An Evaluation of the Retinal Nerve Fibre Layer and Ganglion Cell Layer Thickness in Low Myopes.

Impact of ocular dominance on circumpapillary and macular retinal nerve fibre layer thickness and ganglion cell layer thickness in a healthy pediatric population

Several optical coherence tomography angiography (OCT-A) studies have demonstrated retinal microvascular changes in patients post-SARS-CoV-2 infection, reflecting retinal-systemic microvasculature homology. Post-COVID-19 syndrome (PCS) entails persistent symptoms following SARS-CoV-2 infection. In this study, we investigated the retinal microvasculature in PCS patients using OCT-angiography and analysed the macular retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness via spectral domain-OCT (SD-OCT). Conducted at the Manchester Royal Eye Hospital, UK, this cross-sectional study compared 40 PCS participants with 40 healthy controls, who underwent ophthalmic assessments, SD-OCT, and OCT-A imaging. OCT-A images from the superficial capillary plexus (SCP) were analysed using an in-house specialised software, OCT-A vascular image analysis (OCTAVIA), measuring the mean large vessel and capillary intensity, vessel density, ischaemia areas, and foveal avascular zone (FAZ) area and circularity. RNFL and GCL thickness was measured using the OCT machine’s software. Retinal evaluations occurred at an average of 15.2 ± 6.9 months post SARS-CoV-2 infection in PCS participants. Our findings revealed no significant differences between the PCS and control groups in the OCT-A parameters or RNFL and GCL thicknesses, indicating that no long-term damage ensued in the vascular bed or retinal layers within our cohort, providing a degree of reassurance for PCS patients.

To study the distribution of macular ganglion cell-inner plexiform layer (GC-IPL) thickness and peripapillary retinal nerve fiber layer (RNFL) thickness in children with refractive errors. Two hundred forty-three healthy eyes from 139 children with refractive error ranging from -10.00 to +5.00 D were recruited from the National University Hospital Eye Surgery outpatient clinic. After a comprehensive ocular examination, refraction, and axial length (AL) measurement (IOLMaster), macular GC-IPL and RNFL thickness values were obtained with a spectral domain Cirrus high definition optical coherence tomography system (Carl Zeiss Meditec Inc.). Only scans with signal strength of >6/10 were included. Correlation between variables was calculated using the Pearson correlation coefficient. A multivariate analysis using mixed models was done to adjust for confounders. The mean spherical equivalent refraction was -3.20±3.51 D and mean AL was 24.39±1.72 mm. Average, minimum, superior, and inferior GC-IPL were 82.59±6.29, 77.17±9.65, 83.68±6.96, and 81.64±6.70 μm, respectively. Average, superior, and inferior peripapillary RNFL were 99.00±11.45, 123.20±25.81, and 124.24±22.23 μm, respectively. Average, superior, and inferior GC-IPL were correlated with AL (β=-2.056, P-value 0.000; β=-2.383, P-value 0.000; β=-1.721, P-value 0.000), but minimum GC-IPL was not (β=-1.056, P-value 0.115). None of the RNFL parameters were correlated with AL. This study establishes normative macular GC-IPL and RNFL thickness in children with refractive errors. Our results suggest that high definition optical coherence tomography RNFL parameters and minimum GC-IPL are not affected by AL or myopia in children, and therefore warrants further evaluation in pediatric glaucoma patients.

Differential Effects of Aging in the Macular Retinal Layers, Neuroretinal Rim, and Peripapillary Retinal Nerve Fiber Layer

Purpose To evaluate the influence of systemic and ocular factors on the foveal avascular zone (FAZ) area in young Chinese subjects' healthy eyes. Methods The current observational, cross-sectional study included 344 eyes from 172 healthy individuals (103 women, 69 men). Optical coherence tomography angiography realized with the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to assess the area of superficial FAZ. To determine the related factors and to reveal their potential correlations with the FAZ area, comprehensive examinations including both systemic and ocular ones were executed. Systemic examination involved factors including age, gender, and body mass index, while ocular examination involved factors including BCVA, refractive error, intraocular pressure, axial length (AL), anterior chamber depth, and central corneal thickness. Especially for fundus examination, central macular thickness (CMT), retinal volume, mean retinal thickness, macular blood flow area/vessel density in the superficial retinal layer (SRL) and deep retinal layer (DRL), mean retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL) thickness, C/D rate, rim area, and subfoveal choroid thickness were assessed, using mixed-effects regression models to appropriately account for intereye correlation. Subgroup analyses were performed based on gender and high myopia categories. Results The mean FAZ area was 0.30 ± 0.11 mm2 and varied significantly across gender (P = 0.0024). AL, CMT, and RNFL thickness were found significantly correlated with the FAZ area in the univariate regression analysis (AL, P = 0.0005; CMT, P < 0.0001; and RNFL thickness, P = 0.0461). According to the multivariate results, CMT and macular blood flow in SRL were negatively correlated with FAZ (CMT: P < 0.0001; macular blood flow in SRL: P = 0.00223). Mean retinal thickness, mean GCL thickness, and macular blood flow in DRL were positively correlated with FAZ (mean retinal thickness: P = 0.0005; mean GCL thickness: P < 0.0001; and macular blood flow in DRL: P = 0.0099). Correlation results among these filtered factors and FAZ were more pronounced in non-high-myopic eyes than in high-myopic eyes and had a significant difference when data of male and female subjects were processed separately from each other. Conclusion The present cross-sectional study performed comprehensive systemic and ocular examinations in young Chinese adults and filtered factors affecting FAZ. We indicated that among all the assessed candidate factors, gender, AL, retinal thickness, macular blood flow, RNFL, and GCL thickness affected the FAZ area most significantly. Such findings would facilitate future research concerning the role of FAZ variation in fundus diseases.

Impact of Glaucoma Severity on Rates of Neuroretinal Rim, Retinal Nerve Fiber Layer, and Macular Ganglion Cell Layer Thickness Change

ObjectiveTo investigate associations between baseline macular pigment optical density (MPOD) and retinal layer thicknesses in eyes with and without manifest primary open-angle glaucoma (POAG) in the Carotenoids in Age-Related Eye...

AimsTo quantitatively analyze and compare the differences in retinal neurovascular units (NVUs) between healthy individuals and patients with type 2 diabetes mellitus (DM) by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) techniques and to determine the value of this technique for the early diagnosis of retinal neurovascular damage in patients with diabetes mellitus without retinopathy (NDR).MethodsThis observational case‒control study was conducted from July 1, 2022, to November 30, 2022, at the outpatient ophthalmology clinic of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine. All subjects underwent baseline data entry and mean thickness of the peripapillary retinal nerve fiber layer (pRNFL), the thickness of each retinal layer in the macula 3 × 3 mm, and vascular density (VD) examination.ResultsThe study included 35 healthy individuals and 48 patients with DM. The retinal VD as well as partial pRNFL, macular nerve fiber layer (NFL), and macular ganglion cell layer (GCL) thickness in DM patients exhibited significantly lower VD in the DM group than in the control group (p < 0.05). Age and disease duration of DM patients showed a negative trend with pRNFL thickness, macular NFL thickness, macular GCL thickness, and VD. However, a positive trend was observed between DM duration and partial inner nuclear layer (INL) thickness. Moreover, there was a positive correlation between macular NFL and GCL thickness and VD for the most part, while a negative correlation was shown between INL temporal thickness and DVC-VD. pRNFL-TI and GCL-superior thickness were screened as two variables in the analysis of the predictors of retinal damage in DM according to the presence or absence of DM. The AUCs were 0.765 and 0.673, respectively. By combining the two indicators for diagnosis, the model predicted prognosis with an AUC of 0.831. In the analysis of retinal damage indicators associated with the duration of DM, after regression logistic analysis according to the duration of DM within 5 years and more than 5 years, the model incorporated two indicators, DVC-VD and pRNFL-N thickness, and the AUCs were 0.764 and 0.852, respectively. Combining the two indicators for diagnosis, the AUC reached 0.925.ConclusionsRetinal NVU may have been compromised in patients with DM without retinopathy. Basic clinical information and rapid noninvasive OCT and OCTA techniques are useful for the quantitative assessment of retinal NVU prognosis in patients with DM without retinopathy.

Purpose This study aimed to investigate the characteristics of retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL) thickness, and choroidal thickness in children with moderate-to-high hyperopia (MHH). Methods This was a cross-sectional study that enrolled 53 children with MHH and 53 emmetropic children. Subjects with a spherical equivalent refraction (SER) of +4.0 D or higher were included in the MHH group, and subjects with SER between −1.0 D and +1.0 D were included in the emmetropic group. Ophthalmic examinations, including uncorrected visual acuity, cycloplegic refraction, slit-lamp examination, axial length, and swept-source optical coherence tomography (SS-OCT; DRI OCT Triton-1, Topcon, Tokyo, Japan), were performed. Results The RNFL and GCL in the temporal and inferior quadrants in 1–3 mm of the macular fovea were thinner in the MHH group than in the emmetropic group (all P < 0.05). The MHH group also had a thicker choroidal thickness in all regions (all P < 0.05). The SER was independently correlated with the average choroidal thickness in the optic disc and fovea (coefficient = 4.853, P < 0.001 for the optic disc; coefficient = 5.523, P=0.004 for the fovea), while axial length was negatively correlated with choroidal thickness (coefficient = −12.649, P < 0.001). Axial length was positively associated with RNFL and GCL thickness in the temporal quadrant in 1–3 mm of the macular fovea (coefficient = 0.966, P=0.007 for RNFL and coefficient = 1.476, P=0.011 for the macular fovea). Conclusion Compared with emmetropic children, MMH children had greater choroidal thickness. The characteristics of the RNFL and GCL thickness in MMH children were different from those in emmetropic children.

Objective:The aim of this study is to compare macular pigment optical density levels across four different ethnicities and study its influence on ganglion cell layer and retinal nerve fibre layer thickness across these ethnicities.Methods:Consenting adults visiting the ophthalmology and optometry clinics for a routine eye examination without any ocular comorbidity were enrolled. Participants underwent optical coherence tomography for macular thickness, retinal nerve fibre layer thickness and ganglion cell layer thickness. The macular pigment optical density levels were determined in the dominant eye using the QuantifEye device by trained observers.Results:In total, 336 eyes of 336 participants with a mean age of 39.2 ± 14.4 years were included of which 103 (30%) were Caucasians, 111 (33%) were African Americans, 29 (9%) were South Asian Indians and 94 (28%) were Hispanics. The mean macular pigment optical density value across the entire study population was 0.47 ± 0.15. South Asian Indians (0.58 ± 0.16) and Hispanics (0.52 ± 0.15) had significantly higher mean macular pigment optical density values compared with Caucasians (0.41 ± 0.16) and African Americans (0.38 ± 0.15). Linear regression analysis showed that there was a significant association between ethnicities and macular pigment optical density values when adjusted for age (β coefficient = 0.31, 95% confidence interval = 0.029–0.58, p < 0.001 for South Asian Indian and Hispanic ethnic groups compared with African Americans). There were no differences in the retinal nerve fibre layer and ganglion cell layer thickness across ethnic groups. Linear regression analysis also did not reveal any significant association between macular pigment optical density levels and retinal nerve fibre layer or ganglion cell layer thickness.Conclusion:Caucasians and African Americans have lower macular pigment optical density compared with South Asian Indians and Hispanics. There is no clinically significant association between macular pigment optical density levels and retinal nerve fibre layer and ganglion cell layer thickness in healthy individuals across races.

To examine structural changes in retinal layers over time in patients with non-arteritic anterior ischaemic optic neuropathy (NAION) and determine the layers that predict visual outcomes. The optical coherence tomography parameters in NAION eyes at <2 months, 2-5 months, and 6-18 months from the onset were compared to age-matched normal controls. Generalised estimating equation analysis was used to analyse the changes over time and regression analysis was performed to identify the layer that could predict visual field outcomes. Less than 2 months from the onset, the peripapillary retinal nerve fibre layer (RNFL) (p = 0.001) and macular outer nuclear layer (ONL) (p = 0.024) were significantly thicker in the NAION eyes than in the control eyes. The average peripapillary RNFL, macular RNFL, and ganglion cell layer and inner plexiform layer (GCIPL) showed reductions in thickness within 2-5 months (peripapillary RNFL: -19.8 μm/month, p < 0.001, macular RNFL: -14.5 μm/month, p < 0.001, GCIPL: -26.8 μm/month, p < 0.001). The change of thickness in temporal and superior peripapillary RNFL, GCIPL, inner nuclear layer (INL), and ONL by 2-5 months was associated with the final visual field results (p = 0.018, p < 0.001, p = 0.040, p = 0.020, and p = 0.002, respectively). The peripapillary RNFL swelling initially observed started to decrease within 2-5 months along with macular RNFL and GCIPL thinning. The rate of thickness changes in the peripapillary RNFL, GCIPL, INL, and ONL by 2-5 months was associated with visual field outcomes.

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.

Purpose of the study: To assess the ability of the new Spectralis Optical Coherence Tomography (OCT) Posterior Pole protocol to detect degeneration of the inner retinal layers in patients with bipolar disorder (BD) and to assess the correlation between the neuroretinal thickness and disease duration. Materials and Methods Twenty-five eyes of 25 patients with bipolar disorder and 74 eyes of 74 healthy controls underwent retinal measurements of retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness. Measurements were obtained using the Spectralis-OCT device with the new Posterior Pole protocol which assesses the macular area by analyzing retinal thickness in a grid of 64 (8*8) cells. Results Significant differences (p < 0.05) in RNFL and GCL thickness were found between BD patients and healthy controls, in parafoveal and perifoveal cells respectively. Significant inverse correlations were found between RNFL and GCL thinning at their thickest location and the duration of bipolar disorder. Several predictive variables were observed with a binary logistic regression for the presence/absence of BD: cell 1.3 RNFL (p = 0.028) and GCL in cells 7.8 (p = 0.012), 2.7 (p = 0.043) and 1.3 (p = 0.047). Conclusion Posterior Pole OCT protocol is a useful tool to assess changes in the inner retinal layers in bipolar disorder. These observed changes, especially those affecting the GCL, may be associated with disease evolution and may be predictive of the presence of the disease. OCT data could potentially be a useful tool for clinicians to diagnose and monitor BD patients.

Evaluation of the relationship between clinical parameters and retinal microvascular structures in children with atopic dermatitis: An optical coherence tomography angiography study.

The endoscopic transorbital approach (ETOA) provides minimally invasive access to the skull base, but its orbital trajectory raises concern for subclinical optic nerve or retinal injury. We assessed the structural safety of ETOA using high-resolution optical coherence tomography as an objective neuro-ophthalmic tool, focused mainly on patients without orbital involvement. From 41 consecutive ETOA cases (2017-2024), 16 patients had analyzable baseline and approximately 12-month postoperative imaging and were included: a Group A without orbital involvement (n = 10) and a Group B with orbital or optic nerve involvement but interpretable scans (n = 6). Macular ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (RNFL) thickness were measured with spectral-domain optical coherence tomography. Paired analyses were prespecified for the Group A; the Group B was summarized descriptively. The contralateral eye served as an internal control. Across all 16 patients, no structural or functional deterioration attributable to surgery was observed. In the Group A, GCL thickness in the operated eye decreased slightly from 81.0 µm to 80.5 µm (mean change -0.5 µm), as well as in the contralateral eye used as control (-0.2 µm). RNFL thickness in the operated eye increased from 96.4 µm to 97.3 µm (mean change +0.9 µm), while the contralateral eye decreased (-1.2 µm). These changes were not statistically significant and remained within physiological variability (±2 µm for GCL; ±3 µm for RNFL). Visual acuity, visual fields, color vision, and pupillary responses were preserved, with no signs of functional impairment. In the Group B, the operated eye showed RNFL thinning (≈-7.7 µm), while GCL remained stable. This was attributed to preexisting optic neuropathy or resolution of preoperative disc edema rather than surgical injury. Importantly, functional outcomes (visual acuity, visual fields, color vision, and pupillary responses) improved or remained stable. ETOA does not induce subclinical retinal or optic nerve injury at late follow-up. The approach demonstrated structural and functional safety, particularly in patients without orbital involvement (Group A), where preservation of visual integrity is imperative. These findings support the neuro-ophthalmic safety of the transorbital corridor and justify larger prospective studies.