Alexandre Rosa

Retinal disorders in northern Brazilian patients treated with chloroquine assessed by multifocal ERG.

The effects of chloroquine intake on the retinal function in a Brazilian population of patients were assessed by multifocal electroretinography. Twenty-four randomly chosen eyes of patients treated with chloroquine for rheumatoid arthritis and systemic lupus erythematosus were examined using multifocal electroretinography (mfERG). Control measurements were acquired from 21 randomly chosen eyes of age-matched healthy subjects. None of the study participants had an inherited retinal disease or a Snellen visual acuity reduced to less than 20/40. In patients and control subjects, cumulative chloroquine dose, total daily dose, duration of treatment, retinal examination, visual field defects, visual acuity, and the mfERG were assessed. The average amplitudes and implicit times of the N1, P1, and P2 components of the mfERGs were measured in the central hexagon (R1) and in five rings (R2–R6). The values measured in patients and normal subjects were compared. The P1 amplitudes in R2 were significantly decreased in the patients. In addition, the amplitudes of N1 and N2 in R1 were significantly smaller in the patients. The implicit times of none of the components were significantly different between patients and controls. The response amplitude was not significantly correlated with cumulative dose and duration of intake. There was no correlation with retinal appearance, visual field, and visual acuity. In agreement with earlier data, the central mfERG amplitudes were decreased in chloroquine patients indicating functional alterations in the retina. These changes are also present in a Brazilian population suggesting that the effects of chloroquine are general and that genetic background and life circumstances probably have, if at all, only little effect.

Colour Vision Impairment in Young Alcohol Consumers.

Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject’s ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject’s colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants.

Optical coherence tomography and multifocal electroretinography of patients with advanced neovascular age-related macular degeneration before, during, and after treatment with ranibizumab

PURPOSE To evaluate retinal morphology and function of patients with advanced neovascular age-related macular degeneration (AMD) before, during, and after treatment with ranibizumab. METHODS Twenty-one eyes diagnosed with advanced AMD were studied with optical coherence tomography (OCT) and multifocal electroretinography (mfERG). Three intravitreal injections of ranibizumab were administered at 1-month intervals. Evaluations were performed before the first injection (D0) and at 30 (D30), 60 (D60), and 90 days (D90) after the first injection and compared to an age-matched control group (n=21 eyes). RESULTS The thickness of macular retinal layers increased before treatment due to the presence of intraretinal fluid. A thick retinal pigment epithelium-choriocapillaris complex (RPE-CC) suggested the presence of choroidal neovascular membrane. Intraretinal edema decreased after treatment (P<0.01), but persisting RPE-CC thickness resulted in a subretinal scar. Three different annular retinal areas were studied with mfERG (from center to periphery: rings R1, R2, and R3). The amplitude of the first negative component (N1) decreased in R1, R2, and R3 at D30, D60, and D90 when compared with that in controls (P<0.05); the N1 implicit time was delayed in R3 at D30 (P<0.05). The amplitude of the first positive component (P1) was reduced in R1 and R2 at D30, D60, and D90 when compared with that in controls (P<0.01); the P1 implicit time was delayed in R1 at D0 and D60 (P<0.05), in R2 at D0, D30, and D90 (P<0.01), and in R3 at D30 and D60 (P<0.05). CONCLUSION Ranibizumab reduces intraretinal edema, even in advanced cases. Central macular activity appeared to increase after the initiation of treatment, improving over time.

Avaliação da retinopatia hipertensiva através do potencial oscilatório do eletrorretinograma

PURPOSE: To evaluate the behavior of the scotopic Oscillatory Potentials (OP) of total field electroretinogram (ERG) in hypertensive retinopathy. METHODS: Forty-four patients (n=44) were submitted to clinical evaluation and subdivided in to 2 groups: hypertensives (HT) and normotensives (NT). The hypertensives patients were maintained under placebo during the period of the study. Soon afterwards, they were submitted to ophthalmological evaluation and accomplishment of ERG. Total field electroretinogram (ERG), with recording of the answers: scotopic, maximum scotopic, OP scotopic, photopic and flicker.For analysis of the OP answer the latency of the first 2 peaks and the average value of the width of the first 3 peaks of the compound of 3 consecutive answers, denominated Oscillatory Index (OI) were considered. RESULTS: The sample was composed of 44 patients, with a mean age of 51.55 ± 7.2 range (34 to 68) years, 24 being females. Arterial hypertension affected 26 (59.1%) of the patients, while 18 (40.9%) were normotensives. The average of the obtained IO was 257.41 µv in the NT group and of 217.81 µv in HT (p=0.006). The averages of latencies obtained for peaks 1 (NT-18.42 and HT-17.91) and 2 (NT-24.54 and HT - 24.29) were not different between the groups (p>0.05). CONCLUSIONS: The hypertensive patients presented significantly smaller oscillatory index than the normotensives, suggesting that arterial hypertension might cause dysfunction of the internal retina.

Non-surgical repositioning of dexamethasone implant (Ozurdex®) fragment in a case of anterior chamber migration

Funding: No specific financial support was available for this study. CEP Approval: Not applicable. Disclosure of potential conflicts of interest: None of the authors have any potential conflict of interest to disclose. Received on: Mar 20, 2018 Accepted on: Apr 06, 2018 Corresponding author: Paulo Sérgio Miranda de Oliveira Filho – Universidade Federal do Pará, Rua Augusto Corrêa, 1, Belém, PA, 66075-110. psoliveiramd@gmail.com

Neuroretinite unilateral subaguda difusa (DUSN): atualização continuada

Diffuse unilateral subacute neuroretinitis (DUSN) is a form of uveitis that can potentially lead to blindness. In Brazil and other parts of South America, diffuse unilateral subacute neuroretinitis is an important cause of posterior uveitis in children and healthy young adults. If diagnosed and treated in early stage, allows a resolution of symptoms with improvement of visual acuity. If the disease progresses to the late stage, can result in significant visual loss. In this study, through a literature review, we describe the main characteristics of this disease, including the following aspects: history, etiology, physiopathology, clinical features, diagnosis, differential diagnosis and treatment.