Acute retinal necrosis following intravitreal dexamethasone (Ozurdex®) implant / Necrose aguda de retina após implante de dexametasona intravítrea (Ozurdex®)

A 52-year-old woman undergoing azathioprine treatment for rheumatoid arthritis developed acute retinal necrosis a month after intravitreal dexamethasone (Ozurdex ®) implantation for posterior uveitis in the left eye. Varicella zoster virus (VZV) DNA was detected in the anterior chamber and vitreous samples on polymerase chain reaction (PCR) analysis. Retinal detachment occurred despite systemic and intravitreal antiviral therapy. Favorable structural and functional outcomes were achieved after retinal surgery with silicone oil. To the authors’ knowledge, this is the first reported case of acute retinal necrosis following placement of an Ozurdex® implant. Physicians practicing Ozurdex® implantations should be aware of this unusual but devastating complication. Extra caution and frequent follow-up are required in all immunocompromised patients receiving Ozurdex® implantation.

Uma mulher de idade de 52 anos em tratamento azatioprina para a artrite reumatóide desenvolveu necrose aguda de retina um mês após implantação Ozurdex® para uveíte posterior do olho esquerdo. DNA de varicela zoster (VZV) foi detectado em amostras de câmara anterior e vítreo por análise de PCR. Apesar da terapia antiviral sistêmica e intravítrea, o paciente apresentou descolamento de retina. Desfecho favorável estrutural e funcional foi obtida após a cirurgia retiniana com óleo de silicone. Pelo conhecimento dos autores, este é o primeiro caso relatado de necrose aguda de retina após a colocação de um implante Ozurdex®. Os médicos que implantam Ozurdex® devem estar cientes desta complicação incomum, mas devastadora. É necessário cuidado extra e acompanhamento frequente dos pacientes que recebam o implante Ozurdex® e apresentem qualquer condição imunocomprometedora.

Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis.

Background: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP) is used in the assessment of optic pathway involvement. Objective: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. Materials and Methods: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM) 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P100 amplitude, P100 latency in PVEP and total error scores (TES) in FM 100-Hue test were assessed. Results: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7) and 4.1 ± 4.4 years. MS group showed significantly delayed P100 latency for both checks (P < 0.001). Similarly, MS patients had significantly increased total error scores (TES) in FM-100 Hue (P < 0.001). The correlations between TESs and PVEP amplitudes / latencies were insignificant for both checks (P > 0.05 for all). 14 MS patients (70%) had an increased TESs in FM-100 Hue, 11 (55%) MS patients had delayed P100 latency and 9 (45%) had reduced P100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P100 latency, and 0.173 for P100 amplitude. Conclusions: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS.

Retinal nerve fiber layer thickness analysis in suspected malingerers with optic disc temporal pallor.

Purpose: To investigate the value of temporal retinal nerve fiber layer (RNFLtemporal) thickness in the prediction of malingering. Materials and Methods: This prospective, cross-sectional study was conducted on 33 military conscripts with optic disc temporal pallor (ODTP) and 33 age-and sex-matched healthy controls. Initial visual acuity (VAi) and visual acuity after simulation examination techniques (VAaset) were assessed. The subjects whose VAaset were two or more lines higher than VAi were determined as malingerers. Thickness of the peripapillary RNFL was determined with OCT (Stratus OCT™, Carl Zeiss Meditec, Inc.). RNFLtemporal thickness of the subjects were categorized into one of the 1+ to 4+ groups according to 50% confidence interval (CI), 25% CI and 5% CI values which were assessed in the control group. The VAs were converted to LogMAR-VAs for statistical comparisons. Results: A significant difference was found only in the temporal quadrant of RNFL thickness in subjects with ODTP (P=0.002). Mean LogMAR-VA increased significantly after SETs (P<0.001). Sensitivity, specificity, positive and negative predictive values of categorized RNFLtemporal thickness in diagnosing malingering were 84.6%, 75.0%, 68.8%, 88.2%, respectively. ROC curve showed that RNFLtemporal thickness of 67.5 μm is a significant cut-off point in determining malingering (P=0.001, area under the curve:0.862). The correlations between LogMAR-VAs and RNFLtemporal thicknesses were significant; the correlation coefficient for LogMAR-VAi was lower than the correlation for LogMAR-VAaset (r=−0.447, P=0.009 for LogMAR-VAi; r=−0.676, P<0.001 for LogMAR-VAaset). Conclusions: RNFLtemporal thickness assessment may be a valuable tool in determining malingering in subjects with ODTP objectively.