Neuroretinal Rim Research Articles

Technical difficulties of adequate assessment of intraocular pressure in a patient with glaucoma in the long term after corneal refractive surgery (clinical case)

PURPOSE. To demonstrate a clinical case involving difficulties in adequate assessment of intraocular pressure (IOP) in a patient with glaucoma in the long term after LASIK.METHODS. The study describes the case of patient M. of 58 years old with complaints about decreased distance vision in the right eye during the last year. In 2004 the patient underwent LASIK for moderate myopia. In 2018, asymmetry in the parameters of optic nerve head (size of the optic cup to the optic disc ratio (C/D ratio) was revealed: in the right eye — up to 0.7, narrowing of the visual field from nasal to fixation point; in the left eye — 0.5, visual fields without abnormalities. The IOP measured using the Maklakov method in both eyes corresponded to the average statistical norm — 22 mm Hg. The following diagnosis was established: IIA primary open-angle glaucoma in the right eye, IA primary open-angle glaucoma in the left eye. One-time instillations of latanoprost 0.005% eye drops solution was indicated for both eyes. In subsequent years the IOP was 18–20 mm Hg. After 4 years, the IOP according to the Maklakov method: OD — 18 mm Hg; OS — 21 mm Hg (on the hypotensive regimen — instillations of latanoprost 0.005% eye drops solution). In the right eye: C/D ratio 0.85–0.9 with absolute scotoma in the Bjerrum area 5–15° from fixation; in the left eye: C/D ratio 0.9 with neuro retinal rim loss from below, with absolute scotoma in the blind spot area. The stages of primary open-angle glaucoma were ascertained: IIIA in the right eye, IIA in the left eye.RESULTS. Selective laser trabeculoplasty was performed. Brimonidine 0.1% solution was added due to the lack of complete stabilization of the IOP level on a single instillation of latanoprost 0.005%, after that IOP decreased to 19 mm Hg in both eyes.CONCLUSION. It is necessary to carefully assess the condition of the structures of the optic nerve head in patients after LASIK, regardless of the statistically normal IOP values.

Glaucoma Detection Using Fundus Images of the Retina

In the paper that we are proposing we make use of the image processing technique that can be further used to detect or predict whether the eye is glaucomatic which leads to increase in the size of the optic cup in turn affecting the optic disc. Glaucoma being the second major reason for blindness was very difficult to detect in the early stages. Here in this paper, we make use of the retinal fundus images and glaucoma is being detected using the features that we extract from the fundus images. The first feature that we extract includes one of the basic physiological parameters which is the Cup to Disc ratio (CDR) and the second feature that we extract is the neuro retinal rim which has the inferior, superior, nasal and the temporal quadrants often called the ISNT quadrants which can be used to detect glaucoma in the fundus image of the eye.

A Practical Guide to Measuring Optic Disc Size and its Clinical Correlation in Diagnosing Glaucoma for the Eye Care Professional

This study examines the connection between glaucoma and the optic disc, cup, and neuroretinal rim size. The use of a slit-lamp and funduscopy lens as a technique for determining and estimating the optic disc size is particularly emphasized. Through this study, a clinical manual for working clinicians will be developed by summarizing this information and making it easily accessible for in-office use. PubMed, Science Direct, Ovid, Medline journals, and inter-library journals were used to find papers and abstracts of relevant studies for this review. The most common search terms were: procedures for assessing optic disc size, variance in optic disc size between populations, and ophthalmoscopic methods for measuring optic discs. The search period spanned 2020 to 2022. The following criteria were used to determine whether an article should be included or excluded: a critical evaluation of the various methods used to measure the optic disc, the significance of including population-specific variations in the size of the optic disc, and justifications for the relative risk of glaucoma associated with the size of both the optic disc and the optic cup. According to numerous studies, a slit lamp and funduscopy lens can be used to estimate the size of the optic disc. Additionally, this review discovered a weak association between measures taken at a slit lamp and those taken with more exact office tools, including fundus photography. Using fundoscopic technologies is an effective and affordable method for measuring the optic nerve head while retaining a high level of accuracy. These dimensions can be used to divide the sizes of optic discs into three groups: small, average, and large.

Glaucoma Profile in a Tertiary Eye Hospital of Bangladesh

Background: Glaucoma is a chronic progressive optic neuropathy associated with characteristic optic nerve damage which may lead to certain visual field loss patterns at least some part of which is due to a sub optimal intra ocular pressure. Glaucoma is also known as silent killer of vision.
 Objective: To evaluate the pattern of glaucoma among the patients who were presented to a tertiary eye hospital, in southern region of Bangladesh.
 Method: A prospective observational study was done in outpatient department (OPD) of a tertiary eye hospital from January 2019 to December 2019. All patients with glaucoma were included. Data on age at presentation, gender, laterality, intraocular pressure, cup/disk ratio (C:D) with neuroretinal rim (NRR) and diagnosis were collected from OPD. Patients in age of 1 day - 100 years were included in this study. Patients were grouped into three age groups (0-25 years, 26-50 years and >50 years) and grouped in terms of clinical diagnoses.
 Result: A total of 387 eyes of 292 patients were included. Primary angle closure glaucoma (PACG) was the predominant type (45%) followed by primary open angle glaucoma (POAG) (32%), secondary glaucoma (14%) and normal tension glaucoma (6%). Other types including juvenile glaucoma (2%) and congenital glaucoma (1%) were also present but of lower prevalence.
 Conclusion: Primary angle closure glaucoma (PACG) was the predominant form of glaucoma followed by POAG suggesting that the pattern in Bangladesh could be quite different from that reported for primary glaucoma in the Western literature.
 EMCJ. July 2022; 7(2): 16-20

Surgical decisions in the setting of zonulopathy.

An 85-year-old man with a history of type 2 diabetes, pseudoexfoliation (PXF) in both eyes, and tamsulosin use was referred for the evaluation of a dense cataract in the right eye and a subluxated intraocular lens (IOL) in the left eye. Unfortunately, his surgery in the left eye was complicated by diffuse zonulopathy. The referring surgeon placed a 3-piece IOL in the sulcus. However, the passively fixated 3-piece IOL moved inferiorly causing monocular diplopia for over a year. Because the patient was pleased with the IOL immediately postoperatively, a refixation procedure was performed in the form of sulcus placement with iris suture fixation in the left eye. Fortunately, the iris-fixated IOL in the left eye has remained well centered and stable without cystoid macular edema (CME) or chronic inflammation for over 8 months. The patient is on no ocular medications and has no family history of glaucoma. He now needs cataract surgery in the right eye and is extremely apprehensive because of his difficult course in the left eye. The corrected distance visual acuity is 20/70 in the right eye and 20/25 in the left eye. Intraocular pressures (IOPs) measure 20 mm Hg in the right eye and 14 mm Hg in the left eye by Goldmann tonometry. Pachymetry is 536 µm in the right eye and 543 µm in the left eye. Pupils are round with minimal reactivity and without a relative afferent pupillary defect. Extraocular motility is normal in both eyes, and confrontation visual fields is full in both eyes. Gonioscopy reveals an angle open to the pigmented trabecular meshwork (PTM) in the right eye and the ciliary body in the left eye with 1+ PTM and without peripheral anterior synechia in both eyes. The retinal nerve fiber layer and macular optical coherence tomography are normal in both eyes. On slitlamp examination, pertinent findings include pseudoexfoliative changes at the pupillary margin with poor dilation of 3.5 mm in both eyes; the anterior chamber (AC) is shallow but adequate in the right eye and deep and quiet with rare pigmented cells in the left eye. There is a 5+ nuclear sclerotic cataract with pseudoexfoliative changes on the anterior capsule and no obvious phacodonesis in the right eye and a 3-piece posterior chamber IOL in the sulcus fixated to the iris with 10-0 polypropylene sutures at 6 and 12 o'clock without pseudophacodonesis in the left eye. Dilated fundus examination reveals a cup-to-disc ratio of 0.4 with healthy neuroretinal rims in both eyes, posterior vitreous detachments in both eyes, and no evidence of diabetic retinopathy in both eyes. All other findings are unremarkable. How would you counsel this patient regarding his risk factors for surgery in the right eye? What surgical maneuvers would you use to remove the cataract safely? How would you stabilize the IOL if the capsule bag becomes compromised due to zonulopathy?

Primary open-angle glaucoma in patients with obstructive sleep apnoea in a Colombian population: a cross-sectional study

ObjectiveDetermine the prevalence, functional and structural alterations of primary open-angle glaucoma (POAG) in patients with obstructive sleep apnoea (OSA).DesignCross-sectional.SettingTertiary hospital associated with specialised center in ophthalmologic images in Bogota, Colombia.Participants150...

Geometric Deep Learning to Identify the Critical 3D Structural Features of the Optic Nerve Head for Glaucoma Diagnosis

To compare the performance of 2 relatively recent geometric deep learning techniques in diagnosing glaucoma from a single optical coherence tomographic (OCT) scan of the optic nerve head (ONH); and to identify the 3-dimensional (3D) structural features of the ONH that are critical for the diagnosis of glaucoma. Comparison and evaluation of deep learning diagnostic algorithms. In this study, we included a total of 2247 nonglaucoma and 2259 glaucoma scans from 1725 participants. All participants had their ONHs imaged in 3D with Spectralis OCT. All OCT scans were automatically segmented using deep learning to identify major neural and connective tissues. Each ONH was then represented as a 3D point cloud. We used PointNet and dynamic graph convolutional neural network (DGCNN) to diagnose glaucoma from such 3D ONH point clouds and to identify the critical 3D structural features of the ONH for glaucoma diagnosis. Both the DGCNN (area under the curve [AUC]: 0.97±0.01) and PointNet (AUC: 0.95±0.02) were able to accurately detect glaucoma from 3D ONH point clouds. The critical points (ie, critical structural features of the ONH) formed an hourglass pattern, with most of them located within the neuroretinal rim in the inferior and superior quadrant of the ONH. The diagnostic accuracy of both geometric deep learning approaches was excellent. Moreover, we were able to identify the critical 3D structural features of the ONH for glaucoma diagnosis that tremendously improved the transparency and interpretability of our method. Consequently, our approach may have strong potential to be used in clinical applications for the diagnosis and prognosis of a wide range of ophthalmic disorders.

OCT-Diagnostics of Optic Nerve Disc Edema in Space Flight. Analysis of the Retina, Optic Disc and Neuroretinal Circle Thickness

The article analysis the state of 24 eyes of 12 Russian cosmonauts who made long-term space flights to the ISS in the period from 2016 to 2021. The analysis was carried out by HRA and OCT images study, using the Display function included in the program of Spectralis OCT device. The thickness of the optic nerve head and retina was determined according to the hourly meridians, which allowed us to accurately diagnose and classify the optic disc edema according to the stages of the Frisen scale. By measuring the percentage ratio of the maximum thickness of the nerve disc within its boundaries to the minimum thickness of the retina outside the boundaries of the disc, we determined the digital value of prominence in each temporal hourly meridian, limited by the temporal sector of 95°. The presence of prominence in the extreme temporal meridians, or its absence at all, we regarded as a physiologically healthy state of the optic disc, corresponding to stage 0. This stage was established in 13 eyes (54.2%). Stage I (7 eyes (29.2%)) was diagnosed based on the absence of prominence in the horizontal temporal meridian. The defining feature of stage II is an increase in prominence in the temporal horizontal meridian by more than 10%. Subclinical stage II (prominence is increased, but less than 10%) was diagnosed in two eyes of two cosmonauts (8.3%). Clinically pronounced papilledema II–III stages was diagnosed in two eyes (8.3%) in one cosmonaut, where the maximum value of prominence was 70.1% in the right eye, and on the left – 40.1% in the horizontal meridian. The study shows that an increase in prominence up to 70% in the temporal horizontal meridian at stage III of edema leads to neurodegeneration of the optic nerve fibers in space flight. At stages II–III of edema, an increase in the minimum thickness of the neuroretinal rim compared with all other observations. At 0 – II subclinical stage, according to this indicator, it was impossible to differentiate the state of the optic disc.

Modern achievements in the diagnosis and treatment of glaucoma

Glaucoma is one of the most difficult and significant ocular conditions. The chronic asymptomatic course of glaucoma progression leads to irreversible deterioration of visual functions. Many aspects of its pathogenesis, the features of its clinical presentation, diagnosis and treatment have been identified in recent years. The results of diagnostic methods: tonometry, perimetry, optical coherence tomography - with glaucoma do not have high specificity due to the large diversity of the population. When determining the target intraocular pressure (IOP), we look at the indicators of the choroidal blood flow and biomechanical stress of the cornea and sclera (fibrous membrane of the eye). Studying visual functions is important in the diagnosis and monitoring of glaucoma. The creation of a modern portable device based on a virtual reality helmet allows examination of patients with low central vision. Structural changes in glaucoma affect the optic disc and the inner retinal layers. The proposed classification of atypical discs allows determining the earliest characteristic changes in the neuroretinal rim for glaucoma in cases of difficult diagnosis. The complexity of the diagnosis of glaucoma is also associated with concomitant pathologies in elderly patients. In cases with comorbidity of primary glaucoma and Alzheimer's disease the structural and functional changes revealed by modern research methods for glaucoma are explained by both the process of secondary transsynaptic degeneration and the death of neurons as a result of an increased IOP. The starting treatment is and its type are fundamentally important for preserving visual functions. Drug therapy with prostaglandin analogues contributes to a significant and persistent decrease in the level of IOP, and mainly by utilizing the uveoscleral outflow pathway. Surgical treatment of glaucoma is an effective way to achieve the target IOP values. However, postoperative hypotension affects the bloodstream both in the central and peripapillary retina. Optical coherence tomography angiography helped establishe that the strongest factor that determines postoperative changes is the difference in IOP, not its absolute level.

Facilitating glaucoma diagnosis with intereye neuroretinal rim asymmetry analysis using spectral-domain optical coherence tomography.

To determine whether intereye asymmetry of a three-dimensional neuroretinal rim parameter, the minimum distance band, is useful in differentiating normal eyes from those with open-angle glaucoma. This is a cross-sectional study of 28 normal subjects and 33 glaucoma subjects. Subjects underwent spectral domain optical coherence tomography imaging of both eyes. From high-density raster scans of the optic nerve head, a custom-designed segmentation algorithm calculated mean minimum distance band neuroretinal rim thickness globally, for four quadrants, and for four sectors. Intereye minimum distance band thickness asymmetry was calculated as the absolute difference in minimum distance band thickness values between the right and left eyes. Increasing global minimum distance band thickness asymmetry was not associated with increasing age or increasing refractive error asymmetry. Glaucoma patients had thinner mean neuroretinal rim thickness values compared to normal patients (209.0 μm vs 306.0 μm [P < 0.001]). Glaucoma subjects had greater intereye thickness asymmetry compared to normal subjects for the global region (51.9 μm vs 17.6 μm [P < 0.001]) as well as for all quadrants and all sectors. For detecting glaucoma, a thickness asymmetry value >28.3 μm in the inferior quadrant yielded the greatest sum of sensitivity (87.9%) and specificity (75.0%). Globally, thickness asymmetry >30.7 μm yielded the greatest sum of sensitivity (66.7%) and specificity (89.3%). This study indicates that intereye neuroretinal rim minimum distance band asymmetry measurements, using high-density spectral domain optical coherence tomography volume scans, may be an objective and quantitative tool for assessing patients suspected of open-angle glaucoma.

Detecting Glaucoma from Fundus Photographs Using Deep Learning without Convolutions: Transformer for Improved Generalization

To compare the diagnostic accuracy and explainability of a Vision Transformer deep learning technique, Data-efficient image Transformer (DeiT), and ResNet-50, trained on fundus photographs from the Ocular Hypertension Treatment Study (OHTS) to detect primary open-angle glaucoma (POAG) and identify the salient areas of the photographs most important for each model's decision-making process. Evaluation of a diagnostic technology. Overall 66 715 photographs from 1636 OHTS participants and an additional 5 external datasets of 16 137 photographs of healthy and glaucoma eyes. Data-efficient image Transformer models were trained to detect 5 ground-truth OHTS POAG classifications: OHTS end point committee POAG determinations because of disc changes (model 1), visual field (VF) changes (model 2), or either disc or VF changes (model 3) and Reading Center determinations based on disc (model 4) and VFs (model 5). The best-performing DeiT models were compared with ResNet-50 models on OHTS and 5 external datasets. Diagnostic performance was compared using areas under the receiver operating characteristic curve (AUROC) and sensitivities at fixed specificities. The explainability of the DeiT and ResNet-50 models was compared by evaluating the attention maps derived directly from DeiT to 3 gradient-weighted class activation map strategies. Compared with our best-performing ResNet-50 models, the DeiT models demonstrated similar performance on the OHTS test sets for all 5 ground-truth POAG labels; AUROC ranged from 0.82 (model 5) to 0.91 (model 1). Data-efficientimage Transformer AUROC was consistently higher than ResNet-50 on the 5 external datasets. For example, AUROC for the main OHTS end point (model 3) was between 0.08 and 0.20 higher in the DeiT than ResNet-50 models. The saliency maps from the DeiT highlight localized areas of the neuroretinal rim, suggesting important rim features for classification. The same maps in the ResNet-50 models show a more diffuse, generalized distribution around the optic disc. Vision Transformers have the potential to improve generalizability and explainability in deep learning models, detecting eye disease and possibly other medical conditions that rely on imaging for clinical diagnosis and management.

Stereoscopic vs. monoscopic photographs on optic disc evaluation and glaucoma diagnosis among general ophthalmologists: A cloud-based real-world multicenter study.

PurposeTo investigate whether stereoscopic vs. monoscopic viewing condition influences the evaluation of optic disc photographs for morphologic features and glaucoma likelihood in a general ophthalmologist population from multicenters on a cloud-based platform.MethodsA cross-sectional study of 519 pairs of stereoscopic and monoscopic photographs of optic discs with adequate quality were selected and presented using a cloud-based platform. A total of 21 general ophthalmologists from 14 centers assessed 15 morphologic features based on 5R's rules and estimated glaucoma likelihood for each assigned photograph. There were 93 pairs of stereoscopic and monoscopic photographs evaluated by a panel of glaucoma specialists and set as ground truth. The main outcome measures were the agreement between estimates and ground truth and the inter-grader agreements.ResultsThere were good agreements between ground truth and both monoscopic and stereoscopic estimates (stereo κ 0.532 and mono κ 0.494). There was also a substantial intra-grader agreement between monoscopic and stereoscopic evaluation of glaucoma likelihood (κ 0.636). In eyes with probable glaucoma, the accuracy of the stereo method was greater than that of the mono method (stereo 0.238 vs. mono 0.118) When compared with ground truth, stereoscopic photographs had a better agreement for disc size (stereo κ 0.447 vs. mono κ 0.183), disc color (stereo κ 0.612 vs. mono κ 0.549), neuroretinal rim shape (stereo κ 0.356 vs. mono κ 0.274) on the whole. The stereoscopic method also had a better inter-grade agreement for disc size, disc color, neuroretinal rim shape, and glaucoma likelihood (stereo κ 0.402 vs. mono κ 0.359) on the whole.ConclusionsIn the evaluation of optic disc photographs for morphologic features and glaucoma likelihood, the stereoscopic method showed superiority compared to the monoscopic method for general ophthalmologists. The stereoscopic method is more likely to identify glaucomatous eyes which need medical intervention.

Glaucoma Detection in Myopic Eyes: Structural and Vascular Assessment by Optic Coherence Tomography Methods.

Retinal nerve fiber layer (RNFL) thickness is helpful in the diagnosis of glaucoma in myopic eyes but neuroretinal rim (NRR) thickness is the most valuable measure. However, changes in optical coherence tomography angiography (OCT-A) parameters are insufficient for the diagnosis of mild to moderate glaucoma in myopia. To detect how a multimodal evaluation, which includes RNFL, NRR thickness, and optic nerve head (ONH) OCT-A, affects glaucoma diagnosis in myopic patients. Parameters of healthy myopic and myopic glaucoma eyes with an axial length of ≥24 mm were compared. The ONH structural features and peripapillary RNFL thickness were determined with Cirrus 5000 HD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA). The Cirrus 5000 HD-OCT with AngioPlex was utilized to perform OCT-A imaging. The sensitivity and specificity levels were calculated by the best cut-off values with area under curve (AUC). One hundred healthy myopic and 54 myopic glaucoma eyes were evaluated. In all areas, myopic glaucoma patients exhibited lower RNFL and NRR thickness than healthy myopic individuals ( P <0.05), with the exception of nasal quadrant RNFL thickness ( P =0.152). The mean entire and 4 quadrants of global radial peripapillary capillary (RPC)-perfusion and global RPC flux index (FI) were significantly lower in the group of myopic glaucoma patients except for the nasal quadrant mean RPC perfusion ( P =0.224). The average RNFL and NRR thickness had a significant difference in AUC for the diagnosis of glaucoma in myopic individuals ( P =0.001, for each). The average NRR showed excellent diagnostic performance, whereas the average RNFL showed good diagnostic performance. Average RPC perfusion and average RPC FI showed poor diagnostic ability. The average NRR AUC was more significant than average RPC perfusion and average RPC FI AUC ( P <0.001). Although RNFL thickness was helpful to diagnose glaucoma in patients with myopia, the diagnostic power of NRR thickness performed best. OCT-A parameters showed poor diagnostic accuracy for glaucoma and the observed perfusion decrease in myopic glaucoma eyes was not sufficiently discriminative compared with NRR and RNFL thickness measurements.

A Study on the Association Between Myopia and Elevated Intraocular Pressure Conducted at a Tertiary Care Teaching Hospital in Gujarat, India.

IntroductionGlaucoma is characterized by the loss of retinal nerve fiber tissues and the loss of the neuroretinal rim of the optic nerve head is termed glaucomatous optic neuropathy (GON). The early diagnosis of glaucoma requires measurement of intraocular pressure (IOP) by tonometry. The gold standard method widely used in clinical settings to measure IOP is Goldmann applanation tonometry (GAT). Myopia is also considered a risk factor for glaucoma. Population-based and hospital-based evidence suggests that the prevalence of GON is higher in high myopic eyes than in emmetropic eyes. The present study aims to document the association between myopia and elevated IOP.Materials and methodsA total of 400 medium and high myopic patients attending the ophthalmology outpatient department, in a tertiary care hospital, were measured for IOP using GAT and underwent a detailed clinical evaluation. All the patients also underwent slit lamp biomicroscopic examination and fundus examination. Other data included details on demographic, socio-economic, and occupational history.ResultsA detailed refractive error examination revealed that amongst 400 right eyes, 67.5% had medium myopia, while 66.75% of the left eye were medium myopic. Amongst the medium myopic eyes, the average IOP was 15.51±3.68 mm of Hg, while in high myopic, the average IOP was 16.19±3.33 mm of Hg. A difference of 0.68 mm of Hg with high myopic eyes having higher IOP values than medium myopic eyes was observed, and it was significant statistically with a p-value <0.05.ConclusionThere is a statistically significant association between elevated IOP and the high myopic group. In comparison to IOP measured in medium myopic and high myopic patients, elevated IOP was observed in the high myopic group than in the medium myopic group.

Progression of Glaucoma in Highly Myopic Eyes with Paravascular Inner Retinal Defects

Purpose: To report a case of glaucoma progression in highly myopic eyes with paravascular inner retinal defects.Case summary: Retinal nerve fiber layer (RNFL) defects with cleavage-like irregular margins and internal areas were found around the retinal vessels in highly myopic eyes of a 17-year-old female. On suspicion of paravascular inner retinal defect (PIRD) instead of glaucomatous RNFL defect, observation without treatment was recommended. After 10 years of follow-up, RNFL defects and neuroretinal rim thinning were found around the pre-existing PIRD on fundus photographs. Optical coherence tomography also revealed decreased RNFL thickness.Conclusions: Glaucomatous changes progressed around the pre-existing PIRD area over the 10-year follow-up. This indicates the need for caution when assessing glaucoma in highly myopic eyes with PIRD.

The Pseudo-Hypoplastic Myopic Optic Disc

A 7-year-old girl had 20/25 vision in the right eye (OD) (with correction) and 20/20 vision in the left eye (OS), with no afferent pupillary defect. Retinoscopy showed –4.75 OD and plano OS. Retinal examination showed a small tilted right optic disc, with a temporal crescent of retinal pigment epithelium (RPE) and choroid pierced inferotemporally by a retinal vein (Fig A). OCT showed a smaller right disc with a smaller neuroretinal rim and cup volume (Fig B), but equal retinal nerve fiber layer (RNFL) (Fig B) and ganglion cell thickness (bottom left).

Reproducibility of Neuroretinal Rim Measurements Obtained from High-Density Spectral Domain Optical Coherence Tomography Volume Scans.

PurposeTo compare the reproducibility of two-dimensional (2D) peripapillary retinal nerve fiber layer (RNFL) thickness and three-dimensional (3D) neuroretinal rim measurements using spectral domain optical coherence tomography (SDOCT) in normal and glaucoma subjects.MethodsOne eye per subject for 27 normal and 40 glaucoma subjects underwent repeat SDOCT RNFL thickness scans and optic nerve volume scans on the same day. From the volume scan, custom software calculated five neuroretinal rim parameters: 3D minimum distance band (MDB) thickness, 3D MDB area, 3D rim volume, 2D rim area, and 2D rim thickness. Within-subject variance (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC) were analyzed.ResultsMDB thickness and RNFL thickness have similar reproducibility among normal and glaucoma subjects (eg, global MDB thickness CVs of 2.4% and 3.6%, and global RNFL thickness CVs of 1.3% and 2.2%; P > 0.05 for both comparisons). Reproducibility of MDB thickness was lower in glaucoma patients for the superior and inferior quadrants compared to normal subjects (CVs of 9.6% versus 3.4% and 6.9% versus 2.7%; P < 0.05, respectively). There were no statistically significant differences between both groups for RNFL thickness in the four quadrants. For both patient groups and for all regions, MDB thickness had the lowest CVs among all five neuroretinal rim parameters (eg, global MDB thickness CVs of 2.4% and 3.6% versus 3.0% and 18.9% for the other four neuroretinal rim parameters).ConclusionGlobal MDB and global RNFL thickness are similarly reproducible among normal and glaucoma subjects, though MDB thickness for the superior and inferior quadrants is less reproducible among glaucoma subjects.

Comparison of age-related vascular changes in the optic disc of patients with diabetes, with glaucomatous and non-glaucomatous features

ObjectiveTo identify age-related vascular changes in the optic discs of patients with diabetes with and without signs of glaucoma.Methods and analysisA total of 2153 eyes of 1797 patients with diabetes...

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.

Difference in topographic morphology of optic nerve head and neuroretinal rim between normal tension glaucoma and central retinal artery occlusion

Although central retinal artery occlusion (CRAO) has its own defining pathomechanism and clinical characteristics, morphologic feature of the optic nerve head (ONH) during its later stage is not diagnostic, which makes it difficult to differentiate CRAO from other optic neuropathies. This cross-sectional study was performed to investigate the differences in the topographic morphology of the ONH in eyes with normal-tension glaucoma (NTG) and CRAO. Thirty-one eyes with NTG; 31 eyes with CRAO; and 31 healthy fellow eyes of the subjects with CRAO were included. ONH morphology was evaluated by measuring horizontal rim width (HRW), minimal rim width in the selected horizontal image (MRW), and lamina cribrosa curvature index (LCCI) in horizontal B-scan images obtained using enhanced depth-imaging optical coherence tomography. HRW was smaller and LCCI was larger in NTG eyes than in both CRAO and healthy fellow eyes (both P < 0.001), while both were comparable between CRAO and healthy fellow eyes. MRW differed significantly among the three groups, being smallest in NTG eyes followed by CRAO and healthy fellow eyes (P < 0.001). NTG and CRAO eyes with a similar degree of RNFL loss differed in ONH morphology, indicating that mechanisms of ONH damage differ between these two conditions.