Review Article

The role of optical coherence tomography in neuro-ophthalmology

The role of optical coherence tomography in neuro-ophthalmology

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Abstract: Optical coherence tomography (OCT) is an ocular imaging technique that can complement the neuro-ophthalmic assessment, and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway. Indeed, OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system (CNS), including optic neuritis (ON) associated with: multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. Recent advancements in enhanced depth imaging (EDI) OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen (ODD). Moreover, OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD. In the setting of idiopathic intracranial hypertension (IIH), OCT has shown benefit in tracking responses to treatment, with respect to reduced retinal nerve fiber layer (RNFL) measures and morphological changes in the angling of Bruch’s membrane. Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy. Causes of compressive optic neuropathies may be readily diagnosed with OCT, even in the absence of overt visual field defects. Furthermore, OCT values may offer some prognostic value in predicting post-operative outcomes in these patients. Finally, OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss, and an unrevealing fundus examination. In this review, our over-arching goal is to highlight the potential role of OCT, as an ancillary investigation, in the diagnosis and management of various optic nerve disorders.

Abstract: Optical coherence tomography (OCT) is an ocular imaging technique that can complement the neuro-ophthalmic assessment, and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway. Indeed, OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system (CNS), including optic neuritis (ON) associated with: multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. Recent advancements in enhanced depth imaging (EDI) OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen (ODD). Moreover, OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD. In the setting of idiopathic intracranial hypertension (IIH), OCT has shown benefit in tracking responses to treatment, with respect to reduced retinal nerve fiber layer (RNFL) measures and morphological changes in the angling of Bruch’s membrane. Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy. Causes of compressive optic neuropathies may be readily diagnosed with OCT, even in the absence of overt visual field defects. Furthermore, OCT values may offer some prognostic value in predicting post-operative outcomes in these patients. Finally, OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss, and an unrevealing fundus examination. In this review, our over-arching goal is to highlight the potential role of OCT, as an ancillary investigation, in the diagnosis and management of various optic nerve disorders.

Original Article

Using a rigid lens as endocapsular supporting device in cataract surgery for moderate subluxated cataracts

Using a rigid lens as endocapsular supporting device in cataract surgery for moderate subluxated cataracts

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Background: To present a surgical technique using a rigid intraocular lens as endocapsular supporting device in manual small incision cataract surgery (MSICS) for treating mild-moderate subluxated cataracts.

Methods: In our technique, a single-piece rigid polymethyl methacrylate (PMMA) lens was implanted in the bag following the nucleus removal, with its axis vertical to the zonular dialysis. This endocapsular-implanted IOL stretched the bag and provided sufficient stability and lens centration. This technique was performed in 19 eyes with subluxated cataracts, with zonulysis of ≤120 degree and nuclear sclerosis of grade ≤3. Mean follow-up time was 9.8 months.

Results: All eyes had endocapsular IOL implantation during surgery. Intraoperative extension of the dialysis did not occur in any eye. The IOL was placed in the bag in all but 1 case, in which dislocation of the IOL haptic into the vitreous occurred. Though the IOL was slightly decentered in 3 cases, it kept stable. All patients were asymptomatic.

Conclusions: This approach provides a simplified and practical strategy for surgically managing subluxation with mild-moderate zonular loss.

Background: To present a surgical technique using a rigid intraocular lens as endocapsular supporting device in manual small incision cataract surgery (MSICS) for treating mild-moderate subluxated cataracts.

Methods: In our technique, a single-piece rigid polymethyl methacrylate (PMMA) lens was implanted in the bag following the nucleus removal, with its axis vertical to the zonular dialysis. This endocapsular-implanted IOL stretched the bag and provided sufficient stability and lens centration. This technique was performed in 19 eyes with subluxated cataracts, with zonulysis of ≤120 degree and nuclear sclerosis of grade ≤3. Mean follow-up time was 9.8 months.

Results: All eyes had endocapsular IOL implantation during surgery. Intraoperative extension of the dialysis did not occur in any eye. The IOL was placed in the bag in all but 1 case, in which dislocation of the IOL haptic into the vitreous occurred. Though the IOL was slightly decentered in 3 cases, it kept stable. All patients were asymptomatic.

Conclusions: This approach provides a simplified and practical strategy for surgically managing subluxation with mild-moderate zonular loss.

Review Article

Design and recent results of large-scale cohort epidemiology studies on refractive error in children in Shanghai

Design and recent results of large-scale cohort epidemiology studies on refractive error in children in Shanghai

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Abstract: Between 2011 and 2013, two large-scale cohort epidemiology studies were launched in Shanghai: the SCALE study, which aimed to provide ocular public health services to cover the entire youth population in Shanghai, and the SCES, which was based on sample surveys and aimed to provide information on the prevalence and incidence of visual impairment and different types of refractive errors. A total of 910,245 children and adolescents were finally enrolled in the SCALE study; three possible methods for monitoring refractive error without mydriasis were tested, and the agreement between the refractive outcomes of three commonly used autorefractors were examined to ensure the accuracy of the results of the SCALE study. A total of 8,627 children were enrolled in the SCES, and the baseline prevalence of different refractive errors, different behaviors associated with 1 year myopic shifts, and the different patterns of 2-year myopia progression between internal migrant and local resident school children have been analyzed. In some subset samples of the SCALE study and the SCES, several refraction components such as choroidal thickness (ChT) and crystalline lens power were also measured, to further elucidate the relationships between the refraction components and myopia as well as the mechanism of myopia incidence and development. The three methods used in Shanghai to prevent and intervene with childhood myopia: increasing outdoor time, low concentration atropine, and use of orthokeratology lens are also addressed in this review.

Abstract: Between 2011 and 2013, two large-scale cohort epidemiology studies were launched in Shanghai: the SCALE study, which aimed to provide ocular public health services to cover the entire youth population in Shanghai, and the SCES, which was based on sample surveys and aimed to provide information on the prevalence and incidence of visual impairment and different types of refractive errors. A total of 910,245 children and adolescents were finally enrolled in the SCALE study; three possible methods for monitoring refractive error without mydriasis were tested, and the agreement between the refractive outcomes of three commonly used autorefractors were examined to ensure the accuracy of the results of the SCALE study. A total of 8,627 children were enrolled in the SCES, and the baseline prevalence of different refractive errors, different behaviors associated with 1 year myopic shifts, and the different patterns of 2-year myopia progression between internal migrant and local resident school children have been analyzed. In some subset samples of the SCALE study and the SCES, several refraction components such as choroidal thickness (ChT) and crystalline lens power were also measured, to further elucidate the relationships between the refraction components and myopia as well as the mechanism of myopia incidence and development. The three methods used in Shanghai to prevent and intervene with childhood myopia: increasing outdoor time, low concentration atropine, and use of orthokeratology lens are also addressed in this review.

Original Article
Review Article

Myasthenia gravis

Myasthenia gravis

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Abstract: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder which causes fluctuating weakness in ocular, bulbar and limb skeletal muscles. There are two major clinical types of MG. Ocular MG (OMG) affects extra ocular muscles associated with eye movement and eyelid function and generalized MG results in muscle weakness throughout the body. Patients with OMG have painless fluctuating extra ocular muscles weakness, diplopia and ptosis accompanied by normal visual acuity and pupillary function. Frequently, patients with OMG develop generalized MG over 24 months. Pure OMG is more often earlier in onset (<45 years) than generalized MG. It can also occur as part of an immune-genetic disorder or paraneoplastic syndrome related to thymus tumors. Diagnosis is based on clinical manifestations, laboratory findings, electrophysiological evaluation and pharmacologic tests. Therapeutic strategies for MG consist of symptom relieving medications (e.g., acetylcholine esterase inhibitors), immunosuppressive agents, and surgical intervention (e.g., thymectomy).

Abstract: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder which causes fluctuating weakness in ocular, bulbar and limb skeletal muscles. There are two major clinical types of MG. Ocular MG (OMG) affects extra ocular muscles associated with eye movement and eyelid function and generalized MG results in muscle weakness throughout the body. Patients with OMG have painless fluctuating extra ocular muscles weakness, diplopia and ptosis accompanied by normal visual acuity and pupillary function. Frequently, patients with OMG develop generalized MG over 24 months. Pure OMG is more often earlier in onset (<45 years) than generalized MG. It can also occur as part of an immune-genetic disorder or paraneoplastic syndrome related to thymus tumors. Diagnosis is based on clinical manifestations, laboratory findings, electrophysiological evaluation and pharmacologic tests. Therapeutic strategies for MG consist of symptom relieving medications (e.g., acetylcholine esterase inhibitors), immunosuppressive agents, and surgical intervention (e.g., thymectomy).

Review Article
Original Article

Objective electrophysiological contrast sensitivity with monofocal and multifocal intraocular lenses: a prospective clinical study

Objective electrophysiological contrast sensitivity with monofocal and multifocal intraocular lenses: a prospective clinical study

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Background: To compare objective electrophysiological contrast sensitivity function (CSF) in patients implanted with either multifocal intraocular lenses (MIOLs) or monofocal intraocular lenses (IOLs) by pattern reversal visual evoked potentials (prVEP) measurements.

Methods: Fourty-five cataract patients were randomly allocated to receive bilaterally: apodized diffractive-refractive Alcon Acrysof MIOL (A), full diffractive AMO Tecnis MIOL (B) or monofocal Alcon Acrysof IOL (C). Primary outcomes: 1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies. Secondary outcomes: psychophysical CSF measured with VCTS-6500, photopic uncorrected distance (UDVA), and mesopic and photopic uncorrected near and intermediate visual acuities (UNVA and UIVA respectively).

Results: Electrophysiological CSF curve had an inverted U-shaped morphology in all groups, with a biphasic pattern in Group B. Group A showed a lower CSF than group B at 4 and 8 cpd, and a lower value than group C at 8 cpd. Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B. Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups. Mesopic UNVA and UIVA were better in group B.

Conclusions: Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs. This may be related to the visual acuity under certain conditions or to IOL characteristics. This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.

Background: To compare objective electrophysiological contrast sensitivity function (CSF) in patients implanted with either multifocal intraocular lenses (MIOLs) or monofocal intraocular lenses (IOLs) by pattern reversal visual evoked potentials (prVEP) measurements.

Methods: Fourty-five cataract patients were randomly allocated to receive bilaterally: apodized diffractive-refractive Alcon Acrysof MIOL (A), full diffractive AMO Tecnis MIOL (B) or monofocal Alcon Acrysof IOL (C). Primary outcomes: 1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies. Secondary outcomes: psychophysical CSF measured with VCTS-6500, photopic uncorrected distance (UDVA), and mesopic and photopic uncorrected near and intermediate visual acuities (UNVA and UIVA respectively).

Results: Electrophysiological CSF curve had an inverted U-shaped morphology in all groups, with a biphasic pattern in Group B. Group A showed a lower CSF than group B at 4 and 8 cpd, and a lower value than group C at 8 cpd. Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B. Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups. Mesopic UNVA and UIVA were better in group B.

Conclusions: Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs. This may be related to the visual acuity under certain conditions or to IOL characteristics. This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.

Perspective

Degenerative myopia: mechanical theories revisited

Degenerative myopia: mechanical theories revisited

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Abstract: The article discusses the early abandonment of mechanical theories about eye enlargement in degenerative myopia at the turn of the 20th century. At that time, the number of theories about myopia grew unrestricted, but with scant support from the experimental field. The mechanical theories vanished as a new wave of metabolism-based theories appeared, propelled by the huge advances in molecular biology. Modern techniques allow reconsidering those theories and to put them to test with higher confidence.

Abstract: The article discusses the early abandonment of mechanical theories about eye enlargement in degenerative myopia at the turn of the 20th century. At that time, the number of theories about myopia grew unrestricted, but with scant support from the experimental field. The mechanical theories vanished as a new wave of metabolism-based theories appeared, propelled by the huge advances in molecular biology. Modern techniques allow reconsidering those theories and to put them to test with higher confidence.

Visual Impairment and Rehabilitation

AB106. ORVIS: a directory of tools for vision rehabilitation

AB106. ORVIS: a directory of tools for vision rehabilitation

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Background: The ORVIS infrastructure aims to facilitate the development and availability of valid and adapted tools that will allow functional, perceptual, cognitive and psychological evaluation of low vision clients by researchers and clinicians who work in low vision and visual impairment rehabilitation.

Methods: The tools developed or documented within ORVIS Infrastructure are tests or questionnaires which allow, or will allow to assess—in an accurate and reliable manner—characteristics related to visual impairment. The tools in development are: (I) questionnaire de repérage des hallucinations visuelles liées au syndrome de Charles-Bonnet (QR-SCB); (II) repérage des personnes agées présentant des INDices de déficience VISUELle (IndiVisuel); (III) mesure de l’impact de la déficience visuelle dans les activités quotidiennes (MIDVAQ) and (IV) M’EYE read test. The directory documents 14 tools and offers—within a descriptive sheet—characteristics, components and metrological properties as supported by cited scientific studies.

Results: The ORVIS Infrastructure, which aims at the development and availability of assessment tools, fills researchers’ and clinicians’ needs for measurement tools that are valid, effective and appropriate for use with a visually impaired clientele. Such tools are, especially in French, little known and hard to find, and represent a precious resource for those who want to evaluate the efficacy of treatments or interventions.

Conclusions: ORVIS is available at www.orvis.vision. Between November 2015 and September 2017, the directory has been accessed 1,383 times by 952 unique visitors.

Background: The ORVIS infrastructure aims to facilitate the development and availability of valid and adapted tools that will allow functional, perceptual, cognitive and psychological evaluation of low vision clients by researchers and clinicians who work in low vision and visual impairment rehabilitation.

Methods: The tools developed or documented within ORVIS Infrastructure are tests or questionnaires which allow, or will allow to assess—in an accurate and reliable manner—characteristics related to visual impairment. The tools in development are: (I) questionnaire de repérage des hallucinations visuelles liées au syndrome de Charles-Bonnet (QR-SCB); (II) repérage des personnes agées présentant des INDices de déficience VISUELle (IndiVisuel); (III) mesure de l’impact de la déficience visuelle dans les activités quotidiennes (MIDVAQ) and (IV) M’EYE read test. The directory documents 14 tools and offers—within a descriptive sheet—characteristics, components and metrological properties as supported by cited scientific studies.

Results: The ORVIS Infrastructure, which aims at the development and availability of assessment tools, fills researchers’ and clinicians’ needs for measurement tools that are valid, effective and appropriate for use with a visually impaired clientele. Such tools are, especially in French, little known and hard to find, and represent a precious resource for those who want to evaluate the efficacy of treatments or interventions.

Conclusions: ORVIS is available at www.orvis.vision. Between November 2015 and September 2017, the directory has been accessed 1,383 times by 952 unique visitors.

Visual Impairment and Rehabilitation
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  • 眼科学报

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
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  • Eye Science

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
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