Validating the utility of the Kestenbaum number in various types of optic atrophy

To investigate the difference of retinal nerve fiber layer (RNFL) thickness and macular fovea thickness/volume between multiple sclerosis (MS) patients and healthy normal individuals using optical coherence tomography (OCT) and assess its association with visual field parameters. Thirty consecutive MS patients and 28 healthy controls were recruited in this prospective study. Comprehensive standardized ophthalmic examinations included visual acuity, cycloplegic refraction, intraocular pressure, gonioscopy, visual field, and RNFL thickness and macular fovea thickness/volume detection using Humphrey OCT. Mean values for the thickness of the peripapillary RNFL and macular volume were calculated. Associations between visual field parameters and RNFL thickness/macular volume were analyzed by Pearson correlation analysis. The RNFL thicknesses in each quadrant, the average macular thickness, and the average macular volume in MS patients were all less than those in healthy controls, with statistically significant differences. The RNFL thickness and macular fovea thickness/volume were greater in eyes without optic neuritis than in eyes with optic neuritis. The average visual field parameters had positive correlations with the RNFL thickness and negative correlations with macular parameters in MS patients. OCT measurements can effectively identify the nerve changes of MS patients, which provide more data for the diagnosis of MS.

To assess the association between the serum levels of uric acid (UA) and primary open-angle glaucoma (POAG). In this pilot study, 46 eyes of 23 patients with a clinical history of POAG and 30 eyes of 15 healthy subjects were included. All patients underwent a complete ophthalmological examination, including best corrected visual acuity (BCVA), intraocular pressure (IOP), and gonioscopy. Visual field parameters, such as mean deviation (MD) and pattern standard deviation (PSD), and optical coherence tomography (OCT) values of the optic nerve head, including retinal nerve fiber layer (RNFL) thickness and vertical cup/disc ratio (VCDR), were noted. A blood sample was collected from each subject for serum UA measurement. IOP, MD, PSD, RNFL thickness, and VCDR resulted significantly different in POAG patients, when compared with controls (p < 0.05). POAG patients showed significantly lower levels of mean serum UA than healthy controls (4.00 ± 0.66 mg/dL vs 4.95 ± 0.86 mg/dL, respectively, p < 0.0001). Furthermore, severe POAG patients showed mean serum levels of UA lower than mild POAG patients (3.36 ± 0.70 mg/dL vs 4.22 ± 0.51 mg/dL, respectively, p = 0.01). Visual field and OCT parameters were statistically correlated with the mean serum levels of UA in POAG eyes (p < 0.05). Results suggest that in POAG patients, serum UA levels may be decreased and correlated with visual field and OCT parameters worsening. Further larger multi-center prospective studies are necessary to confirm our findings and establish the role of UA in glaucoma.

PurposeThough there are many reports regarding the structure-function relationship in glaucoma, they are too complicated to apply to the routine clinical setting. The aim of this study was to investigate the direct relationship between peripapillary retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and visual field (VF) severity indices computed by standard automated perimetry.MethodsThis cross-sectional comparative study included 104 glaucomatous patients and 59 healthy subjects. Peripapillary RNFL thickness was measured by spectral domain (SD) and time domain (TD) OCTs. Four glaucoma VF severity indices, including mean deviation (MD), pattern standard deviation (PSD), Collaborative Initial Glaucoma Treatment Study (CIGTS) VF score, and Advanced Glaucoma Intervention Study (AGIS) VF score, were calculated using standard automated perimetry. The Pearson's correlation coefficients (r) between the average and quadrants of peripapillary RNFL thicknesses and the four VF severity indices were calculated.ResultsIn glaucomatous eyes, the r value between the average RNFL thickness measured by SD OCT and each VF severity index were 0.562, -0.514, -0.577, and -0.567 for the MD, PSD, CIGTS VF score, and AGIS VF score, respectively (all p < 0.001). Among each quadrant, the inferior RNFL thickness showed the largest r value; 0.587, -0.552, -0.613, and -0.598 for the MD, PSD, CIGTS VF score, and AGIS VF score, respectively (all p < 0.001). Measurements by TD OCT showed similar strengths of association with SD OCT.ConclusionsModerate correlation was identified between peripapillary RNFL thicknesses measured by SD/TD OCT and glaucoma VF severity indices. Among each quadrant, the inferior RNFL thickness showed the greatest association with glaucoma VF severity indices. There was no significant difference according to the type of VF severity index or the type of OCTs.

To study the significance of optic disc tomography and retinal nerve fiber layer (RNFL) thickness measurement by spectral-domain optical coherence tomography (OCT) in the diagnosis of glaucoma. It was a noninterventional, observational study. The optic disc topographic parameters and total and regional RNFL thickness were measured by RTVue OCT in 60 normal eyes and 97 glaucomatous eyes. One-way analysis of variance was used to compare the parameters above mentioned between normal and glaucomatous groups. The area under the receiver operating characteristic curve (AUC) and the sensitivity at 80% specificity were used to assess the ability of each testing parameter in the differentiation between normal and glaucoma eyes. There were statistically significant differences in all RTVue OCT measurement parameters (F = 1.024, P = 0.596;F = 36.519, 54.464, 27.659, 36.176, 20.562, 63.833, 30.031, 54.652, 98.146, 78.705, 99.839, 43.728, 75.720, 45.709, 39.380, 33.590, 66.887, 78.335, 45.485;P = 0.000) except disc area. The average RNFL thickness in normal, early, moderate and advanced glaucomatous eyes was 109.950, 93.313, 80.374 and 65.570 µm, respectively. Among the eight regions around the optic disc, the thickest RNFL was located at the inferotemporal (150.066 µm) and superotemporal (146.285 µm) regions in normal eyes, and the superotemporal (108.569, 103.420 and 88.708 µm in early, moderate and advanced glaucomatous eyes, respectively) and inferotemporal (108.201, 102.830 and 86.369 µm in early, moderate and advanced glaucomatous eyes, respectively) regions in glaucomatous eyes. Both in normal and glaucomatous eyes, the thinnest RNFL was located at the nasal and temporal regions, respectively. For optic disc topographic parameters, the highest AUC was vertical cup/disc ratio (AUC = 0.762, 0.946 and 0.988 in early, moderate and advanced glaucomatous eyes, respectively), and the sensitivity at 80% specificity was 62.2%, 76.5% and 99.2% in early, moderate and advanced glaucomatous eyes, respectively. For RNFL thickness, the highest AUC was superotemporal region RNFL thickness (AUC = 0.915) and the sensitivity at 80% specificity was 89.5% in early glaucomatous eyes. The highest AUC was inferior average RNFL thickness (AUC = 0.967) and the sensitivity at 80% specificity was 94.1% in moderate glaucomatous eyes. The highest AUC was average RNFL thickness (AUC = 0.985) and the sensitivity at 80% specificity was 99.2% in advanced glaucomatous eyes. Among the eight regions around the optic disc, RNFL thickness of region ST (AUC = 0.915, 0.926 and 0.966 in early, moderate and advanced glaucomatous eyes, respectively) achieved the highest AUC. RNFL thicknesses of the nasal and temporal regions showed the lowest AUCs. RTVue OCT shows fair discriminating ability in distinguishing normal from glaucomatous eyes. RTVue OCT is a useful equipment for the diagnosis of glaucoma.

Objective To measure RNFL thickness by Frequency-domain optical coherence tomography (OCT) in patients with different stages of primary glaucoma (CACG and POAG),to evaluate the correlation between RNFL thickness and visual field mean defect (MD),to detect RNFL thickness change of early stage primary glaucoma,and to discuss the clinical significance in the early diagnosis of primary glaucoma objectively. Methods Ninety-two subjects of 40 normal and 52 with different stages of primary glaucoma were enrolled in this study.RNFL thickness was measured by Zeiss Cirru HD-OCT,and visual field was tested by Zeiss Humphrey-750.The association between visual field MD and RNFL thickness was evaluated with Pearson correlation coefficients. Results In the normal group,mean RNFL thickness was 112.91±9.36μm; the early period glaucoma group 94.43±7.67μm; the middle period glaucoma group 80.82±10.36μm; the later period glaucoma group 67.86±8.01μm.Visual field MD in each group was-0.88±1.53dB,-4.26±1.83dB,-7.43±2.64dB and -17.06±5.85dB.The differences in mean RNFL thickness and visual field MD between normal and each stage glaucoma group were significant (P ＜0.05) by independent sample t-test.In each stages of glaucoma group,mean RNFL thickness and visual field MD (early period:r =-0.537,middle period:r =-0.615,later period:r=-0.804) correlated significantly (P ＜0.05).In the early period glaucoma group,superior RNFL thickness was 116.32±11.65μm,inferior RNFL thickness 105.58±9.73μm,nasal RNFL thickness 75.40±10.91μm,and temporal RNFL thickness 70.28±13.08μm.In group B,superior RNFL thickness was 140.15±8.79μm,inferior RNFL thickness 137.29±10.07μm,nasal RNFL thickness 90.20±14.19μm,and temporal RNFL thickness 88.43±10.85μm.The difference of superior and inferior RNFL thickness between group A1 and group B had statistical significance tested by independent sample t-test,P ＜0.05; nasal and temporal RNFL thickness between group A1 and group B was tested by independent sample t-test,P ＞0.05,there was no statistical significance difference. Conclusions Frequency-domain OCT detected that the average of RNFL thickness become thinning with the progression of disease in the primary glaucoma patients,have negative correlation with vision MD,it is able to objectively reflect the degree of glaucomatous optic nerve damage.Frequency-domain OCT can show significantly decreased superior and inferior RNFL thickness of the early period primary glaucoma,which shows good ability in distinguishing normal from early period primary glaucomatous eyes. Key words: Optical coherence tomography (OCT); Retinal nerve fiber layer (RNFL); Mean defect (MD); Early diagnosis primary glaucoma

This study aims to investigate prognostic factors for visual recovery in patients with ethambutol-induced toxic optic neuropathy (EON) by analyzing visual field (VF) tests, retinal nerve fiber layer (RNFL) thickness on optical coherence tomography (OCT), and other variables. We retrospectively reviewed 46 eyes of 23 patients with EON who had been followed up for more than six months. Patients were categorized into recovery (n = 12) and non-recovery (n = 11) groups based on visual recovery at six months after discontinuation of ethambutol. In the recovery group, initial best-corrected visual acuity (BCVA) and VF tests were better (p < 0.001), body weight (p = 0.04) was higher and the number of patient with diabetes (p = 0.007) was lower than in the non-recovery group. Baseline BCVA, VF tests, inferior and nasal RNFL thickness were correlated with visual outcomes. Univariate analysis showed that younger age (p = 0.024), higher body weight (p = 0.033), better initial BCVA (p < 0.001), better VF tests (p = 0.007), no hypertension (p = 0.044) and no diabetes (p = 0.009) were significant associated with a good visual outcomes. Multivariate analysis confirmed baseline BCVA as the only significant prognostic factor. Better BCVA at baseline are associated with favorable visual outcomes in EON patients. VF parameters, age, hypertension, diabetes, and body weight could also be considered possible predictors. Although RNFL thickness has significant correlation with visual outcomes, it does not appear to be a reliable factor to predict visual recovery.

Glaucoma patients had a reduction in the inner annulus peripapillary choroidal microvascular density (PCMD) that became worse as the glaucoma severity progressed, which might provide new evidence supporting the vascular theory. To compare PCMD among normal tension glaucoma (NTG), primary open angle glaucoma (POAG), and healthy controls using optical coherence tomography (OCT) angiography (OCTA). The study included 40 POAG, 25 NTG, and 33 healthy controls. All subjects underwent OCT and OCTA testing. The inner annulus and outer annulus PCMD, as well as peripapillary vessel density (VD), were calculated. One-way analysis of variance was used to compare the vascular parameters of the 3 groups. Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between PCMD and glaucomatous severity factors. The spatial positional relationship between PCMD and corresponding peripapillary retinal nerve fiber layer (RNFL) thickness and visual field (VF) mean deviation (MD) was also assessed. The average and 4 quadrants of the inner annulus PCMD and peripapillary VD in the 2 glaucomatous groups were significantly lower than in normal eyes ( P <0.05). Strong correlations were found between inner annulus PCMD and VF MD, peripapillary VD, and RNFL in POAG patients. Similarly, the inner annulus PCMD in NTG patients was strongly correlated with peripapillary VD and RNFL (all r >0.5). Strong positional correlations were found between inner superior quadrantal PCMD and RNFL thickness in both POAG and NTG patients ( r =0.566 and 0.731, respectively). Likewise, inner inferior quadrantal PCMD exhibited a strong correlation with RNFL thickness in POAG patients ( r =0.608). Strong positional correlations were also found between inner superior PCMD and VF MD in both POAG and NTG patients ( r =0.589 and 0.622, respectively). Inner inferior PCMD exhibited a moderate correlation with VF MD in both POAG and NTG patients ( r =0.487 and 0.440, respectively). The study found that the inner annulus PCMD decreased to varying degrees in NTG and POAG patients. The inner annulus PCMD was closely related to the structural and visual function parameters of glaucoma in both NTG and POAG. Furthermore, inner PCMD demonstrated a spatial correlation with corresponding RNFL thickness and VF MD.

RE-PERG is altered in presence of primary neuronal degeneration of retinal ganglion cells, both in glaucoma and other diseases. A previous study showed that in a model of retrograde degeneration (vascular dementia) RE-PERG was normal. In this study, we enrolled patients with pituitary adenoma (PA) to evaluate RE-PERG findings in another model of retrograde degeneration compared with healthy controls (HC). Based on the outcome of the present and our previous studies with RE-PERG, and reviewing the literature, we discuss the physiopathology of glaucoma. Twelve PA patients and 14 age-matched HC were recruited. All participants performed visual field (VF) test, retinal nerve fiber layer (RNFL) and ganglion cells complex (GCC) thickness measurement by means of optical coherence tomography (OCT), visual evoked potentials (VEPs) and RE-PERG, a non-invasive, fast steady-state pattern electroretinogram (SS-PERG) sampled in five consecutive blocks of 130 events. VEPs amplitude was significantly lower in PA with respect to HC (6.8±0.6 vs 7.4±0.6 µV; p=0.045). VEPs latency was higher in PA (123.2±5.8 vs 103.6±4.1 msec; p<0.01). As for VF, mean defect (MD) and pattern standard deviation (PSD) were higher in PA (-6.6±2.6 vs -0.01±1.02 dB; p<0.01 and 8.5±3.1 vs 1.5±0.3; p<0.01, respectively). RNFL thickness was lower in PA (88±8.1 vs 97±9.3 µ; p=0.01). There was no statistically significant difference between PA and HC for RE-PERG. There was a significant correlation among MD, PSD, VEPs amplitude, PERG amplitude and RNFL thickness in the PA group, whereas no correlation was found with SDPh, which remains as normal as in the HC group. Our findings confirm that RE-PERG is not altered in retrograde degeneration. Based on the outcome of the present and our previous studies about RE-PERG and glaucoma, we assume that in glaucoma a double mechanism of retinal ganglion cells degeneration, both retrograde and primary, can coexist.

The aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression. A total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearman's correlation coefficients and with linear regression analysis. Macular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (rho=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (rho=0.60; P<0.001). Although FD-OCT RNFL and macular thickness measurements were both correlated with VF loss, the correlation was stronger with quadrantic macular than with RNFL thickness measurements in patients with temporal hemianopia. Such measurements could potentially be used to quantify neuronal loss in patients with chiasmal compression.

Background: Glaucoma is a disease that belongs to a group of neurodegenerative diseases, such as impaired visual field and optic neuropathy with progressive damage to the optic nerve and retinal nerve fiber layer (RNFL) which is caused by the loss of ganglion cells and axon of the optic. Changes in the optic nerve and RNFL may occur prior to the abnormalities of the visual field nerves. Currently, the visual field examination should be performed to diagnose glaucoma but with patient-subjective result. Before it is detectable, visual field abnormalities are likely going to lose its ganglion cells by 40%. The purpose of this study was to assess and compare the peripapillary retinal nerve fiber layer (RNFL) between the normal and glaucoma eyes with vertical cup disc ratio (CDR) 0.4 to 0.7 in eye clinic Cipto Mangunkusumo Hospital (RSCM) Kirana. Methods: A total of 40 eyes of normal group and 34 eyes of glaucoma following Humphrey field analyzer examination and Optical Coherence Tomography (OCT) were evaluated. Peripapillary RNFL thickness between normal and glaucoma eyes were analyzed and compared each other. Eyes of glaucoma group then were grouped into early-stage glaucoma, according to the criteria in the initial stages of the examination results of Humphrey field analyzer. Result of peripapillary RNFL thickness was analyzed to get a cut off value. Results: Peripapillary RNFL thickness in the normal group with vertical CDR 0.4 to 0.7 was 111.3±9.8 μm to 118.0±3.0 μm, and glaucoma groups with vertical CDR 0.4 to 0.7 was 105.6±12.6 μm to 113.7±6.1 μm. Retinal nerve fiber layer thickness in normal group compared to glaucoma group in the superior quadrant, inferior, nasal, temporal and average on CDR 0.4 to 0.7 was not statistically significant (p&gt;0.05), except on vertical CDR 0.6 average peripapillary RNFL (p&lt;0.05). Cut off value of peripapillary RNFL in superior quadrant was 164 μm, inferior 169.5 μm, nasal 82.5 μm, temporal 73.5 μm and average 111.8 μm. Conclusion: There was no difference in changes of peripapillary RNFL along with the progression of vertical CDR but clinically, peripapillary RFNL thickness in glaucoma group is thinner than that of normal group with the same vertical CDR except in temporal quadrant. Keywords: Retinal nerve fiber layer (RNFL), cup disc ratio (CDR), optical coherence tomography (OCT)

Background: Spectral-domain optical coherence tomography (OCT) can identify the presence of localized glaucomatous structural damage. The peripapillary retinal nerve fiber layer (RNFL) thickness is a popular OCT parameter used for glaucoma diagnosis and monitoring progression. Aim: To measure the peripapillary RNFL thickness, the pattern of RNFL defect, and association of RNFL with the severity of glaucoma using Spectralis Spectral Domain – OCT in patients with primary open-angle glaucoma (POAG) at a glaucoma clinic in a tertiary care teaching hospital in south India. Methods: Cross-sectional study design. Peripapillary RNFL thickness of 109 glaucomatous eyes of 56 patients aged 40–75 years having POAG, ocular hypertension, or suspected to have glaucoma but without visual field (VF) defects were included in the study. The cross-sectional thickness of RNFL using a 3.46 mm circle centered around the disc in 6 segments were measured and defects in the RNFL were identified by comparing measurements from each patient with the normative database. Results: The study included 109 eyes with 51 (46.79%) preperimetric eyes and 58 (53.21%) POAG eyes (with field defects). The average global thickness in the study population was 91.31 ± 12.81 µm for preperimetric eyes and 67.76 ± 17.33 µm for eyes with glaucoma. There was significant thinning in all segments between eyes with POAG and normal eyes with the mean difference highest in the inferotemporal segment (mean difference of 73.05) and the superotemporal segment (mean difference of 55.85). The global RNFL thickness had a coefficient of − 0.015 (standard error [SE] 0.003, 95% confidence interval [CI]: 0.02–0.009, R2 = 0.29) for mild glaucoma, −0.010 (SE 0.004, 95% CI: 0.02–0.003, R2 = 0.12) for moderate and − 0.18 (SE: 0.001, 95% CI: 0.022–0.014, R2 = 0.60) for severe glaucoma compared to preperimetric eyes in a linear regression model that adjusted for age and gender. Global and sector-wise RNFL thickness also had a significant area under Receiver Operator Characteristic (0.84, 95% CI: 0.78. 0.91) that showed the ability to discriminate between preperimetric and glaucomatous eyes. Possible “floor effect” of RNFL thickness was shown by 7 eyes with advanced glaucoma cases. Conclusion: RNFL thinning can be used as a parameter to assess glaucomatous structural loss that can aid in early diagnosis and monitoring of disease progression, to grade the severity of the disease in primary open-angle glaucoma, and when VFs cannot be done.

Structure–Function Relationships Using Spectral-Domain Optical Coherence Tomography: Comparison With Scanning Laser Polarimetry

PV058 / #431Poster Topic:AS06 - ComorbiditiesBackground/PurposeRetinopathy is a common ocular manifestation in SLE, and it is often caused by microangiopathy resulting from immune complex deposition, leading to vasculitis and thrombosis in the retinal microcirculation. Antiphospholipid antibodies (aPL) are present in around 30% of SLE patients, with 10% developing antiphospholipid syndrome (APS). Retinal involvement in APS can manifest as arterial and venous thrombosis. While macrovascular involvement manifests with prominent symptoms such as amaurosis fugax or transient diplopia, microvascular involvement may remain asymptomatic and manifest at the retinal level with microhaemorrhages, microaneurysms, and cotton-wool spots. This study aimed to evaluate the association between aPL positivity and preclinical retinal vascular changes in SLE patients.MethodsThis cross-sectional, two-center study included 112 SLE patients and 134 healthy controls recruited from Hospital Clinic de Barcelona and Policlinico Tor Vergata in Rome. Patients underwent ophthalmological evaluations, including visual acuity measurement, slit-lamp biomicroscopy, intraocular pressure measurement, and fundus examination. Retinal structural changes, such as macular thickness (MT) and retinal nerve fiber layer (RNFL) thickness, were assessed using spectral-domain optical coherence tomography (SD-OCT). Retinal vascular changes, including vessel density (VD), vascular perfusion (VP), and foveal avascular zone (FAZ), were evaluated using OCT angiography (OCTA). Statistical analysis was performed to compare differences between SLE subgroups stratified based on aPL positivity or the presence of APS.This cross-sectional, two-center study included 112 SLE patients and 134 healthy controls recruited from Hospital Clinic de Barcelona and Policlinico Tor Vergata in Rome. Patients underwent ophthalmological evaluations, including visual acuity measurement, slit-lamp biomicroscopy, intraocular pressure measurement, and fundus examination. Retinal structural changes, such as macular thickness (MT) and retinal nerve fiber layer (RNFL) thickness, were assessed using spectral-domain optical coherence tomography (SD-OCT). Retinal vascular changes, including vessel density (VD), vascular perfusion (VP), and foveal avascular zone (FAZ), were evaluated using OCT angiography (OCTA). Statistical analysis was performed to compare differences between SLE subgroups stratified based on aPL positivity or the presence of APS.ResultsOCTA analysis revealed decreased vascular parameters in SLE patients compared to controls in both cohorts. Specifically, the Barcelona cohort showed significant reductions in VD and VP (Table 1), while the Rome cohort showed significant reductions in parafoveal superficial VD. No clear association was found between aPL positivity and alterations in OCTA vascular parameters in SLE patients. However, a possible correlation between aPL positivity and variations in RNFL thickness was observed in both cohorts (Table 2 and Table 3).Table 1.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA) parameters at Barcelona cohort, right eyea.Table 2.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA) parameters at Barcelona cohort, by antiphospholipid antibodies, right eyea.Table 3.Spectral-domain Optical Coherence Tomography (SD-OCT) and Angiography by Optical Coherence Tomography (OCTA} parameters at Rome cohort, by antiphospholipid antibodies, right eyea.ConclusionsWhile SLE patients exhibited significant alterations in vascular OCTA parameters compared to healthy controls, the study did not find a definitive association between aPL positivity and changes in OCTA parameters in SLE patients. However, the study suggests a potential correlation between aPL positivity and variations in RNFL thickness in both cohorts. Further studies are needed to confirm these results and understand their biological significance.

Background: Anti-tuberculosis therapy (ATT), particularly ethambutol, is known to cause optic neuropathy. Early detection of structural and functional optic nerve changes is essential to prevent irreversible visual impairment. Aim: To evaluate clinical and functional optic nerve changes in patients receiving anti-tuberculosis therapy over a six-month follow-up period. Materials and Methods: This prospective longitudinal study included 50 patients undergoing ATT. Participants were evaluated at baseline, 3 months, and 6 months. Clinical examination included fundus evaluation, color vision testing, optical coherence tomography (OCT) for retinal nerve fiber layer (RNFL) thickness, and automated perimetry. Repeated-measures analyses were performed using Cochran's Q test, McNemar test, Friedman test, Wilcoxon signed-rank test, and paired t-test. Structural?functional correlations were assessed using Pearson and Spearman correlation coefficients. Results: Ocular involvement was observed in 44% of patients. RNFL thinning increased significantly from 0% at baseline to 20% at 3 months and 36% at 6 months (Cochran's Q = 27.11, p = 0.000001). Mean RNFL thickness decreased significantly over time (Baseline: 104.11 &plusmn; 7.31 ?m; 6 months: 95.32 &plusmn; 12.77 ?m; Friedman X² = 17.76, p = 0.000139). Visual field defects increased from 0% at baseline to 16% at 6 months (Cochran's Q = 14.25, p = 0.000805). A significant reduction in visual field mean deviation was observed at 6 months (p = 0.000595). Strong positive correlations were noted between RNFL thickness and visual field mean deviation (r = 0.674, p < 0.001) and color vision score (r = 0.772, p < 0.001). Conclusion: Anti-tuberculosis therapy is associated with progressive structural and functional optic nerve changes. OCT-measured RNFL thinning correlates strongly with functional visual impairment, emphasizing the importance of periodic ophthalmic monitoring in patients receiving ATT.

Tomographie par cohérence optique (OCT) en neuro-ophtalmologie