Optical Coherence Tomography Optic Nerve Research Articles

Homonymous Hemiatrophy of Macular Ganglion Cell Layer as a Marker of Retrograde Neurodegeneration in Multiple Sclerosis-A Narrative Review.

Retrograde axonal neurodegeneration along the visual pathway-either direct or trans-synaptic-has already been demonstrated in multiple sclerosis (MS), as well as in compressive, vascular, or posttraumatic lesions of the visual pathway. Optical coherence tomography (OCT) can noninvasively track macular and optic nerve changes occurring as a result of this phenomenon. Our paper aimed to review the existing literature regarding hemimacular atrophic changes in the ganglion cell layer identified using OCT examination in MS patients without prior history of optic neuritis. Homonymous hemimacular atrophy has been described in post-chiasmal MS lesions, even in patients with normal visual field results. Temporal and nasal macular OCT evaluation should be performed separately in all MS patients, in addition to an optic nerve OCT evaluation and a visual field exam.

Optic Nerve Head and Retinal Changes in Idiopathic Intracranial Hypertension: Correlation with Short-Term Cerebrospinal Fluid Pressure Monitoring.

We aimed to assess the status of the optic nerve and retina by optical coherence tomography (OCT) in a group of patients with idiopathic intracranial hypertension (IIH) on the basis of dynamic changes in intracranial pressure. This observational and cross-sectional study included patients affected by idiopathic intracranial hypertension with papilledema (IIHWP) and patients with idiopathic intracranial hypertension without papilledema (IIHWOP). All participants underwent an OCT examination of the macula and optic nerve head. Parameters related to intracranial pressure, including cerebrospinal fluid (CSF) opening pressure (oCSFp), CSF mean pressure (mCSFp), and pulse wave amplitude (PWA), were included in the analysis. Out of the 22 subjects enlisted for the study, a total of 16 patients suggestive of IIH were finally enrolled. Papilledema was detected in nine subjects (56.2%) and seven patients were affected by IIHWOP (43.7%). The OCT examination showed a higher mean RNFL thickness in IIHWP patients in comparison to IIHWOP in both eyes (p < 0.05 and p < 0.01, respectively). Intracranial pressure (ICP) measurements showed that IIHWP had higher values of oCSFp, mCSFp, and PWA compared to IIHWOP (p = 0.0001, p = 0.0001, and p = 0.0001, respectively). In addition, ICP parameters significantly correlated with RNFL. Clinical parameters suggestive of idiopathic intracranial hypertension are associated with retina and optic nerve OCT parameters. OCT is a useful tool to detect these alterations in a non-invasive fashion.

Correlations between optic nerve OCT and macular functional alterations in patients who undergone successful RRD surgery

Purpose: The aim is to study the correlation between macular function measured by macular integrity assessment (MAIA) microperimetry and optic nerve (ON) evaluated by ON optical coherence tomography (OCT) in patients undergoing surgery after RRD.Methods: Cross‐sectional unicentric study including 64 eyes with RRD surgically treated compared with 136 healthy eyes. All underwent an ophthalmological examination including MAIA and ON OCT according to the total retina (TR) protocol and the retinal nerve fibre layer (RNFL) protocol.Results: Significant decrease in sensitivity and Macular Average Threshold were achieved in RRD group while macular integrity was higher. Temporal (T) sector of the TR protocol and superior (S) and inferior (I) sectors of the RNFL protocol showed greater thickness in the RRD group. Positive correlations were achieved between S sector of the OCT in both protocols and fixation stability P1; nasal (N) sector in the TR protocol and MAIA inferior outer (IO) sector; I sector in the TR protocol and MAIA IO and inferior inner (II) sectors while in the RNFL protocol with MAIA IO sector; T sector in the TR protocol and Macular Average Threshold; C (central) sector in the TR protocol and MAIA IO and II sectors. Negative correlations were showed between S sector in the RNFL protocol and MAIA C sector while in the TR protocol with BCEA 63% area; N sector in the RNFL protocol and MAIA central nasal (CN) sector; I sector in the RNFL protocol and MAIA IO sector and Macular Integrity; T sector in the RNFL protocol and MAIA C sector while in the TR protocol with BCEA 63% and 95% angles; C sector in the RNFL protocol and MAIA C and CN sectors.Conclusions: RRD causes loss of macular sensitivity together with anatomical changes in the ON. Inferior sectors of MAIA showed more correlations with the OCT TR protocol while C sectors correlated with the RNFL protocol.

Deep Transfer Learning for Ethnically Distinct Populations: Prediction of Refractive Error Using Optical Coherence Tomography.

The mismatch between training and testing data distribution causes significant degradation in the deep learning model performance in multi-ethnic scenarios. To reduce the performance differences between ethnic groups and image domains, we built a deep transfer learning model with adaptation training to predict uncorrected refractive errors using posterior segment optical coherence tomography (OCT) images of the macula and optic nerve. Observational, cross-sectional, multicenter study design. We pre-trained a deep learning model on OCT images from the B&VIIT Eye Center (Seoul, South Korea) (N = 2602 eyes of 1301 patients). OCT images from Poona Eye Care (Pune, India) were chronologically sorted into adaptation training data (N = 60 eyes of 30 patients) for transfer learning and test data (N = 142 eyes of 71 patients) for validation. Deep learning models were trained to predict spherical equivalent (SE) and mean keratometry (K) values via transfer learning for domain adaptation. Both adaptation models for SE and K were significantly better than those without adaptation (P < 0.001). In myopia/hyperopia classification, the model trained on circular optic disc OCT images yielded the best performance (accuracy = 74.7%). It also performed best in estimating SE with the lowest mean absolute error (MAE) of 1.58 D. For classifying the degree of corneal curvature, the optic nerve vertical algorithm performed best (accuracy = 65.7%). The optic nerve horizontal model achieved the lowest MAE (1.85 D) when predicting the Kvalue. Saliency maps frequently highlighted the retinal nerve fiber layers. Adaptation training via transfer learning is an effective technique for estimating refractive errors and K values using macular and optic nerve OCT images from ethnically heterogeneous populations. Further studies with larger sample sizes and various data sources are needed to confirm the feasibility of the proposed algorithm.

Trends in Imaging Utilization Among United States Medicare Beneficiaries and the Impact of the COVID-19 Pandemic.

This study characterizes trends in ophthalmic imaging volume and utilization in the United States among and assesses the potential impact of the COVID-19 pandemic using data from the Centers for Medicare and Medicaid Services. Utilization of macular optical coherence tomography (OCT), optic nerve OCT, and fundus photography steadily increased from 2013 to 2020 and was not impacted by the COVID-19 pandemic. At the same time, there was minimal adoption of anterior segment OCT and a decline in the utilization of dye-based angiography. Utilization patterns may be impacted by the advent of new technologies, role of the clinician, and alignment with treatment paradigms. [Ophthalmic Surg Lasers Imaging Retina 2023;54:661-665.].

Prevalence of peripapillary hyperreflective ovoid mass-like structures (PHOMS) in suspected papilloedema in children.

Suspected papilloedema is a frequent cause of referral to paediatric ophthalmology clinics. Recent publications have described a new finding called peripapillary hyperreflective ovoid mass-like structures (PHOMS) that may cause pseudopapilloedema. We evaluated the optical coherence tomography (OCT) scans of the optic nerve in all children referred with suspected papilloedema for the presence of PHOMS and report their frequency. The optic nerve OCT scans from children seen in our suspected papilloedema virtual clinic between August 2016 and March 2021 were evaluated for the presence of PHOMS by three assessors. A Fleiss' kappa statistic was calculated to test the agreement between the assessors for the presence of PHOMS. A total of 220 scans from 110 patients were evaluated during the study period. The mean patient age was 11.2 SD ± 3.4, (range 4.1-16.8). PHOMS were identified in at least one eye in 74 (67.3%) patients. Of these, 42 (56.8%) patients had bilateral and 32 (43.2%) had unilateral PHOMS. Excellent agreement between assessors for the presence of PHOMS (Fleiss' kappa 0.9865) was observed. PHOMS were common in association with other identified causes of pseudopapilloedema (81.25%) but were also common in papilloedema (66.67%) and otherwise normal discs (55.36%). Misdiagnosis of papilloedema can lead to unnecessary and invasive tests. PHOMS are found frequently within the paediatric population referred for suspected disc swelling. They appear to be an independent cause of pseudopapilloedema but are often seen in conjunction with true papilloedema and other causes ofpseudopapilloedema.

Retinal Nerve Fiber Layer Analysis in Children With Migraine With and Without Aura Using Optical Coherence Tomography: A Case-Control Study.

To evaluate retinal nerve fiber layer (RNFL) thickness in children with migraine, with and without aura, compared to healthy controls using optical coherence tomography (OCT). In this cross-sectional case-control study, patients with a diagnosis of migraine with aura (MwA) or without aura (MwoA) were considered and healthy children were included as controls. Age, sex, duration of migraine, number of episodes per month, duration of episodes, and use of prophylactic treatment with magnesium were recorded. All patients underwent complete ophthalmologic, neurologic, and pediatric examination. Optic nerve OCT images were obtained using Heidelberg Spectralis OCT (Heidelberg Engineering) and mean global RNFL thickness and the average thickness for each sector were noted. Thirty-seven children were included: 17 with migraine (9 MwoA and 8 MwA) and 20 controls, the mean age being 13.8 ± 2.9 (range: 8 to 16) and 13.4 ± 2.5 (range: 7 to 16) years, respectively. No significant differences in RNFL thickness were found when comparing all patients who had migraine with healthy controls. However, children with MwA showed statistically significant reductions in RNFL thickness in the temporal (mean difference: 7.83; 95% CI: 0.52 to 15.14, P = .027) and inferior-temporal (mean difference: 16.06; 95% CI: 1.95 to 30.16, P = .027) sectors compared to patients with MwoA. None of the other sectors showed statistically significant differences between groups (all P > .05). In the migraine group, negative correlations were detected between the number of episodes per month and RNFL thickness in the nasal-superior quadrant (r = -.420; P = .021). Children with MwA may present a decrease in RNFL thickness, which is associated with the number of episodes per month. [J Pediatr Ophthalmol Strabismus. 2023;60(3):196-202.].

Retinal nerve fibre layer and ganglion cell layer changes in children who recovered from COVID-19: a cohort study

ObjectiveTo investigate the optic nerve and macular parameters of children who recovered from COVID-19 compared with healthy children using optical coherence tomography (OCT).DesignCohort study.SettingHospital Clinico San Carlos, Madrid.PatientsChildren between 6...

Optical Coherence Tomography May Help Distinguish Glaucoma from Suprasellar Tumor-Associated Optic Disc.

Purpose This study aimed to differentiate patients with bilateral disc cupping associated with suprasellar tumor from patients with open-angle glaucoma by analyzing differences in optical coherence tomography (OCT) of the optic nerve. Methods In this retrospective cross-sectional study, we collected data from the eyes of 25 patients with suprasellar craniopharyngioma or pituitary macroadenomas (group 1) and 35 patients with primary open-angle glaucoma (POAG) (group 2), seen between 2001 and 2015, all with a visual acuity of ≥20/40, for whom Stratus Time-Domain (TD) optic nerve OCT scans were available. The main outcome measures were the retinal nerve fiber layer (RNFL) thickness, disc area, cup volume, cup/disc ratio, and rim area. Results A total of 31 patients met the inclusion criteria and were included in the study: 16 with suprasellar tumors and 15 with POAG. Both groups were similar in terms of gender and age (P > 0.05). The glaucoma group had a borderline greater total RNFL thickness (74.2 μm versus 62.8 μm, P=0.07), disc area (2.70 mm2 versus 2.16 mm2, P=0.004), and cup volume (0.20 mm3 versus 0.08 mm3, P=0.02). In multivariate, glaucoma was associated with increased total RNFL thickness (OR = 1.116 per μm, P=0.008), increased disc area (OR = 2.402 per 100 μm2, P=0.002), and decreased rim area (OR = 0.272 per 100 μm2, P=0.011). Of these, the parameter with the greatest AUC was the disc area (AUC = 0.79). Using the Youden index, the optimal cut-off point identified for stratification was a disc area greater than 2.33 μm2. Conclusions In patients with bilateral disc cupping, a decreased total RNFL thickness and smaller disc area seem to be associated with suprasellar tumors (when compared with open-angle glaucoma). These findings may aid in early diagnosis of cupping from suprasellar tumors, before compressive visual loss occurs.

Intravitreal bevacizumab for the treatment of nonarteritic anterior ischemic optic neuropathy: a prospective trial

There is currently no accepted treatment for Nonarteritic Anterior Ischemic Optic Neuropathy (NAION). One new therapeutic approach involves decreasing optic nerve edema with intravitreal bevacizumab in order to resolve a proposed compartment syndrome. In this non-randomized controlled clinical trial, 1.25 mg intravitreal bevacizumab was compared with natural history. Patients were examined at baseline, 1, 3, and 6 months with a full neuro-ophthalmic exam, automated perimetry, and optic nerve optical coherence tomography (OCT) measurements. The primary outcome measure was change in mean deviation on Humphrey visual field testing. Secondary outcome measures were change in visual acuity and optic nerve OCT thickness. Incidence and type of complications were also recorded. Twenty-five patients were enrolled (17 treatment and 8 control). There was no significant effect of treatment on the primary outcome measure of mean deviation score (P=0.4). There was similarly no effect of group assignment on the secondary outcome measures of change in mean Early Treatment Diabetic Retinopathy Study letters (P=0.33) or nerve fiber layer thickness on OCT (P=0.11). In the bevacizumab group, there was one case of a corneal abrasion and two cases of recurrent NAION. No other complications were noted. We found no difference between bevacizumab and natural history for change in visual field, visual acuity, or optic nerve OCT thickness. Based on the current evidence we would not recommend the use of intravitreal bevacizumab to treat patients with the new onset of NAION.