The diagnostic accuracy of photopic negative responses evoked by broadband and chromatic stimuli in a clinically heterogeneous population

PURPOSE

To compare the diagnostic accuracy of the photopic negative response (PhNR) elicited by red-blue (RB) and white-white (WW) stimuli, for detection of retinal ganglion cell (RGC) dysfunction in a heterogeneous clinical cohort.

METHODS

Adults referred for electrophysiological investigations were recruited consecutively for this single-centre, prospective, paired diagnostic accuracy study. PhNRs were recorded to red flashes (1.5 cd·s·m-2) on a blue background (10 cd·m-2) and to white flashes on a white background (the latter being the ISCEV standard LA 3 stimulus). PhNR results were compared with a reference test battery assessing RGC/optic nerve structure and function including optical coherence tomography (OCT) retinal nerve fibre layer thickness and mean RGC volume measurements, fundus photography, pattern electroretinography and visual evoked potentials. Primary outcome measures were differences in sensitivity and specificity of the two PhNR methods.

RESULTS

Two hundred and forty-three participants were initially enrolled, with 200 (median age 54; range 18-95; female 65%) meeting inclusion criteria. Sensitivity was 53% (95% confidence intervals [CI] 39% to 68%) and 62% (95% CI 48% to 76%), for WW and RB PhNRs, respectively. Specificity was 80% (95% CI 74% to 86%) and 78% (95% CI 72% to 85%), respectively. There was a statistically significant difference between sensitivities (p = 0.046) but not specificities (p = 0.08) of the two methods. Receiver operator characteristic (ROC) area under the curve (AUC) values were 0.73 for WW and 0.74 for RB PhNRs.

CONCLUSION

PhNRs to red flashes on a blue background may be more sensitive than white-on-white stimuli, but there is no significant difference between specificities. This study highlights the value and potential convenience of using white-on-white stimuli, already used widely for routine ERG assessment.

[Nonarteritic anterior ischemic optic neuropathy (nAION)]

Nonarteritic anterior ischemic optic neuropathy (nAION) is the second most common degenerative disease of the optic nerve. The pathogenesis remains elusive. A transient ischemia in the short posterior ciliary arteries not triggered by thromboembolic events is suspected. The typical history of a sudden onset of scotoma without associated pain in conjunction with (sectorial) optic disc swelling, an afferent pupillary defect and a visual field defect are of decisive diagnostic importance. The most urgent diagnostic measure is the exclusion of arteritic AION. There are no proven treatment approaches. Frequently used but without clear study results, is the treatment with steroids and secondary prophylaxis with acetylsalicylic acid (ASA). Recurrence in the ipsilateral or contralateral eye is possible.

[Glaucoma treatment by transscleral cyclophotocoagulation in micropulse technology in a low-income setting]

BACKGROUND

Glaucoma is the leading cause of irreversible blindness worldwide. The prevalence of glaucoma is particularly high in rural regions of Tanzania. Poverty and an inadequate ophthalmic infrastructure increase the difficulty of glaucoma treatment.

OBJECTIVE

Due to the limited access to eye drops or surgical therapy, the effectiveness of transscleral cyclophotocoagulation in micropulse technology (CPC-M) in advanced glaucoma was investigated in the present study.

MATERIALS AND METHODS

We included n = 50 eyes of 35 adult patients with advanced glaucoma and a glaucoma-typical papillary excavation with cupdisc ratio (CDR) ≥ 0.9, regardless of the glaucoma entity. The mean intraocular pressure (IOP) prior to treatment was 34 mm Hg (± 14 mm Hg). The operation was performed under retrobulbar anesthesia with the A.R.C. FOX 810 diode laser (A.R.C. Laser, Nuremberg, Germany; mean energy 127 J ± 10 J).

RESULTS

An IOP between 6 and 21 mm Hg or an IOP reduction by at least 20% of the initial value was defined as success. The success criteria were met by 71% of reevaluated eyes (n = 21) 3 months after treatment, and mean IOP was 19 mm Hg (± 13 mm Hg). Mean IOP 9 months postoperatively (n = 20) was 18 mm Hg (± 10 mm Hg) and the success criteria were met in 65% of cases. Seven eyes did not meet the success criteria: six eyes had a further increase in IOP and one eye showed intraocular hypotension.

CONCLUSION

The CPC‑M represents a good, inexpensive, and easily accessible treatment option for advanced glaucoma in order to reduce the likelihood of blindness in a low-income setting.

The changing landscape of optic neuritis: a narrative review

Optic neuritis (ON) is an inflammatory optic neuropathy that is often a harbinger of central nervous system (CNS) demyelinating disorders. ON is frequently misdiagnosed in the clinical arena, leading to either inappropriate management or diagnostic delays. As a result, patients may fail to achieve optimal recovery. The treatment response to corticosteroids and long term risk of multiple sclerosis was established in the first clinical trials conducted roughly 30 years ago. Spontaneous resolution was observed in the vast majority of patients and intravenous high-dose corticosteroids hastened recovery; half of the patients eventually developed multiple sclerosis. Over the ensuing decades, the number of inflammatory conditions associated with ON has significantly expanded exposing substantial variability in the prognosis, treatment, and management of ON patients. ON subtypes can frequently be distinguished by distinct clinical, serological, and radiological profiles allowing expedited and specialized treatment. Guided by an increased understanding of the immunopathology underlying optic nerve and associated CNS injuries, novel disease management strategies are emerging to minimize vision loss, improve long-term surveillance strategies, and minimize CNS injury and disability. Knowledge regarding the clinical signs and symptoms of different ON subtypes is essential to guide acute therapy, prognosticate recovery, accurately identify underlying CNS inflammatory disorders, and facilitate study design for the next generation of clinical and translational trials.

[Relative micro- and macrodiscs-a challenge in optical coherence tomography-based glaucoma diagnostics?]

Optical coherence tomography provides high-resolution imaging and measurement of glaucoma-relevant structures of the posterior pole. Minimal rim width, retinal nerve fiber layer, and ganglion cell layer thickness are parameters that enhance interpretation of micro- and macrodiscs in relation to a normative database. They are a valuable supplement to ophthalmoscopy and sensory testing in glaucoma diagnostics.

[Peripapillary and macular vessel density in eyes with different phases of thyroid-associated ophthalmopathy]

Objective: To analyze the characteristics of vessel density in the optic disc and macular area of patients with different phases of thyroid-associated ophthalmopathy (TAO) and their correlation with visual function. Methods: This case-control study was conducted at the Department of Ophthalmology of Peking Union Medical College Hospital between June 2019 and September 2019. TAO patients and healthy volunteers were included in the study. Patients with a clinical activity score greater than or equal to 3 points were categorized as active TAO. Dysthyroid optic neuropathy (DON) patients with a course less than 6 months were categorized as acute phase of DON, and those more than 6 months were in the chronic group. Healthy volunteers were in the control group. Each group included 12 subjects, with right eyes for analysis. There were 6 males and 6 females in each group. All participants underwent comprehensive ophthalmic examination including best corrected visual acuity and visual field examination for the mean defect (MD). Best corrected visual acuity was subsequently converted to logarithm of minimum angle of resolution (logMAR). Optical coherence tomography was used to measure the thickness of the retinal nerve fiber layer (RNFL) and retinal ganglion cell complex (GCC). Optical coherence tomography angiography was used to the peripapillary and macular vessel density. The differences in the vessel densities in the optic disc and macular area between groups and their correlation with different factors were analyzed. Analysis of variance, non-parametric Mann-Whitney U test and Spearman coefficient were conducted for statistical analysis. Results: There was no significant difference in age among the four groups (P>0.05). The logMAR of the acute DON group was 0.1 (0.0, 0.2), worse than the control group, which was 0.0 (0.0, 0.0) (U=114.000, P<0.05). The overall vessel densities of the optic disc in acute DON and chronic DON were significantly lower than the control group (54.70%±2.31% and 54.31%±3.65% vs. 57.54%±2.17%; t=3.104, 2.636; both P<0.05). The overall superficial vessel densities of the macular area in active TAO, acute DON and chronic DON were significantly lower than the control group (46.07%±3.06% and 42.26%±5.05% and 45.63%±3.87% vs. 49.34%±3.08%), and the differences were statistically significant (t=2.614, 4.147, 2.603; all P<0.05). There was no statistically significant difference in the size of the foveal avascular zone or the density of deep blood vessels in the macular area among the four groups (all P>0.05). In the active TAO period, there was no correlation between the MD value, RNFL thickness, GCC thickness and the vessel densities of the optic disc and macular area (all P>0.05). The vascular density of the whole layer of the optic disc in acute DON was negatively correlated with the MD value (r=-0.591, P<0.05) and positively correlated with the RNFL thickness and GCC thickness (r=0.595, 0.693; both P<0.05). In chronic DON, the overall capillary density of the optic disc was negatively correlated with the MD value (r=-0.673, P<0.05); the superficial overall blood vessel density of the macular area was positively correlated with the thickness of RNFL and GCC (r=0.732, 0.712;both P<0.01). Conclusions: In active TAO, only the blood supply to the superficial layer of the macular area is decreased. In the acute and chronic phases of DON, the blood supply to the superficial layer of the macular area and the optic disc is both reduced; the smaller the blood vessel density, the more severe the visual field defect, and the thinner the RNFL and GCC. (Chin J Ophthalmol, 2020, 56:824-831).

Radiation-Induced Optic Neuropathy: Literature Review

Radiation-induced optic neuropathy (RION) is a rare disease caused by exposure of the optic nerves to radiation during radiotherapy procedures for head and neck tumours. The purpose of this study was to review and summarise the epidemiology, risk factors, clinical presentations, pathphysiology characteristics, diagnosis, and management of RION. Its occurrence is associated with cumulative doses of radiation above 50 Gy, presence of multi-morbidities and the presence of concomitant chemotherapy and radiotherapy. It manifests with acute, painless, and monocular loss of vision, and these symptoms appear late after the radiation exposure. The diagnosis of the disease occurs by exclusion and, mainly, by the clinical analysis of the case associated with the time of radiation exposure. Treatment does not seem promising and there is not an effective cure. In this review, we mainly focus on compiling existing information on the topic and providing knowledge for early diagnosis and more efficient treatment.

Development and clinical deployment of a smartphone-based visual field deep learning system for glaucoma detection

By 2040, ~100 million people will have glaucoma. To date, there are a lack of high-efficiency glaucoma diagnostic tools based on visual fields (VFs). Herein, we develop and evaluate the performance of 'iGlaucoma', a smartphone application-based deep learning system (DLS) in detecting glaucomatous VF changes. A total of 1,614,808 data points of 10,784 VFs (5542 patients) from seven centers in China were included in this study, divided over two phases. In Phase I, 1,581,060 data points from 10,135 VFs of 5105 patients were included to train (8424 VFs), validate (598 VFs) and test (3 independent test sets-200, 406, 507 samples) the diagnostic performance of the DLS. In Phase II, using the same DLS, iGlaucoma cloud-based application further tested on 33,748 data points from 649 VFs of 437 patients from three glaucoma clinics. With reference to three experienced expert glaucomatologists, the diagnostic performance (area under curve [AUC], sensitivity and specificity) of the DLS and six ophthalmologists were evaluated in detecting glaucoma. In Phase I, the DLS outperformed all six ophthalmologists in the three test sets (AUC of 0.834-0.877, with a sensitivity of 0.831-0.922 and a specificity of 0.676-0.709). In Phase II, iGlaucoma had 0.99 accuracy in recognizing different patterns in pattern deviation probability plots region, with corresponding AUC, sensitivity and specificity of 0.966 (0.953-0.979), 0.954 (0.930-0.977), and 0.873 (0.838-0.908), respectively. The 'iGlaucoma' is a clinically effective glaucoma diagnostic tool to detect glaucoma from humphrey VFs, although the target population will need to be carefully identified with glaucoma expertise input.

Modeling a potential SANS countermeasure by experimental manipulation of the translaminar pressure difference in mice

The spaceflight-associated neuro-ocular syndrome (SANS), which may present after prolonged exposure to microgravity, is thought to occur due to elevated intracranial pressure (ICP). Intracranial pressure interacts with intraocular pressure (IOP) to define the translaminar pressure difference (TLPD; IOP-ICP). We combined inducible models of ICP and IOP elevation in mice to interrogate the relationships among ICP, IOP, and TLPD, and to determine if IOP elevation could mitigate the phenotypes typically caused by elevated ICP and thereby serve as a countermeasure for SANS. Ten C57BL6J mice of both genders underwent experimental elevation of ICP via infusion of artificial cerebrospinal fluid into the subarachnoid space. One eye also underwent experimental elevation of IOP using the bead injection model. Intraocular pressure and ICP were monitored for 2 weeks. Optokinetic-based contrast sensitivity was measured at baseline and after 2 weeks, and post-mortem studies of optic nerve and retina anatomy were performed. Photopic contrast sensitivity was reduced more in IOP elevated than control eyes. Scotopic contrast sensitivity was reduced similarly in IOP elevated and control eyes. However, the pattern of scotopic vision loss was not uniform in IOP elevated eyes; there was minimal loss in eyes that most closely approximated the normal TLPD. Optic nerve axon loss, increased optic nerve disorganization, and retinal ganglion cell loss all occurred similarly between IOP elevated and control eyes. Elevation of IOP in eyes with elevated ICP may counterbalance some effects on vision loss but exacerbate others, suggesting complex relationships among IOP, ICP, and TLPD.

Remote screening of retinal and optic disc diseases using handheld nonmydriatic cameras in programmed routine occupational health checkups onsite at work centers

Purpose

To evaluate the first year outcomes of a remote screening program for detection of retinal diseases using handheld nonmydriatic cameras in occupational routine checkups performed onsite at work centers.

Methods

Cross-sectional, first year screening program outcomes audit. Participants were volunteers recruited from staff within work centers. Retinal fundus images were captured by technicians, and images and data were anonymized and sent securely to a remote server. A team of ophthalmologists, all retinal specialists, remotely read the images using a custom-made software and sent telematic reports of findings within 24–48 h. The main items evaluated were the detection of retinal abnormalities and the relationship between retinal findings and demographic data such as age and sex.

Results

A total of 19,881 workers were evaluated in 52 centers. Mean age was 41.1 years old, 43.9% men and 56.1% women. Mean duration of the test was around 2 min. Of the workers, 7.8% presented abnormalities in retinal fundus images, being the main findings choroidal nevus (2.4%), macular pigment abnormalities (1.5%), glaucomatous optic disc (1.2%), and macular signs of high myopia (1.1%). The presence of abnormalities was associated with greater age, being 5%, 7.9%, 12.6%, and 19.7% in workers less than 40 years, from 40 to 49, 50–59, and ≥ 60 years (p < 0.05), respectively. Men had more abnormalities in retinal fundus images than women (8.6 vs. 7.2; p < 0.05 RR: 1.2; CI 1092–1322).

Conclusions

Mass screening of retinal and optic disc abnormalities during occupational health routine checkups is a feasible, quick, and efficient tool for early detection of potential vision-threatening disease markers.

Using Enhanced Depth Imaging Optical Coherence Tomography-Derived Parameters to Discriminate between Eyes with and without Glaucoma: A Cross-Sectional Comparative Study

INTRODUCTION

New technologies have been developed in order to decrease interpersonal influence and subjectivity during the glaucoma diagnosis process. Enhanced depth imaging spectral-domain OCT (EDI OCT) has turned up as a favorable tool for deep optic nerve head (ONH) structures assessment.

OBJECTIVE

A prospective cross-sectional study was conducted to compare the diagnostic performance of different EDI OCT-derived parameters to discriminate between eyes with and without glaucoma.

MATERIAL AND METHODS

The following ONH parameters were measured: lamina cribrosa (LC) thickness and area; prelaminar neural tissue (PLNT) thickness and area; average Bruch's membrane opening - minimum rim width (BMO-MRW), superior BMO-MRW, and inferior BMO-MRW. Peripapillary retinal nerve fiber layer (pRNFL) thickness was also obtained.

RESULTS

Seventy-three participants were included. There were no significant differences between AUCs for average BMO-MRW (0.995), PLNT area (0.968), and average pRNFL thickness (0.975; p ≥ 0.089). However, AUCs for each of these 3 parameters were significantly larger than LC area AUC (0.701; p ≤ 0.001). Sensitivities at 80% specificity were: PLNT area = 92.3%, average BMO-MRW = 97.4%, and average pRNFL thickness = 94.9%.

CONCLUSIONS

Comparing the diagnostic performance of different EDI OCT ONH parameters to discriminate between eyes with and without glaucoma, we found better results for neural tissue-based indexes (BMO-MRW and PLNT area) compared to laminar parameters. In this specific population, these neural tissue-based parameters (including PLNT area, which was investigated by the first time in the present study) had a diagnostic performance comparable to that of the conventional pRNFL thickness protocol.

[Lamina cribrosa defect and progress of glaucoma]

Lamina cribrosa (LC) is considered as the original site of glaucomatous damage of axons of retinal ganglion cells, and therefore understanding the morphological changes in the LC will help to uncover the pathogenesis of glaucoma. Previous studies have indicated that the progress of glaucomatous optic neuropathy may be associated with the LC defects. Based on imaging by swept source optical coherence tomography B-Scan of the optic discs of patients with glaucoma, for the first time the spontaneous local LC defects have been found to balance the gradient between intraocular and cerebrospinal fluid pressures, which in turn can slow down the progress of glaucomatous optic neuropathy. This article provides the direct evidence supporting the role of intraocular and cerebrospinal fluid pressure gradient in the pathogenesis of glaucoma. This finding will increase our understanding of the mechanisms underlying glaucoma and help to develop novel strategies for its treatment and prognosis analysis. (Chin J Ophthalmol, 2020, 56: 17-20).

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters

A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH.

Optic Nerve Atrophy in N-methyl-D-aspartate (NMDA) Encephalitis

N-methyl-D-aspartate receptor (NMDA) encephalitis is a recently described autoimmune disease that typically presents with prodromal symptoms including upper respiratory tract infection, headache, fever, nausea, vomiting and diarrhea. Psychiatric symptoms follow within weeks, including anxiety, insomnia, mania, paranoia and grandiose delusions. The diagnosis is confirmed by the detection of NMDA antibodies in the serum or cerebrospinal fluid (CSF).1 Tumours, especially teratomas, are frequently associated with NMDA encephalitis; however, only 5% of male patients older than 18 years have been found to have an underlying tumour. Optic neuropathy associated with NMDA encephalitis is being increasingly recognised in the literature2-6 and was reviewed most recently by Mugavin et al.2 in 2017. In this report, we present a case of bilateral optic neuropathy in a young man diagnosed with NMDA receptor encephalitis.

[Orbital complications]

A disease or symptom of disease spreading from the vicinity of the orbit to the internal structures of the orbit is referred to as an orbital complication. Orbital complications can have a traumatic, inflammatory, allergic, or autoimmunologic cause. They are more frequent in children than adults. The present review aims to provide a description of orbital complications, their etiology, pathogenesis, and treatment. Recent literature in the field is acknowledged and discussed, and results from the authors' own patient groups are analyzed. Particular attention is paid to orbital complications due to acute sinusitis and those caused by acute hemorrhage. The term "orbital phlegmon" frequently used for orbital complications with inflammatory causes is confusing and should be replaced by differentiated grading. Diagnosis and treatment of orbital complications requires interdisciplinary collaboration, whereby inclusion of ophthalmologists is particularly important. Treatment of orbital complications depends on their cause. In inflammatory cases affecting only the preseptal tissues and compartment, conservative therapy is indicated. If clinical findings worsen within 24 h of conservative therapy, or if the patient presents with a high-grade orbital complication with loss of visual acuity or impairment of globe mobility, surgery is required. In cases of acute hemorrhage into the orbit, a procedure for decreasing intra-orbital pressure is mandatory (i. e., canthotomy, cantholysis, orbital decompression).

[The importance of combined application of visual electrophysiology examination and OCT in optic neuropathy]

This article briefly analyzes the advantages and limitations of visual electrophysiology and OCT, and explains the complementarity of visual electrophysiology and OCT and the advantages of combined application in typical optic neuropathy, so as to provide guidance on how to combine the functional and morphological inspections in the clinical diagnosis and treatment of optic neuropathy. (Chin J Ophthalmol, 2019, 55: 161-163).

Structure-function relationships in glaucoma using enhanced depth imaging optical coherence tomography-derived parameters: a cross-sectional observational study

Background

To investigate structural and functional correlations in glaucoma patients using enhanced depth imaging spectral-domain optical coherence tomography (EDI OCT)-derived parameters.

Methods

We prospectively enrolled healthy participants and glaucomatous patients with a wide range of disease stages. All participants underwent visual field (VF) testing (SITA - Standard 24–2; Carl Zeiss Meditec, Dublin, CA) and EDI OCT imaging (Spectralis; Heidelberg Engineering Co., Heidelberg, Germany). The following optic nerve head parameters were measured on serial vertical EDI OCT B-scans by two experienced examiners masked to patients clinical data: lamina cribrosa (LC) thickness and area, prelaminar neural tissue thickness and area, anterior LC depth, Bruch’s membrane opening (BMO) and average, superior, and inferior BMO-minimum rim width (BMO-MRW). Only good quality images were considered, and whenever both eyes were eligible, one was randomly selected for analysis. Scatter plots were constructed to investigate correlations between each anatomic parameter and patient’s VF status (based on VF index [VFI] values).

Results

A total of 73 eyes of 73 patients were included. All EDI OCT parameters evaluated differed significantly between glaucomatous and control eyes (P ≤ 0.045). A secondary analysis, in which glaucomatous patients were divided according to VF mean deviation index values into 3 groups (mild [G1; > − 6 dB], moderate [G2; − 6 to − 12 dB] and advanced [G3; <− 12 dB] glaucoma), revealed that average BMO-MRW was the EDI OCT parameter that presented more significant differences between the different stages of glaucoma. Significant structure-function correlations were found between VFI values and prelaminar neural tissue area (R² = 0.20, P = 0.017), average BMO-MRW (R² = 0.35, P ≤ 0.001), superior BMO-MRW (R² = 0.21, P = 0.012), and inferior BMO-MRW (R² = 0.27, P = 0.002). No significant correlations were found for LC area and anterior LC depth (P ≥ 0.452).

Conclusions

Evaluating the distribution pattern and structure-function correlations of different laminar and prelaminar EDI OCT-derived parameters in glaucomatous patients, we found better results for neural tissue-based indexes (compared to LC-derived parameters). The diagnostic utility of each parameter deserves further investigations.

Electronic supplementary material

The online version of this article (10.1186/s12886-019-1054-9) contains supplementary material, which is available to authorized users.

Effective Delivery of Exogenous Compounds to the Optic Nerve by Intravitreal Injection of Liposome

Purpose

To improve the treatment efficiency of optic nerve diseases by delivering therapeutic materials to the optic nerve directly.

Methods

We tried to optimize liposomal composition to deliver a payload to the optic nerve efficiently when it is injected intravitreally. After loading dexamethasone into this liposome, we tested the therapeutic effect of liposomes in this treatment using a murine model of ischemic optic neuropathy.

Results

Our optimized liposome can deliver its payload to the optic nerve more efficiently than other tested compositions. Moreover, dexamethasone-loaded liposomes had a significant therapeutic effect in a murine model of ischemic optic neuropathy.

Conclusions

Here, we demonstrate the optimal composition of liposomes that could efficiently deliver intravitreally injected exogenous compounds to the optic nerve. We expect that the intravitreal injection of liposomes with the suggested composition would improve the delivery efficacy of therapeutic compounds to the optic nerve.

[Focus on the controversial problems of orbital decompression in the treatment of dysthyroid optic neuropathy]

Dysthyroid optic neuropathy (DON) is the most common cause of visual loss in thyroid associated ophthalmopathy, for which steroid pulse therapy and orbital decompression are the common treatments currently. While steroid pulse therapy was recommended as the first-choice for DON, orbital decompression remained as an indispensable therapy although controversies on such treatment still exist. The mechanism, approaches and outcomes of orbital decompression, as well as its advantages and disadvantages over steroid pulse therapy were retrospectively reviewed, and it was suggested that the combination therapy of steroid pulse therapy and surgical decompression might be the better choice for the treatment of DON. (Chin J Ophthalmol, 2018, 54: 488-490).

Factors Affecting ISNT Rule Satisfaction in Normal and Glaucomatous Eyes

Purpose

To determine the factors that influence the satisfaction of the ‘ISNT rule’ (neural rim width: inferior ≥ superior ≥ nasal ≥ temporal) in normal and glaucomatous eyes.

Methods

The medical records of patients that visited Boramae Medical Center, Seoul, Korea, were reviewed. Each group of normal and glaucomatous eyes was divided into subgroups based on whether or not they satisfied the ISNT rule. ISNT rule assessment was performed by measuring the rim width with stereoscopic optic disc photographs using ImageJ software. Logistic regression analysis was performed to determine the factors that affect ISNT rule satisfaction.

Results

Seventy-seven normal eyes and 97 glaucomatous eyes were included in the study. The ISNT rule was intact in 59 (76.6%) of the normal eyes and was violated in 71 (73.2%) of the glaucomatous eyes. Logistic regression analysis revealed a significant influence of axial length in violation of the ISNT rule in the normal eye group, while the mean deviation value was a significant factor for violation of the ISNT rule in the glaucomatous eye group.

Conclusions

The ISNT rule should be cautiously applied when evaluating normal eyes with long axial lengths. In addition, the ISNT rule might not be as effective for detecting early glaucoma.

[Development of en face optical coherence tomography and its application in ocular fundus diseases]

Optical coherence tomography (OCT) is able to obtain the cross-sectional image of the fundus noninvasively and quickly. The cross-sectional image in vivo almost matches the histological section of the retina. OCT has become the most important imaging tool in ophthalmology. Based on the latest OCT technology, en face OCT is a new imaging technique that reveals the structure of retinal and choroidal sections approximately paralleled to the retina surface. Compared to the conventional OCT, en face OCT provides more comprehensive information and makes more accurate diagnosis and assessment of the prognosis. En face OCT is widely used in ocular fundus diseases, such as macular epiretinal membrane, macular hole, macular edema, age-related macular degeneration and retinal vascular disease, glaucoma and neuro-ophthalmology. This article reviews the related concepts, principles and clinical applications of en face OCT. (Chin J Ophthalmol, 2017, 53: 956-960).

[Clinical features of traumatic optic neuropathy in 265 cases]

Objective: To analyze the clinical features and the pathogenetic law of traumatic optic neuropathy through epidemiologic study. Methods: 265 cases (275 eyes) with TON treated in Department of Otorhinolaryngology Head and Neck Surgery, the Affiliated Hospital of Qingdao University from April 1999 to August 2015 were retrospectively analyzed. Multiple Logistic regression analyses were used to evaluate potential prognostic factors on visual acuity. Results: TON occured mostly in young (194/265, 73.21%) man (235/265, 88.68%), the majority of patients came from villages and towns (209/265, 78.87%). Traffic accident (197/265, 74.34%) remained the main etiology, with strike (36/265, 13.58%) and fall (17/265, 6.42%) as the common etiology. Most patients had head injuries. The effective rate of vision improvement was 53.45%(147/275). Multiple logistic regression analyses identified that initial visual acuity with light perception or better vision, optic canal fracture and orbital wall fracture were visual acuity key factors of TON (χ(2) value was 24.674, 19.755, 9.175, respectively, all P<0.01), initial visual acuity with light perception or better vision was the protective factor on visual acuity recovery (OR=5.008, P<0.001), the presence of optic canal fracture and orbital wall fracture were the risk factors on visual acuity recovery (OR value was 0.110, 0.329, respectively, all P<0.01). Conclusions: Ton occurs mostly in young man because of traffic accident. Visual impairment of TON is severe. The suitable preventive measures should be carried out according to its epidemiological features.

[Therapeutic outcomes and influence factors of maximal orbital decompression in the treatment of severe dysthyroid optic neuropathy]

Objective: To evaluate the effectiveness of maximal orbital decompression in treatment for severe dysthyroid optic neuropathy (DON) of thyroid associated ophthalmopathy (TAO) and predictive factors of this therapy. Methods: The group consisted of 21 patients (30 eyes) with DON. The diagnosis was based on the following criteria: Deterioration of best corrected visual acuity (VA≤0.1), enlargement of extraocular muscles and sign of apical crowding in CT imaging, loss of colour vision.

EXCLUSION CRITERIA

VA of DON>0.1 or other diseases with visual function damage. Maximal 3-wall orbital decompression was undergone. Clinical outcomes were recorded and assessed including pre- and postoperative VA, age, clinical activity score (CAS), thyroid hormonal status and duration of DON. The pre- and postoperative VA were compared by Wlicoxon signed rank analysis. The relationships between the change of VA and age(<50 years vs ≥50 years), thyroid hormonal status(hyperthyroidism vs hypothyroidism), CAS(<3 vs ≥3), duration (<3 months vs ≥3 months), pre-VA(<0.01 vs ≥0.01) were made statistically by Mann-Whitney U-test, rank correlation analysis,and Logistic regression analysis. Results: Thirty eyes of 21 patients (11 male, 10 female) were included in this study. Hyperthyroidism was recorded in 13 cases, the other 8 cases with hypothyroidism. The average age at the time of diagnosis was 52.9 years (range, 33.0-71.0 years). The median of the duration of DON was 4.5 months (range, 1.0-12.0 months). Twenty-eight eyes (28/30, 93%) showed improvement of visual acuity after surgery (Z=-4.62, P=0.000). There was positive correlation between pre- and postoperative VA(r=0.38, P<0.05 ). Patients with VA of 0.01 or better had better postoperative VA than those with poorer VA (0.10 vs 0.50, Z=-2.09, P=0.037). There was negative correlation between the duration and degree of improvement of postoperative VA (r=-0.44, P<0.05). Other factors such as age, thyroid hormonal status, CAS were not statistical factors for postoperative VA (Z=-1.83--0.97, P>0.05 ) and improvement of postoperative VA (Z=-1.80--0.82, P>0.05). Conclusions: Maximal orbital decompression is safe and effective for management of visual damage in severe DON in this small sample study. Preoperative VA and duration of DON were important predictive factors for surgical outcome. Earlier diagnosis and treatment are possibly useful for improvement of prognosis of DON but large sample data are needed.(Chin J Ophthalmol, 2017, 53:416-423).

[The advances in research on precisely inducing retinal ganglion cells from stem cells]

The injury and repair of retinal neurons is a common scientific problem in the occurrence, development and prognosis of neuronal visual impairment. Transplant of retinal ganglion cells (RGCs) differentiated from stem cells opens a new avenue for treatment of glaucoma and optic neuronal degenerative diseases. For the goal to explore the optimal method for RGCs replacement, this review summarizes the current information regarding the classification and application of stem cells, the growth characteristics of RGCs and the precise methods to induce RGCs, and discusses some important issues that need resolving and are related to RGCs transplantation. It is hoped that this article will provide useful theoretical basis for the research of this field. (Chin J Ophthalmol, 2017, 53: 381-385).

Mesenchymal stem cell therapy in retinal and optic nerve diseases: An update of clinical trials

Retinal and optic nerve diseases are degenerative ocular pathologies which lead to irreversible visual loss. Since the advanced therapies availability, cell-based therapies offer a new all-encompassing approach. Advances in the knowledge of neuroprotection, immunomodulation and regenerative properties of mesenchymal stem cells (MSCs) have been obtained by several preclinical studies of various neurodegenerative diseases. It has provided the opportunity to perform the translation of this knowledge to prospective treatment approaches for clinical practice. Since 2008, several first steps projecting new treatment approaches, have been taken regarding the use of cell therapy in patients with neurodegenerative pathologies of optic nerve and retina. Most of the clinical trials using MSCs are in I/II phase, recruiting patients or ongoing, and they have as main objective the safety assessment of MSCs using various routes of administration. However, it is important to recognize that, there is still a long way to go to reach clinical trials phase III-IV. Hence, it is necessary to continue preclinical and clinical studies to improve this new therapeutic tool. This paper reviews the latest progress of MSCs in human clinical trials for retinal and optic nerve diseases.

The prevalence and causes of visual impairment in young Turkish men

Objective:

To explore the causes and prevalence of visual impairment in young Turkish men.

Methods:

The health examination data of the candidates that are saved in National Defense Ministry of Turkey was used. The data of the candidates examined between 1 January 2009 and 31 December 2011 were evaluated. The total number of the candidates was 1777500. The candidates requiring advanced examination are referred to secondary and tertiary examination hospitals.

Results:

Fourteen thousand eight hundred sixty two(14862) out of 1777500 candidates were declared unfit for compulsory military service because of ophthalmic causes. The prevalence of ophthalmologic diseases causing unfitness for military service was found 0.746% for 2009, 0.871% for 2010 and 0.889% for 2011. These included high refractive errors which was the most frequent pathology causing unfitness (40.1%). Nonsurgical retina, vitreous and optic nerve diseases were the most frequent cause of visual impairment (0.212%). Corneal and lens pathologies were the second most frequent cause of blindness (0.101%).

Conclusions:

The data bank in National Defense Ministry analyzed in this study is not directly intended to explore the causes and prevalence of visual impairment in Turkey. However this study gives considerable knowledge about the causes and prevalence of visual impairment in Turkey.

Obstructive sleep apnea and nonarteritic anterior ischemic optic neuropathy: evidence for an association

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most prevalent optic nerve disorder among patients over 50 years of age, characterized by sudden onset, painless visual loss, with an accompanying relative afferent pupillary defect and optic disc edema. Although the pathophysiology of NAION has not been fully elucidated, several risk factors have been considered, including advanced age, systemic hypertension, diabetes mellitus, and certain optic disc morphologies. An association between obstructive sleep apnea (OSA) and NAION has also been recognized. One prospective cohort study indicated that the relative risk of OSA among patients with NAION was 4.9; a later retrospective cohort study demonstrated that patients with OSA not treated with continuous positive airway pressure (CPAP) had a 16% increased hazard of developing NAION compared to patients without OSA.The following review will discuss the most recent understanding of the relationship between OSA and NAION, with implications for further research and prevention strategies.

A ketogenic diet may offer neuroprotection in glaucoma and mitochondrial diseases of the optic nerve

Glaucoma is a chronic optic nerve disease in which the primary damage occurs to the retinal ganglion cell axons. Therapies that prevent the death of retinal ganglion cells should be theoretically beneficial. Despite promising preclinical studies, however, almost all clinical studies with pharmacological approaches for neuroprotection in neurologic and eye diseases, including glaucoma, have so far failed to show efficacy. As the evidence supporting the neuroprotective efficacy of a ketogenic diet (KD) in a number of neurodegenerative diseases continues to grow, it is conceivable that this metabolic approach might be useful in chronic glaucoma. Putative cellular mechanisms underlying the neuroprotective activity of the KD have been identified in neurological studies, including effects on energy metabolism, the GABA system, glutamate-mediated toxicity, antioxidant mechanisms, programmed cell death, anti-inflammatory mechanisms, and the production of kynurenic acid. Of note, the same mechanisms are thought to be involved in glaucoma. Given these mechanistic similarities, testing the KD for its efficacy in neurodegenerative diseases of the eye is proposed.

Risk factors associated with the severity of thyroid-associated orbitopathy in Korean patients

Purpose

The purpose of this study is to identify risk factors for severe thyroid-associated orbitopathy (TAO) and compressive optic neuropathy in Korean patients.

Methods

This study was a retrospective comparative case series. All TAO patients who were first seen at our institution between 2005 and 2009 and who had follow-up periods of at least 6 months were included. Patients were divided into mild or moderate and severe TAO groups. Cases were also segregated based on the presence or absence of optic neuropathy. Demographics, smoking status, comorbidities, thyroid hormonal status, thyroid autoantibody levels, and clinical presentations were assessed.

Results

A total of 99 patients (83 with mild to moderate courses and 16 with severe courses; 90 without optic neuropathy and 9 with optic neuropathy) were included in this study. On multiple logistic regression analysis, smoking status was a predictive risk factor for a severe course of TAO and the development of optic neuropathy (odds ratios = 6.57 and 10.00, respectively). Other factors such as age, gender, free T4 level, thyroid binding-inhibiting immunoglobulin, and a history of diabetes were not predictive of severe TAO or optic neuropathy.

Conclusions

Although various factors may influence the severity of TAO and the development of optic neuropathy, this study showed that smoking was a risk factor for severe TAO and the development of optic neuropathy. Therefore, it is important for patients with Graves' disease to refrain from smoking. Frequent and careful observation should also be performed in current smokers, as TAO patients who smoke are susceptible to a severe course and/or optic neuropathy.

Optic neuropathy associated with Castleman disease

A 44-year-old woman with Castleman disease presented with acute visual loss in the left eye. A full ophthalmologic examination and imaging were performed. Visual acuity was 20/20 in the right eye and 20/100 in the left eye. Total dyschromatopsia, a relative afferent pupillary defect, and a cecocentral scotoma were observed in the left eye. Mild disc edema, without leaking during fluorescein angiography, was also observed. Magnetic resonance imaging revealed a small cystic epidermoid-like lesion in the right prepontine and suprasellar cistern. Her visual acuity did not improve and deteriorated to 20/200 in the left eye at 22 months after the initial visual loss. Optic neuropathy may rarely be associated with Castleman disease and suggests a poor prognosis.

Traumatic optic neuropathy accompanying orbital grease gun injury

We report a case of traumatic optic neuropathy accompanying a grease gun injury to the orbit. A 48-year-old man with a grease gun injury visited our clinic with decreased visual acuity, proptosis and limited extraocular movement (EOM). Orbital CT revealed a crescent mass of fat in the medial intraconal space. The grease was exuded from a lacerated conjunctival wound. The visual evoked potential (VEP) test demonstrated a decreased response in the left eye. Proptosis and EOM were improved after surgical removal of the grease. Systemic high-dose corticosteroid therapy was administered for suspected traumatic optic neuropathy, after which VEP nearly recovered, while visual acuity was slightly improved. A second surgery for traumatic cataract did not further improve visual acuity.