Genetic diversity and persistent colonization of <Emphasis Type="Italic">Enterococcus faecalis</Emphasis> on ocular surfaces

Purpose

Enterococcus faecalis causes severe acute endophthalmitis and often leads to poor visual outcomes. Conjunctival bacterial cultures occasionally grow atypical bacteria including E. faecalis, which can potentially contribute to the development of postoperative endophthalmitis. However, the characteristics of these ocular E. faecalis strains are unknown. This study is the first attempt to determine the population characteristics of E. faecalis clinical isolates from eye infections and ocular commensals.

Study design

Retrospective

Methods

Twenty-eight E. faecalis ocular isolates were collected from 23 patients at 3 referring hospitals. The multilocus sequence typing (MLST) data were analyzed using the eBURST program. Phenotypes of cytolysin and gelatinase, antibiotic susceptibility, and mutations of the quinolone resistance-determining regions (QRDRs) of gyrA and parC were also examined. Pulsed-field gel electrophoresis (PFGE) was performed for strains from the same patients.

Results

PFGE revealed that 3 patients retained identical strains for 10 months to 2 and a half years. MLST identified 12 sequence types (STs), which were clustered into 3 clonal complexes (CCs) and 8 singletons, with ST179 the largest. Thirteen of the 23 isolates (56.5%) belonged to CC58, CC8, or CC2, which have previously been reported to be major CCs. Six of the 23 strains (26.0%) exhibited high-level quinolone resistance derived from mutations of the QRDRs in both gyrA and parC.

Conclusions

The sequence types of E. faecalis ocular isolates were divergent, with no eye-specific lineages observed. Persistent colonization of E. faecalis on the ocular surface was demonstrated in patients with chronic ocular surface diseases.

     

<Emphasis Type="Italic">MTHFR</Emphasis> and <Emphasis Type="Italic">MTHFD1</Emphasis> gene polymorphisms are not associated with pseudoexfoliation syndrome in South Indian population

Purpose

Pseudoexfoliation syndrome (PEX) is a late onset disorder of extracellular matrix turnover, associated systemically with cardiovascular and cerebrovascular disease. To evaluate the suggested association of polymorphisms of homocysteine metabolism genes MTHFR (rs1801131, rs1801133) and MTHFD1 (rs8006686) with PEX.

Methods

A case–control association study was undertaken, comprising a total of 1472 individuals including 860 unrelated PEX cases and 612 ethnic-matched cataract controls (CC). All the study subjects were genotyped for three SNPs using the TaqMan allelic discrimination assay. Association and statistical analysis were performed with PLINK 1.07 and STATA 11.1.

Results

Among the three SNPs genotyped, MTHFR polymorphisms did not exhibit significant association with PEX (rs1801131; p = 0.549, rs1801133; p = 0.408). The intronic SNP rs8006686 showed nearly significant association (p = 0.069), and however did not remain significant after Bonferroni correction.

Conclusion

Our study suggests no significant genetic association of MTHFR (rs1801131, rs1801133) and MTHFD1 (rs8006686) polymorphisms in South Indian PEX patients.

     

Assessment of corneal backward light scattering in the healthy cornea and factors affecting corneal transparency

Purpose

To quantify normative corneal optical density (COD) values of healthy individuals and to investigate alterations in the COD in relation to their ocular and demographic characteristics.

Study design

Prospective, cross-sectional, and observational.

Methods

In total, 588 eyes from 588 healthy participants with clear corneas were consecutively enrolled. Corneal densitometry values expressed in standardized grayscale units (GSU) from different corneal layers and zones obtained using the rotating Pentacam Scheimpflug system were analyzed.

Results

The mean (SD) COD over the 12-mm diameter area was 14.4?±?2.74 GSU. A significant positive correlation was found between the participants’ age and the total COD (r?=?0.756, P?<?.001). No significant differences were found between males and females with respect to COD (P?=?.51). No significant correlation was found between the COD measurements and refractive error, pachymetry, and keratometry (P?>?.05 for all comparisons). On the other hand, COD was negatively correlated with white-to-white (WTW) corneal diameter (r?=???0.415, P?<?.001). Moreover, the WTW corneal diameter was correlated with the COD in any zone and layer of the cornea (P?<?.05 for all comparisons).

Conclusions

Wide variations in COD can be detected even in corneas deemed clinically clear. Age and corneal diameter that seem to influence corneal transparency should be taken into account when evaluating corneal backscatter.

     

Fluorescein and indocyanine-green angiography in ocular syphilis: an exploratory study

Background

Fluorescein (FA) and indocyanine-green angiography (ICGA) may offer valuable information concerning disease severity and prognosis in ocular syphilis. The aim of the present study is to describe angiographic patterns encountered in the context of ocular syphilis, and to explore the associations between specific angiographic manifestations and severity of disease presentation, as well as disease evolution after treatment.

Methods

We performed a retrospective institutional study with the inclusion of 23 patients with ocular syphilis presenting to the uveitis clinic of the Jules-Gonin Eye Hospital in a 10-year period. FA and ICGA were performed following a standard protocol for posterior uveitis. Patterns of fluorescence were noted, and statistical associations between each angiographic pattern and any demographic, clinical, or laboratory parameter at baseline and after treatment were sought.

Results

The presence of any dark dots in ICGA was significantly associated with anterior uveitis (p?=?0.031). The presence of hot spots in ICGA was significantly associated with longer duration of symptoms prior to initial visit (p?=?0.032) and with male gender (p?=?0.012). Weak non-significant trends were found associating vascular staining in FA with anterior uveitis (p?=?0.066), vitritis (p?=?0.069), and younger age (p?=?0.061), as well as disc hyperfluorescence in FA with seropositivity for HIV (p?=?0.089) and macular edema in FA with longer disease duration (p?=?0.061). The presence of any dark dots in ICGA exhibited a weak trend of association with anterior uveitis and/or vitritis (p?=?0.079).

Conclusions

Out of the several associations identified implicating specific angiographic features, we underline the possible role of the presence of dark dots in ICGA for identifying active inflammation, and the role of hot spots in ICGA as markers of long-standing disease. Vascular staining in FA appears to be more common in patients with severe ocular inflammation with presence of anterior uveitis and/or vitritis.

     

Visual consequences of electronic reader use: a pilot study

Background

With the increasing prevalence of electronic readers (e-readers) for vocational and professional uses, it is important to discover if there are visual consequences in the use of these products. There are no studies in the literature quantifying the incidence or severity of eyestrain, nor are there clinical characteristics that may predispose to these symptoms with e-reader use.

Purpose

The primary objective of this pilot study was to assess the degree of eyestrain associated with e-reader use compared to traditional paper format. The secondary outcomes of this study were to assess the rate of eyestrain associated with e-reader use and identify any clinical characteristics that may be associated with the development of eyestrain.

Methods

Forty-four students were randomly assigned to study (e-reader iPAD) and control (print) groups. Participant posture, luminosity of the room, and reading distance from reading device were measured during a 1-h session for both groups. At the end of the session, questionnaires were administered to determine symptoms.

Results

Significantly higher rates of eyestrain (p = 0.008) and irritation (p = 0.011) were found among the iPAD study group as compared to the print ‘control’ group. The study group was also 4.9 times more likely to report severe eyestrain (95 % CI [1.4, 16.9]). No clinical characteristics predisposing to eyestrain could be identified.

Conclusions

These findings conclude that reading on e-readers may induce increased levels of irritation and eyestrain. Predisposing factors, etiology, and potential remedial interventions remain to be determined.

     

Clinical characteristics according to the laterality of ocular torsion in unilateral superior oblique palsy

Background

To compare clinical characteristics according to the laterality of objective ocular torsion in patients with unilateral superior oblique palsy (SOP).

Methods

This retrospective study included all patients with a diagnosis of unilateral SOP. They were classified into subgroups according to correspondence between the paretic eye and the extorted eye using fundus photography. Ocular alignment and muscle action were tested by the prism and alternate cover tests and 4-scale movement measure. Various clinical factors, including the amount of preoperative ocular torsion and change in ocular torsion postoperative, were compared between the accordance and disaccordance groups.

Results

A total of 70 Asian patients (140 eyes) were included and underwent fundus photography preoperatively. Excyclotorsion in the paretic eye was defined as accordance (45 patients), excyclotorsion in the nonparetic eye was defined as disaccordance (25 patients). The presence of horizontal strabismus was detected in 28 (62%) patients in the accordance group and only 8 (32%) patients in the disaccordance group (p?=?0.024). All horizontal strabismus observed in the accordance group involved exodeviation. The proportion of horizontal strabismus surgery was also significantly larger in the accordance group than the disaccordance group (p?=?0.039). Among those patients, there were 26 who underwent fundus photography postoperatively. There was significant reduction in ocular excyclotorsion postoperatively in the accordance group (p?=?0.001), but no significant reduction postoperatively in the disaccordance group (p?=?0.270). There was no significant correlation between the amount of torsional reduction and the amount of vertical deviation reduction (p?=?0.979).

Conclusions

In cases of preoperative excyclotorsion in paretic eyes, careful consideration of combined horizontal misalignment which may require surgical correction is helpful to manage unilateral SOP.

     

Changes in the size of the foveal avascular zone after vitrectomy with internal limiting membrane peeling for a macular hole

Purpose

To determine the size of the foveal avascular zone (FAZ) before and after vitrectomy for a macular hole (MH).

Study Design

Retrospective case series study.

Methods

Twenty-five eyes of 25 patients with a unilateral MH that had undergone vitrectomy with internal limiting membrane peeling were studied. The unaffected 17 fellow eyes were studied in the same way. En face images of the parafoveal region were obtained by optical coherence tomography angiography, and the images were used to measure the FAZ before and 1 month after the vitrectomy. The relationships between the different FAZ sizes and the ocular parameters were determined by Pearson product moment correlation analysis.

Results

Compared with the preoperative superficial FAZ (sFAZ), the postoperative sFAZ was significantly reduced (P < 0.001). The postoperative sFAZ was significantly smaller than that of the fellow eye (P < 0.001). The size of the postoperative sFAZ was significantly correlated with that of the preoperative sFAZ, the postoperative foveal thickness (FT), and the sFAZ of the fellow eyes (r = 0.520, P = 0.008; r = ?0.515, P = 0.012; and r = 0.702, P = 0.002, respectively). The size of the postoperative deep FAZ (dFAZ) was significantly correlated with the postoperative FT and the dFAZ of the fellow eyes (r = ?0.441, P = 0.035; and r = 0.499, P = 0.049, respectively). However, no significant correlation was found between the size of the postoperative FAZ and the size of the preoperative MH.

Conclusions

MH closure leads to a significant decrease in the size of the FAZ symmetrical to the size of the fellow eye. The size of the postoperative FAZ is influenced by the postoperative FT independently of the size of the MH.

     

Assessing posterior ocular structures in β-thalassemia minor

Purpose

The aim of this study was to investigate the effect of β-thalassemia minor on choroidal, macular, and peripapillary retinal nerve fiber layer thickness.

Methods

To form the sample, we recruited 40 patients with β-thalassemia minor and 44 healthy participants. We used spectral-domain optical coherence tomography to take all measurements of ocular thickness, as well as measured intraocular pressure, axial length, and central corneal thickness. We later analyzed correlations of hemoglobin levels with ocular parameters.

Results

A statistically significant difference emerged between patients with β-thalassemia minor and the healthy controls in terms of mean values of subfoveal, nasal, and temporal choroidal thickness (p = 0.001, p = 0.016, and p = 0.010, respectively). Except for central macular thickness, differences in paracentral macular thicknesses between the groups were also significant (superior: p < 0.001, inferior: p = 0.007, temporal: p = 0.001, and nasal: p = 0.005). Also, no statistically significant differences were noted for retinal nerve fiber layer thickness between two groups.

Conclusion

Mean values of subfoveal, nasal, temporal choroidal, and macular thickness for the four quadrants were significantly lower in patients with β-thalassemia minor than in healthy controls.

     

The association of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> with choroidal and retinal nerve fiber layer thickness

Purpose

To investigate the effect of Helicobacter pylori (H. pylori) infection on choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT).

Methods

The study included 25 patients with H. pylori infection and 25 healthy individuals as the control group. Helicobacter pylori patients were classified as the pre-treatment (Group 1; n: 25) and the post-treatment (Group 2; n: 25). RNFLT and CT were measured before and after treatment of H. pylori infection, using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany). The axial length and intraocular pressure were also measured.

Results

The mean subfoveal CT was 320.96 ± 29.15 μm in Group 1 and 287.48 ± 49.17 in the control group (p = 0.007), while the mean subfoveal CT did not show any difference between Group 2 and the control group (p > 0.05). No statistically significant difference was determined between the H. pylori patients and the control group in respect of RNFLT values (p > 0.05).

Conclusions

CT increases during H. pylori infection and returns to the normal range within 6 weeks of treatment. RNFLT does not show any change during H. pylori infection. The data related to the subfoveal CT may be useful in understanding the pathogenesis of central serous chorioretinopathy developing in H. pylori patients.

     

Alterations in corneal epithelial thickness in patients with congenital myogenic eyelid ptosis

Purpose

To evaluate whether the corneal epithelial thickness (CET) maps obtained by optical coherence tomography (OCT) of the congenital myogenic eyelid ptosis differ from controls.

Methods

CET maps of 13 patients with congenital myogenic eyelid ptosis (m/f = 9/4; mean age 20.5 ± 7.5) and randomly selected one eye of 13 controls (m/f = 7/6; mean age 21.5 ± 6.5) were investigated. Three pachymetry scans of each eye were performed by OCT (RTVue-XR, Optovue Inc., USA), and the scan with the highest signal strength index was selected for the analysis.

Results

In ptosis group: Minimum corneal epithelial thickness was thinner (p = 0.029), standard deviation of thickness was higher (p = 0.039), the negative of min–max values were higher (p = 0.007). This difference was originating from the significant thinness of the superior sectors (S, SN, ST) of the corneal epithelium than the inferior counterparts (I, IT, IN) (p = 0.001, p = 0.017, p = 0.002), respectively. There was no difference regarding total corneal thickness measurements.

Conclusions

The mechanic effects of ptotic eyelid to the ocular surface may reshape the corneal epithelium, which can be objectively detected by OCT.

     

Association between the <Emphasis Type="Italic">8</Emphasis>-<Emphasis Type="Italic">oxoguanine DNA glycosylase</Emphasis> gene Ser326Cys polymorphism and age-related cataract: a systematic review and meta-analysis

Purpose

To investigate the association between the 8-oxoguanine DNA glycosylase (OGG1) gene Ser326Cys (rs1052133) polymorphism and age-related cataract (ARC).

Methods

MEDLINE and EMBASE were searched to identify potential studies published before May 19, 2017, investigating the association between the OGG1 gene Ser326Cys polymorphism and ARC risk. The quality of eligible studies was assessed using the Newcastle–Ottawa Scale tool. The association between the OGG1 gene Ser326Cys polymorphism and ARC was analyzed using meta-analysis. Publication bias and sensitivity analyses were also performed.

Results

Six studies were included in this systematic review, and five of these studies with Hardy–Weinberg equilibrium were included in a meta-analysis. The sample size of the meta-analysis was 3716, including 1831 patients with cataract and 1885 controls. Odds ratios (ORs) were 0.67 (95% confidence interval (CI) 0.52–0.85), 0.90 (95% CI 0.54–1.51), 0.52 (95% CI 0.32–0.85) and 0.72 (95% CI 0.56–0.92) for recessive, dominant, additive and allele contrast models, respectively. Sensitivity analysis indicated that the results of the meta-analysis were robust. No publication bias was observed.

Conclusions

The OGG1 gene Ser326Cys polymorphism was associated with ARC risk.

     

Triple-A syndrome with prominent ophthalmic features and a novel mutation in the <Emphasis Type="Italic">AAAS</Emphasis>gene: a case report

Background

Triple-A syndrome (Allgrove syndrome) is an autosomal recessive disorder characterized by adrenal insufficiency, alacrima, achalasia, and – occasionally – autonomic instability. Mutations have been found in the AAAS gene on 12q13.

Case presentation

We present the case of a 12 year-old boy with classic systemic features of triple-A syndrome and several prominent ophthalmic features, including: accommodative spasm, dry eye, superficial punctate keratopathy, and pupillary hypersensitivity to dilute pilocarpine. MRI showed small lacrimal glands bilaterally. DNA sequencing of PCR-amplified fragments from the 16 exons of the AAAS gene revealed compound heterozygosity for a new, out-of-frame 5-bp deletion in exon 15, c1368-1372delGCTCA, and a previously-described nonsense mutation in exon 9, c938C>T, R286X.

Conclusions

In addition to known ophthalmic manifestations, triple-A syndrome can present with accommodative dysregulation and ocular signs of autonomic dysfunction.

     

Correlative factors’ analysis of postural-related ocular cyclotorsion with image-guided system

Purpose

To explore the correlation between ocular cyclotorsion induced by sitting and supine positions as well as other selected factors, validated by an image-guided system.

Study design

A cross-sectional study conducted in 73 inpatients (85 eyes) who received intraocular operations in China Medical University.

Methods

The ocular cyclotorsion degree was recorded using an image-guided system (Verion Reference Unit, Alcon) by comparing images captured in sitting position, as well as pre- and post-different anesthesia methods in the supine position. Possible correlative factors including age, gender, eye axial length, best corrected visual acuity (BCVA), astigmatism degree, astigmatism axis, anesthesia, and comparison in laterality of eyes on ocular cyclotorsion were analyzed.

Results

The total cyclotorsion rate was 88.24% and the cyclotorsion degree ranged from ? 14.0° to + 12.0° with an average of 4.6° ± 3.4°. Excyclotorsion was predominant OD whereas incyclotorsion was predominant OS (p < 0.05). The effect of eye axial length, BCVA, astigmatism degree, astigmatism axis, anesthesia method, age and gender on cyclotorsion orientation was not statistically significant, neither did these factors show any significant differences in the ocular cyclotorsion degree (p > 0.05). Pre- and post-anesthesia, and different anesthetic methods, did not show any significant influence on the ocular cyclotorsion degree (p > 0.05).

Conclusions

Cyclotorsion orientation seems to be correlated only with eye laterality. None of the other investigated factors, including age, gender, eye axial length, BCVA, astigmatism degree, astigmatism axis and anesthesia seems to affect cyclotorsion orientation or degree.

     

Comparison of visual outcomes and reading performance after bilateral implantation of multifocal intraocular lenses with bilateral monofocal intraocular lenses

Purpose

To compare the visual acuity outcomes, contrast sensitivity function (CS) and reading ability in patients with bilateral multifocal intraocular lenses and patients with bilateral monofocal lenses.

Setting

Vizyon Eye Center, Denizli, Turkey.

Design

Comparative case series.

Methods

Consecutive bilateral cataract patients having implantation of Acriva Reviol MFM 611 multifocal IOLs (Group A) or Acriva BB UD 613 monofocal IOLs (Group B) were included. Parameters analyzed 6 months postoperatively included monocular uncorrected distance (UDVA), binocular uncorrected intermediate (UIVA), binocular uncorrected near (UNVA), CS and bilateral reading performance using MN Read.

Results

The study evaluated 42 eyes in Group A and 40 eyes in Group B. There were no statistically significant differences in UDVA between two groups postoperatively (p = .39). Binocular UIVA and binocular UNVA are better in Group A (p = .00, p = .00). Under photopic and scotopic conditions, contrast sensitivity results were decreased in Group A, especially at high spatial frequencies. No statistically difference were found in reading acuity, critical print size and maximum reading speed between two groups (p = .57, p = .62, p = .22).

Conclusions

This study concludes that multifocal lenses are reliable and efficient replacements for reading glasses since they significantly improve the vision for near or intermediate distance activities.

     

Allogenic cultivated limbal stem cell transplantation versus cadaveric keratolimbal allograft in ocular surface disorder: 1-year outcome

Purpose

To compare the outcome of allogenic ex vivo cultivated limbal stem cell transplantation (LSCT) versus cadaveric keratolimbal allograft in patients with limbal stem cell deficiency (LSCD).

Methods

In this prospective interventional study from Army Hospital Research and Referral in New Delhi, 50 eyes of 40 patients with ocular surface disorder having LSCD underwent either cultivated LSCT (group 1: 25 eyes of 20 patients) or keratolimbal allograft transplantation (group 2: 25 eyes of 20 patients). The outcome measures were gain of two or more lines of best-corrected visual acuity (BCVA), absence of conjunctival vascularization over cornea, corneal neovascularization regression, regression of visually significant corneal opacity (iris details poorly visible), Schirmer’s 1 ≥10 s, tear break-up time (TBUT) ≥10 s, and absence of fluorescein staining.

Results

At 1 year of follow-up, both groups experienced significant improvement in all outcome measures, but there was no significant difference between both groups in improvement of two or more lines of BCVA (P = 0.841), absence of conjunctival vascularization over cornea (P = 0.812), corneal neovascularization (P = 0.074), visually significant corneal opacity (P = 0.075), Schirmer’s 1 ≥10 s (P = 0.814), TBUT ≥10 s (P = 0.382), or absence of fluorescein stain (P = 1.00).

Conclusion

Both allogenic ex vivo cultivated LSCT and cadaveric keratolimbal allograft transplantation are comparable in terms of visual gain and ocular surface restoration.

     

A novel <Emphasis Type="Italic">C</Emphasis>x<Emphasis Type="Italic">50</Emphasis> (<Emphasis Type="Italic">GJA8</Emphasis>) p.H277Y mutation associated with autosomal dominant congenital cataract identified with targeted next-generation sequencing

Background

To unravel the molecular genetic background responsible for autosomal dominant congenital pulverulent nuclear cataracts in a four-generation Chinese family.

Methods

Family history data were collected, ophthalmological examinations were performed, and genomic DNA was extracted from peripheral blood of the family members. The candidate genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The structure modelling of the protein was displayed based on Swiss-Model Server, and its possible changes in the secondary structure were predicted using Antheprot 2000 software. The chemical dissimilarity and possible functional impact of an amino acid substitution were performed with Grantham score, PolyPhen-2, and SIFT predictions. Protein distributions were assessed by confocal microscopy.

Results

A novel heterozygous c.829C?>?T transition that led to the substitution of a highly conserved histidine by tyrosine at codon 277 (p.H277Y) in the coding region of connexin50 (Cx50, GJA8) was identified. Bioinformatics analysis showed that the mutation likely altered the secondary structure of the protein by replacing the helix of the COOH-terminal portion with a turn. The mutation was predicted to be moderately conservative by Grantham score and to be deleterious by both PolyPhen-2 and SIFT with consistent results. In addition, when expressed in COS1 cells, the mutation led to protein accumulation and caused changes in Cx?50 protein localization pattern.

Conclusions

This is a novel missense mutation [c.829C?>?T, (p.H277Y)] identified in exon 2 of Cx50. Our findings expand the spectrum of Cx50 mutations that are associated with autosomal dominant congenital pulverulent nuclear cataract.

     

Associations of macular thickness in spectral-domain OCT with ocular and systemic cardiovascular parameters - The MIPH Eye &amp; Health Study

Purpose

Beyond in-vivo histological analysis of retinal tissue, optical coherence tomography (OCT) allows quantitative image analysis. This study evaluates associations of macular retinal thickness measured with spectral-domain OCT (SD-OCT) and ocular and systemic cardiovascular parameters in adult subjects.

Methods

An epidemiological cross-sectional study was performed in the staff of a European high-tech company. Examination of known cardiovascular risk factors including biochemical blood analysis was performed, and ocular parameters such as refraction, tonometry, SD-OCT imaging of the macula and cornea, and fundus photography were evaluated. Retinal thickness measurements were evaluated according to the ETDRS grid. Associations of macular retinal thickness and systemic cardiovascular and ocular parameters were calculated by multivariate analysis using SPSS software.

Results

Four hundred and twenty-four probands were included. Macular thickness measurement were significantly associated with gender and refraction. Female persons had thinner retinal thickness in all zones. Macular thickness decreased with increasing myopia in all perifoveal measurements. Outer perifoveal measurements were associated with keratometry; a flatter corneal radius was linked to a thinner retina. Tonometry and systemic cardiovascular risk factors were not associated with macular retinal thickness in multivariate analysis (p?>?0.05).

Conclusions

Macular retinal thickness is associated with refraction and gender; cardiovascular risk factors or tonometry do not influence macular retinal thickness measurements. Keratometry might influence outer zone measurements. Our findings provide a dataset for quantitative evaluation of SD-OCT, and evaluate influencing factors.