One-year follow up of a tobacco alcohol optic neuropathy case with atypical course: Conventional assessment and Laser speckle flowgraphy.

PURPOSE: To describe the unexpected one-year course of a probable Tobacco Alcohol Optic Neuropathy (TAON) and the unprecedented Laser Speckle Flowgraphy (LSFG) assessment. CASE REPORT: A 49-year-old Caucasian man with no family history of visual impairment referred because of unilateral and painless visual acuity (VA) decrease in the right eye (RE). Also, color vision and visual evoked potentials were unilaterally altered. Optical coherence tomography (OCT), instead, revealed bilateral thinning of the macular ganglion cell inner plexiform layer. Funduscopy, intraocular pressure, pupillary shape/reactivity and ocular motility were normal. Blood testing revealed macrocytic/normochromic anemia and low levels of vitamin B2 and folic acid. The patient admitted heavy tobacco and alcohol intake for many years. After an initial compliance to the prescribed regimen, the patient quitted the vitamin intake and resumed his smoking and drinking habits. After a 13-month follow up the VA further reduced in the RE; the fellow eye preserved normal visual function despite the bilateral and progressive alterations of the OCT assessment. Both eyes underwent LSFG examination. All the conventional nets evaluated by the instrument (i.e., Mean Tissue, Mean All and Mean Vascular perfusion) were lower in the RE. CONCLUSIONS: Based on patient's behavior, visual deficiencies and laboratory findings, we assumed that the patient suffered from TAON. Also after one year, however, a deep discrepancy between the strictly unilateral, progressive VA impairment and the bilateral, symmetrical OCT alterations persisted. The LSFG data clearly indicate that the perfusion of the two eyes differed, especially referring to tissular vascularization in the optic nerve head area of the RE.

Ethambutol and visual assessment in England: current practice and recommendations.

BACKGROUND: Standard treatment for tuberculosis (TB) in children and adults includes an initial two-month course of ethambutol, a drug that in rare cases can cause optic neuropathy and irreversible vision loss. There is a lack of clear guidance on what vision assessments are needed before and during treatment with ethambutol, with the Royal College of Ophthalmologists, National Institute for Health and Care Excellence, British National Formulary and British Thoracic Society offering different guidance. We aimed to assess how vision is routinely tested in patients treated with ethambutol in TB services across England. METHODS: An online survey developed by Public Health England was sent to all TB services in England in 2018 to assess current practice and inform the development of best practice recommendations for visual assessment of patients treated with ethambutol for TB. RESULTS: Sixty-six TB professionals from across England responded, a response rate of 54%. The results showed variations in practice, including when to omit ethambutol from treatment, the timing and frequency of visual assessment, the type of visual assessment, referral processes and management of visual changes. CONCLUSION: This national survey highlights the need for clear guidelines on the testing of vision for patients taking ethambutol at recommended doses, before and during treatment. We suggest a pragmatic approach to visual assessment to reduce variation in practice, proposing a stepwise pathway for patients on standard TB treatment for local adaptation.

Nutritional peripheral neuropathies.

Nutritional peripheral neuropathies are a global problem, heavily influenced by geopolitical, cultural and socioeconomic factors. Peripheral neuropathy occurs most frequently secondary to B-vitamin deficiencies, which is suspected to increase in years to come due to the popularity of vegan and vegetarian diets and increased use of bariatric surgery.This review will focus on the common B-vitamins for which a causal link to peripheral neuropathy is more established (vitamins B1, B2, B6, B9 and B12). We will review the historical human and animal data on which much of the clinical descriptions of vitamin deficiencies are based and summarise current available tools for accurately diagnosing a nutritional deficiency. We will also review recently described genetic diseases due to pathogenic variants in genes involved in B-vitamin metabolism that have helped to inform the phenotypes and potential causality of certain B-vitamins in peripheral neuropathy (B2 and B9).Endemic outbreaks of peripheral neuropathy over the last two centuries have been linked to food shortages and nutritional deficiency. These include outbreaks in Jamaican sugar plantation workers in the nineteenth century (Strachan's syndrome), World War two prisoners of war, Cuban endemic neuropathy and also Tanzanian endemic optic neuropathy, which remains a significant public health burden today. An improved understanding of lack of which vitamins cause peripheral neuropathy and how to identify specific deficiencies may lead to prevention of significant and irreversible disability in vulnerable populations.

Electrophysiological assessment of nutritional optic neuropathy: a case report.

PURPOSE: To report an unexpectedly asymmetric, progressive nutritional optic neuropathy associated with vitamin A deficient optic canal hyperostosis in a 15-year-old female with a long history of a restricted diet. METHODS: We performed comprehensive ophthalmic assessments in a fifteen-year-old female with a long history of restricted eating who presented with suspected nutritional optic neuropathy, predominantly affecting the right eye vision. RESULTS: A review of computerised tomography and magnetic resonance imaging revealed bilateral optic canal hyperostosis likely associated with vitamin A deficiency. Electrodiagnostic tests and optical coherence tomography provided structure-function evidence of bilateral retinal ganglion cell dysfunction and notably revealed severe loss of temporal fibres in the left eye which showed cecocentral scotoma but normal visual acuity. Although selective damage of the papillomacular bundle has been well-documented in nutritional and toxic optic neuropathies, compressive optic canal hyperostosis secondary to nutritional deficiency has been rarely reported. CONCLUSIONS: Nutritional deficiencies are increasing in high-income countries and may be linked to the rise of gastrointestinal disorders, strict vegan and vegetarian diets and avoidant restrictive food intake disorder (ARFID) associated with conditions such as depression and autism spectrum syndrome (ASD). Our findings highlight the value of electrodiagnostic testing alongside imaging in complex nutritional optic neuropathies to help monitor, guide treatment and preserve remaining sight in a child.

[Electrophysiological and psychophysical studies in assessment of visual functions in patients with hereditary optic neuropathy]. / Elektrofiziologicheskie i psikhofizicheskie issledovaniya v otsenke zritel'nykh funktsii pri nasledstvennoi opticheskoi neiropatii.

PURPOSE: To study the capabilities of electrophysiological and psychophysical examination methods for assessment of the functional state of ganglion cells, retina and optic nerve in patients with hereditary optic neuropathy (HON). MATERIAL AND METHODS: The study included 60 patients (118 eyes) with a genetically confirmed diagnosis of HON. All study patients underwent visual field test (VFT), spectral optical coherence tomography (OCT), flash and pattern visual evoked potentials (VEP) (Flash-VEP, FVEP; Pattern-VEP, PVEP), photopic electroretinography with photonegative response (PhNR) registration and the color vision test. In 24 patients (46 eyes), these parameters were assessed before the start of treatment and one year later. The treatment involved the mitochondria-targeted antioxidant SkQ1 - plastoquinonyl-decyl-triphenylphosphonium bromide (PDTP) in the form of eye drops. RESULTS: The main PVEP components for 1.0° and 0.3° were registered in 20% and in 14% of patient eyes with HON and high visual functions, respectively. After one year of PDTP use, a significant decrease in P100 peak latency was found only in the group with disease duration of ≤1.5 years as of the time of treatment start (p<0.05). Significant differences were observed in the PhNR amplitude (p<0.004) between patients of the main and the control groups, as well as in the PhNR amplitude between patients with visual acuity of ≤0.1 and ≥0.13 (p<0.01). Patients with high visual functions were found to have a correlation between the PhNR amplitude, GCC thickness and the global loss index (GLV). CONCLUSION: Along with VFT, OCT and color vision tests, electrophysiological studies are one of the main methods of examining patients with HON. After one year of PDTP use, there was a significant decrease in the FVEP P2 peak latency in the group with a disease duration of ≤1.5 years as of the time of treatment start. The PhNR amplitude in patients with high visual functions was found to correlate with structural changes in the ganglion cell layer and the retinal nerve fiber layer.

Diagnostic assessment of glaucoma and non-glaucomatous optic neuropathies via optical texture analysis of the retinal nerve fibre layer.

The clinical diagnostic evaluation of optic neuropathies relies on the analysis of the thickness of the retinal nerve fibre layer (RNFL) by optical coherence tomography (OCT). However, false positives and false negatives in the detection of RNFL abnormalities are common. Here we show that an algorithm integrating measurements of RNFL thickness and reflectance from standard wide-field OCT scans can be used to uncover the trajectories and optical texture of individual axonal fibre bundles in the retina and to discern distinctive patterns of loss of axonal fibre bundles in glaucoma, compressive optic neuropathy, optic neuritis and non-arteritic anterior ischaemic optic neuropathy. Such optical texture analysis can detect focal RNFL defects in early optic neuropathy, as well as residual axonal fibre bundles in end-stage optic neuropathy that were indiscernible by conventional OCT analysis and by red-free RNFL photography. In a diagnostic-performance study, optical texture analysis of the RNFL outperformed conventional OCT in the detection of glaucoma, as defined by visual-field testing or red-free photography. Our findings show that optical texture analysis of the RNFL for the detection of optic neuropathies is highly sensitive and specific.

SD-OCT assessment and visual field changes 1 year or more after a single episode of unilateral acute primary angle closure / Avaliação do SD-OCT e mudanças do campo visual 1 ano ou mais após episódio único de fechamento angular primário agudo unilateral

ABSTRACT Objective: To evaluate structural and visual field (VF) changes after ≥1 year of a single acute primary angle closure (APAC) attack using spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP). Methods: Patients with a single unilateral APAC crisis at least 1 year ago were included consecutively from 2013 to 2016. Contralateral eye was used as control. All patients underwent ophthalmic examination, RNFL imaging by SD-OCT, and SAP using Octopus 1-2-3. Results: 54 eyes (27 patients) were enrolled. Male-to-female ratio was 1:2. Mean time for the SD-OCT and SAP assessment after the crisis was 5.0±5.1 (1.0-23.5) years, and IOP was 52.5±9.8 mmHg. In APAC eyes, the thicknesses of all quadrants of peripapillary RNFL (36.3%; P<0.001) and some macular sections (from 2.1% to 4.7%; P<0.01) were reduced compared to contralateral eyes. Additionally, in APAC eyes, the mean defect on VF was negatively and statistically correlated with the reduction of all quadrants of peripapillary RNFL thickness. Conclusion: A single episode of APAC was associated with peripapillary RNFL and macular thickness and with VF defects after ≥1 year of the crisis in the affected eye. Statistically meaningful correlations were found between structural and functional damage.

RESUMO Objetivo: Avaliar alterações estruturais e do campo visual 1 ano ou mais após uma crise única de fechamento angular primário agudo utilizando tomografia de coerência óptica de domínio espectral e perimetria automatizada padronizada. Métodos: Pacientes que apresentaram crise unilateral única de fechamento angular primário agudo há pelo menos 1 ano foram consecutivamente incluídos entre 2013 e 2016. Os olhos contralaterais foram utilizados como controles. Todos os pacientes foram submetidos a exame oftalmológico, avaliação das camadas de fibras nervosas da retina utilizando tomografia de coerência óptica de domínio espectral e perimetria automatizada padronizada com o Octopus 1-2-3. Resultados: Foram incluídos 54 olhos (27 pacientes) com razão homem:mulher de 1:2. O tempo médio após a crise foi de 5,0±5,1 anos (1,0 a 23,5) e a pressão intraocular na crise foi 52,5±9,8mmHg. Nos olhos com fechamento angular primário agudo, todas as espessuras das camadas de fibras nervosas da retina peripapilares (36,3%; p<0,001) e de algumas seções maculares (de 2,1 a 4,7%; p<0,01) estavam reduzidas em comparação aos olhos contralaterais. Além do mais, nos olhos submetidos a fechamento angular primário agudo, o mean defect do campo visual foi estatisticamente e negativamente correlacionado com a redução da espessura de todos os quadrantes peripapilares da camada de fibras nervosas da retina. Conclusão: Um único episódio de fechamento angular primário agudo foi associado com redução na espessura da camada de fibras nervosas da retina peripapilar e da espessura macular e com defeitos de campo visual 1 ano ou mais após a crise no olho afetado. Correlações estatisticamente significativas foram identificadas entre danos estruturais e funcionais.

Quantitative assessment of macular function after surgery for optic disc pit maculopathy: A case report.

RATIONALE: We describe a case of optic disc pit maculopathy (ODP-M) in which vitrectomy with juxtapapillary laser (JPL) treatment led to the reattachment of retinoschisis (RS) as well as serous retinal detachment (SRD). PATIENT CONCERNS: An 80-year-old man complained of distorted vision and decreased visual acuity (VA) in his left eye for 12 months. DIAGNOSIS: We conducted quantitative functional evaluation on the area of RS and SRD using the Humphrey visual field analyzer. Fundus examination and optical coherence tomography showed SRD and RS in connection with the optic disc. The best-corrected logarithm of the minimum angle of resolution (logMAR) VA was 0.7. INTERVENTIONS: The patient underwent JPL treatment combined with pars plana vitrectomy. During surgery, posterior vitreous detachment and tamponade were created with sulfur hexafluoride. OUTCOMES: After surgery, SRD (and subsequently RS) gradually reduced and had completely disappeared at 31 months. VA gradually improved and was 0.0 (logMAR) at 28 months. The analysis of the mean macular thickness of the central 3-mm diameter showed that the macula thickness recovered to 300 µm at 17 months postoperatively. Retinal sensitivity began to improve at 24 months postoperatively and had increased at 48 months postoperatively. LESSONS: In conclusion, vitrectomy with JPL treatment for ODP-M had a favorable anatomical outcome as well as a long-term functional outcome. These findings provide useful information for clinicians who are planning a therapeutic strategy, including the choice of surgical procedure for ODP-M.

Longitudinal Assessment Using Optical Coherence Tomography in Patients with Friedreich's Ataxia.

Ocular abnormalities occur frequently in Friedreich's ataxia (FRDA), although visual symptoms are not always reported. We evaluated a cohort of patients with FRDA to characterise the clinical phenotype and optic nerve findings as detected with optical coherence tomography (OCT). A total of 48 patients from 42 unrelated families were recruited. Mean age at onset was 13.8 years (range 4-40), mean disease duration 19.5 years (range 5-43), mean disease severity as quantified with the Scale for the Assessment and Rating of Ataxia 22/40 (range 4.5-38). All patients displayed variable ataxia and two-thirds had ocular abnormalities. Statistically significant thinning of average retinal nerve fibre layer (RNFL) and thinning in all but the temporal quadrant compared to controls was demonstrated on OCT. Significant RNFL and macular thinning was documented over time in 20 individuals. Disease severity and visual acuity were correlated with RNFL and macular thickness, but no association was found with disease duration. Our results highlight that FDRA is associated with subclinical optic neuropathy. This is the largest longitudinal study of OCT findings in FRDA to date, demonstrating progressive RNFL thickness decline, suggesting that RNFL thickness as measured by OCT has the potential to become a quantifiable biomarker for the evaluation of disease progression in FRDA.

Deep Learning for Retinal Image Quality Assessment of Optic Nerve Head Disorders.

ABSTRACT: Deep learning (DL)-based retinal image quality assessment (RIQA) algorithms have been gaining popularity, as a solution to reduce the frequency of diagnostically unusable images. Most existing RIQA tools target retinal conditions, with a dearth of studies looking into RIQA models for optic nerve head (ONH) disorders. The recent success of DL systems in detecting ONH abnormalities on color fundus images prompts the development of tailored RIQA algorithms for these specific conditions. In this review, we discuss recent progress in DL-based RIQA models in general and the need for RIQA models tailored for ONH disorders. Finally, we propose suggestions for such models in the future.

Visual electrophysiology in the assessment of toxicity and deficiency states affecting the visual system.

Visual disturbance or visual failure due to toxicity of an ingested substance or a severe nutritional deficiency can present significant challenges for diagnosis and management, for instance, where an adverse reaction to a prescribed medicine is suspected. Objective assessment of visual function is important, particularly where structural changes in the retina or optic nerve have not yet occurred, as there may be a window of opportunity to mitigate or reverse visual loss. This paper reviews a number of clinical presentations where visual electrophysiological assessment has an important role in early diagnosis or management alongside clinical assessment and ocular imaging modalities. We highlight the importance of vitamin A deficiency as an easily detected marker for severe combined micronutrient deficiency.

Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension.

In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

Clinical Assessment of Scleral Canal Area in Glaucoma Using Spectral-Domain Optical Coherence Tomography.

PURPOSE: To investigate anterior scleral canal (ASC) area in the eyes with glaucoma using spectral-domain optical coherence tomography (SDOCT). DESIGN: Cross-sectional study. METHODS: This study included 206 eyes of 103 patients with glaucoma, classified as 66 eyes of 33 patients with unilateral glaucoma and 140 eyes of 70 patients with bilateral glaucoma. Radial scan enhanced depth imaging SDOCT centered on the optic disc was performed, and parameters that present ASC area such as ASC opening and the largest ASC area were obtained in each eye. The largest ASC area was the largest cross-sectional area of the ASC region identified between the ASC opening and anterior lamina cribrosa insertion. These parameters were compared between eyes with and without glaucoma in unilateral glaucoma, and eyes with worse and better visual field defect (VFD) in bilateral glaucoma. RESULTS: In the patients with unilateral glaucoma, ASC opening and largest ASC area were significantly larger in the eyes with glaucoma than in those without glaucoma (both P < .001). In bilateral glaucoma, these parameters were significantly larger in the eyes with worse VFD than in those with better VFD (P = .0080 and P = .0018, respectively). Intereye differences of the ASC parameters in the glaucoma patients were significantly greater than that in the normal subjects. CONCLUSIONS: Significantly larger ASC area was first observed in the living human eyes with glaucoma compared to the normal eyes. Further longitudinal studies are required to determine if the ASC area is useful in the prevention and treatment of glaucoma.

Has Spectral-Domain Optical Coherence Tomography Retinal Nerve Fiber Layer Assessment Become the Method of Choice for Glaucoma Evaluation in Clinical Practice?

AIM: The aim of the study was to assess the role of spectral-domain optical coherence tomography (SD-OCT) as a method of choice for early glaucoma diagnosis in glaucoma suspects. DESIGN: This was a retrospective cross-sectional study. MATERIALS AND METHODS: After a comprehensive ophthalmic examination and visual field analysis, 20 patients were included in each of the three groups: Normal group, possible glaucoma, definitive glaucoma, respectively. The optic nerve head (ONH) and peripapillary retinal nerve fiber layer parameters of participants were analyzed using SD-OCT optic disc cube protocol scans. Data was analyzed using one.way analysis of variance test. RESULTS: ONH RNFL defects in possible glaucoma patients were frequently found in superior, inferior, and temporal quadrants. CONCLUSION: Diagnostic capability of SD-OCT parameters for detection of structural changes in the ONH and retinal nerve fiber layer differed in three groups significantly. Hence, using SD-OCT has become an imperative and quick way of timely diagnosis of glaucoma in private practice.

Evaluation of an AI system for the automated detection of glaucoma from stereoscopic optic disc photographs: the European Optic Disc Assessment Study.

OBJECTIVES: To evaluate the performance of a deep learning based Artificial Intelligence (AI) software for detection of glaucoma from stereoscopic optic disc photographs, and to compare this performance to the performance of a large cohort of ophthalmologists and optometrists. METHODS: A retrospective study evaluating the diagnostic performance of an AI software (Pegasus v1.0, Visulytix Ltd., London UK) and comparing it with that of 243 European ophthalmologists and 208 British optometrists, as determined in previous studies, for the detection of glaucomatous optic neuropathy from 94 scanned stereoscopic photographic slides scanned into digital format. RESULTS: Pegasus was able to detect glaucomatous optic neuropathy with an accuracy of 83.4% (95% CI: 77.5-89.2). This is comparable to an average ophthalmologist accuracy of 80.5% (95% CI: 67.2-93.8) and average optometrist accuracy of 80% (95% CI: 67-88) on the same images. In addition, the AI system had an intra-observer agreement (Cohen's Kappa, κ) of 0.74 (95% CI: 0.63-0.85), compared with 0.70 (range: -0.13-1.00; 95% CI: 0.67-0.73) and 0.71 (range: 0.08-1.00) for ophthalmologists and optometrists, respectively. There was no statistically significant difference between the performance of the deep learning system and ophthalmologists or optometrists. CONCLUSION: The AI system obtained a diagnostic performance and repeatability comparable to that of the ophthalmologists and optometrists. We conclude that deep learning based AI systems, such as Pegasus, demonstrate significant promise in the assisted detection of glaucomatous optic neuropathy.

New Observations regarding the Assessment of Cilioretinal Arteries Coexistence with Optic Disc Pit.

Purpose: To investigate the coexistence of cilioretinal arteries (CRAs) with optic disc pit (ODP), and to delineate the characteristics of CRAs related to their number, location of their emergence and their association with the size of ODP. Methods: 47 patients (49 eyes) with ODP were diagnosed and followed-up between 1997 and 2017, using slit-lamp biomicroscopy, color fundus photographs, fluorescein angiography and indocyanine green angiography. The presence of CRAs was recorded in association with the size of the ODP, along with their number and location of emergence. The fellow normal eyes of patients were also analyzed. Results: 42 out of 49 eyes with ODP (85.7%) presented CRAs. In 35 out of 42 eyes (83.3%) CRAs emerged from the pit, either from bottom or from its margin. In 7.1% of cases, CRAs were emerged outside the ODP, while in 9.6% of cases, the type of CRA emergence could be characterized as mixed. The number of CRAs, that ranged from 1 to 4, was positively associated with ODP size. In the fellow normal eyes, CRAs was found in 22.2% of cases, difference which was significant compared to patients with ODP. Conclusion: Based on the high percentage of CRAs coexistence with ODP and the excessive frequency of their emergence from ODP (83.3%), it is supported that ODP as a developmental disorder could go along with further anatomic peculiarities, that also include the presence of multiple CRAs.

Swept-Source OCT for Evaluating the Lamina Cribrosa: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the published literature on the use of swept-source (SS) OCT for evaluating the lamina cribrosa in glaucoma. METHODS: A PubMed and Cochrane Library literature search initially conducted on March 3, 2017, and updated on June 26, 2018, yielded a total of 64 articles. Articles that were reviews or that were not published in English were excluded, and 29 were found to fit the inclusion criteria. The panel methodologist then assigned a level of evidence rating to each study. Fifteen studies were rated level III, 14 studies were rated level II, and no studies were rated level I. RESULTS: Different aspects of the lamina cribrosa were studied using SS-OCT, including the anterior lamina cribrosa curvature, anterior lamina cribrosa depth, anterior lamina cribrosa insertions, laminar thickness, focal lamina cribrosa defects (FLCDs), and lamina cribrosa microarchitecture. In general, imaging of the anterior lamina can be achieved reliably, although shadowing from blood vessels at the neuroretinal rim remains an issue. Imaging of the posterior lamina can be achieved with varying levels of success. In glaucoma, there is posterior migration of the anterior lamina cribrosa insertions as well as increased thinning and posterior curvature of the lamina cribrosa. Focal lamina cribrosa defects appear more commonly in glaucoma, and this may hint at the pathogenesis of axonal damage. In addition, there may be remodeling of the microarchitecture of the lamina, resulting in more variable laminar pores. There are limited studies comparing SS-OCT with spectral-domain (SD) OCT with regard to imaging of the lamina, but the difference in image quality between enhanced depth imaging (EDI) with SD-OCT and SS-OCT seems minimal. CONCLUSIONS: Imaging of the lamina cribrosa using SS-OCT has demonstrated that the lamina cribrosa is likely biomechanically active and that significant changes occur in glaucoma. The diagnostic utility of SS-OCT for lamina cribrosa imaging is promising, but standardized nomenclature, automated measurements, and longitudinal studies with larger and more diverse sample sizes are needed.

A 30 s test for quantitative assessment of a relative afferent pupillary defect (RAPD): the infrared pupillary asymmetry (IPA).

BACKGROUND: Detection of a relative afferent pupillary defect (RAPD) by the swinging-light test can be challenging in clinical practice (dark eyes, anisocoria, dark environment). We developed a new method of RAPD quantification based on the recording of the infrared pupillary asymmetry (IPA) with a standard optical coherence tomography (OCT) device. METHODS: The diagnostic value of the IPA for detection of the RAPD was determined by receiver-operating characteristic (ROC) curves and area under the curve (AUC). RESULTS: Twenty-nine subjects were included in this study (17 controls and 12 unilateral optic neuropathies). The IPA was significantly greater in unilateral optic neuropathies (0.39) compared to controls (0.18, p = 0.001). The diagnostic value was good with a ROC-AUC of 0.843. Importantly, the IPA correlated significantly with the inter-eye percentage difference of the macular ganglion cell-inner plexiform layer (mGCIPL) thickness (R = 0.53, p = 0.01). Assessment of the IPA took less than 30 s. CONCLUSION: The present data show that the IPA is a practical and rapid test that can be applied in a clinical setting. The IPA may be a valuable functional outcome measure for clinical trials, complementing structural retinal OCT data in a biological meaningful way. The IPA should be further investigated for suitability for optic neuritis treatment trials.

Objective assessment of visual acuity: a refined model for analyzing the sweep VEP.

PURPOSE: The aim of this study was to develop a simple and reliable method for the objective assessment of visual acuity by optimizing the stimulus used in commercially available systems and by improving the methods of evaluation using a nonlinear function, the modified Ricker model. METHODS: Subjective visual acuity in the normal subjects was measured with Snellen targets, best-corrected, and in some cases also uncorrected and with plus lenses (+ 1 D, + 2 D, + 3 D). In patients, subjective visual acuity was measured best-corrected using the Freiburg Visual Acuity Test. Sweep VEP recordings to 11 spatial frequencies, with check sizes in logarithmically equidistant steps (0.6, 0.9, 1.4, 2.1, 3.3, 4.9, 7.3, 10.4, 18.2, 24.4, and 36.5 cpd), were obtained from 56 healthy subjects aged between 17 and 69 years (mean 42.5 ± 15.3 SD years) and 20 patients with diseases of the lens (n = 6), retina (n = 8) or optic nerve (n = 6). The results were fit by a multiple linear regression (2nd-order polynomial) or a nonlinear regression (modified Ricker model) and parameters compared (limiting spatial frequency (sflimiting) and the spatial frequency of the vertex (sfvertex) of the parabola for the 2nd-order polynomial fitting, and the maximal spatial frequency (sfmax), and the spatial frequency where the amplitude is 2 dB higher than the level of noise (sfthreshold) for the modified Ricker model. RESULTS: Recording with 11 spatial frequencies allows a more accurate determination of acuities above 1.0 logMAR. Tuning curves fitted to the results show that compared to the normal 2nd-order polynomial analysis, the modified Ricker model is able to describe closely the amplitudes of the sweep VEP in relation to the spatial frequencies of the presented checkerboards. In patients with a visual acuity better than about 0.5 (decimal), the predicted acuities based on the different parameters show a good match of the predicted visual acuities based on the models established in healthy volunteers to the subjective visual acuities. However, for lower visual acuities, both models tend to overestimate the visual acuity (up to ~ 0.4 logMAR), especially in patients suffering from AMD. CONCLUSIONS: Both models, the 2nd-order polynomial and the modified Ricker model performed equally well in the prediction of the visual acuity based on the amplitudes recorded using the sweep VEP. However, the modified Ricker model does not require the exclusion of data points from the fit, as necessary when fitting the 2nd-order polynomial model making it more reliable and robust against outliers, and, in addition, provides a measure for the noise of the recorded results.

Sonographic Assessment of Optic Disc Cupping and its Diagnostic Performance in Glaucoma.

PURPOSE: The purpose of this study was to assess the optic cup diameter sonographically in glaucoma patients and in the normal population and correlate it with their photographic parameters to propose a cut-off value as a predictive index of glaucoma. METHODS: A total of 95/50 primary open-angle glaucoma and 87/44 control patients with clear media underwent visual field assessment, fundus photography, and B-scan ultrasound. Photographic vertical cup diameter (PVCD) of cases and controls were recorded after magnification correction using the Bengtsson formula. Sonographic vertical cup diameter (SVCD) was measured in the vertical transverse position. RESULTS: The mean SVCD was 1.13±0.23 mm in glaucoma and 0.72±0.25 mm in controls (P=0.001). The mean PVCD was 1.024±0.199 mm in glaucoma and 0.636±0.217 mm in controls (P=0.001). A strong correlation between PVCD and SVCD in both groups was found (correlation coefficient r=0.857; P=0.001; glaucoma and r=0.795; P=0.001; control). SVCD had a positive correlation with vertical cup disc ratio (r=0.675; P=0.001 in glaucoma patients) and (r=0.797; P=0.001 in controls) cup area (r=0.798; P=0.001; glaucoma) and (r=0.727, P=0.001; control) a negative correlation with vertical neuroretinal rim diameter (r=-0.5187; P=0.000; glaucoma patients) and (r=-0.699; P=0.001; controls). No correlation of SVCD was found with severity of field grade changes. The receiving operative curve analysis was performed, and Youden's optimal cut-off method was used to find a cut-off value for SVCD, which came out to be 1.06, with 65.3% (95% confidence interval, 54.8-74.7) sensitivity and 94.3% (95% confidence interval, 87.1-97.1) specificity. CONCLUSIONS: The sonographic evaluation of the optic cup is a reliable noninvasive procedure and a potentially useful tool in the assessment of nonviewable suspected glaucomatous cups.