Influence of Climate on Clinical Diagnostic Dry Eye Tests: Pilot Study.

PURPOSE: To analyze dry eye disease (DED) tests and their consistency in similar nonsymptomatic population samples living in two geographic locations with different climates (Continental vs. Atlantic). METHODS: This is a pilot study including 14 nonsymptomatic residents from Valladolid (Continental climate, Spain) and 14 sex-matched and similarly aged residents from Braga (Atlantic climate, Portugal); they were assessed during the same season (spring) of two consecutive years. Phenol red thread test, conjunctival hyperemia, fluorescein tear breakup time, corneal and conjunctival staining, and Schirmer test were evaluated on three different consecutive visits. Reliability was assessed using the intraclass correlation coefficient and weighted kappa (κ) coefficient for quantitative and ordinal variables, respectively. RESULTS: Fourteen subjects were recruited in each city with a mean (± SD) age of 63.0 (± 1.7) and 59.1 (± 0.9) years (p = 0.08) in Valladolid and Braga, respectively. Intraclass correlation coefficient and κ values of the tests performed were below 0.69 and 0.61, respectively, for both samples, thus showing moderate to poor reliability. Subsequently, comparisons were made between the results corresponding to the middle and higher outdoor relative humidity (RH) visit in each location as there were no differences in mean temperature (p ≥ 0.75) despite RH values significantly differing (p ≤ 0.005). Significant (p ≤ 0.05) differences were observed between Valladolid and Braga samples on tear breakup time (middle RH visit, 2.76 ± 0.60 vs. 5.26 ± 0.64 seconds; higher RH visit, 2.61 ± 0.32 vs. 5.78 ± 0.88 seconds) and corneal (middle RH, 0.64 ± 0.17 vs. 0.14 ± 0.10; higher RH, 0.60 ± 0.22 vs. 0.0 ± 0.0) and conjunctival staining (middle RH, 0.61 ± 0.17 vs. 0.14 ± 0.08; higher RH, 0.57 ± 0.15 vs. 0.18 ± 0.09). CONCLUSIONS: This pilot study provides initial evidence to support that DED test outcomes assessing the ocular surface integrity and tear stability are climate dependent. Future large-sample studies should support these outcomes also in DED patients. This knowledge is fundamental for multicenter clinical trials. Lack of consistency in diagnostic clinical tests for DED was also corroborated.

Adaptation to multifocal and monovision contact lens correction.

PURPOSE: To compare visual performance with the Biofinity multifocal (MF) contact lens with monovision (MV) with the Biofinity single-vision contact lens. METHODS: A crossover study of 20 presbyopic patients was conducted. Patients were randomized first into either an MF or an MV lens for 15 days for each modality, with a washout period between each lens type. Measurements included monocular and binocular high- and low-contrast logarithm of the minimum angle of resolution visual acuity (VA) at distance and near visions, binocular distance contrast sensitivity function, and near stereoacuity. RESULTS: At 15 days, patients lost fewer than two letters (half a line of VA) of binocular distance and near VA, with the MF and MV lens under high- and low-contrast conditions (P > 0.05 for both comparisons). No statistically significant differences were seen in binocular VA at near or distance with either lens. However, the monocular distance VA improved significantly in the nondominant eye, with the MF lens by one line over the 15-day period under high-contrast (P = 0.023) and low-contrast (P = 0.035) conditions; this effect was not seen with the MV lens. Contrast sensitivity function was within the normal limits with both lenses. The stereoacuity was significantly (P < 0.01) better with MF than with MV. CONCLUSIONS: Multifocal contact lens correction provided satisfactory levels of VA comparable with MV without compromising stereoacuity in this crossover study. The near vision significantly improved in the dominant eye, and the distance vision improved in the nondominant eye from 1 to 15 days with the MF lens, suggesting that patients adapted to the multifocality overtime, whereas this was not true for MV.

Light distortion and spherical aberration for the accommodating and nonaccommodating eye.

To evaluate how different amounts of induced spherical aberration (SA) affect the light distortion (LD) phenomena, tests were performed using an experimental device to measure the distortion (haloes, glare, and so on) of a point source. To simulate the effect of SA, eight different phase plates between +0.300 and −0.300 µm of SA for a 5-mm aperture were used in a random and double-masked experimental design. Measurements were performed at a distance of 2 m in a darkened room in 10 eyes of five subjects with a mean age of 26.4±6.1 years and a mean refractive error of −0.50±0.70 D. Data were obtained with natural pupil and after pupil dilatation. The measurements with this experimental system showed a significant increase in all distortion parameters with cycloplegia for the phase plates with the higher positive SA (+0.300 and +0.150 µm). The disturbance index increased from 14.86±6.12% to 57.98±36.20% (p<0.05) with the +0.300 µm plate. The same effect was observed through at a much lower rate when the eye could accommodate. Plates inducing negative SA did not change the LD compared to the control condition without induction of SA or even decreased the effect of distortion. Pupillary dilation and cyclopegia led to a significant increase in the size of the LD when increasing values of SA were induced. Accommodation and pupillary constriction are capable of compensating the degradation of the optical quality induced.

Light-distortion analysis as a possible indicator of visual quality after refractive lens exchange with diffractive multifocal intraocular lenses.

PURPOSE: To study the perception of light distortion after refractive lens exchange (RLE) with diffractive multifocal intraocular lenses (IOLs). SETTING: Clínica Oftalmológica das Antas, Porto, Portugal. DESIGN: Retrospective comparative study. METHODS: Refractive lens exchange was performed with implantation of an AT Lisa 839M (trifocal) or 909MP (bifocal toric) IOL, the latter if corneal astigmatism was more than 0.75 diopter (D). The postoperative visual and refractive outcomes were evaluated. A prototype light-distortion analyzer was used to quantify the postoperative light-distortion indices. A control group of eyes in which a Tecnis ZCB00 1-piece monofocal IOL was implanted had the same examinations. RESULTS: A trifocal or bifocal toric IOL was implanted in 66 eyes. The control IOL was implanted in 18 eyes. All 3 groups obtained a significant improvement in uncorrected distance visual acuity (UDVA) (P < .001) and corrected distance visual acuity (CDVA) (P = .001). The mean uncorrected near visual acuity (UNVA) was 0.123 logMAR with the trifocal IOL and 0.130 logMAR with the bifocal toric IOL. The residual refractive cylinder was less than 1.00 D in 86.7% of cases with the toric IOL. The mean light-distortion index was significantly higher in the multifocal IOL groups than in the monofocal group (P < .001), although no correlation was found between the light-distortion index and CDVA. CONCLUSIONS: The multifocal IOLs provided excellent UDVA and functional UNVA despite increased light-distortion indices. The light-distortion analyzer reliably quantified a subjective component of vision distinct from visual acuity; it may become a useful adjunct in the evaluation of visual quality obtained with multifocal IOLs. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Peripheral refraction with eye and head rotation with contact lenses.

PURPOSE: To evaluate the impact of eye and head rotation in the measurement of peripheral refraction with an open-field autorefractometer in myopic eyes wearing two different center-distance designs of multifocal contact lenses (MFCLs). METHODS: Nineteen right eyes from 19 myopic patients (average central M ± SD = -2.67 ± 1.66 D) aged 20-27 years (mean ± SD = 23.2 ± 3.3 years) were evaluated using a Grand-Seiko autorefractometer. Patients were fitted with one multifocal aspheric center-distance contact lens (Biofinity Multifocal D(®)) and with one multi-concentric MFCL (Acuvue Oasys for Presbyopia). Axial and peripheral refraction were evaluated by eye rotation and by head rotation under naked eye condition and with each MFCL fitted randomly and in independent sessions. RESULTS: For the naked eye, refractive pattern (M, J0 and J45) across the central 60° of the horizontal visual field values did not show significant changes measured by rotating the eye or rotating the head (p > 0.05). Similar results were obtained wearing the Biofinity D, for both testing methods, no obtaining significant differences to M, J0 and J45 values (p > 0.05). For Acuvue Oasys for presbyopia, also no differences were found when comparing measurements obtained by eye and head rotation (p > 0.05). Multivariate analysis did not showed a significant interaction between testing method and lens type neither with measuring locations (MANOVA, p > 0.05). There were significant differences in M and J0 values between naked eyes and each MFCL. CONCLUSION: Measurements of peripheral refraction by rotating the eye or rotating the head in myopic patients wearing dominant design or multi-concentric multifocal silicone hydrogel contact lens are comparable.

Validation of a method to measure light distortion surrounding a source of glare.

Our objective was to validate a new device dedicated to measure the light disturbances surrounding bright sources of light under different sources of potential variability. Twenty subjects were involved in the study. Light distortion was measured using an experimental prototype (light distortion analyzer, CEORLab, University of Minho, Portugal) comprising twenty-four LED arrays panel at 2 m. Sources of variability included: intrasession and intersession repeated measures, pupil size (3 versus 6 mm), defocus (+0.50 ) correction for the working distance, angular resolution (15 deg versus 30 deg), temporal stimuli presentation, and pupil size. Size, shape, location, and irregularity parameters have been obtained. At a low speed of presentation of the stimuli, changes in angular resolution did not have an effect on the results of the parameters measured. Results did not change with pupil size. Intensity of the central glare source significantly influenced the outcomes. Examination time was reduced by 30% when a 30 deg angular resolution was explored instead of 15 deg. Measurements were fast and repeatable under the same experimental conditions. Size and shape parameters showed the highest consistency, whereas location and irregularity parameters showed lower consistency. The system was sensitive to changes in the intensity of the central glare source but not to pupil changes in this sample of healthy subjects

Performance of three multipurpose disinfecting solutions with a silicone hydrogel contact lens.

PURPOSE: To evaluate the clinical performance of a silicone hydrogel (Si-Hy) soft contact lens (CL) in combination with three different multipurpose disinfecting solutions (MPDSs). METHODS: This was a prospective, randomized, single-masked, crossover, and comparative study in which 31 habitual soft CL wearers were randomly assigned to one of the three MPDSs (Synergi, COMPLETE RevitaLens, and OPTI-FREE PureMoist) for 1 month with a 1-week wash-out period between each exposure. All subjects were successfully refitted with a Si-Hy CL (Biofinity). Subjects were then scheduled for follow-up visits after 1 month of lens wear, being evaluated at 2 and 8 hours after lens insertion. Visual Analogue Scales (VAS) were used to gauge comfort rating. RESULTS: The tarsal conjunctiva showed a significantly different degree of lid redness between the MPDSs at the 2-hour visit (P < 0.05, Kruskal-Wallis test), being lower for COMPLETE RevitaLens compared to the other two MPDSs (Mann-Whitney U test). Furthermore, a significantly different degree of lid roughness at the 8-hour visit was seen (P < 0.05, Kruskal-Wallis test), being higher for Synergi (Mann-Whitney U test). The subjective comfort was similar with the three MPDSs. CONCLUSION: Tarsal conjunctival response should be also considered in the context of the clinical performance of MPDs at the ocular surface.

Antimicrobial Activity and Mechanism of Action of New N-Heteroaryl-1H-(benz)Imidazoles.

The antimicrobial activity of sixteen new N-heteroarylated 1H-(benz)imidazoles was evaluated against clinically relevant bacteria (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and fungi (Candida, Aspergillus and dermatophyte) species according to the Clinical and Laboratory Standards Institute guidelines. None of the tested compounds were active against Gram negative bacteria, but only against S. aureus, that was particularly susceptible to N-thianthrenyl- and N-dibenzothienyl imidazole derivatives. Most of the imidazole derivatives showed a broad spectrum of antifungal activity in all tested fungal strains, including fluconazole-resistant species, with a particularly low minimum inhibitory concentration (MIC) for dermatophytes. N-(dibenzofuran-4-yl)-1H-imidazole (1) and N-(dibenzothien-4-yl)-1H-imidazole (3) showed the highest antifungal potential, being most active against C. albicans. Some N-heteroarylated benzimidazoles showed low activity for fungi with the exception of 3-(1H-benzo[d]imidazol-1-yl)quinoline (14) which was selective against dermatophytes (MIC=4-16 µg/mL). The effect of the active compounds in the inhibition of the dimorphic transition, ergosterol biosynthesis and mitochondrial activity was evaluated in Candida albicans. Compounds 1 and 3 showed the capacity to inhibit the germ tube formation in C. albicans, reduced the ergosterol production and impaired the mitochondrial function. Compounds 1 and 3 showed antimicrobial activity and low cytotoxicity, being of interest for further investigation concerning specially the development of new antifungal agents.

Clinical performance and "ex vivo" dehydration of silicone hydrogel contact lenses with two new multipurpose solutions.

PURPOSE: To compare the performance of two novel multipurpose disinfecting solutions (MPDS) in preventing silicone hydrogel contact lens dehydration, provide higher scores of subjective comfort and stable optical quality during a month of lens wear in neophyte volunteers. METHOD: This is a prospective, double-blind, contralateral and randomised study involving the contra lateral use of Complete RevitaLens and Biotrue MPDS. Twenty-five neophytes wore Air Optix Aqua for 1 month. Volunteers were evaluated on day 1 and day 30 at 2 and 10h after lens insertion. Tear film stability using Tearscope Plus (Keeler, UK), whole eye aberrations for 4.5mm pupil size (IRx3, ImaginEyes, France) and subjective comfort (0-10 score) along with the dehydration values obtained with a gravimetric method were collected at each follow-up visit. RESULTS: NIBUT values decreased significantly with both care systems from baseline to 10h visit on day 1 (p=0.032 and 0.016, mean difference=-6.7s and -7.0 s, for Complete Revitalens and Biotrue, respectively). Dehydration rates and ocular aberrations did not change significantly over the month of follow-up (p>0.05, ANOVA with Bonferroni post hoc corrections), nor between visits within the same day (p>0.05, paired sample T-test). End-of-day dryness sensation worsened similarly with both MPDS after 1 month (p=0.021 and 0.005, mean difference=-1.4 and -1.3, for Complete Revitalens and Biotrue, respectively). CONCLUSIONS: Regardless of their different chemical compositions in terms of moisture additives both MPDS solutions evaluated performed similarly regarding objective measures of dehydration, tear stability and optical quality but presented significant differences in subjective symptoms.

Avaliação cognitiva em um paciente com hidrocefalia de pressão normal / Cognitive evaluation in one patiente after normal pressure hydrocephalus

A hidrocefalia de pressão normal (HPN) é uma síndrome caracterizada por uma tríade sintomática, onde estão presentes os sintomas de apraxia de marcha, demência e incontinência urinária. Os autores relatam um caso dessa entidade em um homem de 68 anos que desenvolveu HPN, encontrando-se no quadro de demência moderada, o qual após cirurgia de sistema de derivação ventrículo-peritoneal, apresentou recuperação cognitiva nas esferas de memória verbal, memória de execução e memória visual. Os aspectos cognitivos, foram avaliados por meio de testes neuropsicológicos, antes e após a cirurgia. Concluem os autores que a tríade sintomática apresentada pela hidrocefalia de pressão normal desenvolvida em idosos pode ser tratadas mediante da cirurgia de derivação ventrículo-peritoneal.