Neuroretinal Rim Research Articles

Monitoring of several morphometric parameters of the optic nerve and retina in persons without glaucoma and patients with primary open-angle glaucoma using various types of spectacle correction

Purpose: to perform long-term monitoring of the state of several morphometric parameters of the retina and optic nerve in persons without glaucoma and patients with primary open-angle glaucoma (POAG) in the conditions of achieving tolerant and target IOP against the background of the use of various types of spectacle correction. Material and methods: 139 patients aged 40–60 years with various types of clinical refraction were examined, 41 subjects (81 eyes) of them were without glaucoma, 98 patients (164 eyes) had POAG at stage I–II. In addition to standard methods, the scope of the examination included optical coherence tomography (OCT) of the optic nerve and the central area of the retina to determine the thickness of the retinal nerve fiber layer (RNFL), retinal ganglion cell complex (RGCC) and the area of the neuroretinal rim (NRR). The study was conducted in 4 observation groups. The first (21subjects) and the second (20 subjects) groups were represented by persons without glaucoma who used monofocal spectacle correction and progressive spectacle correction for near work, respectively. The third (50 subjects) and the fourth (48 subjects) groups were composed of patients with POAG who also used, respectively, monofocal spectacle correction for near vision or progressive spectacle correction against the background of topical hypotensive therapy with the achievement of tolerant and target IOP. The follow-up period was three years. Results: There were no significant changes in the area of NRR (p 0,5) and in the thickness of RNFL (p 0,2) and RGCC (p 0,3) over the three-year follow-up period in all patients without glaucoma. In patients with POAG who applied progressive correction, no negative dynamics was revealed in the NRR area (p 0,5) and in the thickness of RNFL (p 0,5) and RGCC (p 0,5) during the follow-up period. POAG patients with using monofocal correction had noticeable losses in RNFL and RGCC thickness (p 0,05) without a significant decrease in the area of NRR (p 0,3). Conclusion: The progressive spectacle correction using provides accommodative regulation of IOP in POAG and implements an indirect neuroprotective effect.

Applicability of ISNT rule to retinal nerve fiber layer thickness by SD-OCT in normal subjects.

The usefulness of the Inferior>Superior>Nasal>Temporal (ISNT) rule for the neuroretinal rim (NRR) has been widely used in differentiating normal eyes from glaucoma, but only a few studies have assessed whether this classical ISNT rule applies to the retinal nerve fibre layer (RNFL). This study aimed to determine the applicability of the ISNT rule for the peripapillary RNFL thickness in normal eyes using Spectral Domain Optical Coherence Tomography (SD-OCT) and assess if variants of the ISNT rule apply. A cross-sectional study was conducted on 120 eyes of 62 healthy subjects who fulfilled the study criteria. Peripapillary RNFL thickness was measured by OCT scan and each eye's global, superior, temporal, nasal, and inferior quadrant thickness was noted. The values obtained were analyzed to determine the percentage of eyes obeying the ISNT rule and its variants. The ISNT rule for RNFL thickness was applicable for normal subjects in only 53.33% of cases. Removing the nasal quadrant from analysis increased the number of eyes obeying the IST rule to 71.66%. Further exclusion of the temporal quadrant showed almost the same results (75%) for the IS rule. The ISNT rule for RNFL thickness could be validated in only 53.33% of normal individuals. Though documented as useful for NRR during ophthalmoscopy in glaucoma diagnosis, the ISNT rule did not apply to the quadrant values on RNFL on SD-OCT examination.

Myopia and Other Refractive Error and Their Relationships to Glaucoma Screening.

A large disk, a large parapapillary delta zone and a long axial length may be used as screening criteria to detect glaucomatous optic neuropathy in highly myopic eyes. To describe aspects for screening of glaucomatous optic neuropathy in dependence of refractive error, under special consideration of high myopia. Studies on the anatomy of the myopic optic nerve head and results of investigations on the relationship between glaucomatous optic neuropathy and axial myopia were included. In the range from hyperopia to moderate myopia, refractive error is not a strong glaucoma risk factor and may not be included in glaucoma screening strategies. Care should be taken, that in moderate myopia, a shift of Bruch´s membrane opening usually into the temporal direction leads to parapapillary gamma zone and a corresponding shortening of the horizontal disk diameter. In these moderately myopic eyes, a secondarily small optic disk with a correspondingly small optic cup should not lead to an overlooking of intrapapillary glaucomatous changes. Prevalence of glaucomatous or glaucoma-like optic nerve atrophy (GOA) steeply increases with longer axial length in highly myopic eyes (cutoff approximately -8 diopters/axial length 26.5mm), with prevalences higher than 50% in extremely high myopia. Besides longer axial length, morphological parameters associated with GOA in highly myopic eyes are a secondarily enlarged disk and large parapapillary delta zone. Both parameters, together with long axial length, may be used as screening criteria in high myopia for GOA. The latter is characterized by an abnormal neuroretinal rim shape, that is, vessel kinking close to the intrapapillary disk border. Factors associated with nonglaucomatous optic neuropathy are larger gamma zone and longer axial length, potentially due to an axial elongation-related retinal nerve fiber stretching.

EVALUATION OF MACULAR GANGLION CELL COMPLEX USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY IN GLAUCOMA SUSPECT PATIENTS AND TO CORRELATE IT WITH NORMAL POPULATION

PURPOSE:. To evaluate macular ganglion cell complex in glaucoma suspect patients and normal population RESULTS The difference between values of neuroretinal rim thickness,rim area,disc area,average CDR,vertical CDR and cup volume among glaucoma suspect and normal (controls) was found to be statistically significant (p value<0.001). The difference between values of superior,nasal,inferior,temporal and average RNFL thickness among glaucoma suspect and normal (controls) was found to be statistically significant(p value<0.001). The difference between values of superotemporal, superior, superonasal, inferonasal, inferior, inferotemporal, average and minimum GCIPL (Ganglion cell Inner plexiform layer) thickness in µm, as estimated on OCT macula, was found to be statistically significant among glaucoma suspect patients and normal (controls) (p value <0.001). Upon applying Spearman’s rho correlation coefficient test in glaucoma suspect patients for GCIPL thickness and RNFL thickness, statistically significant correlation was found between Inferior RNFL thickness with Inferotemporal GCIPL thickness(p value 0.029) and Temporal RNFL thickness with Inferotemporal GCIPL thickness .(p values 0.006). Upon applying Spearman’s rho correlation coefficient test in normal (controls) for GCIPL thickness and RNFL thickness,statistically significant correlation was found between Superior RNFL thickness with Superior GCIPL thickness(p value 0.038), Superior RNFL thickness with Superonasal GCIPL thickness (p values 0.012 ), and Average RNFL thickness with Average GCIPL thickness (p value 0.033) CONCLUSION: In our study we found there is statistically significant reduction in thickness in all measured quadrants of Macular GCIPL and RNFL in glaucoma suspect patients compared to normal. Also, a statistically significant correlation was found between Inferior RNFL thickness with Inferotemporal GCIPL thickness and Temporal RNFL thickness with Inferotemporal GCIPL thickness in glaucoma suspect patients,suggesting good diagnostic ability of inferotemporal macular GCIPL thickness.

Quantitative assessment of colour fundus photography in hyperopia children based on artificial intelligence

ObjectivesThis study aimed to quantitatively evaluate optic nerve head and retinal vascular parameters in children with hyperopia in relation to age and spherical equivalent refraction (SER) using artificial intelligence (AI)-based...

Optic disc characteristics on digital fundus photographs in Saudi children.

To assess the optic disc parameters in healthy Saudi children. This study recruited 85 children who were medically free, born full-term, cooperative, and aged 3-17 years. The children underwent a thorough ophthalmological examination (visual acuity, refraction post-cycloplegia, fundus photography) at the ophthalmology clinic of King Abdulaziz University Hospital, Jeddah. Fundus photographs obtained by a fundus camera were evaluated by the Retinal Size Tool program. Forty-eight participants were male (56.5%). The mean birth weight was 2.97±0.8kg and the median gestational age was 39 weeks (range, 37-40 weeks). The median areas of the neuroretinal rim, cup, and optic disc were 1.82mm2 (range, 0.84-2.83mm2), 0.47mm2 (range, 0.18-1.25mm2), and 2.33mm2 (range, 1.15-3.52mm2), respectively. The older age group had smaller neuroretinal areas compared to the younger age groups. The variables demonstrated no apparent correlation to axial length, refraction, or birth parameters. The cup size increased together with the optic disc (r=0.659, p<0.001). Sex and refraction did not correlate with any of the studied factors. This study yielded normative data for the optic disc parameters of healthy Saudi children. The data can be used as a reference in the pediatric ophthalmology clinic to aid the identification of optic disc abnormalities.

Longitudinal changes in optic disc cupping from the baseline in chiasmal lesion optic neuropathy and glaucoma

We aimed to investigate the changes in cupping in chiasmal lesion optic neuropathy (chON) compared to baseline optic disc and glaucoma. We used a novel study design to enroll patients who had fundus photographs incidentally taken during routine health check-ups prior to the onset of optic neuropathy. In 31 eyes (21 patients) with chON and 33 eyes (30 patients) with glaucoma, we investigated the change in cup-to-disc (C/D) area from the baseline to overt cupping using flicker analysis. Compared to the baseline, 23 eyes (74.2%) had increased cup size and 3 (9.7%) had vascular configuration changes in the chONgroup; in contrast, all glaucoma eyes exhibited changes in cup size and vascular configuration. The increase in C/D area ratio was significantly smaller in chON (0.04 ± 0.04) compared to glaucoma (0.10 ± 0.04, P < 0.001); the minimum residual neuroretinal rim width showed a more pronounced difference (29.7 ± 8.2% vs 7.1 ± 3.9%, P < 0.001). The changes distributed predominantly towards the nasal direction in chON, contrasting the changes to the arcuate fibers in glaucoma. In conclusion, our results provide the first longitudinal evidence of true pathological cupping in chONcompared to photographically disease-free baseline. The marked difference in the residual minimum rim width reaffirms the importance of rim obliteration in the differential diagnosis between the two diseases.

Susceptibility of optic nerve head in children with posture-related elevation of intraocular pressure

Background/AimsThis work aimed to investigate changes in optic nerve head (ONH) morphometry based on Bruch membrane opening in children with extensive nocturnal intraocular pressure (IOP) elevations.MethodsThe course of Bruch membrane opening-based optic nerve head (ONH) morphometry was analysed in thirty-two patients younger than 18 years with evaluable SD-OCT examinations of the ONH and nocturnal posture-dependent IOP elevation above 25 mmHg. Longitudinal changes in neuroretinal rim tissue, as measured by Bruch Membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (RNFL) thickness, were assessed.ResultsOne year after the 24 h IOP measurement, global BMO-MRW (− 1.61 ± 16.8 µm, n.s.; p = 0.611) and RNFL (+ 0.64 ± 3.17 µm; n.s.; p = 0.292) measurements were not significantly different from the baseline. No significant BMO-MRW reduction (− 3.91 ± 24.3 µm; n.s. p = 0.458) or deviation in RNFL thickness (+ 1.10 ± 3.52 µm) was observed at the four-year follow-up. Absolute IOP values measured in the supine position did not correlate with changes in global BMO-MRW or RNFL thickness.ConclusionPosture-dependent IOP elevations do not seem to influence retinal nerve fibre layer thickness or Bruch membrane opening-based morphometric data in childhood.

Morphological differences of the neuroretinal rim between temporally tilted and non-tilted optic discs in healthy eyes

This study aimed to compare morphological differences of the neuroretinal rim between the temporally tilted and non-tilted optic discs in healthy eyes. We prospectively enrolled participants aged 20–40 years with temporally tilted or non-tilted optic discs. The optic nerve head parameters were analyzed using spectral domain-optical coherence tomography. The angle between the Bruch’s membrane opening (BMO) plane and BMO-minimum rim width (BMO-MRW) was termed “BMO-MRW angle”. Peripapillary retinal nerve fiber layer thickness (pRNFLT) and BMO-based parameters were compared between the temporally tilted and non-tilted disc groups. As a result, 55 temporally tilted disc eyes and 38 non-tilted disc eyes were analyzed. Global pRNFLT, global BMO-MRW, and total BMO-minimum rim area (BMO-MRA) were similar between the two groups (p = 0.138, 0.161, and p = 0.410, respectively). In the sectoral analysis, temporally tilted disc group exhibited thicker BMO-MRW in the temporal sector (p = 0.032) and thinner in the nasal superior and nasal sectors (p = 0.025 and p = 0.002, respectively). Temporally tilted disc group showed larger BMO-MRA in the temporal, temporal superior, and temporal inferior sectors (p < 0.001, p < 0.001, and p < 0.016, respectively), alongside a higher BMO-MRW angle in the temporal sector and lower in the nasal superior and nasal sectors. In conclusion, the neuroretinal rim, represented by BMO-MRW and BMO-MRA, showed morphological differences between temporally tilted and non-tilted optic discs in healthy eyes. BMO-MRW and BMO-MRA showed temporalization in the same manner as pRNFLT in the temporally tilted disc eyes. The BMO-MRW angle showed that in temporally tilted disc eyes, optic nerve fibers met the BMO plane steeply in the nasal sector and gently in the temporal sector than in non-tilted disc eyes, suggesting potential stress region of optic nerve fibers in temporally tilted disc eyes.

Automated vertical cup-to-disc ratio determination from fundus images for glaucoma detection

Glaucoma is the leading cause of irreversible blindness worldwide. Often asymptomatic for years, this disease can progress significantly before patients become aware of the loss of visual function. Critical examination of the optic nerve through ophthalmoscopy or using fundus images is a crucial component of glaucoma detection before the onset of vision loss. The vertical cup-to-disc ratio (VCDR) is a key structural indicator for glaucoma, as thinning of the superior and inferior neuroretinal rim is a hallmark of the disease. However, manual assessment of fundus images is both time-consuming and subject to variability based on clinician expertise and interpretation. In this study, we develop a robust and accurate automated system employing deep learning (DL) techniques, specifically the YOLOv7 architecture, for the detection of optic disc and optic cup in fundus images and the subsequent calculation of VCDR. We also address the often-overlooked issue of adapting a DL model, initially trained on a specific population (e.g., European), for VCDR estimation in a different population. Our model was initially trained on ten publicly available datasets and subsequently fine-tuned on the REFUGE dataset, which comprises images collected from Chinese patients. The DL-derived VCDR displayed exceptional accuracy, achieving a Pearson correlation coefficient of 0.91 (P = 4.12 × 10–412) and a mean absolute error (MAE) of 0.0347 when compared to assessments by human experts. Our models also surpassed existing approaches on the REFUGE dataset, demonstrating higher Dice similarity coefficients and lower MAEs. Moreover, we developed an optimization approach capable of calibrating DL results for new populations. Our novel approaches for detecting optic discs and optic cups and calculating VCDR, offers clinicians a promising tool that significantly reduces manual workload in image assessment while improving both speed and accuracy. Most importantly, this automated method effectively differentiates between glaucoma and non-glaucoma cases, making it a valuable asset for glaucoma detection.

From the past to the present, optical coherence tomography in glaucoma: a practical guide to a common disease.

Glaucoma comprises a group of disorders of the optic nerve that cause degenerative optic neuropathy, characterised by failure of neuroretinal rim tissue in the optic nerve head, retinal nerve fibre layer, and retinal ganglion cells. Glaucoma imposes a serious epidemiological threat, with an steady increase in the global number of cases. In the current ophthalmological practice, glaucoma is diagnosed via a series of examinations, including routine funduscopic examination, ocular tonometry, gonioscopy, measurement of the visual field, and assessment using the optical coherence tomography (OCT) technique. Nowadays, the OCT technique helps in systematising the diagnostic pathway and is a basic diagnostic tool for detection of early glaucomatous eye changes. It is also vital in assessing progression and monitoring treatment results of patients. The aim of this review was to present the OCT technique as a main tool in diagnosing and monitoring glaucoma.

Transforming glaucoma diagnosis: transformers at the forefront.

Although the Vision Transformer architecture has become widely accepted as the standard for image classification tasks, using it for object detection in computer vision poses significant challenges. This research aims to explore the potential of extending the Vision Transformer for object detection in medical imaging, specifically for glaucoma detection, and also includes an examination of the Detection Transformer for comparative analysis. The analysis involves assessing the cup-to-disc ratio and identifying signs of vertical thinning of the neuroretinal rim. A diagnostic threshold is proposed, flagging a cup-to-disc ratio exceeding 0.6 as a potential indicator of glaucoma. The experimental results demonstrate a remarkable 90.48% accuracy achieved by the pre-trained Detection Transformer, while the Vision Transformer exhibits competitive accuracy at 87.87%. Comparative evaluations leverage a previously untapped dataset from the Standardized Fundus Glaucoma Dataset available on Kaggle, providing valuable insights into automated glaucoma detection. The evaluation criteria and results are comprehensively validated by medical experts specializing in the field of glaucoma.

Glaucoma Detection Based on Texture Feature of Neuro Retinal Rim Area in Retinal Fundus Image

One method for detecting glaucoma is by comparing ratios in the area of neuroretinal rim. Comparing area ratios in the neuroretinal rim is difficult for ophthalmologists since it requires high accuracy and is highly dependent on the patient's retinal condition. In this study, we sought to perform neuro retinal rim feature extraction based on histogram and gray level co-occurrence matrix (GLCM) of normal retinal images and glaucoma, automatically distinguish between normal eyes and eyes with glaucoma, and evaluate the method's validity using the measures of accuracy, sensitivity, and specificity We adopted a machine learning approach in conducting automatic feature extraction of the retinal rim through three main stages: 1) image acquisition, 2) pre-processing, and 3) classification. We used a dataset from RIM-ONE for normal eyes images and DRISTHI-GS for glaucoma images.Classification was carried out on 154 images (80 images for glaucoma images and 74 images for normal images). Regarding true positive, false negative, false positive, and true negative, we examined the sensitivity, specificity, and accuracy of automatic extraction and classification. The highest findings are 96.10%, 98.75%, and 93.24%, respectively. This study showed that automatic texture features and classification are possible, accurate and important in detecting glaucoma.

Progressive Changes in the Neuroretinal Rim and Retinal Nerve Fiber Layer in Glaucoma: Impact of Baseline Values and Floor Effects

ObjectiveTo determine whether more severe baseline damage impedes measurement of minimum rim width (MRW) and peripapillary retinal nerve fibre thickness (RNFLT) change in glaucoma patients because of a floor effect. DesignProspective longitudinal cohort study in a hospital-based setting. SubjectsThe study included patients with open-angle glaucoma and healthy control subjects. Participants had at least 5 years of follow-up with optical coherence tomography every 6 months. MethodsBaseline global and sectorial MRW and RNFLT values were classified as within normal limits, borderline, or outside normal limits based on reference normative values. Regression analysis was used to determine the magnitude and significance of MRW and RNFLT change. Additionally, the follow-up period for each participant was divided into two equal halves (1st and 2nd periods) to determine whether there was attenuation of MRW and RNFLT change with follow-up time. Main Outcomes MeasuresRates of global and sectoral MRW and RNFLT changes (slopes). ResultsA total of 97 patients with glaucoma (median age, 70.3 years) and 42 healthy subjects (median age, 64.8 years) were followed for a median of 6.9 years and 7.0 years, respectively. The median mean deviation of visual field test for glaucoma patients was -4.30 dB (interquartile range: -7.81 to -2.06 dB, range: -20.68 to 1.37 dB). Statistically significant changes in global and sectoral MRW and RNFLT were detected across all baseline classifications, however, there was tendency for less change with increasing baseline damage. In glaucoma patients, RNFLT slopes, but not MRW slopes, were significantly more positive (less change) in the 2nd period compared to the 1st. There were also no differences in either MRW or RNFLT slopes in the 1st and 2nd periods in healthy subjects. Conclusions and RelevanceSignificant MRW and RNFLT changes were detected at all levels of baseline damage. However, an attenuation in the rate of RNFLT change compared to MRW indicate an earlier floor effect in RNFLT measurements globally and in equivalent sectors. Because the axonal component of these measurements should be equivalent, our results suggest important differences in tissue remodelling at the level of the optic nerve head and peripapillary retina.

Echographic Optic Nerve Evaluation: A Novel Diagnostic Modality in Glaucoma

Introduction: Primary Open-Angle Glaucoma (POAG) is considered a leading cause of blindness among all others. Different technologies such as Scanning Laser Polarimetry (SLP) and Optical Coherence Tomography (OCT) closely correlate in measuring structural parameters of the Retinal Nerve Fiber Layer (RNFL) and Optic Nerve Head (ONH). Visual impairment related to glaucomatous damage is attributed to the RNFL. Earlier studies have shown that retro-bulbar optic nerve thickness is reduced in glaucoma and have suggested that this is also the result of RNFL destruction. Aim: To investigate the correlation between the orbital and intraocular portions of the optic nerve among POAG patients. Materials and Methods: This was a hospital-based crosssectional study done in a tertiary care ophthalmic institute from October 2019 to February 2021. One eye of 32 volunteers with newly diagnosed POAG underwent optic disc analysis using OCT and echographic measurements of the retrobulbar optic nerve. For statistical calculations, Statistical Package for Social Sciences (SPSS) Statistics version 20.0 software (IBM Corp., Armonk, NY, USA) was used. Spearman’s rho (rs) was used as the index of correlation between retrobulbar optic nerve dimensions and ONH topographical data. A correlation between OCT-based RNFL and optic disc parameters was compared with retrobulbar optic nerve dimensions measured with the help of Ultrasonography- Brightness (USG B) Scan. Results: Orbital Optic Nerve Diameter (OND) and Optic Nerve Cross-sectional Area (ONCSA) significantly and positively correlated with Neuro-retinal Rim (NR) area (OND: p-value=0.00001; ONCSA: p-value=0.00001) and average nerve fiber layer thickness (OND: p-value=0.0001; ONCSA: p-value=0.00002). The Retrobulbar ONCSA-to-disc area ratio (ONCSA/D) was found to have a statistically demonstrable positive correlation with Neuro-retinal Rim Area/Disc area ratio (NR/D) (p=0.00003). Conclusion: This study showed that retrobulbar optic nerve dimensions correlate well with SD-OCT-based ONH parameters. Echographic measurements of the retrobulbar optic nerve add a new biomarker in the diagnosis of glaucoma.

The predictive value of parameters of optic disk in evaluating the progression of myopia

Aims/Purpose: To analyse the parameters of the optic nerve head (ONH) as markers of the progression of myopia with the usage of optical coherence tomography (OCT).Methods: 72 patients (144 eyes) aged 9–57 years with myopia were investigated. The standard OCT parameters of the ONH, the ovality index (OI), the zone of parapapillary atrophy (PPA), location of the lamina cribrosa (LC) of the sclera and the trunk of the central retinal vessels (CRV) were evaluated. Data was statistically approved.Results: A positive correlation between the axial length (AL) and the optic disc cup area, its horizontal and vertical diameters was found. Whilst the volume and the depth of the optic disc cup increased till the AL reached a certain critical value (26.3 mm) with subsequent reduction. An inverse correlation between the AL and the neuroretinal rim area, volume and rim/disc ratio was revealed. These changes in the ONH can be explained by scleral remodelling during elongation of the eye. Formation of γ‐zone PPA and an increase in the β‐zone PPA was accompanied by the tendency of thinning of the retinal nerve fibre layer (RNFL) in the inferior, nasal‐superior and superior sectors of the ONH. In 27.63% cases tilted optic discs were noted, of which 61.90% were vertically and 38.1% ‐ horizontally tilted. The direction of the tilt was determined by the location of the PPA zone with a tendency to thinning of the RNFL in the same sectors. A positive correlation between the AL of eye and the location of the LC of sclera was found. In 29.17% the superficial location of the LC was determined. In 54.17% elongation was accompanied by displacement of the trunk of the CRV on ONH in the nasal ‐ 71.79%, or in the superior‐nasal direction ‐ 28.21%.Conclusions: The revealed changes of optic disc cup, neuroretinal rim and the parapapillary zones; a superficial displacement of LC of sclera and ‘nasalization’ of the trunk of CRV; a decrease in the OI with growth in the AL; relationships of the PPA zone with a tendency to thinning of the RNFL and direction of the tilt can be useful as OCT markers in interpreting normative data in patients with myopia, predicting its progression, and also in differential diagnosis with glaucomatous optic neuropathy.

Superior segmental optic nerve hypoplasia with normotensive glaucoma: A case report

We report a 27-year-old woman with a cup disk ratio of 0.75:1, with a focal superior neuroretinal rim loss and corresponding nerve fiber layer defect in both eyes. Intraocular pressure was 10 mm Hg in both eyes with normal anterior segment. Perimetry showed inferior arcuate defects in both eyes. A diagnosis of superior segmental optic nerve hypoplasia (SSOH) was made. On follow-up, there was progression in field defects, which were confirmed by repeat field tests, despite normal intraocular pressures. We concluded that there was coexisting normotensive glaucoma (NTG) in this patient.

Central retinal vessel trunk exit location: An important factor while evaluating the neuroretinal rim.

Optic nerve head (ONH) evaluation plays a key role in differentiating normal from glaucomatous disk. Thinning of the inferior neuroretinal rim (NRR) has been noted in early glaucoma. However, NRR thickness in different quadrants appears to depend on various factors including central retinal vessel trunk exit (CRVT) position. We evaluated ocular parameters that determined the NRR thickness in the different quadrants of normal eyes. Retrospective review of demographic and ocular data from 773 eyes of 388 subjects with normal ONH over one year was undertaken. Nearly 54% were males, and the mean age was 43.2 years. The CRVT exit was central in 50% (773). The common site for noncentral CRVT was superotemporal (ST) [37%, 141/384] followed by inferotemporal (IT) [35%, 135/384]. With noncentral CRVT, the probability that the inferior, superior, nasal and temporal (ISNT) rule was not followed was 1.42 times ( P < 0.001). The thinnest rim quadrant (TRQ) was mostly ST (69%) irrespective of CRVT location. The TRQ was IT in 40% when CRVT was noncentral and 82% with IT CRVT exit. With noncentral CRVT, round disks favored noncompliance [132 (54.1%), odds ratio (OR) 2.56] with the ISNT rule. The OR of noncompliance with the ISNT rule increases 1.89 times with inferonasal CRVT and 1.22 times with a unit increase in the axial length. TRQ was IT in IT CRVT, and noncompliance with the ISNT rule was observed with large disks, longer axial length, and noncentral CRVT. This implies that despite the ISNT rule being violated these eyes do not have optic nerve pathology and should not be subjected to unnecessary diagnostic tests.

Quantitative analysis of optic disc changes in school-age children with ametropia based on artificial intelligence.

To explore changes in the optic disc and peripapillary atrophy (PPA) in school-age children with ametropia using color fundus photography combined with artificial intelligence (AI) technology. Based on the retrospective case-controlled study, 226 eyes of 113 children aged aged 6-12y were enrolled from October 2021 to May 2022. According to the results of spherical equivalent (SE), the children were divided into four groups: low myopia group (66 eyes), moderate myopia group (60 eyes), high myopia group (50 eyes) and emmetropia control group (50 eyes). All subjects underwent un-aided visual acuity, dilated pupil optometry, best-corrected visual acuity (BCVA), intraocular pressure, ocular axis measurement and color fundus photography. The width of PPA, horizontal diameter ratio of PPA to the optic disc and area ratio of PPA to the optic disc were significantly different among the four groups (P<0.05). The width of the nasal and temporal neuroretinal rim, the roundness of the optic disc, the height of PPA, the vertical diameter ratio of PPA to the optic disc, and the average density of PPA in the high myopia group were significantly different compared with the other three groups (P<0.05). There were strong negative correlations between SE and area ratio of PPA to the optic disc (r=-0.812, P<0.001) and strong positive correlation between axial length (AL) and area ratio of PPA to the optic disc (r=0.736, P<0.001). In school-age children with high myopia, the nasal and temporal neuroretinal rims are narrowed and even lost, which have high sensitivity. The area ratio of the PPA to the optic disc could be used as an early predictor of myopia progression, which is of great significance for the development prevention and management of myopia.

Diagnostic value of three-dimensional neuroretinal rim thickness for differentiation of superior segmental optic nerve hypoplasia

Little is known about the diagnostic utility of three-dimensional neuroretinal rim thickness (3D-NRRT) for differentiating patients with superior segmental optic nerve hypoplasia (SSOH) from normal-tension glaucoma (NTG). Since SSOH is defined by characteristic optic nerve head features, investigation of diagnostic usefulness of 3D-NRRT is necessary. In this cross-sectional study, 49 SSOH eyes, 52 NTG eyes, and 41 normal eyes were enrolled. Retinal nerve fiber layer thickness (RNFLT) and 3D-NRRT values, as obtained in the right-eye orientation by optical coherence tomography (OCT), were recorded. On RNFLT clock-hour comparison, the 11–3 clock-hour sectors were significantly thinner for SSOH than for NTG (all P < 0.01). As for 3D-NRRT, whereas the 1 and 2 sectors were significantly thinner for SSOH (P < 0.001, P = 0.004), the 6–11 sectors were significantly thinner for NTG (all P < 0.01). The area under receiver operating characteristic (AUROC) curves of the superior and nasal quadrants of RNFLT (0.838, 0.729) were significantly greater than those of 3D-NRRT (0.518, 0.588; P < 0.001, P = 0.043). However, the AUROCs of the inferior and temporal quadrants were significantly greater for 3D-NRRT (0.728, 0.760) than for RNFLT (0.527, 0.550; P = 0.008, P = 0.019). The appropriate use of 3D-NRRT can be useful in differentiating SSOH from NTG.