BcHnm1, a predicted choline transporter, modulates conidial germination and virulence in Botrytis cinerea.

Previous network-based comparative genomic analysis between major lifestyles of fungal plant pathogens highlighted that HNM1, a predicted choline transporter, is part of the necrotroph core-genome's functions. In this work we have generated and characterized deletion mutants and developed complemented strains for the HNM1 homolog (Bchnm1) in the necrotrophic model fungal plant pathogen Botrytis cinerea. The Bchnm1 deletion mutants exhibited reduced conidia germination and germ tube elongation. The functional activity of the Δbchnm1 deletion mutants was illustrated by reduced necrotic colonization of B. cinerea on tomato and French bean leaves. The role of BcHnm1 in germination was also supported by qRT-PCR results that illustrated increased Bchnm1 transcript levels during the early infection stages (at 16 h post inoculation) of the WT strain on tomato plant leaves, and during conidia germination (in-vitro). In line with the predicted function of BcHnm1 in choline transport, Δbchnm1 deletion mutant showed an attenuated choline import capacity. The potential role of choline in the WT B. cinerea was further demonstrated by an increase in conidia germination (by 100%) in the presence of 1 mM exogenous choline while growth in the presence of hemicholinium-3, an inhibitor of choline transporter, showed 40% inhibition in germination. In contrast to the WT, exogenous choline and the inhibitor did not affect conidia germination in the Δbchnm1 deletion mutants. Collectively, this study shows for the first time that BcHnm1, a predicted choline transporter, is important for conidial germination, germ tube elongation, response to exogenous choline, and virulence in plant pathogenic fungi.

Secretion-Based Modes of Action of Biocontrol Agents with a Focus on Pseudozyma aphidis.

Plant pathogens challenge our efforts to maximize crop production due to their ability to rapidly develop resistance to pesticides. Fungal biocontrol agents have become an important alternative to chemical fungicides, due to environmental concerns related to the latter. Here we review the complex modes of action of biocontrol agents in general and epiphytic yeasts belonging to the genus Pseudozyma specifically and P. aphidis in particular. Biocontrol agents act through multiple direct and indirect mechanisms, which are mainly based on their secretions. We discuss the direct modes of action, such as antibiosis, reactive oxygen species-producing, and cell wall-degrading enzyme secretions which can also play a role in mycoparasitism. In addition, we discuss indirect modes of action, such as hyperbiotrophy, induced resistance and growth promotion based on the secretion of effectors and elicitors from the biocontrol agent. Due to their unique characteristics, epiphytic yeasts hold great potential for use as biocontrol agents, which may be more environmentally friendly than conventional pesticides and provide a way to reduce our dependency on fungicides based on increasingly expensive fossil fuels. No less important, the complex mode of action of Pseudozyma-based biocontrol agents can also reduce the frequency of resistance developed by pathogens to these agents.

Characterization of the Role of a Non-GPCR Membrane-Bound CFEM Protein in the Pathogenicity and Germination of Botrytis cinerea.

The necrotrophic fungus Botrytis cinerea, is considered a major cause of postharvest losses in a wide range of crops. The common fungal extracellular membrane protein (CFEM), containing a conserved eight-cysteine pattern, was found exclusively in fungi. Previous studies in phytopathogenic fungi have demonstrated the role of membrane-bound and secreted CFEM-containing proteins in different aspects of fungal virulence. However, non-G protein-coupled receptor (non-GPCR) membrane CFEM proteins have not been studied yet in phytopathogenic fungi. In the present study, we have identified a non-GPCR membrane-bound CFEM-containing protein, Bcin07g03260, in the B. cinerea genome, and generated deletion mutants, ΔCFEM-Bcin07g03260, to study its potential role in physiology and virulence. Three independent ΔCFEM-Bcin07g03260 mutants showed significantly reduced progression of a necrotic lesion on tomato (Solanum lycopersicum) leaves. Further analysis of the mutants revealed significant reduction (approximately 20-30%) in conidial germination and consequent germ tube elongation compared with the WT. Our data complements a previous study of secreted ΔCFEM1 mutants of B. cinerea that showed reduced progression of necrotic lesions on leaves, without effect on germination. Considering various functions identified for CFEM proteins in fungal virulence, our work illustrates a potential new role for a non-GPCR membrane CFEM in pathogenic fungi to control virulence in the fungus B. cinerea.

Transcriptome Profiling Data of Botrytis cinerea Infection on Whole Plant Solanum lycopersicum.

Botrytis cinerea is a foliar necrotrophic fungal-pathogen capable of infecting >580 genera of plants, is often used as model organism for studying fungal-host interactions. We used RNAseq to study transcriptome of B. cinerea infection on a major (worldwide) vegetable crop, tomato (Solanum lycopersicum). Most previous works explored only few infection stages, using RNA extracted from entire leaf-organ diluting the expression of studied infected region. Many studied B. cinerea infection, on detached organs assuming that similar defense/physiological reactions occurs in the intact plant. We analyzed transcriptome of the pathogen and host in 5 infection stages of whole-plant leaves at the infection site. We supply high quality, pathogen-enriched gene count that facilitates future research of the molecular processes regulating the infection process.

MFS transporter from Botrytis cinerea provides tolerance to glucosinolate-breakdown products and is required for pathogenicity.

Glucosinolates accumulate mainly in cruciferous plants and their hydrolysis-derived products play important roles in plant resistance against pathogens. The pathogen Botrytis cinerea has variable sensitivity to glucosinolates, but the mechanisms by which it responds to them are mostly unknown. Exposure of B. cinerea to glucosinolate-breakdown products induces expression of the Major Facilitator Superfamily transporter, mfsG, which functions in fungitoxic compound efflux. Inoculation of B. cinerea on wild-type Arabidopsis thaliana plants induces mfsG expression to higher levels than on glucosinolate-deficient A. thaliana mutants. A B. cinerea strain lacking functional mfsG transporter is deficient in efflux ability. It accumulates more isothiocyanates (ITCs) and is therefore more sensitive to this compound in vitro; it is also less virulent to glucosinolates-containing plants. Moreover, mfsG mediates ITC efflux in Saccharomyces cerevisiae cells, thereby conferring tolerance to ITCs in the yeast. These findings suggest that mfsG transporter is a virulence factor that increases tolerance to glucosinolates.

Using genomic analysis to identify tomato Tm-2 resistance-breaking mutations and their underlying evolutionary path in a new and emerging tobamovirus.

In September 2014, a new tobamovirus was discovered in Israel that was able to break Tm-2-mediated resistance in tomato that had lasted 55 years. The virus was isolated, and sequencing of its genome showed it to be tomato brown rugose fruit virus (ToBRFV), a new tobamovirus recently identified in Jordan. Previous studies on mutant viruses that cause resistance breaking, including Tm-2-mediated resistance, demonstrated that this phenotype had resulted from only a few mutations. Identification of important residues in resistance breakers is hindered by significant background variation, with 9-15% variability in the genomic sequences of known isolates. To understand the evolutionary path leading to the emergence of this resistance breaker, we performed a comprehensive phylogenetic analysis and genomic comparison of different tobamoviruses, followed by molecular modeling of the viral helicase. The phylogenetic location of the resistance-breaking genes was found to be among host-shifting clades, and this, together with the observation of a relatively low mutation rate, suggests that a host shift contributed to the emergence of this new virus. Our comparative genomic analysis identified twelve potential resistance-breaking mutations in the viral movement protein (MP), the primary target of the related Tm-2 resistance, and nine in its replicase. Finally, molecular modeling of the helicase enabled the identification of three additional potential resistance-breaking mutations.

Multivariate Analysis to Predict the Horizontal Anterior Chamber Diameter from Other Anterior Chamber Parameters Using Scheimpflug Imaging: Is There a Better Method Than Adding a Fixed Constant?

PURPOSE: To evaluate the predictive association between the horizontal anterior chamber diameter (HACD) and other measurements using Scheimpflug imaging, and to assess whether a method superior to using fixed constants can be proposed. METHODS: This hospital-based study was performed in the Cornea and Refractive Surgery Services, New Medical Center (NMC) specialty hospital, Abu Dhabi. Initially, 100 candidates were included serially in the model building group (group1). All candidates underwent detailed evaluation and Scheimpflug imaging (CSO, Sirus, Italy). Subsequently, another 100 candidates were included serially in the validation group (group 2). Candidates in both groups underwent the same tests. RESULTS: In group 1, the mean HACD was 12.25 ± 0.48 mm. This measurement correlated significantly with the horizontal visible iris diameter (HVID), anterior chamber depth, angle (ACA), and volume (ACV) (r = 0.2-0.7). The overall regression equation was HACD = 5.62 + 0.01 × ACV + 0.45 × HVID - 0.013 × ACA (adjusted R2 = 0.66, p < 0.001). Situation-based equations derived from the outcomes of group 1 were tested in group 2. Equation A included all factors found significant during model-building, Equation B included only non-volumetric significant factors, and situation C only included the HVID. Equations D through F used direct substitution by HVID plus a constant to predict HACD (the constant was 0.0, 0.5, and 1.0 for Equations D, E, and F, respectively). The predicted HACD (pHACD) was within ±0.5 mm of the actual HACD (aHACD) in 93%, 88%, 87%, 83%, 69%, and 16% case for Equations A, B, C, D, E, and F, respectively. The mean prediction error was -0.14 ± 0.27 mm (p = 0.08), -0.15 ± 0.28 mm (p = 0.03), -0.18 ± 0.30 mm (p = 0.001), -0.18 ± 0.32 mm (p < 0.001), 0.33 ± 0.35 mm (p < 0.001), and 0.83 ± 0.35 mm (p < 0.001) for Equations A, B, C, D, E, and F, respectively. CONCLUSION: Regression equations using Scheimpflug-derived anterior chamber parameters may predict HACD to varying degrees, depending on the input parameters. Adding 0.5 or 1.0 mm to the corneal diameter (CD) to estimate the HACD is not recommended.

Assessment of bilateral pupillary centroid characteristics at varying illuminations and post-photopic flash response using an automated pupillometer.

BACKGROUND: The aim was to assess the symmetry and magnitude of illumination-dependent centroid shift and of post-photic flash re-dilatation response for normal pupils. METHODS: This cross-sectional, observational, inter-eye comparative study was performed at a specialty hospital. Fifty eyes (25 volunteers) without any ocular abnormality underwent pupillometry for scotopic (0.4 lux), mesopic (4.0 lux), photopic conditions (40 lux) and for rate of pupillary re-dilatation after a photopic flash (500 lux) with an inbuilt pupillometer on a Scheimpflug device (Sirius, CSO, Italy). Main outcome measures were pupillary centroids at different illuminations and time-dependent pupil diameters after a photic flash response. RESULTS: The mean pupil size for scotopic, photopic and mesopic pupils were significantly different (p < 0.001, ANOVA) for right and left eyes, analysed separately. The post-photic flash re-dilatation diameter was measured at zero, one, two, four, six, eight and 10 seconds after the flash. The mean diameters at given times post-photic flash were comparable in fellow eyes (p > 0.5, t-test) and highly correlated (r ≥ 0.8, p < 0.05 at all timed comparisons). The mean pupil diameter followed a time-dependent cubic function for both the right and left eyes. Speed was also governed by a time-dependent cubic function for both the right and the left eyes. CONCLUSIONS: Fellow eye symmetry is seen in illumination-governed centroid shifts and the post-flash re-dilatation response. The pupil dilates back briskly with a time-dependent cubic function, which is similar for fellow eyes in normal patients.

Evaluation of the Robustness of Current Quantitative Criteria for Keratoconus Progression and Corneal Cross-linking.

PURPOSE: To evaluate the robustness of numerical indications of corneal cross-linking by evaluating the inter-session reliability of recently used parameters of progression in keratoconus. METHODS: In this observational study, 100 eyes of 100 patients with keratoconus underwent analysis with the Sirius Scheimpflug Topography System (CSO, Firenze, Italy) by a single user. Two sessions (three scans per session) were performed 2 to 4 weeks apart. Cases having poor quality scans, recent visual deterioration, and ocular surgery were excluded. The corneal variables measured were thinnest point and apex characteristics (pachymetry, polar coordinates), volume, central simulated keratometry (flat, steep, average, astigmatism), central corneal thickness, maximum elevation (anterior, posterior), symmetry indices (front, back), and Baiocchi-Calossi-Versaci index. Intra-session (first session, all three measurements) and inter-session (one measurement from each session, selected randomly) statistics were computed. RESULTS: There were no significant differences in the six measurements for all variables (P > .05, analysis of variance). The intra-session and inter-session intraclass correlations were high (0.937 to 0.997) and within-subject standard deviations (Sw) were satisfactory (< 5 µm for thickness, < 0.50 diopters [D] for curvature, and < 0.11 mm, < 5° for polar coordinates). Inter-session repeatability (2.77 × Sw) was found to be satisfactory when compared to previously used central keratometric (> 1.00 D increase) or pachymetric (> 2%/> 5% decrease) guidelines to define progression. Apex power repeatability (1.24 D) was found to be poorer than previously used recommendations (1.00 D change). CONCLUSIONS: The criteria used to define keratoconus progression were satisfactory when compared to inter-session reliability of corneal parameters. Because higher variability was noted at apex, its curvature repeatability cut-off may be raised to 1.25 D for identifying progressive keratoconus. [J Refract Surg. 2016;32(7):465-472.].

Single session, intrauser repeatability of anterior chamber biometric and corneal pachy-volumetric parameters using a new Scheimpflug+Placido device / Repetibilidad intra-usuario en una única sesión de las medidas de parámetros biométricos de la cámara anterior y volumétricos de la córnea utilizando un nuevo dispositivo Scheimpflug+Placido

Purpose: To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. Methods: In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experienced user. The candidates were asked to keep both eyes closed for 5min before the scans. Exclusion criteria were previous ocular surgery, corneal scarring and anterior segment/posterior segment anomalies. Only the right eyes were used for the analysis. Both corneal (central, minimum, and apical thickness, volume, horizontal visible iris diameter, and apical curvature) and anterior chamber (volume, depth, angle, horizontal diameter) measurements were evaluated. Results: There was no difference in the means of repeated measurements (p>0.05, ANOVA). Intraclass correlations between the measures were high and ranged from 0.995-0.997 for corneal to 0.964-0.997 for anterior chamber (AC) parameters. The precision of repeatability measures (1.96×Sw) was approximately 5μ for the central and minimum corneal thickness, 8μ for the apical corneal thickness, 0.06mm for AC (anterior chamber) depth and less than 2° for the AC angle. Conclusions: Sirius Scheimpflug system has high repeatability for both corneal and AC parameters in normal eyes (AU)

Objetivo: Analizar la repetibilidad intra-usuario en una única sesión del dispositivo basado en cámara Scheimpflug, en la medición de diversos parámetros para caracterizar la cámara anterior (CA) y la córnea. Métodos: En este estudio observacional, se realizó a cien sujetos normales un análisis con cámara rotatoria de Scheimpflug utilizando el sistema Sirius 3D (Costruzione Strumenti Oftalmici, Italia). Se realizaron dos escaneos en condiciones de oscuridad por parte del mismo usuario experimentado. Se solicitó a los sujetos que mantuvieran ambos ojos cerrados durante los cinco minutos previos al escaneo. Los criterios de exclusión fueron: cirugía ocular previa, cicatrices en la córnea y anomalías de los segmentos anterior/posterior. Únicamente se utilizaron los ojos derechos en el análisis. Se evaluaron las mediciones tanto de la córnea (espesor central, mínimo y apical, volumen, diámetro horizontal del iris visible, y curvatura apical) como de la cámara anterior (volumen, profundidad, ángulo, diámetro horizontal). Resultados: No se produjo diferencia en las medias de las mediciones repetidas (p>0,05, ANOVA). Las correlaciones intra-clase entre las mediciones fueron elevadas, oscilando entre 0,995-0,997 para los parámetros de la córnea y 0,964-0,997 para los de la cámara anterior (CA). La precisión de las mediciones de repetición (1,96×Sw) fue de aproximadamente 5 micrones para el espesor central y mínimo de la córnea, 8 micrones para el espesor apical de la córnea, 0,06mm para la profundidad de la CA (cámara anterior), e inferior a 2 grados para el ángulo de la CA. Conclusiones: El Sistema Sirius, basado en el uso de una cámara Scheimpflug, tiene una elevada capacidad de repetición para las mediciones de los parámetros de la córnea y la CA en ojos normales (AU)

Comparison of Ocular Monochromatic Higher-order Aberrations in Normal Refractive Surgery Candidates of Arab and South Asian Origin.

PURPOSE: To compare the ocular monochromatic higher-order aberration. (HOA) profile in normal refractive surgery candidates of Arab and South Asian origin. METHODS: This cross-sectional, observational, comparative study was performed in the cornea department of a specialty hospital. Normal refractive surgery candidates with no ocular morbidity except refractive error were recruited. Refractive surgery candidates underwent a preoperative evaluation, including wavefront aberrometry with the iDesign aberrometer (AMO, Inc., Santa Ana, California, United States). The HOA from right eyes were analyzed for HOA signed, absolute, and polar Zernike coefficients. RESULTS: Two hundred Arab participants (group 1) and 200 participants of South-Asian origin (group 2) comprised the study sample. The age and refractive status were comparable between groups. The mean of the HOA root mean square (RMS) was 0.36 ± 17 µ and 0.38 ± 18 µ for Arab and South-Asian eyes, respectively (P < 0.05, rank sum test [RST]). Of the 22 higher order signed Zernike modes, only Z3 (-3), Z3 (-1),3 (1), Z4 (-4), Z4 (-2), Z4 (0), Z4 (4), and Z5 (-5) were significantly different from zero (one sample t-test, P < 0.002, with a Bonferroni correction of 0.05/22). All the signed and absolute Zernike terms were comparable between groups (RST, P > 0.002 [0.05/22]). The polar coefficients for coma, trefoil, spherical aberration, and tetrafoil were comparable between groups (P > 0.05, RST). Combined RMS values of third, fourth, fifth, and sixth order also were comparable between groups (P > 0.05, RST). CONCLUSIONS: Preoperative whole eye HOA were similar for refractive surgery candidates of Arab and South-Asian origin. The values were comparable to historical data for Caucasian eyes and were lower than Asian (Chinese) eyes. These findings may aid in refining refractive nomograms for wavefront ablations.

Highly efficient de novo mutant identification in a Sorghum bicolor TILLING population using the ComSeq approach.

Screening large populations for carriers of known or de novo rare single nucleotide polymorphisms (SNPs) is required both in Targeting induced local lesions in genomes (TILLING) experiments in plants and in screening of human populations. We previously suggested an approach that combines the mathematical field of compressed sensing with next-generation sequencing to allow such large-scale screening. Based on pooled measurements, this method identifies multiple carriers of heterozygous or homozygous rare alleles while using only a small fraction of resources. Its rigorous mathematical foundations allow scalable and robust detection, and provide error correction and resilience to experimental noise. Here we present a large-scale experimental demonstration of our computational approach, in which we targeted a TILLING population of 1024 Sorghum bicolor lines to detect carriers of de novo SNPs whose frequency was less than 0.1%, using only 48 pools. Subsequent validation confirmed that all detected lines were indeed carriers of the predicted mutations. This novel approach provides a highly cost-effective and robust tool for biologists and breeders to allow identification of novel alleles and subsequent functional analysis.

Differences in central and non-central keratoconus, and their effect on the objective screening thresholds for keratoconus.

PURPOSE: To evaluate the differences in central and non-central keratoconus (based on cone location), and their effect on the objective screening thresholds for keratoconus. METHODS: This comparative case series was performed at tertiary care cornea and refractive surgery service. Three groups were made: KC apex within central 2 mm (central keratoconus, n = 50), apex outside central 2mm (non-central keratoconus, n = 50) and normal controls (n = 100, with 50 cases each with apex within and outside central 2 mm). All cases underwent clinical evaluation and corneal topography (CSO, Sirius, Italy). Apex keratometry (ApexK), simulated keratometry at 3 mm (SimK), central corneal thickness (CCT) and minimum corneal thickness (MCT), anterior corneal higher-order aberrations root mean square (HOARMS), and Zernike's coefficients up to fourth order at different zones were measured. RESULTS: In spite of the keratoconic groups having comparable ApexK (p > 0.05), central keratoconus had higher SimK and thinner CCT and MCT (p < 0.001). HOARMS was significantly more for central keratoconus at 3 mm zones. These findings had moderate to large effect size (Cohen's d). Receiver operating curve analysis was carried out to compare central keratoconus and non-central keratoconus with control group. ApexK and HOARMS had best discriminative parameters. Using single parametric suspicion cut-offs of 'either SimK steep >47.2 D or CCT < 491.6 µ' had a good sensitivity (0.98) for central keratoconus, but not for non-central keratoconus (0.80). Changing this cut-off to 'either SimK steep K ≥ 45.8 D or CCT ≤ 503 µ' gave a sensitivity and specificity of 0.95 and 0.87 for non-central keratoconus and 0.99 and 0.87 for central keratoconus. CONCLUSION: Non-central keratoconus has lesser effect on SimK, pachymetry and smaller-aperture HOARMS. Using 'SimK steep >47.2 D or CCT < 491.6 µ' may miss timely referral for topography in many of these cases. Using more stringent criteria of SimK steep K ≥ 45.8 D or CCT ≤ 503 µ to get a corneal topography done to rule out keratoconus is recommended, especially in cohorts with higher risk.

Single session, intrauser repeatability of anterior chamber biometric and corneal pachy-volumetric parameters using a new Scheimpflug+Placido device.

PURPOSE: To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. METHODS: In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experienced user. The candidates were asked to keep both eyes closed for 5min before the scans. Exclusion criteria were previous ocular surgery, corneal scarring and anterior segment/posterior segment anomalies. Only the right eyes were used for the analysis. Both corneal (central, minimum, and apical thickness, volume, horizontal visible iris diameter, and apical curvature) and anterior chamber (volume, depth, angle, horizontal diameter) measurements were evaluated. RESULTS: There was no difference in the means of repeated measurements (p>0.05, ANOVA). Intraclass correlations between the measures were high and ranged from 0.995-0.997 for corneal to 0.964-0.997 for anterior chamber (AC) parameters. The precision of repeatability measures (1.96×Sw) was approximately 5µ for the central and minimum corneal thickness, 8µ for the apical corneal thickness, 0.06mm for AC (anterior chamber) depth and less than 2° for the AC angle. CONCLUSIONS: Sirius Scheimpflug system has high repeatability for both corneal and AC parameters in normal eyes.

Predictive Analysis Between Topographic, Pachymetric and Wavefront Parameters in Keratoconus, Suspects and Normal Eyes: Creating Unified Equations to Evaluate Keratoconus.

PURPOSE: To perform prediction analysis between topographic, pachymetric and wavefront parameters in keratoconus, suspects, and normal cases and to look at the possibility of a unified equation to evaluate keratoconus. METHODS: This cross-sectional, observational study was done in cornea services of a specialty hospital. Fifty eyes of 50 candidates with a diagnosis of normal, keratoconus suspect, and keratoconus were included in each group (total 150 eyes). All eyes underwent detailed analysis on Scheimplug + Placido device (Sirius, CSO, Italy). Main parameters evaluated were topographic [maximum keratometry (Max Km), average keratometry and astigmatism at 3, 5, and 7 mm], pachymetric [central and minimum corneal thickness (MCT) and their difference, corneal volume] and corneal aberrations [higher order aberrations root-mean-square (HOARMS), coma, spherical, residual].Central tendency, predictive fits and regression models, were computed. RESULTS: The measured variables had a significant difference in mean between the three groups (Kruskal-Wallis, p < 0.001). Max Km, MCT, and HOARMS had significant fits with other topographic, pachymetric and wavefront parameters, respectively. Inter-relations between these three (Max Km, MCT, and HOARMS) were also stronger for keratoconus (R(2) from 0.75 to 0.33) compared to suspect/normal eyes (R(2) from 0.15 to 0.003). These three variables (Max Km, MCT and HOARMS) were used as representative variables to create the unified equations. The equation for the pooled data was (Kmax = 59.5 + 2.3 × HOARMS-0.03 × MCT; R(2)= 0.7, p < 0.001). CONCLUSIONS: Major variables used for grading keratoconus (MaxKm, MCT, HOARMS) can be linked by linear regression equations to predict the pathology's behavior.

Femtosecond Laser-assisted Wavefront-guided LASIK Using a Newer Generation Aberrometer: 1-Year Results.

PURPOSE: To evaluate long-term outcomes of wavefront-guided LASIK with a new advanced aberrometer. METHODS: Fifty eyes of 25 LASIK candidates with myopia and/or astigmatism underwent aberrometry (iDesign Advanced WaveScan; Abbott Medical Optics, Santa Ana, CA), femtosecond laser-assisted flap creation, and excimer ablation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SEQ), and astigmatism outcomes were measured at 1, 3, 6, and 12 months postoperatively. RESULTS: The sphere, cylinder, and SEQ were -4.29 ± 1.94, -0.75 ± 0.76, and -4.67 ± 2.01 diopters (D), respectively, preoperatively and 0.03 ± 0.13, -0.09 ± 0.13, and -0.02 ± 0.14 D, respectively, 12 months postoperatively (P < .001). The postoperative log-MAR CDVA (-0.07 ± 0.09) and UDVA (-0.04 ± 0.09) were better than the preoperative logMAR CDVA (0.07 ± 0.10) (P < .01). Ninety-four percent achieved a 12-month logMAR UDVA of 0.0 or less (20/20 or better Snellen) and 100% achieved 0.3 or less (20/40 or better Snellen), compared to a preoperative logMAR CDVA of 0.0 or worse in 54% and 0.3 or less in 100%. Postoperative SEQ was within ±0.50 D in 98%. The regression plot for achieved (y) vs intended (x) correction at 12 months was (y = 0.98 × - 0.09, R(2) = 0.99, P < .001). No cases lost CDVA. The target and 12-month surgically induced astigmatisms (TIA and SIA) were 0.91 ± 0.75 and 0.82 ± 0.70, respectively. The regression plot between them was SIA = 0.91 × TIA - 0.01 (R(2) = 0.95, P < .001). The angle of error was -0.29° ± 12.6° and index of success was 0.13 ± 0.25. There was only a mild, nonsignificant increase of higher-order aberrations after surgery, and the postoperative wavefront was stable on follow-up. CONCLUSIONS: Wavefront-guided LASIK with iDesign aberrometry appears to be safe and effective in this long-term, consecutive case series.

Comparative Evaluation of the Corneal and Anterior Chamber Parameters Derived From Scheimpflug Imaging in Arab and South Asian Normal Eyes.

PURPOSE: To evaluate the differences in the normal corneal and anterior segment Scheimpflug parameters in Arab and South Asian eyes. METHODS: This hospital-based study was performed at a cornea and refractive surgery service in Abu Dhabi. A total of 600 consecutive normal candidates of South Asian (group 1, n = 300) and Arab (group 2, n = 300) origins underwent Scheimpflug imaging (Sirius; Costruzione Strumenti Oftalmici, Italy). One eye was randomly selected for evaluation. RESULTS: The age and sex distributions in both groups were comparable. The pachymetric variables were statistically higher in group 2 (group 2 vs. group 1, 544.3 ± 32.2 µm vs. 535.1 ± 31.4 µm for central corneal thickness, 541.0 ± 32.6 µm vs. 531.9 ± 31.5 µm for minimum corneal thickness, 571.7 ± 43.2 µm vs. 558.1 ± 42.3 µm for apical thickness, and 58.1 ± 4.2 vs. 57.3 ± 4.3 mm³ for the corneal volume; P < 0.05). The anterior chamber volume (group 2 vs. group 1: 166.4 ± 16.4 vs. 161.6 ± 20.5 mm³) and angle (group 2 vs. group 1: 44.6 ± 6.2 vs. 43.5 ± 5.8 degrees) were also higher for group 2 (P < 0.05). Central corneal curvature and apical corneal curvature (apex K) were higher in group 1 (P < 0.05) with comparable astigmatism. The flat keratometry (K), steep K, and apex K were 43.6 ± 2.2 diopters (D), 44.9 ± 1.8 D, and 45.7 ± 1.8 D for group 1, and 43.1 ± 2.2 D, 44.5 ± 2 D, and 45.2 ± 1.9 D for group 2. The effect size (Cohen d) for significant parameters ranged from 0.2 to 0.3. CONCLUSIONS: Normal eyes of Arab ethnicity tend to have statistically thicker and flatter corneas and less-crowded anterior segments than those of the South Asian counterparts. These epidemiological differences have a mild to moderate biological effect size (Cohen d), but they should be considered when evaluating these eyes for anterior segment or corneal procedures.

Urrets-Zavalia syndrome after laser-assisted in situ keratomileusis (LASIK).

We report a case of fixed, non-reactive pupil (Urrets-Zavalia syndrome) in a 34-year-old patient following laser-assisted in situ keratomileusis (LASIK) caused probably by intermittent postoperative intraocular pressure fluctuations. This case highlights the possibility of a fixed and dilated pupil even after LASIK, a technically non-intraocular surgery, which is due to a preventable cause: postoperative intraocular pressure fluctuations. To the best of our knowledge, this is the first report of Urrets-Zavalia syndrome following LASIK.

A novel Hartman Shack-based topography system: repeatability and agreement for corneal power with Scheimpflug+Placido topographer and rotating prism auto-keratorefractor.

The purpose of this study is to analyze the repeatability and agreement of corneal power using a new Hartman type topographer in comparison to Scheimpflug+Placido and autorefractor devices. In this cross sectional, observational study performed at the cornea services of a specialty hospital, 100 normal eyes (100 consecutive candidates) without any previous ocular surgery or morbidity except refractive error were evaluated. All candidates underwent three measurements each on a Full gradient, Hartman type topographer (FG) (iDesign, AMO), Scheimpflug+Placido topographer (SP) (Sirius, CSO) and rotating prism auto-keratorefractor (AR) (KR1, Nidek). The parameters assessed were flat keratometry (K1), steep keratometry (K2), steep axis (K2 axis), mean K, J 0 and J 45. Intra-device repeatability and inter-device agreement were evaluated. On repeatability analysis, the intra-device means were not significantly different (ANOVA, p > 0.05). Intraclass correlations (ICC) were >0.98 except for J 0 and J 45. In terms of intra-measurement standard deviation (Sw), the SP and FG groups fared better than AR group (p < 0.001, ANOVA). On Sw versus Average plots, no significantly predictive fit was seen (p > 0.05, R (2) < 0.1 for all the values). On inter-device agreement analysis, there was no difference in means (ANOVA, p > 0.05). ICC ranged from 0.92 to 0.99 (p < 0.001). Regression fits on Bland-Altman plots suggested no clinically significant effect of average values over difference in means. The repeatability of Hartman type topographer in normal eyes is comparable to SP combination device and better than AR. The agreement between the three devices is good. However, we recommend against interchanging these devices between follow-ups or pooling their data.