Biometric and corneal characteristics in marfan syndrome with ectopia lentis

PURPOSE

To describe the biometric and corneal characteristics of patients with Marfan Syndrome (MFS) and ectopia lentis.

STUDY DESIGN

Observational, descriptive, prospective study. Subjects Individuals with MFS with ectopia lentis (EL).

METHODS

Fourty-four eyes of 23 patients underwent Scheimpflug analysis using the Pentacam (Oculus, Wetzlar, Germany), axial length (AL) using the IOL master 700 (Carl Zeiss AG, Oberkochen, Germany), endothelial cell count (ECC) using the CEM-350 (NIDEK, Maihama, Japan) and corneal biomechanics evaluation with the Ocular Response Analyzer: ORA (Reichert Ophthalmic Instruments, Buffalo, New York, USA) and Corvis (Oculus, Wetzlar, Germany). Statistical analysis was performed using IBM SPSS Statistics 25.0.

RESULTS

The direction of lens subluxation was most frequently supero-nasal 40.9% (18/44). Mean keratometry (Km) was 40.22±1.76 Diopters (D); mean corneal astigmatism was 1.68±0.83 D; total corneal aberrometric root mean square (RMS) was 2.237±0.795μm; higher-order aberrations (HOAs) RMS were 0.576±0.272μm; mean AL was 25.63±3.65mm; mean ECC was 3315±459cell/mm2; mean CBI was 0.13±0.24, mean TBI was 0.31±0.25, mean posterior elevation was 4.3±4.5μm; mean total corneal densitometry was 16.0±2.14 grayscale units (GSU).

CONCLUSION

Increased axial length, flatter and thicker corneas with higher regular astigmatism, normal densitometry, normal corneal biomechanical indices and normal posterior elevation were observed in Marfan patients with EL.

Comparison of the biometric characteristics after long term implantation of iris-fixated phakic intraocular lens in explanted and non-explanted groups of eyes

PURPOSE

To evaluate and compare the biometric characteristics of the anterior chamber of a group of patients with significant endothelial cell loss (ECL) that required phakic IOL (pIOL) explantation and a group of patients who did not fulfill the explantation criteria related to corneal decompensation.

DESIGN

Retrospective consecutive interventional case series METHODS: The study included all consecutive patients implanted with pIOL at Oftalmosalud Instituto de Ojos, Lima, Peru, between 2001 and 2012. The explanted group (E-group) consisted of eyes in which the pIOLs were explanted due to ECL and the non-explanted group (NE-group) consisted of eyes randomly selected in which the pIOL was not explanted with a minimum follow-up time of eight years. Slit-lamp biomicroscopy, visual acuity, refraction, endothelial cells count, and anterior segment OCT were assessed at the preoperative evaluation for both groups and before explantation in the E-group and eight years post implantation in the NE-group.

RESULTS

265 eyes were implanted with pIOL. The annual percentage of ECL was 1.47% and 5.55% in the NE-group and the E-group, respectively (p < .001). The mean minimum endothelial lens distance (min-ELD) was 1.44 ± 0.22 mm and 1.05 ± 0.23 mm in the NE-group and the E-group, respectively (p < 0.001). The mean time for explantation was 12.58 ± 3.79 years for the NE-group. Annual ECL could accurately discriminate between NE-group and E-group, a cutoff point of 3.5 (%/year) or 86.5 (cells/years) had a 100% sensitivity and specificity. A cutoff of 1.21 mm in the min-ELD, has a 91% sensitivity and 79% specificity to discriminate between E-group and NE-group.

CONCLUSION

pIOL explantation due to ECL occurs in eyes with a significantly postoperative lower min-ELD. Annual ECL and min-ELC can effectively discriminate between explanted and non-explanted groups.

Dual RNA-sequencing of Fusarium head blight resistance in winter wheat

Fusarium head blight (FHB) is a devastating fungal disease responsible for significant yield losses in wheat and other cereal crops across the globe. FHB infection of wheat spikes results in grain contamination with mycotoxins, reducing both grain quality and yield. Breeding strategies have resulted in the production of FHB-resistant cultivars, however, the underlying molecular mechanisms of resistance in the majority of these cultivars are still poorly understood. To improve our understanding of FHB-resistance, we performed a transcriptomic analysis of FHB-resistant AC Emerson, FHB-moderately resistant AC Morley, and FHB-susceptible CDC Falcon in response to Fusarium graminearum. Wheat spikelets located directly below the point of inoculation were collected at 7-days post inoculation (dpi), where dual RNA-sequencing was performed to explore differential expression patterns between wheat cultivars in addition to the challenging pathogen. Differential expression analysis revealed distinct defense responses within FHB-resistant cultivars including the enrichment of physical defense through the lignin biosynthesis pathway, and DON detoxification through the activity of UDP-glycosyltransferases. Nucleotide sequence variants were also identified broadly between these cultivars with several variants being identified within differentially expressed putative defense genes. Further, F. graminearum demonstrated differential expression of mycotoxin biosynthesis pathways during infection, leading to the identification of putative pathogenicity factors.

Late approach for LASIK flap striae

A 24-year-old man was referred for postrefractive surgery evaluation. The patient had a history of uneventful laser in situ keratomileusis (LASIK) in both eyes 3 months previously. According to the surgeon who originally performed the surgery, on slitlamp examination, only microstriae in the left eye was detected on postoperative day 1 and a more conservative follow-up approach was adopted without further immediate intervention. The patient returned only 3 months after surgery, complaining of low vision in the left eye that, according to the patient, had been present since postoperative week 2. The patient was then referred for examination and surgical procedure with a diagnosis of significant postoperative striae. The slitlamp examination revealed a LASIK flap with striae, epithelial filling, and a wrinkled appearance (Figure 1JOURNAL/jcrs/04.03/02158034-202312000-00017/figure1/v/2023-11-20T151558Z/r/image-tiff). There were no signs of infection or inflammation. Originally, the LASIK flap was programmed to be 110 μm. Preoperative manifest refraction in the right eye was -5.25 (20/20) and in the left eye was -5.25 (20/20). Assuming it is a case of late-approach LASIK flap striae, how would you proceed? Would you try to hydrate and lift the flap and just reposition it? Would you avoid lifting and associate phototherapeutic keratectomy (PTK) with excimer laser on top of the flap? Would you consider topo-guided surgery with regularization of the visual axis or even amputation of the flap?

Interface Fluid Syndrome After Descemet Membrane Endothelial Keratoplasty in Patients With History of LASIK

PURPOSE

The aim of this study was to evaluate the visual, pachymetric, tomographic, and biomicroscopic findings in a series of cases with laser in situ keratomileusis (LASIK) flap interface fluid syndrome (IFS) after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Six cases were included in this study; all patients had a history of LASIK and underwent DMEK for the treatment of bullous keratopathy. After uneventful surgery, all patients presented with corneal edema and IFS under the LASIK flap, which was demonstrated with anterior segment optical coherence tomography (AS-OCT). Visual acuity, clinical findings, pachymetry, endothelial cell count, and AS-OCT were documented during the management of these cases.

RESULTS

IFS appears 2.33 days (±1.03) after DMEK. One case improved with conservative treatment. In 5 cases, the LASIK flap was lifted, the fluid was drained, and the flap was replaced. The mean best-corrected visual acuity after fluid drainage was 0.44 logMAR (range 0.18-1.0) and mean central corneal thickness was 538 μm ± 160. Total resolution of the IFS was achieved at 14.5 days (range 4-30) after DMEK. AS-OCT showed resolution of the flap interface in 5 of 6 cases, while 1 patient required second DMEK due to reaccumulation of the interface fluid.

CONCLUSIONS

IFS can occur after DMEK in patients with previous LASIK. AS-OCT is a valuable tool for monitoring these cases preoperatively and postoperatively. Early surgical management is often needed to achieve resolution.

A global-temporal analysis on Phytophthora sojae resistance-gene efficacy

Plant disease resistance genes are widely used in agriculture to reduce disease outbreaks and epidemics and ensure global food security. In soybean, Rps (Resistance to Phytophthora sojae) genes are used to manage Phytophthora sojae, a major oomycete pathogen that causes Phytophthora stem and root rot (PRR) worldwide. This study aims to identify temporal changes in P. sojae pathotype complexity, diversity, and Rps gene efficacy. Pathotype data was collected from 5121 isolates of P. sojae, derived from 29 surveys conducted between 1990 and 2019 across the United States, Argentina, Canada, and China. This systematic review shows a loss of efficacy of specific Rps genes utilized for disease management and a significant increase in the pathotype diversity of isolates over time. This study finds that the most widely deployed Rps genes used to manage PRR globally, Rps1a, Rps1c and Rps1k, are no longer effective for PRR management in the United States, Argentina, and Canada. This systematic review emphasizes the need to widely introduce new sources of resistance to P. sojae, such as Rps3a, Rps6, or Rps11, into commercial cultivars to effectively manage PRR going forward.

Long Term Corneal Flattening After Corneal Crosslinking in Patients with Progressive Keratoconus

Purpose

We evaluate the long-term visual, refractive, and keratometric outcomes after corneal crosslinking (CXL) in patients with progressive keratoconus (KC) and the incidence of an extreme corneal flattening effect.

Settings

Oftalmosalud Institute of Eyes, Lima, Perú.

Design

Retrospective cohort study.

Methods

Forty-five eyes that underwent CXL with epithelial removal between June 2006 and September 2011. Data analysis was performed at preoperative evaluation, 1 year postoperatively, and at least 10 years or more postoperatively. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and Scheimpflug (Pentacam) analysis. Progression was defined by an increase in steep keratometry (Ks) of 1.5D or greater between 2 examinations. Extreme flattening effect was defined as a decrease in K values equal to or greater than 5 diopters (D).

Results

Mean follow-up time was 11 ± 1.07 years (range 10-13 years). There was a significant improvement in Ks, UCVA, CDVA, and spherical equivalent at the last visit. The overall rate of progression was 2.22% (1/45). Extreme flattening was observed in 15.5% (7/45) of the eyes, and this was associated with a loss of CDVA in 4.44% (2/45) of the eyes. One eye with corneal flattening of 11.5 D lost 7 lines of CDVA and required corneal transplantation.

Conclusion

CXL is a safe and effective procedure to stop the progression of KC with a good overall long-term success rate. Extreme corneal flattening may be more common than commonly recognized, and severe corneal flattening associated with a decrease in CDVA may occur.

Comparison of preoperative simulated and postoperative real safety distances using anterior segment OCT in patients with phakic IOL according to iris configuration

AIM: To compare the simulated safe distance (SSD) preoperatively versus real safe distance (RSD) postoperatively in patients with iris-claw phakic intraocular lens (pIOL) implantation according to iris configuration. METHODS: Totally 60 eyes of 60 patients underwent pIOL implantation for surgical correction of myopia. Anterior chamber depth (ACD) was measured with the IOLMaster 700, and nasal and temporal safety distances (SD) were measured pre- and postoperatively using Anterior Segment Visante-OCT. SD was defined as a line measured between the edge of the optic or its simulated image to the endothelium. Eyes were divided into 3 groups: convex, concave, and plane according to preoperatory iris configuration. Statistical analysis was performed using the R program, for the comparison of independent groups and multiple comparisons, the Kruskal-Wallis test and the Dunn test were used respectively. RESULTS: Mean difference between nasal preoperative SSD and postoperative RSD was -0.36±0.38, -0.29±0.48, and -0.18±0.30 mm in the concave, convex, and plane group, respectively. Mean difference between temporal SSD and RSD was -0.36±0.37, -0.14±0.38, and -0.24±0.33 mm in the concave, convex, and plane group, respectively. There were statistically significant differences between SSD and RSS for both nasal and temporal sides in the concave and plane group (P<0.002). CONCLUSION: Preoperative SSD and postoperative RSD for iris-claw pIOL shows significant differences in patients with concave and plane iris.

The false positive rates for detecting keratoconus and potential ectatic corneal conditions when evaluating astigmatic eyes with Scheimpflug Technology

PURPOSE

To quantify the false positive rates for keratoconus (KC) and potential ectatic corneal conditions in highly astigmatism eyes when using published parameters/indices obtained from the Pentacam and Galilei units.

SETTING

Oftalmosalud Instituto de Ojos, Lima, Peru.

DESIGN

Prospective cohort study.

METHODS

67 consecutive eyes with corneal astigmatism > 1.5 D, with a minimum follow ups of 36 months after an uneventful LASIK procedure were included. Indices for KC and other potential ectatic corneal conditions (subclinical KC, forme fruste KC, suspect KC) were obtained using the Pentacam and Galilei Scheimpflug cameras.

MAIN OUTCOME MEASURES

The false positive rates for KC and potential ectatic corneal conditions were measured. Cut off values provided by previous studies and company-based parameters were used to assess the rate of false positivity.

RESULTS

The range of false positive rates for a KC diagnosis depending on the lowest and highest cutoff values were: index of height decentration (61% - 1%), index of surface variance (76% - 0%), Posterior elevation (55% - 0%), maximum Ambrosio Relational thickness (100% - 13%), Belin Ambrosio enhanced ectasia display total deviation value (100% - 4%), Average pachymetric progression index (69% - 3%), Pachymetry at the thinnest point (58% - 1%), CSI Center Surround Index (100%), Differential sector index (51%).

CONCLUSION

The false positive rates for KC and ectatic corneal conditions vary dramatically depending on the cut-off values used. Some indexes used for diagnosis of potential ectatic corneal conditions are inaccurate in normal, highly astigmatic eyes.

Comparing the vision quality using double-pass technique in eyes with corrected refractive errors and emmetropic eyes

PURPOSE

To evaluate the vision quality by measuring the objective light scatter index and objective optical quality parameters (Strehl Ratio and Modulation Transfer Function) in patients with emmetropia and ametropia.

METHODS

This prospective, cross-sectional study included 408 eyes. The ametropic group comprised of eyes with best-corrected visual acuity of 0.0 logMAR or better and present at least a refractive error of ≥0.25 D. Patients underwent slit lamp examination, visual acuity, refraction, and vision quality using the HD Analyzer.

RESULTS

The mean objective light scatter indices were 0.62 ± 0.63, 0.77 ± 0.70, 0.74 ± 0.30, 0.93 ± 0.55, and 0.85 ± 0.61, and mean Strehl Ratio and Modulation Transfer Function scores were 38.17 ± 10.4, 37.37 ± 10.06, 29.84 ± 9.71, 33.2 ± 12.11, and 33.13 ± 10.09 in emmetropes, myopia, hyperopia, spherical equivalent of ≥0, and spherical equivalent of <0, respectively. Differences in all variables were significant between emmetropic and corrected hyperopic and between spherical equivalent of ≥0, and spherical equivalent of <0 eyes (p<0.05).

CONCLUSION

In spectacle-corrected conditions (with trial frames), emmetropic and simple myopic eyes had significantly better vision quality compared to hyperopic and astigmatic eyes. The clinical significance of these results should be investigated in further studies.

Intracorneal circular ring implant with femtosecond laser: Pocket versus tunnel

PURPOSE

To evaluate and compare visual and refractive outcomes after implantation of the intracorneal continuous ring 360° arc (ICCR) versus the intracorneal ring segment 340° arc (ICRS) using femtosecond laser for central keratoconus.

SETTING

Research Department, Oftalmosalud, Instituto de Ojos, Lima, Peru.

METHODS

Randomized study that included 40 eyes of 32 patients diagnosed with central keratoconus between November 2014 and March 2015. Twenty eyes had an implantation of ICCR (MyoRing, Dioptex GmbH, Austria) through an intrastromal pocket and 20 eyes had an implantation of ICRS (Keraring, Mediphacos, Brazil) through an intrastromal tunnel. Both procedures were performed with a femtosecond laser (LDV Z6 model, Ziemer Ophthalmic Systems AG). Visual acuity (VA), refraction, and Scheimpflug imaging analysis were performed pre- and postoperatively at 1 month and 1 year. Comparisons of means were performed using the Student's t-test.

RESULTS

At 1 year, uncorrected VA improved 0.77 LogMAR (p < 0.001) in the ICCR group and 0.79 LogMAR (p = 0.01) in the ICRS group; mean sphere improvement was 5.13 Diopters (D) in the ICCR group and 6.27 D in the ICRS group (p < 0.001 both); mean Steeper Keratometry improvement was 4.24 D in the ICCR group and 5.53 D in the ICRS group (p < 0.001 both). In the ICCR group, mean decrease in the pachymetry at the thinnest point of the cornea was 32.16 µm (p = 0.01), and in the ICRS group, mean increase was 4.2 µm at 1 year (p = 0.61).

CONCLUSION

Intracorneal continuous ring 360° arc (ICCR) and intracorneal ring segment 340° (ICRS) are effective treatments for central keratoconus. No significant differences between rings were found on visual acuity, refraction, and keratometry improvement.

A Systematic Review of Subclinical Keratoconus and Forme Fruste Keratoconus

PURPOSE

To identify the definitions used for the terms sub-clinical keratoconus and forme fruste keratoconus in published articles.

METHODS

This was a prospective, systematic literature review of the electronic database in PubMed, the Cochrane Library, and LILACS Database of all studies using the keywords "subclinical keratoconus" and/or "forme fruste keratoconus" until August 18, 2017. Two independent reviewers analyzed the data. The inclusion criteria for articles were having analyzed subclinical keratoconus or forme fruste keratoconus eyes with a sample size greater than 10 eyes; containing the definition of subclinical keratoconus or forme fruste keratoconus; and the quality of published reports was assessed using standards quality index methods. The following aspects of the selected articles were then analyzed: inclusion criteria for definition and technology used.

RESULTS

A total of 198 and 95 studies, respectively, including the definition of subclinical keratoconus and forme fruste keratoconus were collected in an initial search, of which 165 and 73 studies, respectively, were excluded. Definitions for subclinical keratoconus and forme fruste keratoconus included the criteria of having keratoconus in the fellow eye in 72.72% (24 of 33) and 77.27% (17 of 22) of the articles, respectively. A total of 96.97% (32 of 33) and 90.90% (20 of 22) of the studies used more than one parameter to define subclinical keratoconus and forme fruste keratoconus, respectively. The most common extra parameters included normal slit-lamp examination and cornea on slit-lamp biomicroscopy and inferior-superior asymmetry and/or bowtie pattern with skewed radial axes.

CONCLUSIONS

This review demonstrates the lack of unified criteria to define subclinical keratoconus and forme fruste keratoconus. According to the literature review, the most common subclinical keratoconus definition used refers to an eye with topographic signs of keratoconus and/or suspicious topographic findings under normal slit-lamp examination and keratoconus in the fellow eye and the most common forme fruste keratoconus definition refers to an eye with normal topography, normal slit-lamp examination, and keratoconus in the fellow eye. [J Refract Surg. 2020;36(4):270-279.].

Histology and RNA Sequencing Provide Insights Into Fusarium Head Blight Resistance in AAC Tenacious

Fusarium head blight (FHB) is a serious fungal disease affecting wheat and other cereals worldwide. This fungus causes severe yield and quality losses from a reduction in grain quality and contamination of grain with mycotoxins. Intensive breeding efforts led to the release of AAC Tenacious, which was the first spring wheat cultivar registered in Canada with a resistant (R) rating to FHB. To elucidate the physiological mechanisms of resistance, we performed histological and transcriptomic analyses of AAC Tenacious and a susceptible control Roblin after inoculation with Fusarium graminearum (Fg). The spikelet and rachis of infected wheat spikes were hand sectioned and monitored by confocal and fluorescent microscopy. Visible hyphae were observed within the inoculated spikelets for AAC Tenacious; however, the infection was largely restricted to the point of inoculation (POI), whereas the adjacent florets in Roblin were heavily infected. Significant cell wall thickening within the rachis node below the POI was evident in AAC Tenacious compared to Roblin in response to Fg inoculation. Rachis node and rachilla tissues from the POI and the rachis node below the POI were collected at 5 days post inoculation for RNAseq. Significant changes in gene expression were detected in both cultivars in response to infection. The rachis node below the POI in AAC Tenacious had fewer differentially expressed genes (DEGs) when compared to the uninoculated control, likely due to its increased disease resistance. Analysis of DEGs in Roblin and AAC Tenacious revealed the activation of genes and pathways in response to infection, including those putatively involved in cell wall modification and defense response.

Biomicroscopic Findings and Management of Anterior Stromal Necrosis After Long-term Implantation of Intacs

PURPOSE

We sought to evaluate the visual, refractive, and biomicroscopic findings pre- and posttreatment of observed anterior stromal necrosis (ASN) after long-term Intacs intracorneal ring segment (ICRS) implantation.

DESIGN

Consecutive interventional case series.

METHODS

All consecutive patients implanted with Intacs ICRS at a single center by 1 of the authors between October 2006 and October 2011 with a minimum follow-up time of 5 years were included. All Intacs were implanted using the Prolate system console and instrumentation from Addition Technology Inc (Chicago, Illinois, USA). The slit lamp, refractive, and visual findings and the management of those patients are described in detail. The primary outcome measures included the size of the epithelial defect overlying the Intacs body, the intended implantation depth measured by high-magnification slit lamp photography, and the management of the cases described in detail. The percentage of eyes with ASN out of those that reached the 5-year follow-up is reported.

RESULTS

One hundred twenty-seven eyes (84 patients) were implanted with 215 ICRSs during the study period, and 77.16% (98/127) eyes had a follow-up of ≥5 years, out of which 9 eyes (7 patients) had ASN corresponding to at least 9.18% (95% confidence interval 4.29%-16.72%). The mean ± standard deviation time between implantation and ASN diagnosis was 10.5 ± 1.3 years.

CONCLUSION

After 5 years of implantation, INTACS-treated eyes could present with an ASN over the ICRS body. Longer-term follow-up of patients implanted with INTACS is important to monitor if this complication keeps occurring over time.

Mapping of Major Fusarium Head Blight Resistance from Canadian Wheat cv. AAC Tenacious

Fusarium head blight (FHB) is one of the most devastating wheat disease due to its direct detrimental effects on grain-yield, quality and marketability. Resistant cultivars offer the most effective approach to manage FHB; however, the lack of different resistance resources is still a major bottleneck for wheat breeding programs. To identify and dissect FHB resistance, a doubled haploid wheat population produced from the Canadian spring wheat cvs AAC Innova and AAC Tenacious was phenotyped for FHB response variables incidence and severity, visual rating index (VRI), deoxynivalenol (DON) content, and agronomic traits days to anthesis (DTA) and plant height (PHT), followed by single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) marker genotyping. A high-density map was constructed consisting of 10,328 markers, mapped on all 21 chromosomes with a map density of 0.35 cM/marker. Together, two major quantitative trait loci for FHB resistance were identified on chromosome 2D from AAC Tenacious; one of these loci on 2DS also colocated with loci for DTA and PHT. Another major locus for PHT, which cosegregates with locus for low DON, was also identified along with many minor and epistatic loci. QTL identified from AAC Tenacious may be useful to pyramid FHB resistance.

Correlation between lens thickness and lens density in patients with mild to moderate cataracts

PURPOSE

To determine the relationships between lens thickness (LT), lens density and anterior segment parameters in patients with mild to moderate cataracts.

SETTING

Oftalmosalud Instituto de Ojos, Lima, Perú.

DESIGN

Prospective, single-centre, cross-sectional study.

METHODS

169 eyes with age-related mild to moderate cataracts had lens density assessed using the Lens Opacification Classification System III, the built-in Pentacam HR Nucleus Staging software and ImageJ software. LT and axial length (AL) were measured with the IOLMaster 700, and angle parameters were measured using anterior segment optical coherence tomography. Pearson correlation coefficients and Kruskal-Wallis tests were used for statistical analyses.

RESULTS

Nuclear colour score was the only clinical parameter with a weak significant correlation with LT (r=0.24, p=0.003) after accounting for age, AL, gender and anterior chamber depth (ACD). The maximum value of average lens density and the mean nuclear density were significantly correlated with LT (r=0.24, p=0.003 and -0.17, p=0.03, respectively) after controlling for the same factors. Central LT greater than 4.48 mm was present in 54.5% of the eyes with a nuclear opalescence grade 1.

CONCLUSIONS

LT is independent of lens density in mild to moderate cataracts after accounting for age, AL, ACD and gender contrary to previous studies.

Comparison of eye-rubbing effect in keratoconic eyes and healthy eyes using Scheimpflug analysis and a dynamic bidirectional applanation device

PURPOSE

To compare the effect of eye rubbing on Scheimpflug imaging parameters and corneal biomechanics in eyes with keratoconus and healthy eyes.

SETTING

Oftalmosalud Instituto de Ojos, Lima, Peru.

DESIGN

Prospective cohort study.

METHODS

The study included healthy and keratoconus patients who attended the institution between January 2017 and July 2017. Eye rubbing was performed for 1 minute followed by a 5-second break, followed by further rubbing for 1 minute. Baseline tests were performed before rubbing; post-rubbing tests were performed immediately after (0 minutes), and then again at 7 minutes and 14 minutes. Parameters related to anterior and posterior curvature and elevation, pachymetry, and corneal biomechanics obtained from tomography with a rotating Scheimpflug camera (Pentacam HR) and a dynamic bidirectional applanation device (Ocular Response Analyzer) were measured and compared between healthy and keratoconic eyes.

RESULTS

The study included 30 healthy eyes and 31 keratoconic eyes. In the healthy group, the immediate mean changes in steeper anterior keratometry, posterior astigmatism, anterior chamber volume (ACV), flattest posterior keratometry, and Goldmann-correlated intraocular pressure (IOPg) after eye rubbing were 0.07 diopters (D) ± 0.15 (SD), -0.01 ± 0.08 D, 0.03 ± 7.06 mm³, -0.001 ± 0.04 mm, and -1.21 ± 1.99 mm Hg, respectively, whereas the mean changes in the keratoconus group were -0.03 ± 0.32 D, 0.14 ± 0.50 D, -5.09 ± 8.45 mm³, 0.03 ± 0.06 mm, and -1.61 ± 1.41 mm Hg, respectively. There were statistically significant differences between the preoperative and postoperative eye-rubbing values of posterior astigmatism, ACV, and IOPg in the keratoconus group (P = .03, P = .0003, and P = .001, respectively) but not in the healthy group (P = .65, P = .85, and P = .23, respectively).

CONCLUSIONS

Unlike the healthy eyes group, the keratoconus group experienced significant changes in ACV, IOP, and corneal posterior astigmatism after eye rubbing.

Consensus on the management of astigmatism in cataract surgery

This project was aimed at achieving consensus on the management of astigmatism during cataract surgery by ophthalmologists from Latin America using modified Delphi technique. Relevant peer-reviewed literature was identified, and 21 clinical research questions associated with the definition, classification, measurement, and treatment of astigmatism during cataract surgery were formulated. Twenty participants were divided into seven groups, and each group was assigned three questions to which they had to respond in written form, after thoroughly reviewing the literature. The assigned questions with corresponding responses by each group were discussed with other participants in round 4 – presentation of findings. The consensus was achieved if approval was obtained from at least 80% of participants. The present paper provides several agreements and recommendations for management of astigmatism during cataract surgery, which could potentially minimize the variability in practice patterns and help ophthalmologists adopt optimal practices for cataract patients with astigmatism and improve patient satisfaction.

Long-term efficacy and safety after corneal collagen crosslinking in pediatric patients: Three-year follow-up

Purpose:

To evaluate the effectiveness of standard corneal collagen crosslinking for children with progressive keratoconus.

Methods:

Prospective study including 26 eyes of 26 patients younger than 18 years old with progressive keratoconus at Oftalmosalud Instituto de Ojos, Lima, Peru. Standard epi-off corneal crosslinking was performed in all eyes between January 2012 and January 2013. Pre- and postoperative evaluation (at 3 years) included uncorrected and best-corrected visual acuity and Scheimpflug analysis. Crosslinking failure was defined as an increase in maximum keratometry (Kmax) of more than 1 diopter after 1 year or more.

Results:

Mean uncorrected visual acuity improvement was 0.24 LogMAR (p = 0.07) and mean best-corrected visual acuity improvement was 0.18 LogMAR (p = 0.01). None of the eyes lost more than one line in the best-corrected visual acuity. Four eyes (15.38%) lost two lines in the uncorrected visual acuity at 3 years postoperative. Mean steeper keratometry improvement was 1.14 diopters (p = 0.60). Progression rate was 23.07%.

Conclusion:

Standard epi-off corneal collagen crosslinking is safe and effective to halt the progression of the keratoconus with significant improvement in the best-corrected visual acuity at 3-year follow-up.

Identifying and Managing Root Rot of Pulses on the Northern Great Plains

Pulse crops (annual grain legumes such as field pea, lentil, dry bean, and chickpea) have become an important component of the cropping system in the northern Great Plains of North America over the last three decades. In many areas, the intensity of damping-off, seedling blight, root rot, and premature ripening of pulse crops is increasing, resulting in reduction in stand establishment and yield. This review provides a brief description of the important pathogens that make up the root rot complex and summarizes root rot management on pulses in the region. Initially, several specific Fusarium spp., a range of Pythium spp., and Rhizoctonia solani were identified as important components of the root rot disease complex. Molecular approaches have recently been used to identify the importance of Aphanomyces euteiches on pulses, and to demonstrate that year-to-year changes in precipitation and temperature have an important effect on pathogen prevalence. Progress has been made on management of root rot, but more IPM tools are required to provide effective disease management. Seed-treatment fungicides can reduce damping-off and seedling blight for many of the pathogens in this disease complex, but complex cocktails of active ingredients are required to protect seedlings from the pathogen complex present in most commercial fields. Partial resistance against many of the pathogens in the complex has been identified, but is not yet available in commercial cultivars. Cultural practices, especially diversified cropping rotations and early, shallow seeding, have been shown to have an important role in root rot management. Biocontrol agents may also have potential over the long term. Improved methods being developed to identify and quantify the pathogen inoculum in individual fields may help producers avoid high-risk fields and select IPM packages that enhance yield stability.

First Report of Fusarium cuneirostrum Causing Root Rot Disease in Dry Bean (Phaseolus vulgaris) in Canada

Root rot is a major disease of dry bean and can cause significant yield reductions due to weakened root systems and poor plant stands. An in-depth study on root rot pathogen identification was conducted in 2011 in three commercial dry bean fields from the major production areas in Manitoba. Ten plants, sampled at each of four random sites within each field, were rated for disease severity. Twenty roots were processed for pathogen isolation and identification in the laboratory. Roots were cut into eight sections (~1 cm) and surface-sterilized in a laminar flow bench. Four root sections were placed on potato dextrose agar plates amended with 0.02% streptomycin sulfate (PDA-Strep) and four root sections were placed on peptone-pentachloronitrobenzene agar amended with 0.1% streptomycin sulfate and 0.012% neomycin sulfate. Afterward, 960 monosporic cultures were obtained representing 320 single spore isolates of potential root rot pathogens per commercial field. Common monosporic cultures from each field were subcultured on PDA-Strep and Spezieller Nährstoffarmer Agar (SNA) media. Based on morphological characteristics, 74 isolates were identified as Fusarium cuneirostrum (1). Colonies grew slowly on PDA-Strep with undulated margins, radial cream-grey mycelia, and conidia pustules with a cream-greyish pigmentation. Sporodochial conidia were falcate, mostly 5-septate, with a wedge shape and slightly protruding basal foot cell (56.3 to 71.8 × 4.6 to 6.2 μm on average). Species identity was confirmed for two isolates by sequencing the translation elongation factor 1 alpha (EF1-α) gene (2), the internal transcribed spacer (ITS) region (4), and the ribosomal intergenic spacer (IGS) (3) (GenBank Accession Nos. KF530848, KF530849, and KF025648 to 51). Sequence homology was compared using BLAST analysis and the FUSARIUM-ID database. The F. cuneirostrum isolates were deposited at the Canadian Collection of Fungal Cultures (DAOM 242540 and 242541). Pathogenicity screenings of two isolates was performed using sterilized seed of navy bean cv. Envoy. Seeds were germinated on moist filter paper for 3 days at 25°C and then inoculated by immersion in a prepared conidial suspension (2.5 × 10⁵ conidia/ml) for 5 min. Seeds of the controls were immersed in sterile water. After inoculation, the germinated seeds were planted in 10-cm diameter pots, filled with sterile soilless mix (Sunshine #3). In the greenhouse, the experiment was arranged as a completely randomized design with three replicates with four germinated seeds per isolate, and was repeated twice. Disease assessment was performed 14 days after inoculation. Infected plants displayed dark brown lesions on the hypocotyl and primary root with a disease severity of 4 scored on a 0 to 5 scale. Fusarium cuneirostrum was re-isolated from roots of symptomatic plants. To our knowledge, this is the first report of F. cuneirostrum causing root rot of dry bean in Canada. It has been previously isolated from mung bean (Vigna radiata) in Ontario (1). References: (1) T. Aoki et al. Mycoscience. 46:162, 2005. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (4) H. Wang et al. J. Clin. Microbiol. 49:1890, 2011. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

Independent Population Validation of the Belin/Ambrósio Enhanced Ectasia Display: Implications for Keratoconus Studies and Screening

With advances in technology and imaging, finding diagnostic criteria that are both sensitive and specific for keratoconus while using the latest corneal imaging modalities is paramount. The Belin/Ambrósio enhanced ectasia display final ‘D’ index, tested on an independent population, illustrated excellent false positive rates for refractive screening while eliminating 99% of keratoconus corneas. A false positive rate of 0% is achieved with a final ‘D’ of 2.69, meeting the more stringent criteria for treatment studies.

How to cite this article

Villavicencio OF, Gilani F, Henriquez MA, Izquierdo L Jr, Ambrósio RR Jr, Belin MW. Independent Population Validation of the Belin/Ambrósio Enhanced Ectasia Display:Implications for Keratoconus Studies and Screening. Int J Kerat Ect Cor Dis 2014;3(1):1-8.

Effects of glucans and eicosapentaenoic acid on differential regulation of phenylpropanoid and mevalonic pathways during potato response to Phytophthora infestans

The effects of Phytophthora infestans glucans, eicosapentaenoic acid (EPA) and isolates of this pathogen, on the differential expression of eight genes from the phenylpropanoid and the mevalonate (Ac-MVA) pathways were analyzed in potato by semi-quantitative RT-PCR and qRT-PCR. The application of EPA had an elicitor effect in Russet Burbank (RB) and Defender (DF) in response to inoculation with a US8 isolate of P. infestans, thereby reducing symptoms of late blight. Such effect was associated with the expression of PAL-1 and PAL-2, since the latter occurred only when EPA was followed by inoculation, whereas these genes were down-regulated in individual treatments RB + EPA, RB + US8, DF + EPA, and DF + US8. The glucan fraction did not by itself suppress phenylpropanoid genes, but its combination with the pathogen resulted in a down-regulation of PAL-1, PAL-2 and CHS. The addition of the glucan fraction to the elicitor EPA, had a negative effect (RB + EPA + GL + US8) since plants showed higher disease symptoms than the ones pretreated with water then infected with US8, and in comparison with RB + EPA + US8 and RB + GL + US8. Exclusive up-regulation of 4CL in DF + US11 and of CHS in DF + EPA + GL + US8, DF + EPA + US11, DF + GL + US11 and DF + EPA + GL + US11, where late blight lesions were not detected, could be associated with potato protection against late blight. Along with previous findings in this pathosystem, these data suggest that genetic resistance in potato against P. infestans is not the result of isolated reactions against the pathogen, but rather the combination of many factors in-line with a polygenic/horizontal resistance.

Alteration of secondary metabolites' profiles in potato leaves in response to weakly and highly aggressive isolates of Phytophthora infestans

Phytophthora infestans is the cause of late blight, a devastating disease in potato and tomato. Many of the mechanisms underlying P. infestans pathogenesis and defense responses in potato are still unclear. We investigated the effects of P. infestans on the changes in the accumulation of secondary metabolites in potato cultivars using whole plants. Four preformed flavonoids and one terpenoid compound produced in potato tissues were differentially affected by the P. infestans inoculation. In Russet Burbank, the accumulation of catechin and rutin was suppressed by both P. infestans isolates US-11 and US-8, while the flavanone P3 was associated with susceptibility to this pathogen. On the other hand, catechin, flavonol-glycoside P2, and an unidentified terpenoid (T1), may be involved in the defense of cultivar Defender to both tested P. infestans isolates, providing new evidence that different preformed flavonoids and terpenoids in potato may play important roles in its defense or susceptibility to P. infestans. These results add to the pool of data showing the involvement of other phenolics and terpenes in potato resistance to microbial pathogens.

Artiflex phakic intraocular lens implantation after corneal collagen cross-linking in keratoconic eyes

PURPOSE

To evaluate the safety, efficacy, and stability of the Artiflex (Ophtec BV) foldable anterior iris-claw phakic intraocular lens (PIOL) following corneal collagen cross-linking (CXL) in select cases of progressive keratoconus.

METHODS

This prospective, comparative study, conducted between March 2007 and June 2008, involved 11 eyes with progressive keratoconus. Inclusion criteria were progressive keratoconus (Amsler-Krumeich classification grades I and II) with no corneal opacities, corneal thickness >450 μm, endothelial cell count >2500 cells/mm(2), anterior chamber depth >3.2 mm, spherical equivalent refraction >4.50 diopters (D) (with a cylinder component <2.00 D), and no other treatment for keratoconus other than contact lens. Each patient underwent CXL in the keratoconic eye with implantation of the Artiflex IOL 6 months thereafter. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refraction and topographic profiles were examined at 1, 6, and 12 months after the CXL procedure.

RESULTS

All eyes achieved UDVA of 0.3 logMAR or better. Final spherical and cylindrical error ranged from 0 to -1.50 D and 0 to -1.75 D, respectively. No eyes lost lines of preoperative CDVA. Statistically significant reductions in mean maximum (2.14 D, P<.001) and minimum (1.17 D, P=.02) keratometry values were present 12 months after the CXL procedure. No complications were observed.

CONCLUSIONS

Combined CXL and Artiflex implantation was a safe and effective treatment in this subset of eyes with progressive keratoconus. Good results in terms of visual acuity, postoperative residual refractive error, and keratometry values were identified.

Double aspiration/single irrigation system for bimanual lens cortex removal in cataract surgery

The authors describe a bimanual double aspiration/single irrigation system (DASIS) for cataract surgery that efficiently and safely performs aspiration of the entire cortex, including subincisional space. DASIS uses standard and common instruments such as an irrigation/aspiration handpiece in one hand and a single-aspiration handpiece in the other, joined with a short silicone tube using a three-way stopcock. DASIS allows access to 360° of the cortex without a hand exchange, reducing wound leakage and maintaining chamber stability.

Detection of an abnormally thick LASIK flap with anterior segment OCT imaging prior to planned LASIK retreatment surgery

PURPOSE

To report a case of an abnormally thick flap that was detected with the use of anterior segment optical coherence tomography (OCT) prior to planned LASIK retreatment surgery.

METHODS

A 43-year-old man presented 6 years after bilateral LASIK surgery with uncorrected visual acuity (UCVA) of 20/20 in the right eye and 20/100 in the left eye, and best spectacle-corrected visual acuity (BSCVA) of 20/20 in the right eye and 20/20 in the left eye (refraction -2.25 -1.25 x 131). Anterior segment OCT was performed before LASIK retreatment surgery in the left eye.

RESULTS

The flap was found to be 394 microm and the residual stromal bed was too thin (152 microm) to allow for safe LASIK retreatment surgery. After waiting 4 months to ensure refractive stability, photorefractive keratectomy was performed. Postoperative UCVA was 20/20 plano.

CONCLUSIONS

The use of anterior segment OCT in the preoperative examination for planned LASIK retreatment surgery provided more reliable data.