Maria Kiyoko Oyamada

Relationship between optical coherence tomography, pattern electroretinogram and automated perimetry in eyes with temporal hemianopia from chiasmal compression.

PURPOSE To evaluate the relationship between pattern electroretinogram (PERG) amplitude, macular and retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), and visual field (VF) loss on standard automated perimetry (SAP) in eyes with temporal hemianopia from chiasmal compression. METHODS Forty-one eyes from 41 patients with permanent temporal VF defects from chiasmal compression and 41 healthy subjects underwent transient full-field and hemifield (temporal or nasal) stimulation PERG, SAP and time domain-OCT macular and RNFL thickness measurements. Comparisons were made using Students t-test. Deviation from normal VF sensitivity for the central 18 degrees of VF was expressed in 1/Lambert units. Correlations between measurements were verified by linear regression analysis. RESULTS PERG and OCT measurements were significantly lower in eyes with temporal hemianopia than in normal eyes. A significant correlation was found between VF sensitivity loss and full-field or nasal, but not temporal, hemifield PERG amplitude. Likewise a significant correlation was found between VF sensitivity loss and most OCT parameters. No significant correlation was observed between OCT and PERG parameters, except for nasal hemifield amplitude. A significant correlation was observed between several macular and RNFL thickness parameters. CONCLUSIONS In patients with chiasmal compression, PERG amplitude and OCT thickness measurements were significant related to VF loss, but not to each other. OCT and PERG quantify neuronal loss differently, but both technologies are useful in understanding structure-function relationship in patients with chiasmal compression. (ClinicalTrials.gov number, NCT00553761).

Mutations in PCYT1A Cause Spondylometaphyseal Dysplasia with Cone-Rod Dystrophy

Spondylometaphyseal dysplasia with cone-rod dystrophy is a rare autosomal-recessive disorder characterized by severe short stature, progressive lower-limb bowing, flattened vertebral bodies, metaphyseal involvement, and visual impairment caused by cone-rod dystrophy. Whole-exome sequencing of four individuals affected by this disorder from two Brazilian families identified two previously unreported homozygous mutations in PCYT1A. This gene encodes the alpha isoform of the phosphate cytidylyltransferase 1 choline enzyme, which is responsible for converting phosphocholine into cytidine diphosphate-choline, a key intermediate step in the phosphatidylcholine biosynthesis pathway. A different enzymatic defect in this pathway has been previously associated with a muscular dystrophy with mitochondrial structural abnormalities that does not have cartilage and/or bone or retinal involvement. Thus, the deregulation of the phosphatidylcholine pathway may play a role in multiple genetic diseases in humans, and further studies are necessary to uncover its precise pathogenic mechanisms and the entirety of its phenotypic spectrum.

Fundus-Based and Electroretinographic Strategies for Stratification of Late-Stage Vogt-Koyanagi-Harada Disease Patients

PURPOSE To propose an analytic framework for ocular fundus alterations in late-stage Vogt-Koyanagi-Harada (VKH) disease, to describe the characteristics of overall retinal function as measured with full-field electroretinography (ERG), and to correlate the intensity of the fundus changes with full-field ERG alterations and to stratify patients accordingly. DESIGN Cross-sectional case series. METHODS Forty-seven eyes of 26 patients with late-stage VKH disease (> 6 months past disease onset) followed-up at the University of São Paulo School of Medicine underwent fundus photography within 2 months of a full-field ERG examination, both according to predefined protocols. Fundus pictures were evaluated by two observers regarding diffuse fundus depigmentation, nummular lesions, pigment clumps, and subretinal fibrosis, and an overall analysis classified the fundus changes as mild, moderate, or severe. Full-field ERG results were analyzed according to fundus-based stratification and also were stratified into 3 groups solely on the basis of decreasing amplitudes (ERG based or cluster stratification). The concordance between fundus-based and full-field ERG-based stratification strategies was estimated. RESULTS Overall fundus grading showed substantial interobserver concordance (kappa = 0.78). Comparison of full-field ERG parameters of the three fundus-based stratified groups showed diffusely diminished amplitudes with preservation of implicit times (P < .05). Fundus-based and full-field ERG-based stratification strategies also showed substantial concordance (kappa = 0.68). CONCLUSIONS The analytic framework for fundus findings proposed in this study seems reproducible and useful, because the severity categories do correlate with retinal function as measured by full-field ERG. This system may allow more precise exchange of information between practitioners as well as researchers with regard to identifying patients with greater retinal compromise rapidly as well as in comparison of outcomes of different treatment regimens.

Correlation between multifocal pattern electroretinography and Fourier-domain OCT in eyes with temporal hemianopia from chiasmal compression

PurposeTo evaluate the correlation between multifocal pattern electroretinography (mfPERG) and Fourier-domain optical coherence tomography (FD-OCT) with regard to macular and retinal nerve fiber layer (RNFL) thickness in eyes with temporal hemianopia from chiasmal compression.MethodsTwenty-five eyes from 25 patients with permanent temporal visual field defects from chiasmal compression and 25 healthy eyes were submitted to mfPERG using a stimulus pattern of 19 rectangles, standard automated perimetry and FD-OCT measurements. The mfPERG response was determined for groups of three rectangles for the nasal and temporal hemifields and for each quadrant. Macular thickness measurements were registered according to an overlaid OCT-generated checkerboard with 36 checks and averaged for the central area, and for each scanned quadrant and hemifield. RNFL thickness was determined for all twelve 30-degree segments around the disc, and averaged for the segments corresponding to the 6, 7, 8, 9, 10, 11 and 12 o’clock position. Correlations were verified with Pearson’s correlation coefficients and linear regression analysis.ResultsBoth mfPERG amplitudes and OCT measurements were significantly smaller in eyes with temporal visual field defects than in normals. A significant and strong correlation was found between most mfPERG and macular or RNFL thickness OCT parameters.ConclusionsmfPERG amplitudes and OCT measurements are significantly correlated in patients with chiasmal compression. Both technologies can quantify neuronal loss and, if used in combination, may help clarify structure–function relationships in this patient population.

Pfeiffer syndrome type 2: case report

OBJECTIVE To report on a case of Pfeiffer Syndrome, with a discussion of the diagnostic characteristics and features of disease types and the differential diagnosis. DESCRIPTION The authors describe a newborn with cloverleaf skull, extreme bilateral exorbitism and choanal atresia, partial syndactyly of the second and third toes and broad medially-deviated big toes. The case reported was Pfeiffer Syndrome type 2, which usually has a poor prognosis. COMMENTS Pfeiffer Syndrome is a clinically variable disorder and consists of an autosomal dominantly-inherited osteochondrodysplasia with craniosynostosis. It has been divided into three types. Type 1 is commonly associated with normal intelligence and generally good outcome. Types 2 and 3 generally have severe neurological compromise, poor prognosis, early death and sporadic occurrence. Potential for prolonged useful survival outcome can be achieved in some cases with early aggressive medical and surgical management according to recent literature.

Multifocal pattern electroretinography for the detection of neural loss in eyes with permanent temporal hemianopia or quadrantanopia from chiasmal compression

Aims To evaluate the ability of multifocal transient pattern electroretinography (mfPERG) to detect neural loss and assess the relationship between mfPERG and visual-field (VF) loss in eyes with chiasmal compression. Methods 23 eyes from 23 patients with temporal VF defects and band atrophy of the optic nerve and 21 controls underwent standard automated perimetry and mfPERG using a stimulus pattern of 19 rectangles, each consisting of 12 squares. The response was determined for the central rectangle, for the nasal and temporal hemifields (eight rectangles each) and for each quadrant (three rectangles) in both patients and controls. Comparisons were made using variance analysis. Correlations between VF and mfPERG measurements were verified by linear regression analysis. Results Mean±SD mfPERG amplitudes from the temporal hemifield (0.50±0.17 and 0.62±0.32) and temporal quadrants (superior 0.42±0.21 and 0.52±0.35, inferior 0.51±0.23 and 0.74±0.40) were significantly lower in eyes with band atrophy than in controls (0.78±0.24, 0.89±0.28, 0.73±0.26, 0.96±0.36, 0.79±0.26 and 0.91±0.31, respectively). No significant difference was observed in nasal hemifield measurements. Significant correlations (0.36–0.73) were found between VF relative sensitivity and mfPERG amplitude in different VF sectors. Conclusions mfPERG amplitude measurements clearly differentiate eyes with temporal VF defect from controls. The good correlation between mfPERG amplitudes and the severity of VF defect suggests that mfPERG may be used as an indicator of ganglion cell dysfunction. Clinical trial registration number ClinicalTrial.gov identifier number NCT00553761.

Relationship between Pattern electroretinogram, Frequency Domain-OCT and Automated perimetry in Chronic papilledema from Pseudotumor Cerebri Syndrome

PURPOSE We evaluated the ability of transient pattern electroretinogram (PERG) parameters to differentiate between eyes with visual field (VF) loss and resolved papilledema from pseudotumor cerebri syndrome (PTC) and controls, to compare PERG and optical coherence tomography (OCT) with regard to discrimination ability, and to assess the correlation between PERG, frequency domain OCT (FD-OCT), and VF measurements. METHODS The VFs and full-field stimulation PERGs based on 48 and 14-min checks were obtained from patients with PTC (n = 24, 38 eyes) and controls (n = 26, 34 eyes). In addition, FD-OCT peripapillary retinal nerve fiber layer (RNFL) and segmented macular layer measurements were obtained and correlation coefficients were determined. RESULTS Compared to controls, PERG N95 and P50+N95 amplitude measurements with 48-minute checks were significantly reduced in eyes with resolved papilledema from PTC. Both PERG N95 amplitude and OCT parameters were able to discriminate papilledema eyes from controls with a similar performance. Significant correlations, ranging from 0.25 (P < 0.05) to 0.43 (P < 0.01) were found between PERG amplitude values and OCT-measured macular ganglion cell layer thickness, RNFL thickness, and total retinal thickness. The PERG amplitude also was significantly associated with VF sensitivity loss with correlation coefficients ranging from 0.24 (P < 0.05) and 0.35 (P < 0.01). CONCLUSIONS The PERG measurements were able to detect neural loss in PTC eyes with resolved papilledema and were reasonably well correlated with OCT measurements and VF parameters. Thus, PERG may be a useful tool in the monitoring of retinal neural loss in eyes with active papilledema from PTC.

Fundus autofluorescence as a marker of disease severity in Vogt-Koyanagi-Harada disease.

icant past medical history presented to KK Women’s and Children’s Hospital, Singapore, on 21 October 2015 complaining of fever and a ‘black dot’ in her left upper eyelid for 3 days. She just returned from Malaysia with close contact with dogs during the trip. On examination, there was left upper eyelid erythema, oedema and the presence of a dog tick at the eyelid margin (Fig. 1A). Anterior segment examination was unremarkable. A procedure was performed under informed consent with topical tetracaine anaesthesia. Thermal energy was applied using a portable monopolar cautery device to the tick’s body (Fig. 1B), facilitating en bloc removal by inducing detachment of the tick. Microscopic examination of the organism revealed that it belonged to the genus Ixodes (Fig. 1C). There were no complications, and the patient recovered uneventfully. Ocular manifestations of ticks include conjunctivitis, keratitis, uveitis as well as embedment of the organism in the meibomian gland orifice presenting as a mass, oedema and erythema at the eyelid margin. Early removal of tick from its host is crucial as the risk of disease transmission increases significantly after 24 hr of attachment. Therefore, an efficient method of tick removal is crucial to avoid vector transmission of infectious diseases and localized inflammation and infection. There had been several methods of tick removal described in the literature. However, none of these methods is superior in terms of safety and efficacy profile (Fig. 1D). Many chemicals have been studied for tick removal. Compounds such as deodorized kerosene resulted in voluntary detachment in approximately 25% of the ticks that were treated (Knight et al. 1962). However, the use of chemical compounds can pose potential danger of toxicity to the ocular tissues. Chemical eradication of the organism may also precipitate regurgitation by the tick and transmission of infectious agents to its host (Flicek 2007). The use of forceps for direct mechanical tick removal could result in retained mouthparts in ocular tissues as well as fragmentation of its body which would then require further excision, complicating the removal process (Flicek 2007). Blepharoplasty incision allowing for an en bloc excision of the organism has been described (Love et al. 2001). However, this procedure is more invasive with a risk of ocular tissue loss and disruption of the ocular architecture. Tick removal using portable monopolar diathermy is a novel technique to the best of our knowledge. It is simple to perform, requiring only a few sequential thermal burns to the tick body to induce its detachment. This avoids trauma to the surrounding ocular tissues and need for excision. However, this technique might be more suitable for less tenacious ticks with shallow bites. Monopolar cautery for tick removal may be a superior and relative safe novel technique for en bloc removal of tick with minimal trauma to the surrounding ocular tissues.

Pattern-reversal electroretinograms for the diagnosis and management of disorders of the anterior visual pathway

The pattern electroretinogram is an electrophysiological test that assesses the function of inner retinal layers, particularly the ganglion cells layer of retina, using a reversing checkerboard or grating pattern that produces no change in average luminance over time. The normal pattern electroretinogram is composed of a proeminent positive component (P50) and a large later negative component (N95). Since structural damage that compromises the retinal ganglion cell layer can lead to pattern electroretinogram changes, particularly in the N95 amplitude, the test can be useful in the treatment of a number of anterior visual pathway diseases. In this article, we review the methods for recording pattern electroretinogram and its usefulness in the diagnosis and management of diseases including inflammatory, hereditary, ischemic and compressive lesions of the anterior visual pathway.

Fatores técnicos intervenientes na realização do exame de eletrorretinograma multifocal (ERGmf)

PURPOSE To describe the main intervening factors observed during the acquisition and analysis of multifocal electroretinogram (mfERG), that could affect the recorded signal, the obtained responses and their analysis. METHODS The error factors observed during the acquisition of 100 sequential multifocal electroretinogram tests, in the period of May to July, 2005 were analyzed. The examinations of multifocal electroretinogram were carried out in agreement with international guideline recommendations, taking into account the established parameters of equipment, with 61 elements, and visual angle of 30 degrees. All patients had been submitted to complete ophthalmologic examination, excluding those with inadequate transparency of ways, flat corneas and those incapable to visualize a central fixation target. RESULTS The intervening factors, that could cause artifacts and errors in the interpretation of the obtained results, observed and corrected during the acquisition of multifocal electroretinogram were: eccentric or poor fixation, eye movements, orbicular contraction, cervical muscle contraction, inadequate transparency of the corneal electrode, electrode displacement, lens support decentralization, inadequate viewing distance in patients with high refractive errors, eye height inadequacy in relation to the center of the screen, electrical noise in 60 HZ frequency and electromagnetic field and high impedances. Excessive use of filters in wave processing for noise and artifact removal can interfere with the analysis of the obtained results. CONCLUSION Simple observational cares during signal acquisition are of significant importance to ensure accuracy of the topographical electroretinogram information, good waveform morphology and low noise level register. Through their ready correction, the correct and adjusted analysis of the amplitude and of implicit time of peaks N1, P1 and N2 is reliable. Digital smooth system with specific frequency peak removal supply waves with more defined morphology with lower amplitude reduction than other available resources.