Functional evaluation of an iridotomy in primary angle closure eyes.

OBJECTIVE: To evaluate the functional efficacy of an iridotomy in primary angle closure (PAC) eyes by measuring IOP responses to provocative tests before and after iridotomy. DESIGN: Prospective cohort study. SUBJECTS: 50 consecutive adult patients, 40-60 years of age, having primary angle closure. METHODS: Clinical examination, perimetry, biometry and ultrasound biomicroscopy of the angle were done. A darkroom prone provocative test (DRPPT), a mydriatic test and a Valsalva maneuver were performed before and after the iridotomy. MAIN OUTCOME MEASURES: IOP change in response to the provocative tests before and after iridotomy, and correlation with baseline parameters. RESULTS: IOP at baseline and after iridotomy was 14.4 ± 2.7 mmHg and 14.3 ± 2.6 mmHg, respectively (p = 0.)83. There was no significant change on diurnal phasing before and after an iridotomy (p = 0.)11. The mean IOP rise was 5.9 ± 3.7 mmHg on the DRPPT, 4.3 ± 3.5 mmHg on the Mydriatic test and 9.1 ± 4.9 mmHg on the Valsalva maneuver, and was reduced significantly to 3.2 ± 2.1 mmHg, 2.3 ± 1.8 and 6.4 ± 3.5, respectively(p < 0.001 for all tests). The decrease in pupillary block component for all 50 eyes was 46.5 % for the mydriatic test, 45.8 % for the DRPPT and 29.7 % for the Valsalva maneuver. PAC eyes positive on the DRPPT and mydriatic test prior to an iridotomy became negative after laser iridotomy in 75.9 and 84.6 % eyes, respectively, but on the Valsalva maneuver, only 23.8 % became negative. After iridotomy, eyes that continued to be positive on the mydriatic test had a significantly thicker lens (p = 0.02), decreased TCPD (p = 0.014) and narrower trabecular-iris angle (p = 0.048). On the DRPPT, they had a thicker lens (p = 0.03), shorter iris thickness (p = 0.025) and TCPD (p = 0.032), and on the Valsalva maneuver, they had a narrower scleral-ciliary process angle (SCPA; p = 0.019) and shorter TCPD (p = 0.015). CONCLUSIONS: This comprehensive functional evaluation of laser iridotomy in early PAC eyes showed a significant reduction in the pupillary block component of IOP response to provocative testing, possibly decreasing IOP fluctuations over time. An iridotomy does not, however, significantly change mean IOP or diurnal phasing of IOP in PAC eyes. Eyes with a very narrow angle or a thick lens may continue to have angle closure due to other pathomechanisms for angle closure.

3-Methylpiperidinium ionic liquids.

A wide range of room temperature ionic liquids based on the 3-methylpiperdinium cation core were produced from 3-methylpiperidine, which is a derivative of DYTEK® A amine. First, reaction with 1-bromoalkanes or 1-bromoalkoxyalkanes generated the corresponding tertiary amines (Rmßpip, R = alkyl or alkoxyalkyl); further quaternisation reactions with the appropriate methylating agents yielded the quaternary [Rmmßpip]X salts (X(-) = I(-), [CF3CO2](-) or [OTf](-); Tf = -SO2CF3), and [Rmmßpip][NTf2] were prepared by anion metathesis from the corresponding iodides. All [NTf2](-) salts are liquids at room temperature. [Rmmßpip]X (X(-) = I(-), [CF3CO2](-) or [OTf](-)) are low-melting solids when R = alkyl, but room temperature liquids upon introduction of ether functionalities on R. Neither of the 3-methylpiperdinium ionic liquids showed any signs of crystallisation, even well below 0 °C. Some related non-C-substituted piperidinium and pyrrolidinium analogues were prepared and studied for comparison. Crystal structures of 1-hexyl-1,3-dimethylpiperidinium tetraphenylborate, 1-butyl-3-methylpiperidinium bromide, 1-(2-methoxyethyl)-1-methylpiperidinium chloride and 1-(2-methoxyethyl)-1-methylpyrrolidinium bromide are reported. Extensive structural and physical data are collected and compared to literature data, with special emphasis on the systematic study of the cation ring size and/or asymmetry effects on density, viscosity and ionic conductivity, allowing general trends to be outlined. Cyclic voltammetry shows that 3-methylpiperidinium ionic liquids, similarly to azepanium, piperidinium or pyrrolidinium counterparts, are extremely electrochemically stable; the portfolio of useful alternatives for safe and high-performing electrolytes is thus greatly extended.

Novel chiral ionic liquids: physicochemical properties and investigation of the internal rotameric behaviour in the neat system.

Optically active S-alkyl-N,N'-bis((S)-1-phenylethyl)thiouronium salts, abbreviated as (S)-[C(n)petu]Y (where Y is an anion; n = 1, 2, 3, 4, 6, 8, 10, 12 or 16), have been prepared and studied by a broad spectrum of analyses. This consists of density, viscosity, and conductivity determination, followed by a discussion of relevant correlations. Unusual trends depending on the S-alkyl chain length were documented for (S)-[C(n)petu][NTf2] series (where [NTf2](-) = bis{(trifluoromethyl)sulfonyl}amide), including the viscosity decreasing with increasing chain length, and the conductivity showing a maximum between the S-butyl and the S-hexyl derivative. In addition, a hindered rotamerism of the thiouronium cation in dmso-d6 solution was recognised by (1)H and (13)C NMR techniques. Thorough analysis of NMR spectra confirmed that the main contribution comes from rotation about the partial double C-S bond. For the first time, a neat thiouronium ionic liquid system has been subjected to quantitative analysis of hindered rotamerism by dynamic NMR coalescence studies, with estimated activation energy for rotation of 63.9 ± 0.4 kJ mol(-1). Finally, the application of (S)-[C(n)petu]Y salts as chiral discriminating agents for carboxylates by (1)H NMR spectroscopy was further investigated, demonstrating the influence of the S-alkyl chain length on chiral recognition; (S)-[C2petu][NTf2] ionic liquid with the mandelate anion gave the best results.

Buffered chlorogallate(III) ionic liquids and electrodeposition of gallium films.

Buffering of Lewis acidic chlorometallate ionic liquids is a useful tool to modify their properties for electrochemical and catalytic applications. Lewis acidic chlorogallate(iii) ionic liquids containing the 1-octyl-3-methylimidazolium cation, buffered with sodium chloride, were studied using (71)Ga NMR spectroscopy and cyclic voltammetry. All the studied Lewis acidic compositions (0.50 < χGaCl3 ≤ 0.75) could be buffered to mild or moderate acidity, but not to neutrality. Electrodeposition of gallium from such buffered systems was possible, yielding deposits of improved morphology over the unbuffered ionic liquids, due to the constant melt composition maintained by the buffer. These findings were in a stark contrast with older studies on chloroaluminate(iii) ionic liquids buffered with sodium chloride.

Ionic liquid-based routes to conversion or reuse of recycled ammonium perchlorate.

New, potentially green, and efficient synthetic routes for the remediation and/or re-use of perchlorate-based energetic materials have been developed. Four simple organic imidazolium- and phosphonium-based perchlorate salts/ionic liquids have been synthesized by simple, inexpensive, and nonhazardous methods, using ammonium perchlorate as the perchlorate source. By appropriate choice of the cation, perchlorate can be incorporated into an ionic liquid which serves as its own electrolyte for the electrochemical reduction of the perchlorate anion, allowing for the regeneration of the chloride-based parent ionic liquid. The electrochemical degradation of the hazardous perchlorate ion and its conversion to harmless chloride during electrolysis was studied using IR and (35)Cl NMR spectroscopies.

Bilateral iridocorneal endothelial syndrome in a young girl with Down's syndrome.

We describe the occurrence of bilateral iridocorneal endothelial (ICE) syndrome with glaucoma in a young girl with Down's syndrome. A 16-year-old girl with Down's syndrome was found to have secondary glaucoma in the right eye with features of progressive iris atrophy in both eyes. She was uncontrolled on maximum tolerable medical therapy for glaucoma. She underwent an uneventful trabeculectomy with mitomycin-C in her right eye. Scanning electron microscopy of the trabecular meshwork obtained in this case is described.

Scanning laser ophthalmoscopy in an elderly Indian population.

PURPOSE: To study optic nerve head (ONH) characteristics using scanning laser ophthalmoscopy, Heidelberg retina tomograph (HRT), in an elderly population. METHODS: A population-based, cross-sectional study included 1460 eyes of 1460 consecutive, subjects >60 years, in North India. All subjects underwent a detailed ophthalmic evaluation and imaged on HRT. Stereometric parameters, Moorfields regression analysis (MRA) and discriminant function analysis were analyzed. Correlation between ONH parameters and disc area, age, sex, and intraocular pressure was analyzed. RESULTS: Disc size had a normal Gaussian distribution (2.22 ± 0.48 mm2), but all other stereometric parameters showed a wide variation. MRA found 1320 (90.4%) eyes within normal limits, 71 (4.86%), borderline limits, and 69 (4.73%) outside normal limits. Comparison of eyes meeting International Society of Geographical and Epidemiological Ophthalmology criteria for a glaucoma suspect, C:D > 0.7, with those that did not show a statistically significant difference in the cup area, rim area, rim disc ratio, and cup volume (p = 0.02, 0.02, 0.02, 0.03, respectively). An Intraocular pressure (IOP) ≥21 mmHg was seen in 3.01%, and only 12 eyes out of 1460, 0.82%, had an IOP ≥21 mmHg and a cup:disc ratio of more than 0.7. A van Herick estimation of < Grade 3 was seen in 19.4% Conclusions: Stereometric parameter data, MRA, and clinical examination in this population at high risk for glaucoma found that about 10% of individuals over 60 years of age could be classified as glaucoma suspects and would need further evaluation.

Classifying patterns of localized glaucomatous visual field defects on automated perimetry.

AIM: To classify the classic patterns of glaucomatous visual field defects on automated perimetry and to study their proximity to fixation. STUDY DESIGN: Cross-sectional observational study. MATERIALS AND METHODS: About 1120 full threshold 30-2 reliable visual fields of glaucoma patients were analyzed by 2 glaucomatologists. Classically described patterns of visual field defects were identified on the pattern deviation plot and definitions proposed. Interreader agreement between 3 independent (not involved in the classification) readers was determined. Proximity to fixation of the different patterns was assessed. RESULTS: Interreader agreement with 3 readers was found to be 93% or more between any 2 readers using the present system of classification. Central fixation was seen to be involved in 45% of the glaucomatous visual field defects studied overall. CONCLUSIONS: The proposed definitions of topographical glaucomatous field defects based on the pattern deviation probability plot are simple to use in clinical practice with good interreader agreement.

Comparative evaluation of bimatoprost monotherapy in primary chronic angle closure and primary open angle glaucoma eyes: a three-year study.

AIMS: The aim of this study was to compare the long-term efficacy of bimatoprost 0.03% monotherapy in primary open angle glaucoma (POAG) versus primary chronic angle closure glaucoma (PCACG) eyes. METHODS: A total of 55 consecutive primary adult glaucoma patients on bimatoprost monotherapy were prospectively evaluated in this 3-year, open-labeled, uncontrolled study. The primary outcome was the evaluation of a difference in the response to therapy of POAG eyes, as compared to PCACG eyes over a follow-up of 3 years. RESULTS: In the POAG group, the mean intraocular pressure (IOP) at the 36-month followup was found to be increased by 2.10 (+/-3.90) mmHg (confidence interval [CI], 0.975-4.185), compared to the mean IOP at 1 month (P = 0.047). In the PCACG group, the mean IOP at the 36-month follow-up was increased by 3.66) (+/- 3.34) mmHg (CI, 6.241-1.092), compared to the mean IOP at 1 month (P = 0.011). This upward drift in IOP was higher in the PCACG group, compared to the POAG group, but this was not statistically significant (P = 0.54). Patients with POAG and PCACG showed a 50% and 40% chance of having an IOP of <18 mmHg with bimatoprost monotherapy (P = 0.23), respectively, at the 3-year follow-up. CONCLUSIONS: This study showed that bimatoprost 0.03% monotherapy significantly lowers IOP in both POAG and PCACG eyes over a period of 3 years, though its efficacy appeared to decrease over time, to a similar extent, in both groups.

Ultrasound biomicroscopic characteristics of the anterior segment in primary congenital glaucoma.

PURPOSE: To evaluate qualitatively and quantitatively ultrasound biomicroscopic (UBM) features of the anterior segment in eyes with primary congenital glaucoma. METHODS: UBM of 45 eyes of patients with primary congenital glaucoma (39 previously operated and 6 unoperated eyes) and 28 control eyes were included in this study. UBM parameters were correlated with ocular biometry. Iris thickness, ciliary body thickness, ciliary body-lens distance, posterior chamber depth, and anterior chamber angle were measured and compared with control eyes. Other features of the anterior segment were qualitatively evaluated. RESULTS: A thin, stretched-out ciliary body and abnormal tissue at the iridocorneal angle were features seen in 90% of UBM scans. Iris thickness and stretched zonules correlated with the axial length (r = -0.6 and 0.58, respectively; p = 0.04) but not with the mean corneal diameter. Abnormal insertion of the ciliary body to the posterior surface of the iris was noted in eight eyes (17%). CONCLUSIONS: The present study documents characteristic anterior segment dysplasia and ciliary body anomalies in patients with primary congenital glaucoma.

Optical coherence tomographic characteristics in morning glory disc anomaly.

CASE REPORT: Optical coherence tomography (OCT) confirms increased optic nerve head dimensions in morning glory anomaly, and provides evidence of increased retinal nerve fibre layer thickness and reduced macular thickness. COMMENTS: This first report of quantitative data from OCT may provide more useful information to corroborate clinical diagnosis of this rare congenital disorder.

Long-term scanning laser ophthalmoscopy and perimetry in different severities of primary open and chronic angle closure glaucoma eyes.

PURPOSE: To determine rate of change over time on scanning laser ophthalmoscopy, HRT, compared to perimetry, and to determine incidence, parametric changes, and risk factors for progression in primary open angle glaucoma (POAG) and chronic primary angle closure angle glaucoma (CPACG) eyes. METHODS: Prospective clinical study of 116 POAG eyes and 129 CPACG eyes of different severities of glaucoma. Standard automated perimetry and optic nerve head topography were studied at baseline and thereafter every 6 months. Changes in HFA and HRT parameters, in response to IOP, were compared over at least 5 years. RESULTS: Fourteen POAG eyes (12.1%) and 20 CPACG eyes (15.5%) showed progression on SAP over time. Percentage drop of IOP was similar in eyes that progressed and in stable eyes. The change in MD in CPACG eyes was 1.8 dB/year on SAP and 1.36 dB/year in POAG eyes, P = 0.1. Twenty-nine eyes showed progression on HRT with 24 confirmed on SAP. Trend analysis picked up progression more frequently than other HRT parameters. Eyes that progressed in both groups, in all severities of glaucoma, had intermittent fluctuations of ≥ 4 mmHg over mean IOP on ≥3 follow up visits, P ≤ 0.001. CONCLUSION: IOP fluctuations of ≥ 4 mmHg over the mean IOP and duration of disease were associated with progression in POAG and CPACG eyes.

Easily Accessible Rare-Earth-Containing Phosphonium Room-Temperature Ionic Liquids: EXAFS, Luminescence, and Magnetic Properties.

A range of liquid rare earth chlorometallate complexes with the alkyl-phosphonium cation, [P666 14](+), has been synthesized and characterized. EXAFS confirmed the predominant liquid-state speciation of the [LnCl6](3-) ion in the series with Ln = Nd, Eu, Dy. The crystal structure of the shorter-alkyl-chain cation analogue [P4444](+) has been determined and exhibits a very large unit cell. The luminescence properties, with visible-light emissions of the liquid Tb, Eu, Pr, and Sm and the NIR emissions for the Nd and Er compounds, were determined. The effective magnetic moments were measured and fitted for the Nd, Tb, Ho, Dy, Gd, and Er samples.

Mercury capture on a supported chlorocuprate(ii) ionic liquid adsorbent studied using operando synchrotron X-ray absorption spectroscopy.

Mercury scrubbing from gas streams using a supported 1-butyl-3-methylimidazolium chlorocuprate(ii) ionic liquid ([C4mim]2[Cu2Cl6]) has been studied using operando EXAFS. Initial oxidative capture as [HgCl3]- anions was confirmed, this was then followed by the unanticipated generation of mercury(i) chloride through comproportionation with additional mercury from the gas stream. Combining these two mechanisms leads to net one electron oxidative extraction of mercury from the gas with increased potential capacity and efficiency for supported ionic liquid mercury scrubbers.

An ionic liquid process for mercury removal from natural gas.

Efficient scrubbing of mercury vapour from natural gas streams has been demonstrated both in the laboratory and on an industrial scale, using chlorocuprate(II) ionic liquids impregnated on high surface area porous solid supports, resulting in the effective removal of mercury vapour from natural gas streams. This material has been commercialised for use within the petroleum gas production industry, and has currently been running continuously for three years on a natural gas plant in Malaysia. Here we report on the chemistry underlying this process, and demonstrate the transfer of this technology from gram to ton scale.

Prospective evaluation of optic nerve head by confocal scanning laser ophthalmoscopy after intraocular pressure control in adult glaucoma.

PURPOSE: To evaluate and compare changes in scanning laser ophthalmoscopy, HRT II, and perimetry in adult primary open angle and chronic angle closure glaucoma over at least five years. DESIGN: Prospective non-randomized clinical trial. METHODS: 245 eyes of 245 patients, 116 primary open angle glaucoma, POAG eyes and 129 primary angle closure glaucoma, PACG eyes were studied. Standard achromatic perimetry and optic nerve head topography by HRT II were studied serially, at baseline and thereafter every six months. RESULTS: 14 POAG eyes (11.2%) and 20 PACG eyes (15.5%) showed progression on achromatic perimetry. Kaplan-Meier analysis showed a survival rate of 71% at 148 months for PACG and 86% at 144 months in POAG eyes. Eyes that progressed had frequent records (median 3.08 visits, range 2-10 visits) of a rise of IOP of >4 mm, over the target IOP, during follow-up. In stable eyes, PACG required >50% reduction in IOP to achieve stability on HRT, while POAG eyes showed improvement of optic nerve head parameters even with an IOP reduction of 25%. CONCLUSION: Intermittent IOP fluctuations of ≥4 mm Hg over the mean IOP was associated with progression in POAG and CPACG eyes. PACG eyes appeared to progress faster and to a greater extent, and were more resistant to changes in ONH tomography following standard therapy, requiring a larger percentage drop in IOP to manifest improvement in optic nerve head parameters, as compared to POAG eyes.

Electrochemical synthesis of indium(0) nanoparticles in haloindate(III) ionic liquids.

A synthetic route to indium(0) nanoparticles via an electrochemical reduction of haloindate(III) ionic liquids to indium(I), and its subsequent disproportionation to indium(0) and indium(III) in the bulk electrolyte, is described. In this sustainable method, the ionic liquid acts simultaneously as metal source, templating agent, and stabilising agent, with the electron as the only reducing agent. The nature of the ionic liquid cation is demonstrated to strongly affect the morphology and size distribution of the indium(0) nanoparticles.