Optic Nerve Disease Research Articles

Differential diagnosis of optic neuritis and anterior ischemic optic neuropathy

Background. Acute anterior ischemic neuropathy and optic neuritis are among the most common diseases that are the most frequent cause of both reversible and persistent visual acuity reduction. There is a sudden loss of vision, the clinical picture is often similar, and the restoration of visual functions and the prevention of complications in the form of optic nerve atrophy and disease relapses depend on a correct diagnosis and timely prescribed therapy. A significant level of medico-social and economic losses for society in all regions of the world is related to complications, namely the occurrence of optic nerve atrophy due to both optic nerve inflammation (neuritis) and ischemic optic neuropathy. The purpose was to determine the differential signs of optic neuritis and anterior ischemic optic neuropathy. Materials and methods. Eighty-five patients were examined, 52 (61.2 %) women and 33 (38.8 %) men. Seventy-one (83.5 %) participants were employed. The patients were divided into two groups: the first one — 38 patients with optic neuritis (papillitis); the second one — 47 people with ischemic optic neuropathy. General ophthalmological examinations were carried out. Results. Computed perimetry showed the presence of scotoma and quadrantanopia, both in anterior optic neuropathy (typical altitudinal scotomas) and optic neuritis (peripheral and central scotomas). The difference in the indicators of the electrical activity of the visual analyzer according to phosphene between the groups was 15.8 % (p < 0.05), which indicates a more significant increase in the functional activity of the visual analyzer in the group with anterior optic vascular neuropathy. Thinning of the peripapillar nerve fiber layer and partial atrophy of the optic nerve were noted 2 times less often in patients with anterior vascular ischemic neuropathy — 7 (16.3 %) vs. 14 (33.3 %) in those with partial atrophy of the optic nerve (Pearson’s χ2 = 22.59, p = 0.00001). Conclusions. The issue of early differential diagnosis of anterior optic ischemic neuropathy and optic neuritis is relevant, which determines the prognosis of the disease, allows increasing the effectiveness of treatment and preventing irreversible consequences. The therapeutic effect of treating the consequences of damage to the optic nerve is not stable and is weak, and success is not always achieved. First of all, the treatment of the underlying disease is indicated. Computed perimetry showed the presence of scotoma and quadrantanopia in both anterior optic neuropathy (typical altitudinal scotomas) and optic neuritis (peripheral and central scotomas).

Role of Gonadal Steroid Hormones in the Eye: Therapeutic Implications.

Gonadal steroid hormones are critical regulatory substances involved in various developmental and physiological processes from fetal development through adulthood. These hormones, derived from cholesterol, are synthesized primarily by the gonads, adrenal cortex, and placenta. The synthesis of these hormones involves a series of enzymatic steps starting in the mitochondria and includes enzymes such as cytochrome P450 and aromatase. Beyond their genomic actions, which involve altering gene transcription over hours, gonadal steroids also exhibit rapid, nongenomic effects through receptors located on the cell membrane. Additionally, recent research has highlighted the role of these hormones in the central nervous system (CNS). However, the interactions between gonadal steroid hormones and the retina have received limited attention, though it has been suggested that they may play a protective role in retinal diseases. This review explores the synthesis of gonadal hormones, their mechanisms of action, and their potential implications in various retinal and optic nerve diseases, such as glaucoma, age-related macular degeneration (AMD), diabetic retinopathy (DR), or retinitis pigmentosa (RP), discussing both protective and risk factors associated with hormone levels and their therapeutic potential.

Optic Nerve Head in Case of Increased Intraocular Pressure, High Intracranial Pressure and Increased Intracranial Pressure with Simultaneous Intraocular Pressure

The optic nerve, as part of the central nervous system, is surrounded by meninges and cerebrospinal fluid (CSF). This review discusses the effects of increased intraocular pressure (IOP), elevated intracranial pressure (ICP), and the simultaneous rise in both pressures on the optic nerve head (ONH). Increased IOP, caused by the balance of aqueous humor production and drainage, can lead to glaucomatous optic neuropathy, particularly through mechanical and ischemic damage to the lamina cribrosa. Elevated ICP, characterized by increased CSF pressure, can result in optic nerve edema, impairing axonal transport and blood flow. The complex interactions between IOP and ICP are critical for understanding their combined impact on ONH deformation and glaucomatous damage. It is essential to consider both pressures in clinical evaluations and treatment strategies for optic nerve-related diseases. Recent studies suggest that both IOP and ICP influence the optic nerve head morphology and pathology, highlighting the importance of comprehensive management approaches. Further research is needed to elucidate the intricate dynamics of IOP and ICP in the pathogenesis of optic nerve diseases.

Bioengineering strategy to promote CNS nerve growth and regeneration via chronic glutamate signaling

Being part of the mature mammalian central nervous system, impairments of the retina and optic nerves caused by trauma or diseases often cannot be restored. Progressive degeneration of retinal ganglion cells (RGCs) in glaucoma and other optic neuropathies gradually leads to permanent vision loss, which currently has no cure. The purpose of this study is to develop a biocompatible scaffold to support RGC survival and guide axon growth, facilitating optic nerve repair and regeneration. We here report that electrical stimulation (ES) significantly promoted neurite outgrowth and elongation from primary RGCs, mediated through glutamate receptor signaling. To mimic prolonged glutamate stimulation and facilitate sustained nerve growth, we fabricated biocompatible poly-γ-benzyl-L-glutamate (PBG) scaffolds for controlled glutamate release. These PBG scaffolds supported RGC survival and robust long-distance nerve growth in both retinal explants and isolated RGC cultures. In contrast, control polycaprolactone (PCL) scaffolds with similar physical structures showed little benefits on RGC survival or nerve growth. Moreover, PBG scaffolds promoted the differentiation and neurite outgrowth from embryonic stem cell-derived RGC progenitors. The aligned PBG scaffold drove directed nerve elongation along the fiber alignment. Transplantation of PBG-coated biocompatible conduits induced robust optic nerve regeneration in adult mice following nerve transection. Together, the findings present the exciting possibility of driving optic nerve regeneration and RGC progenitor cell differentiation by imitating ES or glutamate signaling. PBG presents a permissive biomaterial in supporting robust and directed axon growth with promising clinical applications in the future. Statement of SignificanceWe here reported compelling findings that demonstrate the potent regenerative effects of a bioengineered scaffold incorporating poly-γ-benzyl-L-glutamate (PBG) on the optic nerve. Retinal ganglion cell (RGC) axons, which form the optic nerve, are incapable of regenerating in adulthood, posing a significant hurdle in restoring vision for patients with optic nerve diseases or injuries. Built upon the finding that electrical stimulation promotes RGC axonal growth through glutamate signaling, we developed PBG scaffolds to provide sustained glutamate stimulation and showed their exceptional effects on driving directed axonal elongation in cultured RGCs and neural progenitors, as well as supporting robust optic nerve regeneration after transection in vivo. The findings hold great promise for reversing vision loss in patients with optic nerve conditions.

Translational Research and Therapies for Neuroprotection and Regeneration of the Optic Nerve and Retina: A Narrative Review

Most retinal and optic nerve diseases pose significant threats to vision, primarily due to irreversible retinal neuronal cell death, a permanent change, which is a critical factor in their pathogenesis. Conditions such as glaucoma, retinitis pigmentosa, diabetic retinopathy, and age-related macular degeneration are the top four leading causes of blindness among the elderly in Japan. While standard treatments—including reduction in intraocular pressure, anti-vascular endothelial growth factor therapies, and retinal photocoagulation—can partially delay disease progression, their therapeutic effects remain limited. To address these shortcomings, a range of neuroprotective and regenerative therapies, aimed at preventing retinal neuronal cell loss, have been extensively studied and increasingly integrated into clinical practice over the last two decades. Several of these neuroprotective therapies have achieved on-label usage worldwide. This narrative review introduces several neuroprotective and regenerative therapies for retinal and optic nerve diseases that have been successfully translated into clinical practice, providing foundational knowledge and success stories that serve as valuable references for researchers in the field.

Recognizing Leber's Hereditary Optic Neuropathy to avoid delayed diagnosis and misdiagnosis.

Leber's Hereditary Optic Neuropathy (LHON) is a maternally inherited optic nerve disease primarily caused by mutations in mitochondrial DNA (mtDNA). The peak of onset is typically between 15 and 30 years, but variability exists. Misdiagnosis, often as inflammatory optic neuritis, delays treatment, compounded by challenges in timely genetic diagnosis. Given the availability of a specific treatment for LHON, its early diagnosis is imperative to ensure therapeutic appropriateness. This work gives an updated guidance about LHON differential diagnosis to clinicians dealing also with multiple sclerosi and neuromyelitis optica spectrtum disorders-related optic neuritis. LHON diagnosis relies on clinical signs and paraclinical evaluations. Differential diagnosis in the acute phase primarily involves distinguishing inflammatory optic neuropathies, considering clinical clues such as ocular pain, fundus appearance and visual recovery. Imaging analysis obtained with Optical Coherence Tomography (OCT) assists clinicians in early recognition of LHON and help avoiding misdiagnosis. Genetic testing for the three most common LHON mutations is recommended initially, followed by comprehensive mtDNA sequencing if suspicion persists despite negative results. We present and discuss crucial strategies for accurate diagnosis and management of LHON cases.

Longitudinal Optical Coherence Tomography Imaging Reveals Hyperreflective Foci Characteristics in Relapsing-Remitting Multiple Sclerosis Patients.

Background/Objectives: Retinal hyperreflective foci, 25-50 µm in diameter, that can be imaged by noninvasive optical coherence tomography (OCT) may represent microglial activity related to inflammation. This study aimed to detect hyperreflective foci in the OCT-hyporeflective avascular outer nuclear layer of the retina in relapsing-remitting MS (RRMS) patients without ongoing eye or optic nerve disease. Methods: A cohort of 13 RRMS patients (8 eyes with and 18 eyes without prior optic neuritis) underwent retinal OCT at baseline, after 1 month, after 6 months, and then every 6 months for 3 years. The data were compared with single-examination data from 106 eyes in 53 age-matched healthy subjects. Results: The prevalence of hyperreflective foci at baseline was higher in RRMS patients than in healthy subjects (46.2% vs. 1.8%, p < 0.005). Patients with optic neuritis had much more foci than those without (p < 0.001). Hyperreflective foci recurred in 23.1% of RRMS patients, bilaterally in one with prior optic neuritis and unilaterally in two without. Conclusions: Patients with RRMS, notably those with prior optic neuritis, had elevated rates of retinal infiltration in the absence of retinal disease, suggesting that the phenomenon may represent elevated activity of an immune surveillance or housekeeping mechanism rather than retinal disease.

Effects of Acute High-Altitude Exposure on Morphology and Function of Retinal Ganglion Cell in Mice.

High altitude retinopathy (HAR) is a retinal functional disorder caused by inadequate adaptation after exposure to high altitude. However, the cellular and molecular mechanisms underlying retinal dysfunction remain elusive. Retinal ganglion cell (RGC) injury is the most important pathological basis for most retinal and optic nerve diseases. Studies focusing on RGC injury after high-altitude exposure (HAE) are scanty. Therefore, the present study sought to explore both functional and morphological alterations of RGCs after HAE. A mouse model of acute hypobaric hypoxia was established by mimicking the conditions of a high altitude of 5000 m. After HAE for 2, 4, 6, 10, 24, and 72hours, the functional and morphological alterations of RGCs were assessed using retinal hematoxylin and eosin (H&E) sections, retinal whole mounts, transmission electron microscopy (TEM), and the photopic negative response (PhNR) of the electroretinogram. Compared with the control group, the thickness of the ganglion cell layer and retinal nerve fiber layer increased significantly, RGC loss remained significant, and the amplitudes of a-wave, b-wave, and PhNR were significantly reduced after HAE. In addition, RGCs and their axons exhibited an abnormal ultrastructure after HAE, including nuclear membrane abnormalities, uneven distribution of chromatin in the nucleus, decreased cytoplasmic electron density, widening and vacuolization of the gap between axons, loosening and disorder of myelin sheath structure, widening of the gap between myelin sheath and axon membrane, decreased axoplasmic density, unclear microtubule and nerve fiber structure, and abnormal mitochondrial structure (mostly swollen, with widened membrane gaps and reduced cristae and vacuolization). The study findings confirm that the morphology and function of RGCs are damaged after HAE. These findings lay the foundation for further study of the specific molecular mechanisms of HAR and promote the effective prevention.

Values of peripapillary retinal nerve fibre layer thickness are different in children and adults

ABSTRACT Clinical relevance The detection of abnormal values of peripapillary nerve fibre layer (pRNFL) thickness measured with optical coherence tomography (OCT) is important for detecting optic nerve disease in children. Background To evaluate the level of agreement between the adult reference database supplied with an OCT device and the present paediatric study database for the measurement of pRNFL thickness in children. This study also aimed to provide reference values for pRNFL thickness according to the spherical equivalent in the paediatric population. Methods This was a cross-sectional study. One hundred and twenty-six healthy children were included, who had undergone a full ophthalmological examination including cycloplegic refraction and examination of pRNFL thickness using the Topcon 3D OCT 2000 device (Topcon Corporation, Tokyo, Japan). Values equal to or below the fifth percentile (≤p5) and above the 95th percentile (>p95) were considered abnormal. Observed agreement and specific agreement were investigated between OCT measurements classified with paediatric and adult reference values for normality. Results Values ≤ p5 in the adult database were recorded for 2 of the 30 values (6.6%) of the pRNFL values by quadrants ≤p5 in the paediatric database and 17 of the 88 (19.3%) values by sectors ≤p5. For values >p95 in the adult database, 88% by quadrants and 72% by sectors would have been classified as being within the normal range using the paediatric database. Conclusion The use of adult reference values currently available in OCT devices can lead to classification errors concerning the normal range of pRNFL thickness in a large proportion of paediatric patients. The use of normative paediatric databases, such as the one discussed in this study, should be taken into consideration.

Causal effect of COVID-19 on optic nerve and visual pathway disorders: genetic evidence of lung-brain axis.

To investigate the potential causal association between COVID-19 exposure and optic nerve and visual pathway disorders through a two-sample bidirectional Mendelian randomization (MR) analysis, and to provide empirical support for the lung-brain axis. This MR analysis utilized publicly accessible summary-level data from genome-wide association studies on COVID-19 (n=158,783) and optic nerve and visual pathway diseases (n=412,181), primarily involving individuals of European descent. The random-effect inverse-variance weighted estimation was applied as the main analytical approach, complemented by MR-Egger, weighted median, and weighted mode methods. The heterogeneity and pleiotropy of the instrumental variables were assessed using Cochran's Q test, leave-one-out sensitivity analysis, MR-Egger intercept test, MR-PRESSO, and funnel plot evaluations. In the forward analysis, the inverse-variance weighted method identified a significant causal effect of COVID-19 on optic nerve and visual pathway disorders (odds ratio = 1.697, 95% confidence interval: 1.086-2.652, p = 0.020). Directionally consistent results were also observed with MR-Egger regression, weighted median, and weighted mode approaches. Conversely, the reverse analysis revealed no causal effects of optic nerve and visual pathway disorders on COVID-19 susceptibility. Our findings suggest that COVID-19 exposure may increase the risk of developing optic nerve and visual pathway disorders, supporting the lung-brain axis hypothesis. These results underscore the importance of vigilant monitoring of the visual system in patients recovering from COVID-19 and suggest potential avenues for future therapeutic strategies.

Lamina Cribrosa Configurations in Highly Myopic and Non-Highly Myopic Eyes: The Beijing Eye Study.

The purpose of this study was to examine characteristics of lamina cribrosa (LC) configuration in highly myopic (HM) eyes. Participants from the Beijing Eye Study 2011, free of optic nerve or retinal diseases, were randomly selected to examine LC depth (LCD) and LC tilt (LCT) using three-dimensional optical coherent tomography images of the optic nerve head (ONH). LCD and LCT were measured as the distance and angle between the LC plane with two reference planes, including the Bruch's membrane opening (BMO) plane and the peripapillary sclera (PPS) plane, respectively. Each parameter was measured in both horizontal and vertical B-scans. The study included 685 individuals (685 eyes) aged 59.6 ± 7.7years, including 72 HM eyes and 613 non-HM eyes. LCD measurements showed no significant differences between HM eyes and non-HM eyes in both horizontal (LCD-BMO = 421.83 ± 107.86µm for HM eyes vs. 447.24 ± 104.94µm for non-HM eyes, P = 0.18; and LCD-PPS = 406.39 ± 127.69µm vs. 394.00 ± 101.64µm, P = 1.00) and vertical directions (LCD-BMO = 435.78 ± 101.29µm vs. 450.97 ± 106.54µm, P = 0.70; and LCD-PPS = 401.62 ± 109.9µm vs. 379.85 ± 110.35µm, P = 0.35). However, the LCT was significantly more negative (tilted) in HM eyes than in non-HM eyes horizontally (LCT-BMO = -4.38 ± 5.94degrees vs. -0.04 ± 5.86degrees, P < 0.001; and LCT-PPS = -3.16 ± 5.23 degrees vs. -0.94 ± 4.71 degrees, P = 0.003), but not vertically (P = 1.00). Although LCD did not differ significantly between HM and non-HM eyes, LCT was more negative in HM eyes, suggesting that the temporal or inferior side of the LC was closer to the reference plane. These findings provide insights into morphological and structural changes in the LC and ONH between HM and non-HM eyes.

Peripapillary RNFL cross-sectional area and its association with other parameters in a Chinese population

BackgroundQuantitative analysis of retinal nerve fibers is important for the diagnosis and treatment of optic nerve diseases. Peripapillary retinal nerve fiber layer (RNFL) cross-sectional area may give a more accurate quantitative assessment of retinal nerve fibers than RNFL thickness but there have been no previous reports of the peripapillary RNFL cross-sectional area or other parameters. The purpose of the current study was to determine peripapillary RNFL cross-sectional area and its association with other factors in an adult Chinese population.MethodsRNFL cross-sectional area was measured during peripapillary circular optical coherence tomography (OCT) scan with a diameter of 12° centered on the optic disc. Correlation between RNFL cross-sectional area and other parameters was evaluated by linear regression analysis in a cross-sectional study of an adult Chinese population.ResultsA total of 2404 eyes from 2404 subjects were examined. Multivariate linear regression analysis showed that larger RNFL cross-sectional area correlated with younger age (p < 0.001), female gender (p = 0.001), no history of diabetes (p = 0.012) and larger optic disc area (p < 0.001).ConclusionsPeripapillary RNFL cross-sectional area is correlated positively with optic disc area, suggesting that eyes with larger optic discs have thicker RNFL. Further studies are needed to confirm whether this correlation is due to differences in the numbers of retinal nerve fibers or other factors.

Hybrid deep learning and optimal graph search method for optical coherence tomography layer segmentation in diseases affecting the optic nerve.

Accurate segmentation of retinal layers in optical coherence tomography (OCT) images is critical for assessing diseases that affect the optic nerve, but existing automated algorithms often fail when pathology causes irregular layer topology, such as extreme thinning of the ganglion cell-inner plexiform layer (GCIPL). Deep LOGISMOS, a hybrid approach that combines the strengths of deep learning and 3D graph search to overcome their limitations, was developed to improve the accuracy, robustness and generalizability of retinal layer segmentation. The method was trained on 124 OCT volumes from both eyes of 31 non-arteritic anterior ischemic optic neuropathy (NAION) patients and tested on three cross-sectional datasets with available reference tracings: Test-NAION (40 volumes from both eyes of 20 NAION subjects), Test-G (29 volumes from 29 glaucoma subjects/eyes), and Test-JHU (35 volumes from 21 multiple sclerosis and 14 control subjects/eyes) and one longitudinal dataset without reference tracings: Test-G-L (155 volumes from 15 glaucoma patients/eyes). In the three test datasets with reference tracings (Test-NAION, Test-G, and Test-JHU), Deep LOGISMOS achieved very high Dice similarity coefficients (%) on GCIPL: 89.97±3.59, 90.63±2.56, and 94.06±1.76, respectively. In the same context, Deep LOGISMOS outperformed the Iowa reference algorithms by improving the Dice score by 17.5, 5.4, and 7.5, and also surpassed the deep learning framework nnU-Net with improvements of 4.4, 3.7, and 1.0. For the 15 severe glaucoma eyes with marked GCIPL thinning (Test-G-L), it demonstrated reliable regional GCIPL thickness measurement over five years. The proposed Deep LOGISMOS approach has potential to enhance precise quantification of retinal structures, aiding diagnosis and treatment management of optic nerve diseases.

To study visual evoked potential in patients with optic nerve diseases

Background: To study Visual Evoked Potential in patients with Optic Nerve diseases. Study design and settings: Cross – Sectional study. Material and Methods: 72 patients were included in our study, aged 12 years and above, diagnosed as optic nerve diseases like optic neuritis, Nonarteritc ischemic optic neuropathy (NAION), hereditary, nutritional and compressive optic neuropathy etc. Flash and Pattern VEPs were used. VEP amplitude and latency were noted. Results: Out of total 144 eyes, 107 eyes were affected. Ethambutol induced Toxic optic neuropathy was the most common etiology, followed by secondary optic neuropathy, idiopathic, traumatic optic neuropathy, optic neuritis, NAION, compressive and post CRAO (Central Retinal Artery Occlusion) optic neuropathy. Mean latency of all affected eyes was 132±22.5 msec. mean amplitude of the all affected eyes was 6.36±2.1 microvolt. Latency was moderately delayed (110-140 msec) in 45.8%, while severely delayed (&gt;140 msec) in 40.3% of total eyes. Amplitude was reduced in 36.5% of total eyes. Prolonged latency with normal amplitude was found in most of the eyes with optic neuritis while latency was also prolonged in fellow eyes of optic neuritis. In case of NAION prolonged latency and reduced amplitude was found in all eyes. Conclusion: Flash or pattern VEP can be used as an important tool for diagnosis of optic neuropathies or revealing of recurrence of disease and for follow up. VEP can also be used to detect subclinical damage in the fellow eyes of optic neuritis and also useful in differentiating the optic neuritis from ischemic optic neuropathy.

Trends in the Prevalence of Common Retinal and Optic Nerve Diseases in China: An Artificial Intelligence Based National Screening.

Retinal and optic nerve diseases have become the primary cause of irreversible vision loss and blindness. However, there is still a lack of thorough evaluation regarding their prevalence in China. This artificial intelligence-based national screening study applied a previously developed deep learning algorithm, named the Retinal Artificial Intelligence Diagnosis System (RAIDS). De-identified personal medical records from January 2019 to December 2021 were extracted from 65 examination centers in 19 provinces of China. Crude prevalence and age-sex-adjusted prevalence were calculated by mapping to the standard population in the seventh national census. In 2021, adjusted referral possible glaucoma (63.29, 95% confidence interval [CI] = 57.12-68.90 cases per 1000), epiretinal macular membrane (21.84, 95% CI = 15.64-29.22), age-related macular degeneration (13.93, 95% CI = 11.09-17.17), and diabetic retinopathy (11.33, 95% CI = 8.89-13.77) ranked the highest among 10 diseases. Female participants had significantly higher adjusted prevalence of pathologic myopia, yet a lower adjusted prevalence of diabetic retinopathy, referral possible glaucoma, and hypertensive retinopathy than male participants. From 2019 to 2021, the adjusted prevalence of retinal vein occlusion (0.99, 95% CI = 0.73-1.26 to 1.88, 95% CI = 1.42-2.44), macular hole (0.59, 95% CI = 0.41-0.82 to 1.12, 95% CI = 0.76-1.51), and hypertensive retinopathy (0.53, 95% CI = 0.40-0.67 to 0.77, 95% CI = 0.60-0.95) significantly increased. The prevalence of diabetic retinopathy in participants under 50 years old significant increased. Retinal and optic nerve diseases are an important public health concern in China. Further well-conceived epidemiological studies are required to validate the observed increased prevalence of diabetic retinopathy, hypertensive retinopathy, retinal vein occlusion, and macular hole nationwide. This artificial intelligence system can be a potential tool to monitor the prevalence of major retinal and optic nerve diseases over a wide geographic area.

Using a smartphone-based digital fundus camera for screening of retinal and optic nerve diseases in veterinary medicine: A preliminary investigation.

Ophthalmoscopy is a valuable tool in clinical practice. We report the use of a novel smartphone-based handheld device for visualisation and photo-documentation of the ocular fundus in veterinary medicine. Selected veterinary patients of a referralophthalmology service were included if one or both eyes had clear ocular media, allowing for examination of the fundus. Following pharmacological mydriasis, fundic images were obtained with a handheld fundus camera (Volk VistaView). For comparison, the fundus of a subset of animals was also imaged with a veterinary-specific fundus camera (Optomed Smartscope VET2). The large field of view achieved by the Volk VistaView allowed for rapid and thorough observation of the ocular fundus in animals, providing a tool to visualise and record common pathologies of the posterior segment. Captured fundic images were sometimes overexposed, with the tapetal fundus artificially appearing hyperreflective when using the Volk VistaView camera, a finding that was less frequent when activating a 'veterinary mode' that reduced the sensitivity of the camera's sensor. The Volk VistaView compared well with the Optomed Smartscope VET2. The main study limitation was the small sample size. The Volk VistaView camera was easy to use and provided good-quality fundic images in veterinary patients with healthy or diseased eyes, offering a wide field of view that was ideal for screening purposes.

Validation of retinal oximetry vessel selection using fluorescein angiography in patients with optic disc drusen

Retinal oximetry could provide insights into the pathophysiology of optic nerve disease, including optic disc drusen (ODD). Vessel selection for oximetry analysis is based on morphological characteristics of arterioles and venules and supported by an overlay of estimated blood oxygen saturations. The purpose of this cross-sectional study was to determine the validity of this vessel selection procedure by comparing it with vessel selection supported by video fluorescein angiography (FA).The study included 36 eyes of 36 patients with ODD who underwent retinal oximetry (Oxymap retinal oximeter T1) followed by FA (Heidelberg Spectralis). Two trained graders selected vessel segments in a pre-defined measurement area around the optic disc. One of these graders additionally performed the vessel segment selection with the support of FA images. When performed by the same grader, FA-supported and non-FA-supported vessel selection did not lead to significant differences in total vessel segment length, estimated oxygen saturations or vessel diameters (all p > 0.05). Inter-grader differences were found for arterial and venous segment lengths and arterial saturation (p < 0.05). A similar tendency was found for the arteriovenous saturation difference (p = 0.10). In conclusion, identifying vessel segments for retinal oximetry analysis based on vessel morphology and supported by a color-coded saturation overlay appears to be a valid method without the need for invasive angiography. A numerically small inter-grader variation may influence oximetry results. Further studies of retinal oximetry in ODD are warranted.

FOSTER-KENNEDY SYNDROME: WHAT FUNDUSCOPY WON'T MISS

Abstract&#x0D; Introduction : Optic nerve is the only visible extension of central nervous system and often represents several intracranial diseases. This case demonstrates the importance of funduscopy in detecting intracranial mass.&#x0D; Case Illustration : A 45-year-old woman suffered progressive blurry vision in both eyes for a year and severe headaches and seizures. The right eye (RE) had no light perception, and the left eye (LE) had 6/60 visual acuity. The relative afferent pupillary defect (RAPD) was positive on the RE. A funduscopic examination revealed a pallor optic disc on the RE and papilledema on the LE, consistent with type 1 Foster- Kennedy Syndrome (FKS). A Head CT scan showed a 5.3x6x5 cm mass in the right frontotemporal lobe. We referred the patient to the neurology and neurosurgery department for further management and surgical intervention.&#x0D; Discussion : FKS is a condition associated with tumors in the frontal lobe, characterized by ipsilateral optic disc atrophy due to direct compression, contralateral papilledema due to increased intracranial pressure, and ipsilateral anosmia in advanced stages. RAPD is a sluggish pupillary response to light stimuli due to unilateral retinal or optic nerve disease that occurs anterior to the lateral geniculate body. True FKS is extremely rare nowadays because of advances in neuroimaging to detect intracranial masses earlier.&#x0D; Conclusion : As a primary care physician, performing a direct funduscopy on patients complaining of decreased vision, headaches, and impaired mental status is essential. Although rare, FKS should be kept in mind while finding a patient with optic disc atrophy and papilledema.

ASSOCIATION BETWEEN ESTROGEN LEVELS WITH INTRAOCULAR PRESSURE IN PRIMARY OPEN ANGLE GLAUCOMA PATIENT

Introduction &amp; ObjectivesThere are studies that state that estrogen deficiency can exacerbate visual disturbances in glaucomapatients. To determine the relationship between estrogen levels and intraocular pressure (IOP) inpatients with POAG.&#x0D; MethodsThis study used a case-control design in 30 POAG patients who came to the OphthalmologyPolyclinic at the University of North Sumatra Hospital and Network Hospital. The data collectionmethod in this study used a consecutive sampling technique starting from February 2022 until thesample was filled. The inclusion criteria in this study were all women with POAG who were ?40years old and willing to be the research sample. The exclusion criteria for this study were patientswith a history of secondary glaucoma or a history of optic nerve disease, a history of ocular surgery(except cataracts), a history of orbital trauma, menstrual disorders, or currently on hormonaltherapy, a history of systemic or autoimmune disease. Data is then collected and analyzed.&#x0D; ResultsOf the 30 patients with POAG, the majority were aged 45-65 years (46.7%) with an average age of55.87(±12.91) years and had suffered from POAG for an average of 1.62(±2.08) years. The averagepatient had an intraocular pressure of 25.07(±6.12) mmHg, MD -12.99(±8.28) dB, VCDR0.78(±0.13) mm, and estrogen levels 2.47(±2.11) pg/dL. There was no significant relationshipbetween estrogen levels and intraocular pressure (p=0.851).&#x0D; ConclusionThere was no significant association between estrogen levels and intraocular pressure in patientswith POAG.

Correlation between color vision, visual acuity, contrast sensitivity and photostress recovery in the visually impaired: a cross-sectional study

Background: To investigate the correlation of colour vision, visual acuity, contrast sensitivity, and photostress recovery time test scores in visually impaired patients. Materials and methods: A total of 133 subjects were enroled and 133 eyes were examined. The pathological group consisted of 76 (57.1%) males with an average age of 68.0 (SD=13.2) and 57 (42.9%) females, with an average age of 68.1 (SD=15.2), Mann–Whitney U test was used to evaluate the differences in K-colour tests, HRR, visual acuity, Contrast Sensitivity test and photostress recovery time test between two different groups of severity. Results: Correlations were found among colour vision tests, visual acuity, contrast sensitivity, and photostress recovery time scores in eyes with age-related macular degeneration, with diabetic retinopathy, with optic nerve diseases, and various other retinal diseases (P&lt;0.05). In patients with moderate-visual impairments. Conclusions: The colour vision test scores correlate with the scores of visual acuity, contrast sensitivity, and photostess recovery time test. It may be a useful clinical surrogate for functional vision.