Paula Yuri Sacai

Association of Optic Disc Size with Development and Prognosis of Leber’s Hereditary Optic Neuropathy

PURPOSEnTo study the optic nerve head (ONH) morphology of patients with Lebers hereditary optic neuropathy (LHON) in a large family from Brazil carrying the 11778/ND4 mutation and in a case series of unrelated Italian families bearing different mitochondrial DNA (mtDNA) pathogenic mutations.nnnMETHODSnEnrolled in the study were 15 LHON-affected patients (LHON-affected) and 45 LHON unaffected mutation carriers (LHON carriers) belonging to the previously reported Brazilian SOA-BR LHON pedigree and 56 LHON-affected and 101 LHON carriers from 45 unrelated LHON Italian pedigrees molecularly defined. The LHON-affected were subgrouped according to the extent of visual recovery. All individuals underwent optic nerve head (ONH) analysis by optical coherence tomography.nnnRESULTSnIn the Brazilian sample, the mean optic disc area was significantly larger in LHON carriers than in the control group (P=0.002). In the Italian sample, the mean optic disc area and vertical disc diameter were significantly higher in LHON carriers than in both LHON-affected (respectively, P=0.008 and P<0.001) and control subjects (P<0.001 in both cases). The LHON-affected with visual recovery had a significantly larger vertical disc diameter when compared with those without visual recovery (P=0.03).nnnCONCLUSIONSnThe results, revealing that the ONH size is larger in LHON carriers than in LHON-affected, suggest a protective role for this anatomic trait. Such a hypothesis is reinforced by the observation that, among the LHON-affected, larger discs correlated with visual recovery and better visual outcome. The findings may be relevant for prognosis and provide a mechanism for identifying nuclear-modifying genes implicated in the variability of penetrance in LHON.

Estudo normativo do eletrorretinograma de campo total em adultos jovens

OBJETIVOS: A proposta deste estudo e estabelecer valores normativos para o eletrorretinograma (ERG) de campo total, em um grupo de voluntarios adultos jovens segundo o protocolo padrao recomendado pela Sociedade Internacional de Eletrofisiologia Visual Clinica (ISCEV). METODOS: Participaram deste estudo 42 voluntarios normais com idades variando de 15 a 26 anos, sendo 20 homens e 22 mulheres. Os eletrorretinogramas de campo total foram obtidos com eletrodos de lente de contato bipolares e seguiram as 5 etapas do protocolo da Sociedade Internacional de Eletrofisiologia Visual Clinica: a) resposta de bastonetes; b) reposta maxima; c) potenciais oscilatorios; d) resposta maxima de cones; e) resposta de cones ao flicker 30 Hz. Os parâmetros analisados foram a amplitude de resposta do pico da onda-a ate o pico da onda-b (pico a pico em mV) e o tempo de culminacao da onda-b (ms). RESULTADOS: As medias (± 1 desvio padrao) da amplitude pico a pico foram: resposta de bastonetes - 241,1 ± 66,9 µV; resposta maxima - 385,4 ± 71,8 µV; potenciais oscilatorios - 180,6 ± 48,6 µV; resposta de cones -102,8 ± 36,3 µV e flicker 30 Hz - 69,2 ± 26,6 µV. Para o tempo implicito da onda-b os valores foram: resposta de bastonetes - 85,2 ± 7,6 ms; resposta maxima -45,6 ± 2,0ms; resposta de cones - 27,8 ± 1,2ms e flicker 30 Hz - 27,9 ± 1,2 ms. Os resultados foram comparaveis entre os grupos masculino e feminino, exceto para a resposta maxima em que as mulheres obtiveram amplitudes estatisticamente maiores (t=2,06; P=0,046). CONCLUSAO: Os valores encontrados estao de acordo com dados normativos da literatura e sao fundamentais para o diagnostico correto de disfuncoes retinianas em pacientes na mesma faixa etaria. Inclusao de outras faixas etarias e o aumento no numero de sujeitos testados sao necessarios para estender valores normativos para o eletrorretinograma.

Visual evoked potentials findings in non-affected subjects from a large Brazilian pedigree of 11778 Leber's hereditary optic neuropathy

To investigate pattern-reversal visual evoked potentials (PRVEP) in asymptomatic maternally and non-maternally related members from a large Brazilian 11778/ND4 LHON pedigree. Transient PRVEP for check sizes 15′ and 60′ were recorded from asymptomatic mutation carriers and non-mutant descendants of affected/non-affected males, all with best-corrected visual acuity of 20/20. A control group of spouses (off-pedigree) was also included. Parameters of N75, P100 and N135 latencies (ms) and N75-P100 peak-to-peak amplitude (μV) as well as temporal dispersion (latency of N135-latency of N75) were determined. Longitudinal testing was obtained in a subseries of carriers in three annual consecutive visits. We tested 48 asymptomatic mutation carriers, 19 descendants of affected males, 9 descendants of non-affected males and 27 off-pedigrees, all of the latter being non-mutant. All non-mutant male descendants did not differ from off-pedigree controls. Statistically prolonged P100 latencies were found in mutation carriers (Pxa0=xa00.0143) when compared with off-pedigrees for check sizes 15′, as well as significantly larger temporal dispersions for both check size 15′ (Pxa0=xa00.0012) and check size 60′ (Pxa0=xa00.0271). Serial testing in 15 mutation carriers disclosed prolonged P100 latencies and larger temporal dispersion that did not change over time. Subclinical PRVEP abnormalities were detected in this large group of asymptomatic carriers of the 11778/ND4 LHON mutation from the same family, confirming and extending previous psychophysical and structural findings of a selective involvement of the parvocellular pathway. PRVEP is a useful test to characterize and monitor visual dysfunction in this devastating disease.

Age norms for monocular grating acuity measured by sweep-VEP in the first three years of age

PURPOSEnTo determine age norms for grating visual acuity and interocular acuity differences measured by the sweep-visually evoked potentials (VEP) technique in the first three years of life.nnnMETHODSnMonocular grating visual acuity was measured using the sweep-VEP in 67 healthy normal infants and children in the first 36 months of life.nnnRESULTSnSweep-VEP grating acuity ranged from 0.80 logMAR (20/125 Snellen equivalent) in the first month of life to 0.06 logMAR (20/20 Snellen equivalent) at 36 months of age. Lower normal limits (95th percentile limit) ranged from 0.95 logMAR (20/180) to 0.12 logMAR (20/25) with a progression of approximately 3 octaves in the first 36 months of age. The largest acceptable interocular acuity difference for clinical purposes was 0.10 logMAR.nnnCONCLUSIONSnAge norms for grating acuity along with interocular acuity differences were determined using the sweep-VEP technique. These norms should be incorporated in clinical practice for precise diagnosis of visual status in infants and preverbal children.

Retinal function in patients treated with tamoxifen.

Tamoxifen, an effective treatment of breast cancer, has been shown to cause ocular toxic effects. The purpose of this study was to determine retinal toxicity by full-field and focal electroretinograms (ERGs) in patients treated with tamoxifen. Full-field and focal ERGs were obtained from three groups: Tamoxifen—14 females (47–72xa0years, mean 58.3xa0±xa09.1) with normal fundus, treated with tamoxifen from 2 to 37xa0months; No Treatment—10 females (39–65xa0years, mean 50.1xa0±xa08.7) with previous breast cancer diagnosis and before tamoxifen treatment; Control—13 normal female volunteers (41–81xa0years, mean 52.7xa0±xa012.1). Peak-to-peak amplitude and b-wave implicit time were measured and statistically analyzed. Mean peak-to-peak amplitudes and implicit time from full-field and focal ERGs were comparable for the three different groups. Low-dosage tamoxifen showed no retinotoxic effect assessed by full-field and focal ERG in this small group of women with breast cancer.

Avaliação dos serviços de assistência ocular em população urbana de baixa renda da cidade de São Paulo - Brasil

PURPOSEnTo evaluate eye care services from the users perspective in a low income population from the east zone of the city of São Paulo--Brazil.nnnMETHODSnA household survey was performed using cluster sampling in three low income districts of the city of São Paulo--Brazil. From July/2004 to January/2005, 1055 interviews with an adult household representative were carried and an eye care system responsiveness questionnaire was administered through individual interview.nnnRESULTSn71.56% of the participants were women. Respondents age ranged from 18 to 92 years (41.42 +/- 15.67 years). Regarding schooling, 525 (49.77%) had four years or less; 489 (46.35%) between five and eleven years, 40 (3.79%) had eleven or more years of study. Eye care services need was reported as 712 (67.49%) declaring themselves or someone else of the household needing and obtaining services and 135 (12.80%) had never needed eye care. The most frequently cited barriers to obtain the eye care service by respondents was cost (77.29%), followed by unsuccessful attempt to obtain eye care (42.21%). General satisfaction for the criteria contained in the questionnaire was 63.37%. In the 36.63% dissatisfied respondents, the most frequently cited claim was the amount of time waited before consultation.nnnCONCLUSIONnThe main barriers to obtain eye care services were cost of medical appointment and lack of access to the services. 63.37% of the individuals in need who had received eye care in last 12 months were satisfied with the service provided.

Sweep visually evoked potentials and visual findings in children with West syndrome

BACKGROUNDnWest syndrome (WS) is a type of early childhood epilepsy characterized by progressive neurological development deterioration that includes vision.nnnAIMnTo demonstrate the clinical importance of grating visual acuity thresholds (GVA) measurement by sweep visually evoked potentials technique (sweep-VEP) as a reliable tool for evaluation of the visual cortex status in WS children.nnnMETHODSnThis is a retrospective study of the best-corrected binocular GVA and ophthalmological features of WS children referred for the Laboratory of Clinical Electrophysiology of Vision of UNIFESP from 1998 to 2012 (Committee on Ethics in Research of UNIFESP n° 0349/08). The GVA deficit was calculated by subtracting binocular GVA score (logMAR units) of each patient from the median values of age norms from our own lab and classified as mild (0.1-0.39 logMAR), moderate (0.40-0.80 logMAR) or severe (>0.81 logMAR). Associated ophthalmological features were also described.nnnRESULTSnData from 30 WS children (age from 6 to 108 months, median = 14.5 months, mean ± SD = 22.0 ± 22.1 months; 19 male) were analyzed. The majority presented severe GVA deficit (0.15-1.44 logMAR; mean ± SD = 0.82 ± 0.32 logMAR; median = 0.82 logMAR), poor visual behavior, high prevalence of strabismus and great variability in ocular positioning. The GVA deficit did not vary according to gender (P = .8022), WS type (P = .908), birth age (P = .2881), perinatal oxygenation (P = .7692), visual behavior (P = .8789), ocular motility (P = .1821), nystagmus (P = .2868), risk of drug-induced retinopathy (P = .4632) and participation in early visual stimulation therapy (P = .9010).nnnCONCLUSIONSnThe sweep-VEP technique is a reliable tool to classify visual system impairment in WS children, in agreement with the poor visual behavior exhibited by them.

Visual acuity and retinal function in patients with Bardet-Biedl syndrome

OBJECTIVE: Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype. METHODS: The visual acuity of a group of 23 patients (15 males) with ages ranging from 6-36 years (meanu200a=u200a15.8±6.4; medianu200a=u200a14.7) was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed. RESULTS: Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%), 20/50-20/150 in 13 (56.5%) patients, 20/200-20/400 in 2 (8.7%) patients and worse than 20/400 in one (4.3%) patient. The mean acuity in the better-seeing eye was 0.7±0.6 logMAR (20/100, Snellen equivalent). Scotopic rod and maximal responses were non-detectable in 21 (91.3%) patients, and cone responses were non-detectable in 15 (65.2%) patients. Elevated dark-adapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6%) patients having thresholds greater than 30 dB. CONCLUSIONS: In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition.

Amblyopia after unilateral infantile cataract extraction after six weeks of age

PURPOSEnTo determine interocular grating acuity difference in children treated for unilateral infantile cataract.nnnMETHODSnA group of 27 children previously treated for unilateral infantile cataract, had their monocular visual acuity measured by sweep visual evoked potentials. Interocular grating acuity difference was calculated as the absolute subtraction of monocular acuity scores. Lens status, opacity severity and eye alignment were considered for analysis.nnnRESULTSnMean interocular grating acuity difference obtained from unilateral cataract patients was 0.58 +/- 0.20 logMAR. This result was significantly larger than 0.10 logMAR used as normative data. Children with severe opacities had a more pronounced amblyopia than the moderate ones. No significant correlation between amblyopia and strabismus or aphakia was found.nnnCONCLUSIONSnInterocular acuity difference in this group of unilateral congenital cataract was more pronounced than previous reports, mainly because of delay in diagnosis, surgery and optical correction.

Alterações encontradas no potencial visual evocado por padrão reverso em pacientes com esclerose múltipla definida

INTRODUCTIONnMultiple sclerosis is an idiopathic demyelinating disease that may affect the optic nerve leading to acute unilateral visual loss, which could be observed by means of evoked visual potential (VEP). This exam is much valued for studying prechiasmatic visual paths in multiple sclerosis.nnnPURPOSEnTo analyze the findings of pattern reversal VEP in patients with prior diagnosis of multiple sclerosis and to compare them to visual acuity.nnnMETHODSnTwenty-four patients with a definite diagnosis of multiple sclerosis were submitted to pattern reversal VEP from October 2001 to March 2007.nnnRESULTSnIn P100 component response, at 15 and 1 degree stimuli, 19 eyes presented latency response up to 115 ms in both stimuli, which coincided in 6 eyes with latency response between 116 and 135 ms; 11 eyes had a latency response higher than 135 ms, and four eyes did not respond to stimuli. Correlating visual acuity with P100 latency for 15, in Pearson r correlation, r=0.85 with p=0.000000123, and for 1 degree, r = 0.87 with p=0.0000000338.nnnCONCLUSIONnApproximately 60.4% of patients presented abnormalities. However, the correlation between the P100 latency (15 and 1 degree) and visual acuity was statistically significant; therefore the better the visual acuity, the better the response to stimuli of the pattern-reversal VEP.