Corneal wavefront-guided photorefractive keratectomy with mitomycin-C for hyperopia after radial keratotomy: Two-year follow-up

PURPOSE: To assess corneal wavefront-guided photorefractive keratectomy (PRK) to correct hyperopia after radial keratotomy (RK). SETTING: Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. DESIGN: Case series. METHODS: Excimer laser corneal wavefront-guided PRK with intraoperative mitomycin-C (MMC) 0.02% was performed. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), corneal aberrations, and haze. RESULTS: The mean time between RK and PRK in the 61 eyes (39 patients) was 18.8 years +/- 3.8 (SD). Before PRK, the mean SE was +4.17 +/- 1.97 diopters (D); the mean astigmatism, -1.39 +/- 1.04 D; and the mean CDVA, 0.161 +/- 0.137 logMAR. At 24 months, the mean values were 0.14 +/- 0.99 D (P<.001), -1.19 +/- 1.02 D (P=.627), and 0.072 +/- 0.094 logMAR (P<.001), respectively; the mean UDVA was 0.265 +/- 0.196 (P<.001). The UDVA was 20/25 or better in 37.7% of eyes and 20/40 or better in 68.9%. The CDVA improved by 1 or more lines in 62.3% of eyes. Two eyes (3.3%) lost 2 or more lines, 1 due to corneal ectasia. Thirty eyes (49.2%) were within +/- 0.50 D of intended SE and 45 (73.8%) were within +/- 1.00 D. From 6 to 24 months, the mean SE regression was +0.39 D (P<.05). A significant decrease in coma, trefoil, and spherical aberration occurred. Three eyes developed peripheral haze more than grade 1. CONCLUSION: Corneal wavefront-guided PRK with MMC for hyperopia after RK significantly improved UDVA, CDVA, and higher-order corneal aberrations with a low incidence of visually significant corneal haze.

Electrophysiological evidence for impairment of contrast sensitivity in mercury vapor occupational intoxication

Contrast sensitivity (CS) was evaluated in 41 former workers from a lamp manufacturing plant who were on disability retirement due to exposure to mercury and 14 age-matched controls. The CS was measured monocularly using the sweep visual evoked potential (sVEP) paradigm at 6 spatial frequencies (0.2, 0.8, 2.0, 4.0, 15.0, and 30 cpd). Statistical difference (p < 0.05) was found between the controls and the patient right and left eyes for 2.0 and 4.0 cpd. According the results in those spatial frequencies the eyes were classified in best and worst. Statistical differences were found between the controls and the best eyes for 2.0 and 4.0 cpd and for 0.8, 2.0, and 4.0 cpd for their worst eyes. No correlation was found between CS results and the time of exposure (mean 8.9 yr +/- 4.1), time away from the mercury source (mean = 6.0 yr +/- 3.9), urinary mercury level at the time of work (mean = 40.6 mu g/g +/-36.3) or with the mercury level at the CS measurement time (mean = 1.6 mu g/g +/-1.1). We show the first evidence of a permanent impairment in CS measured objectively with the sVEP. Our data complement the previous psychophysical works reporting a diffuse impairment in the CS function showing a CS reduction in the low to middle spatial frequencies. In conclusion, non-reversible CS impairment was found in occupational exposure to mercury vapor. We suggest that CS measurement should be included in studies of the mercury effects of occupational exposure. (C) 2007 Elsevier Inc. All rights reserved.

Laser locking to the Hg-199 S-1(0)-P-3(0) clock transition with 5.4x10(-15)/root tau fractional frequency instability

With Hg-199 atoms confined in an optical lattice trap in the Lamb-Dicke regime, we obtain a spectral line at 265.6 nm for which the FWHM is similar to 15 Hz. Here we lock an ultrastable laser to this ultranarrow S-1(0) - P-3(0) clock transition and achieve a fractional frequency instability of 5.4 x 10(-15) / root tau for tau &lt;= 400 s. The highly stable laser light used for the atom probing is derived from a 1062.6 nm fiber laser locked to an ultrastable optical cavity that exhibits a mean drift rate of -6.0 x 10(-17) s-(1) (-16.9 mHzs(-1) at 282 THz) over a six month period. A comparison between two such lasers locked to independent optical cavities shows a flicker noise limited fractional frequency instability of 4 x 10(-16) per cavity. (c) 2012 Optical Society of America

In Vitro Schistosomicidal Activity of Balsaminol F and Karavilagenin C

Five cucurbitane-type triterpenes (1-5), previously isolated from the African medicinal plant Momordica balsamina, along with five ester derivatives (6-10) of karavilagenin C (2), were evaluated for their potential schistosomicidal activity against Schistosoma mansoni adult worms. The natural compounds were isolated from the ethyl acetate-soluble fraction of the methanol extract of the aerial parts of M. balsamina. In a preliminary study, a significant schistosomicidal activity was observed for both the crude methanol extract and the ethyl acetate fraction. The compounds responsible for the activity were found to be balsaminol F (1) and karavilagenin C (2) with LC50 values of 14.7 +/- 1.5 and 28.9 +/- 1.8 mu M, respectively, after 24 h of incubation (positive control praziquantel, LC50 = 1.2 +/- 0.1 mu M). Both compounds (1, 2), at 10-50 mu M, induced significant reductions in the motor activity of the worms and significantly decreased the egg production. Furthermore, they were able (at 10-100 mu M) to separate the adult worm pairs into male and female after 24 h. Compounds 3-5, bearing a sugar moiety as a substituent, and the acylated derivatives of karavilagenin C (6-10) were inactive, suggesting that the presence of free hydroxyl groups in the tetracyclic skeleton might be important for the activity. A correlation between activity and the molecular volume/weight of compounds was also found.

Modulation transfer function and optical quality after bilateral implantation of a+3.00 D versus a+4.00 D multifocal intraocular lens

PURPOSE: To determine whether the improvement in intermediate vision after bilateral implantation of an aspheric multifocal intraocular lens (IOL) with a +3.00 diopter (D) addition (add) occurs at the expense of optical quality compared with the previous model with a +4.00 D add. SETTING: Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil. DESIGN: Prospective randomized double-masked comparative clinical trial. METHODS: One year after bilateral implantation of Acrysof Restor SN6AD1 +3.00 D IOLs or Acrysof Restor SN6AD3 +4.00 D IOLs, optical quality was evaluated by analyzing the in vivo modulation transfer function (MTF) and point-spread function (expressed as Strehl ratio). The Strehl ratio and MTF curve with a 4.0 pupil and a 6.0 mm pupil were measured by dynamic retinoscopy aberrometry. The uncorrected and corrected distance visual acuities at 4 m, uncorrected and distance-corrected near visual acuities at 40 cm, and uncorrected and distance-corrected intermediate visual acuities at 50 cm, 60 cm, and 70 cm were measured. RESULTS: Both IOL groups comprised 40 eyes of 20 patients. One year postoperatively, there were no statistically significant between-group differences in the MTF or Strehl ratio with either pupil size. There were no statistically significant between-group differences in distance or near visual acuity. Intermediate visual acuity was significantly better in the +3.00 D IOL group. CONCLUSION: Results indicate that the improvement in intermediate vision in eyes with the aspheric multifocal +3.00 D add IOL occurred without decreasing optical quality over that with the previous version IOL with a +4.00 D add.

Exploration time of static images implying different body movements causes time distortions

Studies of subjective time have adopted different methods to understand different processes of time perception. Four sculptures, with implied movement ranked as 1.5-, 3.0-, 4.5-, and 6.0-point stimuli on the Body Movement Ranking Scale, were randomly presented to 42 university students untrained in visual arts and ballet. Participants were allowed to observe the images for any length of time (exploration time) and, immediately after each image was observed, recorded the duration as they perceived it. The results of temporal ratio (exploration time/time estimation) showed that exploration time of images also affected perception of time, i.e., the subjective time for sculptures representing implied movement were overestimated.\

Measurements of D-0 and D* production in p plus p collisions at root s=200 GeV

We report measurements of charmed-hadron (D-0, D*) production cross sections at midrapidity in p + p collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays D-0 -&gt; K- pi(+), D*(+) -&gt; D-0 pi(+) -&gt; K-pi(+)pi(+) and their charge conjugates, covering the p(T) range of 0.6-2.0 and 2.0-6.0 GeV/c for D-0 and D*(+), respectively. From this analysis, the charm-pair production cross section at midrapidity is d sigma/dy vertical bar(c (c) over bar)(y-0) = 170+/-45(stat)(-59)(+38()sys) mu b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a fixed-order next-to-leading logarithm calculation.

Comparison of Visual Acuity and Automated Perimetry Findings in Patients With Neuromyelitis Optica or Multiple Sclerosis After Single or Multiple Attacks of Optic Neuritis

Objective: To review the clinical characteristics of patients with neuromyelitis optica (NMO) and to compare their visual outcome with those of patients with optic neuritis (ON) and multiple sclerosis (MS). Methods: Thirty-three patients with NMO underwent neuro-ophthalmic evaluation, including automated perimetry along with 30 patients with MS. Visual function in both groups was compared overall and specifically for eyes after a single episode of ON. Results: Visual function and average visual field (VF) mean deviation were significantly worse in eyes of patients with NMO. After a single episode of ON, the VF was normal in only 2 of 36 eyes of patients with NMO compared to 17 of 35 eyes with MS (P &lt; 0.001). The statistical analysis indicated that after a single episode of ON, the odds ratio for having NMO was 6.0 (confidence interval [CI]: 1.6-21.9) when VF mean deviation was worse than -20.0 dB while the odds ratio for having MS was 16.0 (CI: 3.6-68.7) when better than -3.0 dB. Conclusion: Visual outcome was significantly worse in NMO than in MS. After a single episode of ON, suspicion of NMO should be raised in the presence of severe residual VF deficit with automated perimetry and lowered in the case of complete VF recovery.

Chronic pain associated with the Chikungunya Fever: long lasting burden of an acute illness

Abstract Background Chikungunya virus (CHIKV) is responsible for major epidemics worldwide. Autochthonous cases were recently reported in several European countries. Acute infection is thought to be monophasic. However reports on chronic pain related to CHIKV infection have been made. In particular, the fact that many of these patients do not respond well to usual analgesics suggests that the nature of chronic pain may be not only nociceptive but also neuropathic. Neuropathic pain syndromes require specific treatment and the identification of neuropathic characteristics (NC) in a pain syndrome is a major step towards pain control. Methods We carried out a cross-sectional study at the end of the major two-wave outbreak lasting 17 months in Réunion Island. We assessed pain in 106 patients seeking general practitioners with confirmed infection with the CHIK virus, and evaluated its impact on quality of life (QoL). Results The mean intensity of pain on the visual-analogical scale (VAS) was 5.8 ± 2.1, and its mean duration was 89 ± 2 days. Fifty-six patients fulfilled the definition of chronic pain. Pain had NC in 18.9% according to the DN4 questionnaire. Conversely, about two thirds (65%) of patients with NC had chronic pain. The average pain intensity was similar between patients with or without NC (6.0 ± 1.7 vs 6.1 ± 2.0). However, the total score of the Short Form-McGill Pain Questionnaire (SF-MPQ)(15.5 ± 5.2 vs 11.6 ± 5.2; p < 0.01) and both the affective (18.8 ± 6.2 vs 13.4 ± 6.7; p < 0.01) and sensory subscores (34.3 ± 10.7 vs 25.0 ± 9.9; p < 0.01) were significantly higher in patients with NC. The mean pain interference in life activities calculated from the Brief Pain Inventory (BPI) was significantly higher in patients with chronic pain than in patients without it (6.8 ± 1.9 vs 5.9 ± 1.9, p < 0.05). This score was also significantly higher in patients with NC than in those without such a feature (7.2 ± 1.5 vs 6.1 ± 1.9, p < 0.05). Conclusions There exists a specific chronic pain condition associated to CHIKV. Pain with NC seems to be associated with more aggressive clinical picture, more intense impact in QoL and more challenging pharmacological treatment.