Optic Disc Research Articles

Peripapillary vessels density is closely related to cerebral white matter hyperintensities: An OCTA study.

Chronic cerebral hypoperfusion triggers the development of white matter hyperintensities (WMHs), common in cerebral small vessel disease (CSVD). However, conventional imaging techniques cannot visualize cerebral small vessels. The retina, a direct extension of the central nervous system, has an unclear correlation with WMHs. This study employs Optical coherence tomographic angiography (OCTA) to investigate vascular changes in the retina and explore its correlation with WMHs, aiming to provide a new method for assessing perfusion in early ischemic brain WMHs. Forty-nine patients with WMHs were stratified into mild and moderate/severe WMHs groups based on MRI findings, utilizing the Fazekas and Scheltens scales. OCTA assessed fundus vessel microcirculation. Logistic regression analyzed the correlation between ocular fundus microcirculation and WMH severity and location. Additionally, ROC curves evaluated the diagnostic efficacy of each fundus vascular microcirculation index in determining WMH severity. After adjusting for multiple confounders, finding consistently indicated that the moderate/ severe WMHs group exhibited lower vessel density (VD) in the superior quadrant of the inner peripapillary region compared to the mild group [OR = 0.487, CI (0.255,0.929), p < 0.05]. ROC curves revealed that when combined with age, diabetes, and superior quadrant VD of the inner peripapillary region, specificity could be increased to 94.1%. Peripapillary vessel density correlates closely with the severity of cerebral WMHs. Early morphological changes due to chronic hypoperfusion may initiate from the inner layer of the optic disc, and OCTA could offer a novel method for evaluating blood perfusion in ischemic WMHs.

The association between asymmetric stress distribution on the lamina cribrosa and glaucoma progression.

The purpose of this study was to assess the effect of ocular movements on the progression of glaucoma. A total of 118 primary open-angle glaucoma patients were enrolled, comprising 71 patients in the progression group and 47 patients in the non-progression group. Utilizing three geometric parameters-axial length, optic disc radius, and optic cup deepening-a personalized virtual optic nerve head (ONH) model was designed. ONH biomechanical changes during ocular movement were simulated using a finite element analysis. Simulation results were analyzed and compared between the progression and non-progression groups. In both progression and non-progression groups, ONH strains significantly increased with increasing rotation angle. When the eye rotated by 10°, the stress on the anterior surface of the lamina cribrosa on the temporal side was significantly higher in the progression group compared to the non-progression group (16.19 ± 0.90kPa vs. 13.24 ± 3.00 kPa, P < 0.001). The stress ratio, indicating asymmetric stress distribution, was higher in the progression group than in the non-progression group (0.56 ± 0.13 vs. 0.49 ± 0.19, P = 0.018). Stress ratio significantly increased with increasing optic disc radius (standardized β = 0.303, P < 0.001) and optic cup deepening (standardized β = 0.538, P < 0.001). Asymmetric stress distribution with ocular movement was higher in the progression group. This asymmetry was associated with optic disc radius and optic cup deepening. Therefore, ocular movement may contribute to the progression of glaucoma, with ONH geometry playing a role. WHAT IS KNOWN : Ocular movement is considered one of the physical stress factors affecting the optic nerve head. Ocular movement increased the strain on the optic nerve head and resulted in an asymmetric stress distribution on the lamina cribrosa surface. Asymmetric stress distribution on lamina cribrosa with ocular movement was higher in the glaucoma progression group and associated with optic disc radius and optic cup deepening.

A Case Report of Systemic Steroid Therapy for False Brain Tumors in Children

Study design: Case report. Purpose: to study the efficacy of systemic steroid in pediatric pseudotumor cerebri. Introduction: Pseudotumor cerebri is a condition caused by elevated intracranial pressure presenting most commonly with headache. It is a diagnosis of exculsion. Methods: A 15 year old girl presented in our OPD with headache since 3months, more in the posterior aspect, continuous type with severe intensity, non - radiating. On examination, her best corrected visual acuity in right eye was 6/9 and left eye was 6/6parts. She had normal anterior segment, normal IOP. Fundoscopy showed both optic discs edematous, pink in color with blurry disc margins, tortuous disc vessels, edematous peripapillary area. Rest of the retina was normal. Lumbar puncture showed elevated opening CSF pressure and normal CSF composition. Hence, she was diagnosed with IIH. She was started on oral prednisolone 1mg/kgbw once a day dosage, oral acetazolamide 250mg once a day, topical nepafenac 0.1% one drop thrice a day and timolol 0.5% eye drops twice a day. Discussion: The main goals of treatment are alleviation of symptoms, including headache, and preservation of vision. Steroids were commonly used for treating IIH in the past, but cause significant long - term side effects, such as weight gain, that are undesirable in IIH patients. Furthermore, withdrawal of steroids can cause rebound intracranial hypertension. Thus, steroids should not be used routinely for IIH treatment. Results: By the end of one month, patient was relieved of symptoms, best corrected visual acuity was 6/6 in both eyes with normal IOP, normal optic disc in both eyes. Conclusion: Steroids are an effective way of managing idiopathic intracranial hypertension in pediatric patients.

Optical coherence tomography angiography of peripapillary vessel density in non-arteritic anterior ischemic optic neuropathy and demyelinating optic neuritis

BackgroundIn cases of optic disc edema or a pale optic disc, distinguishing an episode of optic neuritis (ON) from that of non-arteritic anterior ischemic optic neuropathy (NAION) during a clinical examination is challenging. Optical coherence tomography angiography (OCTA) can reveal differences in peripapillary vascular network structures and provide biomarkers for differential diagnosis.MethodsA total of 23 eyes with NAION, 22 eyes with demyelinating ON (DON), and 27 eyes from healthy participants were imaged using OCTA to observe the radial peripapillary capillaries (RPCs). Optical coherence tomography was used to measure peripapillary retinal nerve fiber layer (RNFL) thickness and the macular ganglion cell complex (mGCC). Data for all patients were recorded at 2–3 weeks and more than 3 months after the symptom onset.ResultsA total of 23 affected eyes from 23 patients with NAION (average age 52.17 ± 7.92 years), 22 eyes from 22 patients with demyelinating optic neuritis (DON) (average age 47.88 ± 19.24 years), and 27 eyes from 27 healthy individuals (average age 46.43 ± 14.08 years) were included in the study. There were no significant differences in sex, age, and eye laterality between any two groups (F = 0.968, 0.475, 0.870; p &amp;gt; 0.05). Throughout the course of NAION and DON, the superior RPC, superior mGCC, and peripapillary RNFL decreased with time (p &amp;lt; 0.05). In contrast, the inferotemporal RPC and inferior mGCC did not decrease from the acute to chronic stage in NAION (t = 1.639, 0.834, p = 0.117, 0.413). Compared with the normal group, patients with NAION and DON exhibited a sharp reduction in the average RPC, RNFL, and GCC from the acute to the chronic stage (p &amp;lt; 0.05). Patients with DON exhibited a significant decrease in the inferotemporal RPC and inferior mGCC compared with the patients with NAION (p &amp;lt; 0.05). In contrast, there were no significant differences in the inferior mGCC at the chronic stage between the patients with NAION and those with ON (t = 2.547, p = 0.093).ConclusionVarious structural and microvascular changes were observed in patients with NAION and ON, indicating distinct features of the optic nerve during the different stages of NAION and ON. Peripapillary vascular density, measured using spectral domain OCT (SD-OCT), may be a biomarker to distinguish NAION from ON.

A novel GFAP frameshift variant identified in a family with optico-retinal dysplasia and vision impairment.

Gain-of-function variants in GFAP leads to protein aggregation and is the cause of the severe neurodegenerative disorder Alexander Disease (AxD), while loss of GFAP function has been considered benign. Here, we investigated a six-generation family, where multiple individuals presented with gliosis of the optic nerve head and visual impairment. Whole genome sequencing (WGS) revealed a frameshift variant in GFAP (c.928dup, p.(Met310Asnfs*113)) segregating with disease. Analysis of human embryonic tissues revealed strong expression of GFAP in retinal neural progenitors. A zebrafish model verified that c.928dup does not result in extensive GFAP protein aggregation and zebrafish gfap loss-of-function mutants showed vision impairment and retinal dysplasia, characterized by a significant loss of Müller glia cells and photoreceptor cells. Our findings show how different mutational mechanisms can cause diverging phenotypes and reveal a novel function of GFAP in vertebrate eye development.

Longitudinal OCTA vessel density loss in macula and optic nerve head in healthy, glaucoma suspect and established glaucoma eyes.

To examine longitudinal optical coherence tomography angiography (OCTA) changes in macula and optic nerve head (ONH) in healthy, glaucoma suspect (GS) and primary open-angle glaucoma (POAG) eyes. Healthy, GS and POAG eyes from Diagnostic Innovations in Glaucoma Study with ≥2 years follow-up and four visits of macular/ONH OCTA imaging were included. Rates of macular wiVD (whole-image vessel density) and ONH wiCD (whole-image capillary density) changes were calculated for each diagnosis group using join mixed-effect modelling. Differences in wiVD/wiCD change rates across diagnoses were examined through pairwise comparison. Relationships of baseline 24-2 visual field (VF) mean deviation (MD) with wiVD/wiCD change rates were evaluated for POAG eyes. There were 36, 57 and 79 eyes (25, 38 and 50 subjects) in healthy, GS and POAG groups, respectively. Rates of wiVD (range:-0.72 to -0.92 %/year) and wiCD (range:-0.28 to -0.66 %/year) loss were different from zero in all groups (p<0.05). The rates of wiCD loss differed across all diagnosis groups (p<0.001), while wiVD change rates did not increase when comparing healthy to GS eyes (p=0.167). Baseline VF MD showed a significant but modest correlation with the rates of both wiVD and wiCD loss (p<0.05), and the correlation with wiCD change rate was slightly stronger (R2=0.27 vs 0.16). In glaucoma, there is earlier microvasculature loss in the ONH than in the macula. Moreover, ONH VD loss shows a slightly stronger association with baseline VF than macular VD. Observing ONH VD loss with OCTA may help to monitor early glaucoma, which should be confirmed by future larger studies.

Detection of optic disc in human retinal images utilizing the Bitterling Fish Optimization (BFO) algorithm

Early detection and correct identification of the optic disc (OD) on scanned retinal images are significant for diagnosing and treating several ophthalmic conditions, including glaucoma and diabetic retinopathy. Conventional methods for detecting the OD often struggle with processing retinal images due to noise, changes in illumination, and complex overlapping images. This study presents the development of effective and accurate fixation of the optic disc using the Bitterling Fish Optimization (BFO) algorithm, which enhances the processes of OD imaging in speed and precision. The proposed method begins with image enhancement and noise suppression for preprocessing, followed by applying the BFO algorithm to locate and delineate the OD region. The performance evaluation of the algorithm was conducted within several public domain retinal images, including DRIVE, STARE, ORIGA, DRISHTI-GS, DiaRetDB0, and DiaRetDB1 datasets about some internal metrics: sensitivity (SE), specificity (SP), accuracy (ACC), DICE overlap coefficient, overlap and time of processing respectively. The technique based on BFO provided better results, with 99.33%, 99.94%, and 98.22% accuracy achieved for OD in DRIVE, DRISHTI-GS, and DiaRetDB 1, respectively. The approach also demonstrated high overlaps and good DICE results, with a DICE coefficient of 0.9501 for the DRISHTI-GS database. On average, the processing time per image was less than 2.5 s, proving the approach’s efficiency in computations. The BFO approach has demonstrated its effectiveness and scalability in detecting optic discs in retinal images in an automated manner. It showed impressive performance levels in terms of computation time and accuracy and was variation resistant irrespective of the quality of the image and the pathology present on it. This method holds significant potential for clinical use, providing a meaningful way of diagnosing and managing ocular disease at an early stage.

The relationship between retinal vascular parameters measured by artificial intelligence and the risk of new-onset cardiovascular disease in a Chinese community-based population

Abstract Background Studies on the association between retinal vascular diameter and tortuosity and the risk of new-onset cardiovascular disease (CVD) are controversial. The predictive value of retinal vascular parameters, measured through artificial intelligence (AI), for incident CVD risk in the community population, remains to be explored. Objectives Our study aims to investigate the association between retinal vascular parameters (diameter and tortuosity) measured through AI, and the risk of new-onset CVD in the Chinese community-based population. Methods We conducted a prospective cohort study on subjects from a Beijing community in China who were free of prevalent stroke or myocardial infarction and underwent retinal photography at baseline. By deep-learning algorithm, quantitative retinal vascular parameters were measured 0.5 to 1 disc diameter from the optic disc margin, including central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), arteriolar-to-venular ratio (AVR), curvature tortuosity arteriole (cTORTa), and curvature tortuosity venule (cTORTv). The primary endpoint was a new-onset major adverse cardiovascular event (MACE), defined as a composite of cardiovascular death, first non-fatal stroke, and first non-fatal acute myocardial infarction (AMI). The secondary endpoints included cardiovascular death, first stroke, and first AMI. Cox proportional-hazards regression analyses were performed. Results A total of 3,585 participants were included. The mean age was 56.49 ± 8.94 years, and 2,335 (65.1%) were female. Prevalence of prior hypertension and diabetes was 1594 (44.5%) and 676 (18.9%), respectively. During the follow-up (median, 7.53 years), there were 293 cases of new-onset MACE (8.2%), 44 cardiovascular deaths (1.2%), 226 strokes (6.3%), and 57 AMIs (1.6%). The Kaplan–Meier curves showed significant differences in cumulative hazards of new-onset MACE among tertiles of CRAE, CRVE, AVR, and cTORTa, but not for cTORTv (Figure 1). In Cox proportional-hazards models (Figure 2) adjusting for covariates, CRAE was negatively associated with the risk of new-onset MACE (per 10 μm increase, hazard ratio [HR]=0.95, 95% confidence interval [CI]: 0.92-0.99, P=0.009) and the risk of new-onset stroke (per 10 μm increase, HR=0.96, 95%CI: 0.92-1.00, P=0.04). Similarly, AVR was negatively associated with new-onset MACE risk (per 0.1 increase, HR=0.82, 95%CI: 0.72-0.94, P&amp;lt;0.001) and new-onset stroke risk (per 0.1 increase, HR=0.84, 95%CI: 0.73-0.98, P=0.022). No significant associations were observed between CAVE, cTORTa, and cTORTv with any of the primary or secondary endpoints. Conclusions CRAE and AVR, measured through AI, are associated with the risk of new-onset MACE in the Chinese population. These findings suggest the potential for AI-measured parameters in retinal vasculature to aid in stratifying CVD risk in the general population.

Smartphone Aided Funduscopy in Albino Rabbits

Aims: The methodology, utility and clinical feasibility of using a smartphone camera to obtain images of ocular fundus of albino rabbits with ocular hypertension and normotension were studied. A comparative analysis of fundus images obtained from two popularly used smartphone models, android and iOS device was performed on 36 adult albino rabbits. Study Design: A cross-sectional study involving two cohorts of ocular hypertensive and normotensive albino rabbits. Place and Duration of Study: Department of Veterinary Surgery and Radiology, College of Veterinary and Animal Sciences, Mannuthy for an eight-week period (2023). Methodology: A total of 36 adult albino rabbits (18 males and 18 females; age range 6- 8 months of age) with ocular normotensive eyes and unilateral ocular hypertension-induced models were used. The conscious animals were gently restrained in an acrylic restrainer. Instillation of topical mydriatic solution (tropicamide 0.8% and phenylephrine 5%) facilitated visual examination and enhanced field of view along with auxiliary condensing lenses of 20 and 40 Diopters. A comparison of fundus images obtained from two popularly used smartphone models, android and iOS devices was performed on 36 adult albino rabbits. Results: Fundus images comprising the optic nerve head and peripapillary retina were obtained with adequate spatial resolution and detail. The variation between optic disc of ocular hypertensive eye revealed mild edema and cupping of optic disc. Normal merangiotic retina and optic disc were clearly obtained in normotensive rabbit eyes. The iOS device used in this case yielded better images in resolution and field of view compared to the android version used in this case. Conclusion: Smart phone funduscopy offered good detail in contrast and resolution even in amelanotic eyes of albino rabbits using inbuilt technology without the need for an external adapter or sophisticated additional software. It is an animal-friendly futuristic solution for digital documentation, telemedicine, teaching and clinical prognosis formulation.

Bilateral Idiopathic Neuroretinitis

Background/Objectives: Neuroretinitis (NR) is a rare inflammatory condition characterized by sudden vision loss, optic disc edema and macular star appearance predominantly affecting individuals in their third and fourth decades of life. Methods: This paper describes the case of 33-year-old Caucasian man with no significant medical history complaining of decreased vision for about a week. Results: The ophthalmological exam revealed best-corrected visual acuity (BCVA) for the right eye (RE) of 0.8 (decimal notation) and of 0.9 for the left eye (LE). Intraocular pressure (IOP) was 20 mmHg in RE and 18 mmHg in LE. Slit-lamp examination of both eyes (OU) showed no evidence of intraocular inflammation in the anterior chamber or vitreous cavity. Examination of the posterior pole of the right eye showed bilateral papilledema with an incomplete macular fan pattern. Conclusions: Despite extensive laboratory tests, including serologic and imaging investigations, a definitive etiology remained unclear. It is very important to differentiate NR from other optic nerve disorders, requiring careful clinical evaluation and observation of the evolution of symptoms.

Leber’s idiopathic stellate neuroretinitis - A clinical case

Neuroretinitis is a type of optic neuropathy characterized by an acute unilateral visual loss with optic disc swelling and macular star. A 26-year-old male presented with sudden blurring of vision in the right eye for 15 days. There were no other constitutional symptoms. On examination, visual acuity and color vision were impaired in the right eye. Visual-evoked potential showed a lower amplitude with increased latency on the right side. Perimetry showed centrocaecal scotoma. The right eye fundus showed a distinct neuroretinitis pattern Despite extensive investigation, no specific cause was identified, hence diagnosed as Leber’s idiopathic stellate neuroretinitis. The patient was started on oral prednisolone. Follow-up showed significant improvement.

Comparative evaluation of OCT with OCTA changes at the optic disc and macula in glaucoma suspect and early glaucoma.

To compare the diagnostic ability of macular ganglion cell inner plexiform layer (mGCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thickness on optical coherence tomography (OCT) and macular and peripapillary perfusion changes using OCT angiography (OCTA) in glaucoma suspect and early primary open angle glaucoma (POAG). Ninety patients (30 normal, 30 glaucoma suspects, and 30 early POAG) were recruited in this cross-sectional, prospective study. The average thickness of mGCIPL and pRNFL on spectral domain-OCT and macular vessel density (VD), optic nerve head (ONH) perfusion, and ONH flux index (FI) on OCTA were evaluated for early diagnosis of glaucoma. Macular VD, ONH perfusion, and ONH FI were significantly reduced in early POAG eyes compared to normal. The best correlation was observed between ONH FI and the average RNFL in both glaucoma suspects (r = 0.47, P < 0.01) and early POAG patients (r = 0.53, P < 0.01). Out of all the measured OCTA parameters, only ONH perfusion was significantly lower in glaucomatous eyes compared to glaucoma suspects (P < 0.001). Average GCIPL (0.82) and macular VD (0.76) had the highest area under the receiver operating characteristic (AUROC) curve value among all the OCT and OCTA parameters, respectively, for differentiating glaucoma suspects from controls. Rim area (0.92) and ONH FI (0.81) had the highest AUROC value among all the OCT and OCTA parameters for differentiating early POAG patients from controls. OCTA vascular parameters had a good correlation with structural damage both at the disc and the macula. OCT parameters were superior to OCTA parameters for diagnosis of glaucoma, although OCTA parameters are deranged very early in the disease.

Successful Aflibercept Treatment for Choroidal Neovascularization in a Rare Case of Optic Disc Melanocytoma

Successful Aflibercept Treatment for Choroidal Neovascularization in a Rare Case of Optic Disc Melanocytoma

Multilayered Inverted Internal Limiting Membrane Flap Technique in Optic Disc Pit Maculopathy.

To evaluate the anatomical and visual outcomes of the multilayered inverted internal limiting membrane (ML-ILM) flap technique in the treatment of optic disc pit maculopathy (ODPM). In this retrospective interventional case series, medical records and macular spectral-domain optical coherence tomography images of patients who underwent combined pars plana vitrectomy with ML-ILM flap surgery for ODPM were analyzed. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) at postoperative 6 months were compared with baseline findings. Intraoperative and postoperative complications, fluid resolution time, and recurrence during follow-up were recorded. Five eyes of 5 patients with ODPM were included in the study. According to the preoperative macular fluid characteristics, 2 patients had only intraretinal fluid, while 3 patients had intraretinal and subretinal fluid. The preoperative median BCVA was 1.0 logarithm of the minimum angle of resolution (logMAR) (range, 1.0-1.3 logMAR), and the CMT was 560 μm (range, 452-667 μm). At the 6-month postoperative follow-up, the median BCVA was 0.40 logMAR (range, 0.1-0.7 logMAR), and CMT was 315 μm (range, 265-326 μm) (p=0.042 and p=0.043, respectively). During the 6-month follow-up period, no recurrence or full-thickness macular hole formation was observed. The ML-ILM flap technique is a preferable surgical option to achieve both high anatomical and functional success and flap stabilization.

Retinal neurovascular assessment and choroidal vascularity index in patients with keratoconus

This study aims to evaluate the macular and the optic nerve head thickness and vascular profiles in KC patients and compare them with two groups of healthy emmetrope and subjects with myopic-astigmatism. This cross-sectional study was conducted at Khatam-Al-Anbia Eye Hospital between 2022 and 2023. Subjects aged 18 to 40 were prone to be included in the study. The participants in this study were grouped into three categories: emmetrope (E), myopic-astigmatic (MA), and keratoconus (KC). All participants underwent a comprehensive ocular examination, as well as macular and optic nerve head (ONH) optical coherence tomography angiography (OCTA). In this study, 143 subjects, 50 cases in the KCN group, 46 cases in the E group, and 47 cases in the MA group, enrolled. There was no difference between the three groups regarding age (p = 0.123) and gender (p = 0.632). The superficial and deep capillary densities at the fovea, parafovea, and perifovea were significantly lower in KC patients than in the control groups (p < 0.01). The radial peripapillary capillary (RPC)- all vessels’ density is significantly lower in the KC group (p < 0.001). Besides, the choroidal vascularity index (CVI) and choroidal luminal area (CLA) were considerably higher in KC patients (p < 0.001). The macular and ONH vascular profile in KC patients significantly differs from the vascular profile of healthy controls. Further scientific evidence regarding the systemic implications of keratoconus on the vascular system would be desirable to understand the connections between KC and vascular disease.

Combined evaluation of visual field and optical coherence tomography angiography data in multiple sclerosis patients

Aims: To evaluate Humphrey visual field analyzer (HVFA) data and optical coherence tomography angiography (OCT-A) parameters in multiple sclerosis (MS) patients with optic neuritis (ON) attacks. Methods: 34 eyes of 34 patients with MS diagnosis who had ON attacks were included in the study. After detailed ophthalmoscopic examination, OCT-A and HVFA images were taken. Spearman correlation analysis was used in statistical analysis. Results: The mean age of the participants was 31.52±10.09 years. In the correlation analysis, a moderate correlation was found between mean deviation (MD) and foveal deep blood flow (DF) (rho=0.52), and a weak correlation was found between MD and foveal superficial blood flow (SF) (rho=0.40) and optic disc head blood flow (ODF) (rho=0.38). A weak negative correlation was found between pattern standard deviation (PSD) and DF (rho=-0.37) and ODF (rho=-0.40). Conclusion: This study showed that OCTA data were affected in a manner consistent with HVFA data. More practical and quickly applicable OCTA scans may facilitate the estimation of visual field findings in MS patients.

Controlled Elevation of Intraocular Pressure (CEI) Glaucoma Model in Rats.

Experimental elevation of intraocular pressure (IOP), a major glaucoma risk factor, has been a mainstay of research into mechanisms of glaucomatous optic nerve damage for decades. Methods that produce sustained IOP elevation can mimic the chronic nature of glaucoma and produce optic nerve damage. However, the pressure course for individual animals can be variable, unpredictably high at times, and difficult to monitor with current tonometry methods. All of this can complicate correlations of pressure history with axonal injury. An alternative is to control the extent and duration of IOP elevation over a period of several hour-long enough to produce axonal injury and gene expression changes within the optic nerve head that may indicate cellular mechanisms of glaucomatous optic nerve damage. The prolonged general anesthesia that this requires does have the potential to reduce systemic blood pressure, which may contribute to axonal injury in the face of elevated IOP. This chapter will describe our Controlled Elevation of IOP (CEI) model in laboratory rats. We will include methods for applying this to several animals at a time, as well as how to maintain blood pressure, oxygenation, and body temperature to ensure that the resulting injury and tissue events reflect the effects of elevated IOP on optic nerve tissues and not simply reduced ocular perfusion and ischemia.

PM2.5 Exposure as a Risk Factor for Optic Nerve Health in Type 2 Diabetes Mellitus

(1) Objective: This study investigated the relationship between long-term particulate matter (PM2.5) exposure and optic disc parameters—vertical cup-to-disc ratio (vCDR), vertical optic disc diameter (vDD), and vertical optic cup diameter (vCD)—in patients with type 2 diabetes mellitus (T2DM). (2) Methods: A cross-sectional analysis was conducted using data from 65,750 T2DM patients in the 2017–2018 Shanghai Cohort Study of Diabetic Eye Disease (SCODE). Optic disc parameters were extracted from fundus images, and PM2.5 exposure was estimated using a random forest model incorporating satellite and meteorological data. Multivariate linear regression models were applied, adjusting for confounders including age, gender, body mass index, blood pressure, glucose, time of T2DM duration, smoking, drinking, and physical exercise. (3) Results: A 10 μg/m3 increase in PM2.5 exposure was associated with significant reductions in vCDR (−0.008), vDD (−42.547 μm), and vCD (−30.517 μm) (all p-values &lt; 0.001). These associations persisted after sensitivity analyses and adjustments for other pollutants like O3 and NO2. (4) Conclusions: Long-term PM2.5 exposure is associated with detrimental changes in optic disc parameters in patients with T2DM, suggesting possible optic nerve atrophy. Considering the close relationship between the optic nerve and the central nervous system, these findings may also reflect broader neurodegenerative processes.

Posterior short ciliary arteries ischemia following embolization of anterior ethmoid artery to treat dural arteriovenous fistulas: a case report

BackgroundThe Onyx™ Liquid Embolic System is a non-adhesive liquid embolic agent, which has been proved by the US FDA for embolization of lesions in the peripheral and neurovasculature since 2005. We reported a case of ischemic optic neuropathy after using Onyx-18 to embolize the anterior ethmoid arteries that feeding dural arteriovenous fistulas (DAVF).Case presentationA 57-year-old Asian male presented with anterior cranial fossa DAVF underwent embolotherapy by delivering Onyx-18 through a microcatheter into the anterior ethmoid arteries under angiography guidance. The interventional procedure was successful and no clear evidence was found pointing to untargeted occlusive embolus. But after the surgery the patient experienced delayed painless vision loss in the right eye (RE). The fundoscopy showed unilateral papilledema with pale optic disc in RE, accompanied by significant edema and thickening in the retinal nerve fiber layer (RNFL) of macula. The fundus fluorescence angiography showed that most of the optic disc in RE had postponed or absent fluorescence filling. Visual evoked potential (VEP) confirmed that the amplitude of the P100 component was decreased in RE without significant prolongation of the latency. The patient was diagnosed with anterior ischemic optic neuropathy, but immediate pulse steroid therapy failed to rescue his vision.ConclusionPreoperative evaluation of the patient’s hemodynamic status and fundus examination are essential for assessing the risk of ischemic ocular complications, and the non-adhesive liquid embolic agent Onyx-18 should be used cautiously during endovascular embolization of intracranial artery.

Is the presence of peripapillary hyperreflective ovoid mass-like structures (PHOMS) in children related to the optic disc area, scleral canal diameter and refractive status?

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) have been recently described on optical coherence tomography (OCT) scans of the optic nerve. We aim to determine if there is a causal relationship between OCT measurements of the optic disc area (DA), scleral canal diameter (SCD) and refractive error (spherical equivalent, SE) on the presence of PHOMS. Retrospective analysis of OCT scans which were graded for the presence or absence of PHOMS in children with suspected papilledema was undertaken. Data on disc area, DA (mm2) and scleral canal diameter, SCD (µm) were obtained from OCT scans. Statistical analysis was performed on two subgroups: unilateral PHOMS vs contralateral control; all eyes with PHOMS vs all eyes without PHOMS (controls). Logistic regression analysis was performed. In unilateral PHOMS (n = 32), there was a non-significant tendency towards a larger DA and SCD in the eye with PHOMS (3.33mm2, 1701 µm) compared to the contralateral eye in the same patient (2.83mm2, 1556 µm). Wider analysis of all eyes with PHOMS (n = 116) versus all eyes without (n = 104) showed there was a significant difference between the DA (3.38mm2 versus 2.65mm2 p = <.0001) and SCD (1763 µm versus 1571 µm, p = <.0001). Logistic regression showed that SCD made a significant contribution to predicting the presence of PHOMS (OR 1.0042, p = 0.0017). PHOMS are frequently seen in pseudopapilledema. It would be useful to understand their pathophysiology as an accurate diagnosis in the context of the asymptomatic paediatric population is crucial. We report that a wider scleral canal diameter was significantly associated with the presence of PHOMS.