Exploring charge density distribution and electronic properties of hybrid organic-germanium layers.

Band gap tuning and dielectric properties of small organic ligands adsorbed on bidimensional germanium monolayers (germanene) have been investigated using first-principles calculations. We show that the adsorption of these small groups retains the initially stable free-standing pristine buckled structure form. Charge density and chemical bonding analyses show that the ligands are chemisorbed on the germanium layers. Finally, we demonstrate that the dielectric properties of the bare and ligand adsorbed germanene have a large anisotropy. Our findings of a finite gap open a path for the rational design of nanostructures with possible applications in biosensors and solar cells.

High pressure extraction of olive leaves (Olea europaea): bioactive compounds, bioactivity and kinetic modelling.

In this study, the extraction yield, the mathematical modeling of pressurized liquid extraction (PLE) kinetics with sub- and supercritical carbon dioxide (SC-CO2) of olive leaves (Olea europaea) and the biological activity of the extracts were evaluated. The extraction with PLE was conducted isobarically (10.3 MPa), varying the temperature (20, 40 and 60 °C) and the solvent (ethyl acetate, acetone, ethanol, ethanol:water-80:20, v:v), solvent flow (2 mL min-1) and time (110 min) and the extractions with SC-CO2, varying the temperature between 20 and 60 °C and the pressure between 8 and 25 MPa, keeping the time constant (210 min) and the CO2 flow of 2 mL min-1. In the extracts, antioxidant activity, total phenolic and flavonoid contents and oleuropein were evaluated. The highest total extract yield in the PLE was 30.91% at 60 °C, 10.3 MPa using ethanol:water (80:20, v:v). The yield obtained using the supercritical fluid was 0.68% at 60 °C and 25 MPa. The PLE extract obtained with ethanol at 60 °C presented the highest concentration of total phenolic content (386.42 mg GAE g-1 extract), total flavonoids content (33.43 mg CAT g-1 extract), oleuropein (73.65 mg g-1 extract) and antioxidant activity (82.87%). The overall extraction curves were modeled using the well-established Sovová model and kinetic extraction model based on the Brunauer-Emmett-Teller theory of adsorption. Both kinetic models used were able to correlate well with the experimental data with slightly better results obtained by the former. The alternative PLE extraction technique investigated in this work was found to be suitable for the extraction of olive leaves after short times of extraction obtaining an extract with high biological activities.

Functional Magnetic Resonance Imaging to Assess the Neurobehavioral Impact of Dysphotopsia with Multifocal Intraocular Lenses.

PURPOSE: To investigate the association between dysphotopsia and neural responses in visual and higher-level cortical regions in patients who recently received multifocal intraocular lens (IOL) implants. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty patients 3 to 4 weeks after bilateral cataract surgery with diffractive IOL implantation and 15 age- and gender-matched control subjects. METHODS: Functional magnetic resonance imaging (fMRI) was performed when participants viewed low-contrast grating stimuli. A light source surrounded the stimuli in half of the runs to induce disability glare. Visual acuity, wavefront analysis, Quality of Vision (QoV) questionnaire, and psychophysical assessment were performed. MAIN OUTCOME MEASURES: Cortical activity (blood oxygen level dependent [BOLD] signal) in the primary visual cortex and in higher-level brain areas, including the attention network. RESULTS: When viewing low-contrast stimuli under glare, patients showed significant activation of the effort-related attention network in the early postoperative period, involving the frontal, middle frontal, parietal frontal, and postcentral gyrus (multisubject random-effects general linear model (GLM), P < 0.03). In contrast, controls showed only relative deactivation (due to lower visibility) of visual areas (occipital lobe and middle occipital gyrus, P < 0.03). Patients also had relatively stronger recruitment of cortical areas involved in learning (anterior cingulate gyrus), task planning, and solving (caudate body). Patients reporting greater symptoms induced by dysphotic symptoms showed significantly increased activity in several regions in frontoparietal circuits, as well as cingulate gyrus and caudate nucleus (q < 0.05). We found no correlation between QoV questionnaire scores and optical properties (total and higher order aberration, modulation transfer function, and Strehl ratio). CONCLUSIONS: This study shows the association between patient-reported subjective difficulties and fMRI outcomes, independent of optical parameters and psychophysical performance. The increased activity of cortical areas dedicated to attention (frontoparietal circuits), to learning and cognitive control (cingulate), and to task goals (caudate) likely represents the beginning of the neuroadaptation process to multifocal IOLs.

Intense intrashell luminescence of Eu-doped single ZnO nanowires at room temperature by implantation created Eu-Oi complexes.

Successful doping and excellent optical activation of Eu(3+) ions in ZnO nanowires were achieved by ion implantation. We identified and assigned the origin of the intra-4f luminescence of Eu(3+) ions in ZnO by first-principles calculations to Eu-Oi complexes, which are formed during the nonequilibrium ion implantation process and subsequent annealing at 700 °C in air. Our targeted defect engineering resulted in intense intrashell luminescence of single ZnO:Eu nanowires dominating the photoluminescence spectrum even at room temperature. The high intensity enabled us to study the luminescence of single ZnO nanowires in detail, their behavior as a function of excitation power, waveguiding properties, and the decay time of the transition.

The role of water co-adsorption on the modification of ZnO nanowires using acetic acid.

Density functional theory (DFT) and Car-Parinello molecular dynamic simulations were employed to investigate the interaction of acetic acid with non-polar facets of ultra-thin ZnO nanowires. We consider both a dry and a water environment as well as different molecule coverages for the hydrated system. Our calculations reveal that the fully-covered nanowire is energetically favored in the aqueous environment at room temperature. We also identified a minor influence of liquid water on the denticity of the ligands for the fully modified system. However, a monodentate adsorption is expected for a half-covered nanowire due to strong ligand-water interactions.

Photorefractive keratectomy for myopia and myopic astigmatism correction using the WaveLight Allegretto Wave Eye-Q excimer laser system.

To analyze photorefractive keratectomy (PRK) outcomes in myopia and myopic astigmatism correction using the WaveLight Allegretto Wave Eye-Q(®) excimer laser system (WaveLight Laser Technologie AG, Erlangen, Germany). 222 eyes of 151 patients underwent PRK (mean age 33.5 ± 6.8 years). Pre-operative best spectacle-corrected visual acuity (BSCVA) ranged from 0.4 to -0.1 logMAR (mean -0.03 ± 0.06). Mean spherical equivalent (SE) was -3.29 ± 1.20 D. Efficacy, predictability and safety were evaluated. Minimum follow-up was 3 months. Accountability at 3 and 6 months was 100 and 54 %, respectively (median follow-up 5 months, mean 5.2 ± 2.6 months). At 3 months, mean uncorrected visual acuity (UCVA) was -0.02 ± 0.07 logMAR, BSCVA -0.03 ± 0.05 logMAR, efficacy index 0.98 and safety index 1.02. UCVA was ≥20/16 in 40.1 %, ≥20/20 in 86.5 % and ≥20/25 in 98.2 %. Mean SE was -0.02 ± 0.20 D. Residual refractive error was ± 0.13 D in 81.5 %, ± 0.25 D in 88.7 % and ± 0.50 D in 97.7 %. At 6 months, outcomes were similar: mean UCVA was -0.02 ± 0.07 logMAR, BSCVA -0.03 ± 0.06 logMAR, efficacy index 1.00 and safety index 1.03. UCVA was ≥20/16 in 43.7 %, ≥20/20 in 86.6 % and ≥20/25 in 96.6 %. Mean SE was -0.02 ± 0.17 D. Residual refractive error was ± 0.13 D in 86.6 %, ± 0.25 D in 93.3 % and ± 0.50 D in 98.3 %. Refractive stability was achieved at 3 months. No patient lost more than one line of BSCVA. There were no retreatments. The WaveLight Allegretto Wave Eye-Q is effective, predictable and safe in low-to-moderate myopia and myopic astigmatism PRK correction.

Signature of excitonic insulators in phosphorene nanoribbons.

Phosphorene is a recently developed two-dimensional (2D) material that has attracted tremendous attention because of its unique anisotropic optical properties and quasi-one-dimensional (1D) excitons. We use first-principles calculations combined with the maximally localized Wannier function tight binding Hamiltonian and Bethe-Salpeter equation (BSE) formalism to investigate quasiparticle effects of 2D and quasi-1D blue and black phosphorene nanoribbons. Our electronic structure calculations shows that both blue and black monolayered phases are semiconductors. On the other hand black phosphorene zigzag nanoribbons are metallic. Similar behavior is found for very thin blue phosphorene zig-zag and armchair nanoribbon. As a general behavior, the exciton binding energy decreases as the ribbon width increases, which highlights the importance of quantum confinement effects. The solution of the BSE shows that the blue phosphorene monolayer has an exciton binding energy four times higher than that of the black phosphorene counterpart. Furthermore, both monolayers show a different linear optical response with respect to light polarization, as black phosphorene is highly anisotropic. We find a similar, but less pronounced, optical anisotropy for blue phosphorene monolayer, caused exclusively by the quasi-particle effects. Finally, we show that some of the investigated nanoribbons show a spin-triplet excitonic insulator behavior, thus revealing exciting features of these nanoribbons and therefore provides important advances in the understanding of quasi-one dimensional phosphorus-based materials.

Topical tacrolimus in high-risk corneal transplants.

PURPOSE: The purpose of this study was to assess the use of topical tacrolimus ointment in preventing rejection in high-risk corneal grafts, when added to the standard immunosuppressive regimen. METHODS: We conducted an observational, retrospective study using clinical data of high-risk patients subjected to penetrating keratoplasty, who were treated with topical tacrolimus ointment 0.2 mg/g twice a day plus topical dexamethasone 0.1 mg/ml 6 id and compared it with a similar control group treated with topical dexamethasone 0.1 mg/ml 6 id alone. High-risk status was attributed to patients with previous ipsilateral corneal graft failure, two or more quadrants with corneal neovascularization or an infectious or inflammatory corneal disease. RESULTS: We analysed 53 patients in the trial group versus 53 patients in the control group, with similar age, baseline diagnosis and risk factors, and median follow-up times of 30 and and 24 months, respectively. Survival analysis showed a higher graft survival rate at all follow-up periods for patients treated with topical tacrolimus (p < 0.01). No adverse reactions were reported. DISCUSSION: This study shows that topical tacrolimus ointment increases the survival rate of the graft if added to the previous topical steroid regimen in high-risk patients. CONCLUSION: Topical tacrolimus is safe and effective in prolonging graft survival in high-risk patients.

Scheimpflug Tomographic Indices for Classifying Normal, Down Syndrome and Clinical Keratoconus in Pediatric Patients.

The study aimed to evaluate the precision of different Pentacam indices in diagnosing keratoconus (KC) in pediatric patients with and without Down Syndrome (DS) and determine suitable cutoff values. This prospective multicenter cross-sectional study evaluated 216 eyes of 131 patients aged 6-18 years (mean age 12.5 ± 3.2 years) using Pentacam. Patients were categorized into four groups: KC, forme fruste keratoconus (FK), DS, and control, excluding DS patients with topographic KC. Receiver operating characteristic curves were generated to determine the optimal cutoff points and compare the accuracy in identifying KC and FK in patients with and without DS. In DS patients, corneal morphology resembled KC features. The most effective indices for distinguishing KC in DS patients were the average pachymetric progression index (AUC = 0.961), higher-order aberration of the anterior cornea (AUC = 0.953), anterior elevation (AUC = 0.946), posterior elevation (AUC = 0.947), index of vertical asymmetry (AUC = 0.943), and Belin/Ambrosio enhanced ectasia total derivation value (AUC = 0.941). None of the indices showed good accuracy for distinguishing FK in DS patients. The thresholds of these indices differed significantly from non-DS patients. The results highlighted the need for DS-specific cutoff values to avoid false-positive or false-negative diagnoses in this population.

Comparative Analysis of Combined Topography-Guided Photorefractive Keratectomy and Corneal Crosslinking in Progressive Versus Stable Keratoconus.

PURPOSE: To perform a comparative analysis of visual, refractive, and tomographic outcomes of combined topography-guided photorefractive keratectomy (TG-PRK) and corneal crosslinking (CXL) in patients with progressive versus stable keratoconus. METHODS: Longitudinal retrospective case-control study. Patients with keratoconus submitted to simultaneous TG-PRK and CXL were included, with a minimum follow-up of 12 months up to 3 years. According to predefined disease progression criteria, patients were considered as progressive or stable. RESULTS: A total of 101 eyes from 93 patients were included, 62 considered progressive and 39 stable keratoconus. All baseline characteristics were similar between groups, except for age at surgery (progressive: 23.40 ± 4.22 years; stable: 35.97 ± 9.09; P < 0.001). Logarithm of the minimum angle of resolution CDVA improved significantly in progressive (baseline: 0.48 ± 0.24; 12 months: 0.33 ± 0.29; P < 0.001) and stable (baseline: 0.51 ± 0.24; 12 months: 0.28 ± 0.21; P < 0.001) patients, with no differences between groups. Maximum keratometry decreased significantly in progressive (baseline: 59.18 ± 5.63 diopters; 12 months: 54.73 ± 5.95; P < 0.001) and stable (baseline: 57.77 ± 5.02; 12 months: 53.59 ± 4.20; P < 0.001) patients, with no differences between groups. Index of surface variance significantly improved in progressive (baseline: 109.18 ± 31.74 diopters; 12 months: 94.11 ± 34.11; P < 0.001) and stable (baseline: 102.87 ± 29.52; 12 months: 86.95 ± 27.21; P < 0.001) patients, with no differences between groups. Other tomographic outcomes were also similar between groups. Pachymetry significantly decreased after surgery but remained stable throughout the follow-up. CONCLUSIONS: Combined TG-PRK and CXL is a safe and effective procedure for improving CDVA and regularizing the cornea, with comparable visual, refractive, and tomographic outcomes in both progressive and stable keratoconus. Combined TG-PRK and CXL may be added to the armamentarium of therapeutic tools for visual rehabilitation in patients with stable keratoconus.

The influence of personality on the quality of vision after multifocal intraocular lens implantation.

OBJECTIVE: To assess the possible correlation between patients' personality traits and subjective perception of quality of vision (QoV), after multifocal intraocular lens (mIOL) implantation. METHODS: patients who had bilateral implantation of a non-diffractive X-WAVE or a trifocal lens were assessed 6 months postoperatively. Patients answered the NEO-Five Factor Inventory (NEO-FFI-20) questionnaire ("Big Five five-factor personality model") to examine their personality. Six months following surgery, patients were asked to fill a QoV questionnaire where they graded the frequency of 10 common visual symptoms. Primary outcomes were to evaluate the correlation between personality scores and the reported frequency of visual disturbances. RESULTS: The study comprised 20 patients submitted to bilateral cataract surgery, 10 with a non-diffractive X-WAVE lens (AcrySof® IQ Vivity) and 10 with a trifocal lens (AcrySof® IQ PanOptix). Mean age was 60.23 (7.06) years. Six months following surgery, patients with lower scores of conscientiousness and extroversion reported a higher frequency of visual disturbances (blurred vision, P = .015 and P = .009, seeing double images P = .018 and P = .006, and having difficulties focusing, P = .027 and P = .022, respectively). In addition, patients with high neuroticism scores had more difficulty focusing (P = .033). CONCLUSIONS: In this study, personality traits such as low conscientiousness and extroversion and high neuroticism significantly influenced QoV perception 6 months after bilateral multifocal lens implantation. Patients' personality questionnaires could be a useful preoperative assessment test to a mIOL.

Unveiling excitons in two-dimensional ß -pnictogens.

In this paper, we investigate the optical, electronic, vibrational, and excitonic properties of four two-dimensional ß -pnictogen materials-nitrogenene, phosphorene, arsenene, and antimonene-via density functional theory calculations and the Bethe-Salpeter equation. These materials possess indirect gaps with significant exciton binding energies, demonstrating isotropic behavior under circular light polarization and anisotropic behavior under linear polarization by absorbing light within the visible solar spectrum (except for nitrogenene). Furthermore, we observed that Raman frequencies red-shift in heavier pnictogen atoms aligning with experimental observations; simultaneously, quasi-particle effects notably influence the linear optical response intensively. These monolayers' excitonic effects lead to optical band gaps optimized for solar energy harvesting, positioning them as promising candidates for advanced optoelectronic device applications.

Characterization of an antimicrobial peptide produced by Bacillus subtilis subsp. spizezinii showing inhibitory activity towards Haemophilus parasuis.

Haemophilus parasuis is the pathogen that causes Glässer's disease, a major illness affecting young pigs. The aim of this work was to investigate the antagonistic activity of antimicrobial substances produced by Bacillus species against H. parasuis. Among the tested strains, only Bacillus subtilis ATCC 6633 inhibited H. parasuis growth. The antibacterial substance was purified by ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-50 and ion-exchange chromatography on DEAE-cellulose. The purification was about 100-fold with a yield of 0.33 %. The purified substance was resistant up to 80 °C and pH ranging 3-7, but the substance lost its activity when it was treated with proteases. The peptide had a molecular mass of 1083 Da and its sequence was determined by MS as NRWCFAGDD, which showed no homology with other known antimicrobial peptides. The complete inhibition of H. parasuis growth was observed at 20 µg peptide ml(-1) after 20 min of exposure. The peptide obtained by chemical synthesis also showed antimicrobial activity on H. parasuis. The identification of antimicrobial substances that can be effective against H. parasuis is very relevant to combat this pathogen that causes important losses in swine production.

Customized corneal crosslinking with excimer laser-assisted epithelium removal for progressive keratoconus: 1-year results.

PURPOSE: To evaluate the 1-year visual and tomographic results of customized crosslinking using excimer laser-assisted epithelium removal and topography-guided irradiation in the treatment of progressive keratoconus. SETTING: Coimbra Ophthalmology Unit, Private Practice, Coimbra, Portugal. DESIGN: Prospective nonrandomized clinical trial. METHODS: Eyes with documented progressive keratoconus were enrolled. After de-epithelialization with phototherapeutic keratectomy, customized UV irradiation was performed, designed as 3 concentric circular areas centered on the thinnest point (Mosaic System). Energy exposure was 5.4 J/cm 2 in the outer circle and then increased centripetally to 7.2 J/cm 2 and 10 J/cm 2 . Corrected distance visual acuity (CDVA), refractive outcomes, and Scheimpflug tomographies (Allegro Oculyzer) were assessed at baseline, and 6 months, and 12 months postoperatively. RESULTS: 37 eyes of 32 patients were enrolled in this prospective study. The mean diameter for treated areas was 6.17 ± 0.80 mm, 4.45 ± 0.47 mm, and 2.58 ± 0.14 mm for the outer, medium, and inner circle, respectively. At the 1-year follow-up, the mean CDVA improved significantly from 0.38 ± 0.19 to 0.20 ± 0.16 logMAR ( P < .01), with 34 (91.89%) of the 37 eyes retaining or improving CDVA. The mean preoperative minimum pachymetry decreased from 449.26 ± 41.62 to 443.26 ± 41.06 µm ( P = .02). The maximum keratometry decreased significantly from 58.50 ± 7.84 to 57.05 ± 7.27 diopters ( P < .01). After 1 year, 34 eyes (91.89%) showed no signs of progression. CONCLUSIONS: 1 year postoperatively, patients showed a significant improvement in visual acuity while achieving stabilization of disease progression.

Stability of Subnanometer MoS Wires under a Realistic Environment.

The interaction of small molecules with low-dimensional structures plays a major role in many important practical processes such as metal hydride formation, energy storage systems, and catalysis. In this work, we carried out first-principles density functional theory calculations of hydrogen and oxygen adsorption as well as their diffusion on subnanometer MoS nanowires. The nanowires are robust against adsorption of hydrogen. On the other hand, interaction with oxygen shows that the nanowires can oxidize with a small barrier (0.20 eV). In addition, our findings indicate that the interaction with hydrogen or oxygen does not modify the metallic character of the nanowire. The calculations also show that the singlet state is the most stable for 2O adsorbed on the MoS nanowire. Such results open the path for understanding the behavior of MoS nanowires under a realistic environment.

Comparison of outcomes between cross-linking plus topoguided excimer laser ablation and intrastromal corneal ring segments for keratoconus.

OBJECTIVE: To compare cross-linking (CXL) plus topography-guided photorefractive keratectomy (t-PRK) and intrastromal corneal ring segments (ICRS) in keratoconus patients, at 12 months of follow-up. METHODS: This was a longitudinal, retrospective multi-center study. We included a referred sample of 154 eyes from 149 patients with grade I-III Amsler-Krümeich keratoconus with insufficient corrected-distance visual acuity (CDVA). In group 1 (CXL plus t-PRK, 87 eyes), another possible indication for surgery was evidence of progression. Group 2 (ICRS, 67 eyes) included only eyes with paracentral keratoconus (thinnest point at the inferotemporal quadrant) with coincident axes, and evidence of stabilization was required. A subgroup analysis was performed regarding the disease topographic phenotype. At 12 months postoperatively, visual, refractive, and topographic outcomes were evaluated. RESULTS: Comparison of the outcomes between CXL plus t-PRK (group 1) and ICRS (group 2) showed similar improvements in CDVA (in group 1, CDVA improved 0.18 logMAR, and in group 2 0.12 logMAR, P = .18) and K2 (-2,45 [6.46] D in group 1 and -2.13 [1.67] D in group 2, P = .34) The improvement in cylinder power was greater in group 2 (-2.37 [2.07] D in group 2 versus -1.18 [2.63] D in group 1, P = .003); group 1 had a higher decrease in Kmax (- 3.26 [3.64] versus-1.74 [2.67], P = .001). CONCLUSIONS: Both CXL plus t-PRK and ICRS were equally effective in improving CDVA and topographic parameters in a similar group of keratoconus patients at 12 months.

On the stabilization mechanisms of organic functional groups on ZnO surfaces.

Density functional theory (DFT) calculations have been employed to investigate the interaction between ZnO-(101[combining macron]0) and (12[combining macron]10) surfaces and organic functional groups. We analyze the influence of the surface coverage on the geometries and binding energies under a dry environment. Our calculations show that coverages θ = 1 ML are favored under ligand-rich conditions and a dry environment. However, based on thermodynamic considerations we suggest that these ligands may not be stable against adsorption of liquid water and water vapor.

Electronic structure of molecular hydrogen in MoS2nanopores.

Atom controlled sub-nanometer MoS2pores have been recently fabricated with promising applications, such gas sensing, hydrogen storage and DNA translocation. In this work we carried out first-principles calculations of hydrogen adsorption in tiny MoS2nanopores. Some of the pores show metallic behaviour whereas others have a sizeable band gap. Whereas adsorption of molecular hydrogen on bare pores are dominated by physisorption, adsorption in the nanopores show chemisorption behaviour with high selectivity depending on the pore inner termination. Finally, we show that functionalization with copper atoms leads to does not improve dignificantly the adsorption energies of selected pores.

Anterior Segment Optical Coherence Tomography in the Early Management of Microbial Keratitis: A Cross-Sectional Study.

INTRODUCTION: Infectious keratitis is an important cause of visual loss. The purpose of this study was to investigate anterior segment optical coherence tomography patterns in infectious keratitis and evaluate the role of this tool in the early management of this disorder. MATERIAL AND METHODS: In this cross-sectional study, we included patients with proven infectious keratitis, either by culture or therapeutic trial. Subjects underwent baseline anterior segment optical coherence tomography (Spectralis® anterior segment module, Heidelberg Engineering, Germany) performed by the same operator. We used anterior segment optical coherence tomography vertical and horizontal raster default scans with 6.0 mm scan lines. RESULTS: Twenty-five patients (14 men and 11 women) were included. The most common risk factors identified were ocular trauma (11 cases) and contact lens wear (7 cases). Fifteen patients presented bacterial infection; three, fungal infection; two parasitic infection; and five cases presented a negative microbiological culture. Anterior segment optical coherence tomography depicted nine distinct morphological patterns. DISCUSSION: Anterior segment optical coherence tomography allows the depth of corneal involvement to be assessed. When the only patterns identified were hyperreflective stromal lesion and stromal edema, the visual outcome was better. Cystic spaces were present in severe bacterial keratitis. CONCLUSION: Anterior segment optical coherence tomography can complement biomicroscopy, allowing for a better characterization of corneal involvement at presentation that can help in staging and providing useful prognostic information.

Introdução: As queratites infeciosas são uma causa importante de perda da acuidade visual. O objetivo deste estudo foi investigar padrões das queratites infeciosas na tomografia de coerência ótica do segmento anterior e avaliar o seu papel na orientação precoce desta patologia. Material e Métodos: Neste estudo transversal, incluímos doentes com queratite infeciosa comprovada, por cultura microbiológica ou prova terapêutica. Os doentes foram submetidos a tomografia de coerência ótica do segmento anterior na baseline (Spectralis® anterior segment module, Heidelberg Engineering, Germany) executados pelo mesmo operador. Adquiriram-se cortes verticais e horizontais de 6,0 mm com tomografia de coerência ótica spectral domain. Resultados: Foram incluídos 25 doentes (14 homens e 11 mulheres). Os fatores de risco mais comummente identificados foram o trauma ocular (11 casos) e o uso de lentes de contato (sete casos). Quinze doentes apresentaram infeção bacteriana, três infeção fúngica, dois infeção parasitária e cinco casos apresentaram culturas microbiológicas negativas. Distinguiram-se nove padrões morfológicos na tomografia de coerência ótica do segmento anterior. Discussão: A tomografia de coerência ótica do segmento anterior permite avaliar a profundidade do envolvimento corneano na queratite infeciosa. Quando os únicos padrões identificados eram a lesão estromal hiper-refletiva e edema estromal o outcome visual foi melhor. Os espaços quísticos observaram-se nas queratites bacterianas graves. Conclusão: A tomografia de coerência ótica do segmento anterior permite complementar a biomicroscopia, melhorar o estadiamento e fornecer informação prognóstica útil nas queratites infeciosas.