Determining Factors for Fast Corneal Sensitivity Recovery After Pterygium Excision

Purpose: To establish determining factors for fast corneal sensitivity (CS) recovery after pterygium excision. Methods: Thirty-two eyes of 14 males and 18 females with primary nasal pterygium were recruited. Differences in CS (in the 4 quadrants and the center using a Cochet–Bonnet esthesiometer), pterygium corneal area (PCA), tear osmolarity, tear break-up time, Schirmer test, and ocular symptoms were analyzed before and 1 month after lesion excision. The relationship between CS recovery (difference between the 2 time points; CS1 – CS0) and the other features was assessed. Results: All the studied locations exhibited normal (6 cm) or near-normal mean CS at the 2 time points, except a tendency for moderate hypoesthesia in nasal CS0 (median 4.5; range: 1.5–6.0 cm). Point by point comparison revealed significant postoperative improvements in nasal location (P = 0.008; Wilcoxon signed-rank test) with normal values in 17 eyes (53%) and a median CS1 = 5.0 cm (2.5–5.5 cm) in 15 eyes with no complete recovery. No significant correlation was found between CS0 and the studied variables, and CS1 was only significantly correlated with PCA (rho: -0.441; P < 0.05). CS recovery also showed significant correlation with PCA (rho = -0.516; P < 0.01). Conclusions: CS recovery after pterygium excision showed important variability, and the only studied factor that seems to be determinant could be PCA. It would be advisable to operate when the lesion is relatively small, with lower surgical injury and faster and complete recovery, thus protecting ocular surface homeostasis.Postprint (author's final draft

Effects of Mitomycin C in Early Conjunctival Inflammation after Pterygium Surgery

Purpose: The purpose of this study was to compare inflammatory events and graft characteristics 1 month and 6 months after conjunctival limbal autograft (CLAU) with and without intraoperative mitomycin C (MMC). Methods: This study included 69 eyes of 69 patient’s eyes with pterygium. Clinical data concerning patient demography, preoperative examination including pterygium morphology, recurrence clinical assessment, and complications after CLAU with (MMC+) and without (MMC-) intraoperative MMC were all registered at 1 month and 6 months after surgery. Results: Thirty-five eyes were included in MMC+ and 34 in MMC-. Preoperative data were similar in both groups (Student’s t test and Fisher’s exact test; p > 0.05). Thirty-four (49.6%) eyes in the whole sample showed at least one inflammatory complication at 1 month after surgery. MMC- group showed a significantly higher number of cases with complications (p 0.05; Chi2 test). Pyogenic granuloma developed at the surgical site in three eyes (4.37%), two of those granulomas were at the MMC- group (p > 0.05). Tendency for recurrences was significantly different between both groups (p = 0.0001; Fisher’s exact test) at the end of 6 months. Thirteen (38%) eyes showed recurrence in MMC- and no cases were displayed in MMC+. Presence of at least 1 inflammatory event was only seen in 16 (23%) cases, all of them in MMC-. Specifically, 15 (44%) eyes showed hyperemia and one (3%) eye presented conjunctival hemorrhages. No new cases of pyogenic granuloma or graft contraction were seen at this time point in both groups. Hyperemia was the only specific event with significant differences between MMC- and MMC+ (p = 0.0001; Fisher’s exact test) at 6 months after surgery. Conclusion: The eyes receiving intraoperative MMC after CLAU seem to present less hyperemia and graft contraction after surgery than those that did not receive MMC as an adjuvant factor. Intraoperative MMC could be associated with a lower recurrence rates.Postprint (author's final draft

Reduction of foveal bulges and other anatomical changes in fellow eyes of patients with unilateral idiopathic macular hole without vitreomacular pathologic changes

Purpose: To compare the foveal characteristics in fellow eyes (FE) of patients with unilateral idiopathic macular hole without vitreomacular pathologic changes with eyes of healthy controls. Methods: Forty-seven FE and 52 eyes of 52 age- and sex-matched healthy controls were studied. Quantitative assessment of the dome-shaped appearance of the hyperreflective lines that represent external limiting membrane (ELM_bulge) and inner outer segment junctions (IS/OS_bulge) were made by optical coherence tomography (OCT) images. Inner retinal complex thickness (IRCT) was quantitatively assessed at 1000 and 2000 µm of the foveal center in nasal and temporal quadrants. Presence of alterations in the inner retinal outer layers and central foveal thickness (CFT) were also analyzed. Results: Significantly lower ELM_bulge (p < 0.0001; Mann-Whitney test) and IS/OS_bulge (p < 0.001; student t test) and higher cases with COST alterations, expressed as a diffuse line (p < 0.006; Chi2 test) were found in FE than control eyes. IRCT were significantly reduced in FE at all the studied locations when comparing to control eyes (p < 0.05; student t test), maintaining anatomical proportionality among locations. Conclusion: FE without pathologic vitreomacular interactions seems to present some central cone alterations that may be related to other causes than vitreomacular traction.Preprin

Reduction of foveal bulges and other anatomical changes in fellow eyes of patients with unilateral idiopathic macular hole without vitreomacular pathologic changes

Purpose: To compare the foveal characteristics in fellow eyes (FE) of patients with unilateral idiopathic macular hole without vitreomacular pathologic changes with eyes of healthy controls. Methods: Forty-seven FE and 52 eyes of 52 age- and sex-matched healthy controls were studied. Quantitative assessment of the dome-shaped appearance of the hyperreflective lines that represent external limiting membrane (ELM_bulge) and inner outer segment junctions (IS/OS_bulge) were made by optical coherence tomography (OCT) images. Inner retinal complex thickness (IRCT) was quantitatively assessed at 1000 and 2000 µm of the foveal center in nasal and temporal quadrants. Presence of alterations in the inner retinal outer layers and central foveal thickness (CFT) were also analyzed. Results: Significantly lower ELM_bulge (p < 0.0001; Mann-Whitney test) and IS/OS_bulge (p < 0.001; student t test) and higher cases with COST alterations, expressed as a diffuse line (p < 0.006; Chi2 test) were found in FE than control eyes. IRCT were significantly reduced in FE at all the studied locations when comparing to control eyes (p < 0.05; student t test), maintaining anatomical proportionality among locations. Conclusion: FE without pathologic vitreomacular interactions seems to present some central cone alterations that may be related to other causes than vitreomacular traction.Preprin

Conjunctival Short-term Evolution after Pterygium Excision

Purpose To analyze conjunctival cytological features 1 month after pterygium excision using limbo-conjunctival autograft (LCA) with and without intraoperative mitomycin C and to assess tissue short-term evolution in both situations.; Methods Fifty-nine primary nasal pterygia from 59 patients were excised with LCA. Twenty-nine were treated with intraoperative mitomycin C 0.02% (MMC+) and 30 were treated without it (MMC-). Impression cytology was performed in nasal and temporal conjunctiva before and 1 month after the excision. Goblet cell density (GCD) and nucleus-to-cytoplasm nongoblet epithelial cell ratio were quantified.; Results Surgical strategy comparisons (intergroup comparisons): All the preoperative data were, in mean, within the reference range, except for a slight goblet cell hyperplasia in the area of the lesion in MMC+ but no significant differences were found between the groups (p = 0.079 for GCD and p = 0.245 for nucleus-to-cytoplasm ratio; analysis of variance). Clinically relevant differences after surgery were only shown in nasal GCD that was significantly lower in MMC+ than in MMC- (p = 0.000; analysis of variance), with the mean value in MMC+ slightly below normal values whereas that in MMC- remained normal. Tissue evolution (intragroup comparisons): No clinically relevant changes were found in MMC-. Data from MMC+ displayed no changes 1 month after surgery, except for nasal GCD that showed a significant reduction (p = 0.000; paired t test). Nevertheless, this GCD decrease was more modest than that previously described using mitomycin C without autograft, because in the present study, nasal GCD was not lower but similar to postoperative temporal data of the same eye (p = 0.164; paired t test).; Conclusions Limbo-conjunctival autograft is a good technique for conjunctiva early recovery. When mitomycin C was added, the GCD reduction was lower than described using other surgical techniques. Mitomycin C, in optimal concentration and exposure, associated with LCA could be a good clinical option to minimize pterygium recurrence.Postprint (author's final draft

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Estudio de los cambios morfológicos del epitelio corneal en un modelo animal de ojo seco

[spa] En esta tesis doctoral se ha analizado morfológica y morfométricamente el deterioro que sufre el epitelio corneal de conejo cuando se impide el parpadeo del animal mediante la inserción de un blefarostado. Para ello, se han procesado digitalmente las imágenes de 33 córneas, obtenidas bajo técnicas de microscopía electrónica. Dicho procesado, realizado con el programa de software libre Image J, ha permitido obtener una serie de variables que cuantifican las características celulares, tanto en el epitelio control como en los sometidos al modelo de ojo seco. Posteriormente, se ha realizado un análisis estadístico de los datos. Los resultados obtenidos muestran que el epitelio control aparece como un mosaico celular continuo con diferentes tonos de gris, formas y tamaños. Asociando las variables área y forma celular se pueden discriminar tres tipos celulares. De este modo, las células del epitelio control son en su mayoría células pequeñas, de forma poligonal, tono de gris intermedio-claro y con una elevada densidad de microproyecciones. También aparecen células grandes de forma más circular, tonos más oscuros y densidad de microproyecciones algo menor. La gama de células catalogadas como de tamaño mediano presentan una caracterización más difícil puesto que sus rasgos morfológicos son semejantes tanto a las células grandes como a las pequeñas. A pesar de ello la forma de estas células medianas muestra una marcada tendencia a la pseudopoligonalidad. Cabe señalar también que las células del epitelio sano muestran una clara uniformidad en las uniones intercelulares que aparecen, en su inmensa mayoría, intactas y en la densidad de las microproyecciones que es alta o muy alta en todas las células. Estas dos características son indispensables para una correcta funcionalidad del tejido. Por su parte, los resultados del análisis de las córneas sometidas a diferentes periodos de falta de parpadeo muestran como el deterioro epitelial se inicia entre una y dos horas después de insertar los blefarostatos. Este deterioro se caracteriza, principalmente, por dos alteraciones. Una de ellas es la pérdida progresiva de las uniones intercelulares y la otra es la disminución de la densidad de las microproyecciones. En concreto, las células grandes son las que pierden más precozmente las microproyecciones pero, por el contrario, son las que mantienen mejor la adherencia con sus vecinas. Además, las células presentan, en general, un ligero aumento de tamaño, tendencia hacia la circularidad y uniformidad de los tonos celulares. Gracias a los modelos estadísticos predictivos se han podido establecer, también, las características típicas de cada periodo de privación de parpadeo y el nivel de deterioro en el que se encuentra una córnea determinada. En consecuencia, con esta tesis doctoral se ha desarrollado un criterio cuantitativo que, de forma global, analiza el estado del epitelio corneal. Esta es una herramienta básica para el análisis comparativo de la acción de las lágrimas artificiales de la que, hasta ahora, no se disponía.[eng] To evaluate the changes on the corneal epithelium asociated with a evaporative dry eye model. METHODS. Thirty-tree eyes of 17 New Zealand white rabbits were held open with an eye specula for differents periods of time (12 minutes - 3 hours and 15 minutes). Corneal damage was evaluated by scanning electron microscopy and the digital images were processed for morphometric information with free software program Image J. Finally the data were analyzed statistically with SPSS for Windows. RESULTS. There was significantly changes on epithelium from more than 1 hour without blinking compared with the undessicated eyes. The main features of damage were loss of microvilli density (mean ± sd on the control corneal surface was 48.35 ± 7.25 opposite 34.12 ± 16.74 after more than 1 hour) (p<0.01) and break of intercellular junctions (mean ± sd on the control corneal surface was 0.94 ± 0.11 opposite 0.78 ± 0.3 after more than 1 hour) (p<0.01). Moreover the cells underwent a small but significant (p<0.01) increase in their area and circularity and the cells electron reflex showed a slight but significant (p<0.01) tendency to get darker. By means of logistic regression we were able to predict the degrees of the corneal damage process and we found that the loss of microvilli was earlier than break of intercellular junctions. CONCLUSIONS. The morphometric and statistical analysis of the gradual damage that this dry eye model cause in the corneal epithelium has allowed us to establish an objective and useful method for comparing commercially available artifical tear preparations

Healing indicators after pterygium excision by optical coherence tomography

PurposeTo establish the sequence of tomographic changes in the tissue recovery process after pterygium excision and to propose healing indicators.; MethodsOptical coherence tomography (OCT) images were taken at 1week, 1, 3 and 6months after lesion excision in 73 eyes of 73 patients (33 male, 40 female; mean age 50, S.D. 5.0, range 40-70years) with primary nasal pterygium. Biomicroscopy was performed at each visit and at 12months, to diagnose clinical healing or lesion recurrence. The presence of well demarcated corneal epithelium, conjunctival epithelium, limbal demarcation area, and graft thickening were analysed. Comparisons between tomographic data of both clinical situations were made at each time point using contingency tables.; ResultsEleven eyes displayed lesion recurrence (R group) and 62 eyes showed no recurrence (NR group). Normal anatomical structures, corneal and conjunctival epithelium and limbal demarcation area, were identified by OCT images in a higher percentage of NR cases over time, compared to the R group where most of the cases presented without these markers of tissue recovery. In contrast, the variable graft thickening, which analysed a pathological event, revealed similar results in both groups (p>0.05; Fisher's exact statistic), with a clear decrease of cases which showed graft thickening over time. Differences between groups started at 1month, when no eye had yet presented clinical recurrence, with greater identification of corneal epithelium in the NR group (p=0.04; Fisher's exact statistic). At 3months, corneal and conjunctival epithelium identification tended to be more frequent in the NR than in the R group (in both cases, p=0.0001; Fisher's exact statistic). Finally, at 6months these different patterns consolidated, with a significantly higher number of limbal demarcation areas being identified in the NR group (p=0.001; Fisher's exact statistic). In fact, this landmark of a normally structured limbus was never found in the R group.; ConclusionsThe sequence of tissue restoration, according to OCT images, seems to start in the cornea and end in the limbal area, similar to the process of pterygium injury in reverse. Although the visualisation of corneal epithelium could be an early indicator of successful surgery, identification of the limbal demarcation area, as a normal limbal pattern in OCT images, seems to be a better positive predictive value in diagnosing healing

Genetic and molecular analysis of the recR locus of Escherichia coli K-12

SIGLEAvailable from British Library Document Supply Centre- DSC:D172172 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Femtosecond laser-assisted laser in situ keratomileusis versus photorefractive keratectomy: Effect on ocular surface condition

Purpose: To compare ocular surface characteristics in eyes after femtosecond laser-assisted laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). Setting: Centro de Oftalmologia Barraquer, Barcelona, Spain. Design: Prospective comparative observational study. Methods: Patients with myopia who had femtosecond laser assisted LASIK or PRK were included. Tear osmolarity, the Ocular Surface Disease Index questionnaire, Schirmer I, corneal sensitivity, tear breakup time (TBUT), and corneal fluorescein staining were evaluated preoperatively and 3, 6, and 12 months postoperatively. The Wilcoxon signed-rank test was used for temporal intragroup analysis, and the Mann-Whitney U test was used for intergroup comparisons. Results: The study comprised 44 patients (44 eyes) with myopia. Comparison of the parameters between the femtosecond laser-assisted LASIK group (22 eyes) and the PRK group (22 eyes) showed a similar temporal progression postoperatively. Compared with the preoperative evaluation, corneal sensitivity decreased after 3 months (P = .002 and P = .02, respectively) and 6 months (P = .03 and P = .04, respectively). The TBUT reached the highest mean value after 12 months (P = .01 and P = .04, respectively), and tear osmolarity was slightly increased after 1 year, although the mean values remained within the normal range (P = .01 and P = .04, respectively). The only difference between the 2 groups was lower corneal sensitivity in the femtosecond laser-assisted LASIK group after 3 months (P = .02). The ocular surface condition could be considered clinically unaltered after 1 year in both groups. Conclusion: Femtosecond laser-assisted LASIK and PRK techniques seemed to be safe for the ocular surface condition and to have a similar effect on it.Postprint (author's final draft