Low-cost air quality portable sensors and their potential use in respiratory health.

Air pollution is an environmental risk for the general population and for patients with various diseases, particularly respiratory diseases. Little data are available on personal exposure, but the recent emergence of low-cost air quality sensors (LCSs) should enable a better understanding of the health impacts of air pollution at the individual level. However, the reliability and accuracy of most sensors in the market have not been established, and a thorough understanding of their strengths and limitations is needed. We therefore conducted a review to address the following questions: 1) What is an LCS and what is the extent of its possible application? 2) Is the data obtained a reliable indicator of exposure? 3) What are the advantages and disadvantages of LCSs? 4) Could LCSs be useful in investigating the impact of air pollution on respiratory health? Further studies are needed to promote the use of LCS in research settings and among respiratory patients. This will allow us to monitor exposure levels, provide alerts and study the respiratory effects of individual-level air pollution.

[Contribution of multimodal imaging in the various stages of Stargardt disease]. / Intérêt de l'imagerie multimodale dans les différents stades de la maladie de Stargardt.

PURPOSE: To describe the contribution of multimodal imaging in the various stages of Stargardt disease (STGD). PATIENTS AND METHODS: We retrospectively reviewed 46 eyes of 23 STGD patients with identified ABCA4 mutations. All patients underwent a complete ophthalmic examination, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), fluorescein angiography (FA) and Indocyanine green angiography (ICGA). RESULTS: The mean age of patients was 25.5 years (range 8-56). Fundus examination was normal in 2 patients (subclinical stage), where SD-OCT showed localized retrofoveolar retinal pigment epithelium (RPE) thickening. FAF was normal in 1 eye and showed mild heterogeneous hyper-FAF in 3 eyes. Twelve eyes had mild salt and pepper changes in the macula (early stage) with diffuse retinal atrophy on SD-OCT and mixed hyper and hypoautofluorescence on FAF. Nine patients showed central atrophy with white-yellow flecks distributed in the posterior pole and mid-periphery. This phenotype showed total foveal atrophy on SD-OCT and normal peripapillary area on FAF. Twelve eyes had a large demarcated area of RPE atrophy, pigment clumping and migration extending to the peripheral retina associated with peripapillary atrophy. These eyes showed diffuse retinochoroidal atrophy on OCT with diffuse alterations reaching the peripapillary area on FAF. On FA, it was difficult to analyze the choroidal silence sign in patients with advanced stages of the disease. A hyperfluorescent window defect pattern was also found in patients with white-yellow flecks and did not correspond exactly to them, or to the areas of peripheral autofluorescent lesions. ICGA showed hypocyanescent areas seen at intermediate and late phases with multiple cyanescent points adjacent to them. On ICGA, hypocyanescent areas were more extensive than lesions observed on FAF. CONCLUSIONS: Multimodal imaging is helpful for the diagnosis of early stages of STGD disease and to better understand its pathophysiology. FAF and mostly SD-OCT have supplanted FA in the early, especially subclinical, stages. Over all, ICGA shows more extensive damage, making this tool useful for better understanding STGD and suggesting possible direct damage to the choriocapillaris associated with RPE lesions. In advanced stages, only DNA testing can confirm the diagnosis of STGD.

Effect of Risk Alleles in CFH, C3, and VEGFA on the Response to Intravitreal Bevacizumab in Tunisian Patients with Neovascular Age-related Macular Degeneration.

Purpose. The aim of this pharmacogenetic study was to evaluate the impact of high-risk alleles in factor H, factor C3 and vascular endothelial growth factor (VEGF) on the response to intravitreal bevacizumab in patients with neovascular age-related macular degeneration (AMD) in a Tunisian population. Methods. Ninety patients with active neovascular AMD treated with intravitreal bevacizumab injections were enrolled in the study. Treatment response was evaluated by comparing BCVA at baseline and at 12 months. Patients were classified into either "poor responders" (PR) or "good responders" (GR). Single nucleotide polymorphism (SNP) genotyping was performed for rs1061170 in FH, rs2230199 in C3 andrs699947, rs2010963 and rs3025039 in VEGF. The association between genotype and visual response at 12 months was assessed. Results. Seventy-seven participants were assigned to the GR group and 13 to the PR group. No correlation was found between FH, C3 and VEGF variant alleles and treatment response. However, haplotype analysis of rs699947 ((- 2578) C/A), rs2010963 ((+ 405) C/G) and rs3025039 ((+ 936) C/T) SNPs revealed that the AGT haplotype was associated with a poor response at 12months (p = 0.048). No association was found between treatment response and the cumulative effect of all high-risk alleles of C3, FH and VEGF. All three types of CNV were found in both groups at a comparable frequency. Conclusions. The VEGF haplotype TGA could be used as a marker for poor visual prognosis in Tunisian patients with neovascular AMD treated with bevacizumab.

[Intravitreal bevacizumab in AMD complicated by submacular hemorrhage]. / Injections intravitréennes de bevacizumab dans les hémorragies sous maculaires compliquant la DMLA.

PURPOSE: To evaluate functional and anatomic results of intravitreal bevacizumab as monotherapy at 12 and 24 months in patients with neovascular age-related macular degeneration (AMD) complicated by large submacular hemorrhage. METHODS: Retrospective analysis of a total of 21 patients (22 eyes) with large submacular hemorrhage secondary to age-related macular degeneration between May 2008 and December 2011. Patients were treated with three monthly intravitreal bevacizumab injections (1.25mg/0.05 mL) at a four to six week interval and then PRN. Retreatment was based on the presence of hemorrhage on fundus examination or signs of activity on optical coherence tomography. Changes from baseline best corrected visual acuity (BCVA) scores, central retinal thickness, volume of hemorrhage and number of injections were analyzed. RESULTS: The mean patient age was 72 years (range, 60-89 years). All patients completed at least 12 months of follow-up, and 17 patients fulfilled 24 months. The size of hemorrhage varied from 3 to 9 disc areas with a mean duration of 12.8 days. At baseline, mean initial BCVA was 20/400 (1.3 LogMAR) and improved to 20/160 at 12 months (P<0.001) and 20/164 at 24 months (P<0.001). Mean central retinal thickness decreased significantly from 550 µm to 255 µm at 24 months (P<0.001). The mean number of injections was 3.87 during the first 12 months. No case of recurrent bleeding was detected during the second year. CONCLUSION: Intravitreal bevacizumab may be a beneficial approach for the management of large submacular hemorrhage secondary to AMD.

[SD-OCT contribution in congenital achromatopsia diagnosis (6 patients)]. / Contribution du SD-OCT de la macula dans le diagnostic de l'achromatopsie congénitale : à propos de 6 patients.

PURPOSE: Achromatopsia (ACH) is a congenital autosomal recessive cone disorder. The puspose is to describe particular SD-OCT macular images in ACH. METHODS: The study included 6 patients from 3 consanguineous Tunisian families with congenital nystagmus and amblyopia with ACH. All patients had clinical examination with fundus photography, autofluorescence, 100-Hue Color vision and the appearance and thickness of all retinal layers were evaluated by spectral-domain optical coherence tomography (SD-OCT). RESULTS: All patients had ACH. The feature was loss of inner- and outer-segments (IS/OS) with disruption of the ciliary layer on OCT and an appearance of partial-thickness hole in the outer macular retina. CONCLUSION: This feature seems to be characteristic of ACH. SD-OCT correlated to clinic signs help the diagnosis.

[Macular choroidal thickness assessment with SD-OCT in high myopia with or without choroidal neovascularization]. / Épaisseur choroïdienne fovéolaire au SD-OCT dans la myopie forte avec ou sans néovaisseaux choroïdiens.

PURPOSE: To measure macular choroidal thickness (CT) using spectral-domain optical coherence tomography (SD-OCT) in eyes with myopic macular choroidal neovascularization (CNV), and to compare choroidal thickness in these eyes with highly myopic eyes without CNV. PATIENTS AND METHODS: Sixty-four eyes with myopic CNV matched with 64 highly myopic eyes without CNV by age and axial length (AL) were examined between January 2010 and November 2011. OCT scans were performed with spectral-domain OCT (TOPCON OCT 2000). The reference position was changed from the vitreous to the choroid. OCT scan patterns consisted of seven sections; the subfoveal CT was measured manually between Bruch's membrane and the internal portion of the sclera in eyes with CNV and from the pigment epithelium to the scleral interface in eyes without CNV. RESULTS: In the subgroup with CNV, the mean subfoveal CT was 51.71 µm ± 17.35. A statistically significant negative correlation was found between CT and AL (r=-0.615, P=0.0001). Regression analysis demonstrated a decrease of 8.4 µm per mm of AL. In the subgroup without CNV, matched with the CNV subgroup by age (P=0.597), and AL (P=0.813), the mean subfoveal CT was 93.35 µm ± 34.81 µm. The difference between the two subgroups was statistically significant (P<10(-4)). DISCUSSION: Macular choroidal thickness is reduced in high myopia, especially when complicated by CNV. It has not yet been shown that choroidal thinning may be a risk factor for choroidal neovascularization, but our results may suggest that macular choroidal thinning may lead to hypoxic retinal changes resulting in secretion of VEGF and thus CNV. CONCLUSION: Macular choroidal thinning observed in high myopia with CNV. These findings may suggest that choroidal changes may play a role in the pathogenesis of choroidal neovascularization.

Y402H polymorphism in complement factor H and age-related macular degeneration in the Tunisian population.

To evaluate a possible association between the complement factor H (CFH) Y402H polymorphism and susceptibility to age-related macular degeneration (AMD) in the Tunisian population, as well as the impact of the genotype distribution among different phenotypes and the response to treatment with intravitreal bevacizumab, exon 9 of CFH was analyzed for the Y402H polymorphism by direct sequencing in 135 healthy controls and 127 sporadic unrelated AMD patients classified into the following groups: 12 atrophic AMD (group G1), 115 exudative AMD (G2) and 10 AMD patients who had fibrovascular scarring (G3) that did not allow a precise grading of the phenotype. Seventy patients in G2 were treated with 1.25 mg intravitreal bevacizumab at 6-week intervals until choroidal neovascularization (CNV) was no longer active. The frequency of the CFH 402H allele was significantly higher in AMD patients than in controls (p = 2.62 × 10(-16)). However, subgroup analysis does not reveal any association between the variant allele H and phenotypes of AMD or CNV. Also, there was no significant difference in response to bevacizumab treatment according to Y402H CFH genotype (p = 0.59). A strong association of the 402H allele with susceptibility to AMD in the Tunisian population was confirmed; however, this variant does not appear to be involved in the clinical progression of this disease or in the postintravitreal bevacizumab response.

[Intravitreal bevacizumab injections versus verteporferin photodynamic therapy for macular choroidal neovascularization in high myopia: 24-month follow-up]. / Traitement des néovaisseaux choroïdiens maculaires du myope fort : injection intravitréenne de bevacizumab versus photothérapie dynamique à la vertéporfine à 24 mois.

PURPOSE: To compare the long-term safety and of intravitreal bevacizumab injections (IVB) and verteporferin photodynamic therapy (PDT) in the treatment of choroidal neovascularization (CNV) in high myopia. METHODS: Review of retrospectively collected data of 60 eyes of 60 patients with high myopic choroidal neovascularization treated either with standard PDT (PDT group; n=30) or IVB injections (IVB group; n=30). The two groups were compared at baseline, 3, 6,12 and 24 months. RESULTS: In the IVB group, mean best corrected visual acuity (BCVA) was significantly improved at 3 to 12 months; however, the significance was lost at 24 months. The PDT group showed an insignificant improvement at 3 and 6 months, then worsened at 12 and 24 months. Mean BCVA was better in the IVB group than the PDT group at 3, 6, 12 and 24 months. The decrease in mean central macular thickness was significantly higher in the IVB group than in the PDT group at 3, 6, 12 and 24 months. At 24 months, chorioretinal atrophy was noted in five eyes (16.6%) treated with IVB and in 22 eyes (73.3%) treated with PDT (P=2×10(-5)). CONCLUSION: IVB provides significantly better BCVA than PDT for high myopic CNV over the long-term.

[Prevalence and risk factors of age-related macular degeneration (AMD) in a Tunisian hospital population]. / Prévalence et facteurs de risque de la dégénérescence maculaire liée à l'âge (DMLA) dans une population hospitalière tunisienne.

PURPOSE: To describe the prevalence and the risk factors for the age related macular degeneration (AMD) in a Tunisian hospital population. PATIENTS AND METHODS: A total of 2204 subjects 50 years of age and older were enrolled in a prospective study conducted between august 2004 and February 2009. Medical history was reviewed. Subjects underwent a complete ophthalmic examination, including best corrected visual acuity and slit lamp biomicroscopy with fundus examination. Fundus photography and fluorescein angiography were performed if clinical features of AMD were observed on fundus examination. Cases were classified in early and late stages of AMD. RESULTS: The prevalence of late AMD was higher than early AMD. Significant risk factors are age, male gender, smoking, excessive sunlight exposure and poor consumption of fish. Cardiovascular disease, diabetes and dyslipimia were not significantly associated to a high prevalence of AMD. CONCLUSION: AMD is a multifactorial disease. In our Tunisian hospital population, the prevalence of AMD was higher than in the Europeen population. It can be explained by genetic differences or risk factors. Age, cigarette smoking and sunlight exposure were associated with increasing prevalence of AMD in Tunisia.

[Epidemiologic study of pediatric uveitis: a series of 49 cases]. / Étude épidémiologique des uvéites de l'enfant: à propos de 49 cas.

PURPOSE: To analyze the patterns of pediatric uveitis. PATIENTS AND METHODS: A retrospective study of 49 children with uveitis, examined from January 2000 to December 2009. All patients underwent a complete ophthalmic examination and an etiological search; follow-up varied from six months to seven years. RESULTS: The mean age at onset of uveitis was 11.6 years (range, 5-14 years). The sex ratio was 1.04. Uveitis was bilateral in 59.20% of the patients, anterior in 22 cases (44.9%), intermediate in seven cases (14.3%), posterior in four cases (8.1%), and panuveitis was found in 16 cases (32.7%). In 57.2% of the patients, uveitis was idiopathic. Infectious uveitis was responsible for 14.1% of the cases, the most common of which were toxoplasmosis and toxocarosis. Systemic associations were found in 22.5%, with juvenile idiopathic arthritis in 6.2%. A specific ocular entity was responsible for 6.2% of the cases. Ocular complications occurred in 65.3% of the affected eyes, the most common being cataract (24.5%) and cystoid macular edema (20.5%). The final visual acuity was less than 20/200 in 18%. CONCLUSIONS: Pediatric uveitis is rare but may cause visual loss. In our study, the cause of uveitis in childhood remains most often undiagnosed. Toxoplasmosis and toxocarosis are the most frequent infectious causes. Cataract was the most frequent complication. A strict ophthalmological follow-up is mandatory to improve the prognosis.

[Vogt-Koyanagi-Harada disease associated with interferon-alpha and ribavirin therapy for chronic hepatitis C infection]. / Syndrome de Vogt-Koyanagi-Harada au cours d'une hépatite C chronique sous interféron alpha et ribavirine.

The complex immunological effects of interferon and ribavirin therapy in hepatitis C virus may also exacerbate or trigger the development of autoimmunity. A rare case of Vogt-Koyanagi-Harada disease associated with ribavirin and interferon-alpha treatment for chronic hepatitis C infection is presented. The potential role of interferon and/or ribavirin therapy is discussed. Physicians should be aware of the association between interferon-alpha 2a and ribavirin use for hepatitis C infection and the development of Harada disease. This severe ophthalmological complication requires close follow-up of hepatitis C virus-infected patients on interferon-alpha treatment.