layer/ganglionic cell layer (NFL/GCL) thickness in normal and amblyopic eyes of pediatric patients with uniocular amblyopia

Purpose: To examine central macular and peripapillary retinal nerve fibre layer (RNFL)/ganglion cell layer (GCL) thickness in uniocular amblyopic patients.Methods: This cross sectional observational prospective study conducted on 20 patients (8-18 years) diagnosed with uniocular amblyopia. Central Macular Thickness (CMT) and NFL/GCL thickness was measured by OCT (NIDAC RS 3000 ADVANCE) and data was compared with normal fellow eye.Results: In a study group of 20 children (males=14, females= 6), the mean values of CMT observed in amblyopic eyes is (354 mm) and those of healthy fellow eyes is (253.55 mm). Also, RNFL/GCL thickness was determined in these children where mean value in amblyopic eyes is (121.89 mm) and those of healthy fellow eyes is (119 mm). Amblyopic eyes had slightly greater central macular thickness (macular map) as compared to the healthy fellow eye (p-value of (<0.05). The values of RNFL/GCL thickness showed no change (p- value (>0.05). Conclusions: In children aged predominantly 8 and 18 years, central macular thickness may be increased in eyes with amblyopia, although it is uncertain if this precedes or follows the development of amblyopia. No differences in peripapillary RNFL thickness were found when compared with normal eyes.

Changes in the macular choroidal thickness of children who have type-1 diabetes mellitus, with and without vitamin D deficiency.

To assess the peripapillary retinal nerve fiber layer (RNFL) and macular choroidal thickness (CT) of children who have Type 1 diabetes mellitus (DM), both with and without vitamin D deficiency (VDD). The prospective, case-control study herein comprised that included 46 children with DM and VDD (Group 1), 42 children with DM and normal vitamin D levels (Group 2), and 73 healthy children (Control group). The peripapillary RNFL thickness and macular CT were measured at three different points (subfoveal, 1500μm nasal, and 1500μm temporal from the fovea) and compared. The subfoveal, 1500μm nasal, and 1500μm temporal CT values were determined to be lower in the patients in Group 1 and Group 2 when compared to those in the Control group (P < 0.001). The same parameters were determined to be lower in the patients in Group 1 when compared to those in Group 2, although this difference was not found to be statistically significant (P > 0.05). In all of the quadrants, the RNFL thickness was determined to be similar between the groups, with P > 0.05 for all of the groups, except for the nasal quadrant (P = 0.031). In the correlation analysis of the patients in Group 1, it was revealed that a positive correlation existed between the CT and the vitamin D levels (P < 0.05). The choroids of pediatric diabetic children were thinner when compared to those of healthy children. The alterations in these parameters were more prominent in subjects who were determined to have lower levels of vitamin D.

Analysis of Peripapillary Vessel Density in Ethambutol-induced Optic Neuropathy Using Optical Coherence Tomography Angiography

Purpose: To investigate the changes in peripapillary and macular vessel density in ethambutol-induced optic neuropathy using optical coherence tomography angiography (OCTA).Methods: The medical records of patients diagnosed with ethambutol-induced optic neuropathy were analyzed retrospectively. Patient age, sex, daily dose (mg/day/kg), treatment duration, best-corrected visual acuity (logMAR), color vision (Ishihara color plate tests), and mean deviation of visual field test were evaluated in non-pathological individuals with age and sex controlled as the normal control group. Peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell/inner plexiform layer (GC/IPL) thickness, radial peripapillary capillary (RPC) density, and macular superficial capillary plexus (SCP) density were also compared between the patient and control groups.Results: The study included 22 patient eyes and 31 control group eyes. Comparing the OCTA results between the groups, there were no significant differences in peripapillary RNFL thickness, but the temporal RPC density was significantly (p = 0.025) lower in the patient group (48.00 ± 8.23%) than in controls (52.39 ± 5.58%). For macular structures, the mean GC/IPL thickness and whole SCP density were lower in the patients (p = 0.001 and p = 0.008, respectively). In the patients, the changes in peripapillary RNFL thickness and RPC density were significantly positively correlated (r = 0.811, p &lt; 0.001), as were the mean macular GC/IPL thickness and whole SCP density (r = 0.445, p = 0.037).Conclusions: Patients with ethambutol-induced optic neuropathy had significantly lower temporal RPC and macular SCP densities. Ethambutol toxicity may affect not only axonal degeneration but also peripapillary and macular vascular function.

DISCRIMINATION OF EYES WITH PRIMARY OPEN-ANGLE GLAUCOMA FROM NORMAL USING MACULAR GC-IPL THICKNESS

Objective: Primary open-angle glaucoma (POAG), a neuro-ophthalmological disease, is a condition of slowly progressive loss of retinal ganglion cells which are evident as characteristic optic nerve head vicissitudes and visual field defects, only after death of more than 40% of cells. This huge loss when witnessed is started to treat only if the patient approaches an ophthalmologist with a significant complaint, leading to optic nerve head examination, which means being an asymptomatic disease, it is usually left undiagnosed until advanced. An additional system of diagnosis of the disease earlier in the stage can aid reduce the burden of the blindness of POAG. Methods: Among a total of 62 eyes of 31 subjects, 40 eyes of 20 POAG subjects, and 22 eyes of 11 age-matched healthy subjects were recruited. All of them underwent Spectral Domain Optical Coherence Tomography macular and optic disk scans to note macular ganglion cell–inner plexiform layer (mGCIPL) and retinal nerve fiber layer (RNFL) thicknesses. Statistical analysis was did using an unpaired t-test and calculating a two-tailed p value, in which the significance was indicated by p&lt;0.05. Results: Similar to peripapillary RNFL thickness, the mGCIPL parameters, that is, minimum GCIPL thickness and GCIPL thickness in all sectors decreased significantly in POAG eyes to be able to discriminate them from normal. mGCIPL and RNFL thickness decreased as the severity of glaucoma increased. Conclusion: The minimum GCIPL thickness and that in all sectors can discriminate POAG eyes from healthy eyes significantly and has comparable performance to that of peripapillary RNFL thickness.

Retinal nerve fibre layer and ganglion cell layer thickness changes following intravitreal aflibercept for age-related macular degeneration

Purpose To evaluate the effect of intravitreal aflibercept (IVA) injections on peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) in neovascular age-related macular degeneration (nAMD) patients during a 1-year follow-up. Methods This is a prospective study including 34 patients who were treated with aflibercept for treatment-naive nAMD. Following a loading phase of 3-monthly aflibercept, re-injections were performed on a pro re nata regimen for 12 months. Best-corrected visual acuity, intraocular pressure, and spectral-domain-optical coherence tomography analysis were performed at baseline and 1 month, 3 months, 6 months, and 12 months following treatment. Peripapillary RNFLT and macular GCLT along with the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) were evaluated at each visit. Results Mean number of aflibercept injections was 6.0 ± 1.8. Significant thinning was observed at the central macular ganglion cell layer and at 1 mm superior, temporal, and nasal ganglion cell layer compared to baseline at 1-year (p < 0.05). No significant change of RNFLT was shown (p > 0.05). Mean CMT and SFCT were significantly reduced after IVA therapy (p < 0.05, for both). No correlation was found between injection number and GCLT change. Conclusions Intravitreal aflibercept caused significant ganglion cell layer thinning during a 1-year follow-up without any changes in RNFLT. Intravitreal aflibercept itself may have a chance to induce decreased GCLT in nAMD patients.

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.