Nutritional Description of Processed Foods with Fibre-Related Nutrition Claims in Spain: The BADALI Project.

Fibre is one of the most beneficial nutrients for health and is very frequently used in nutrition claims (NCs) to promote foods. These claims may lead consumers to believe that products bearing them are healthy and/or healthier than those without them. The main objective of this work is to address this belief. This is the first exhaustive analysis of seven processed food types with fibre-related NCs (six cereal-based and one plant-based meat analogues) comparing them with those without these claims. The Spanish Food Database, BADALI, was used for this study. Results show that as many as 88.7% of processed foods with fibre-related NCs are classified as 'less healthy' according to the Nutrient Profile Model developed by the Pan American Health Organization (PAHO-NPM). When compared to foods without these NCs, similar results were obtained in the whole sample. Most of the observed divergences when analysing individual critical nutrients by food type indicate a deterioration of the nutritional quality. Foods with fibre-related NCs contained more fibre. The more frequent use of whole grain cereals or other fibre-specific ingredients may contribute to this. Some other nutritionally relevant differences were observed and half of them reflected a deterioration of the nutritional quality. In addition, these foods presented a lower prevalence of the organic version, as well as similar rates of mineral and vitamin fortification. Therefore, processed foods with fibre-related NCs are not healthy, nor present a better nutritional profile than those without.

Filling gaps in female gout: a cross-sectional study of comorbidities in 192 037 hospitalised patients.

OBJECTIVE: There is room for improvement in the knowledge of female gout, often noted at risk of gender blindness. This study aims to compare the prevalence of comorbidities in women versus men hospitalised with gout in Spain. METHODS: This is an observational, multicentre, cross-sectional study in public and private Spanish hospitals analysing the minimum basic data set from 192 037 hospitalisations in people with gout (International Classification of Diseases, Ninth Revision (ICD-9) coding) from 2005 to 2015. Age and several comorbidities (ICD-9) were compared by sex, with a subsequent stratification of comorbidities by age group. The association between each comorbidity and sex was assessed using multivariable logistic regression. A clinical decision tree algorithm was constructed to predict the sex of patients with gout based on age and comorbidities alone. RESULTS: Women with gout (17.4% of the sample) were significantly older than men (73.9±13.7 years vs 64.0±14.4 years, p<0.001). Obesity, dyslipidaemia, chronic kidney disease, diabetes mellitus, heart failure, dementia, urinary tract infection and concurrent rheumatic disease were more common in women. Female sex was strongly associated with increasing age, heart failure, obesity, urinary tract infection and diabetes mellitus, while male sex was associated with obstructive respiratory diseases, coronary disease and peripheral vascular disease. The decision tree algorithm built showed an accuracy of 74.4%. CONCLUSIONS: A nationwide analysis of inpatients with gout in 2005-2015 confirms a different comorbidity profile between men and women. A different approach to female gout is needed to reduce gender blindness.

Nutritional Description of Organic and Conventional Food Products in Spain: The BADALI Project.

Organic food and drink is undoubtedly a growing market. Consumers perceive organic food as healthy, and nutrition claims (NCs) and fortification may add to this perception. Whether this is true is still a matter of controversy, particularly for organic food products. We present here the first comprehensive study of large samples of six specific organic food types, analysing the nutritional quality (nutrient composition and "healthiness") as well as the use of NCs and fortification. In parallel, a comparison with conventional food is also carried out. For this purpose, the Food Database of products in the Spanish market, BADALI, was used. Four cereal-based and two dairy-substitute food types were analysed. Our results show that as many as 81% of organic foods are considered "less healthy" by the Pan American Health Organization Nutrient Profile Model (PAHO-NPM). Organic foods present a slightly improved nutrient profile compared to conventional foods. However, many of the differences, though statistically significant, are nutritionally irrelevant. Organic foods use NCs very frequently, more than conventional foods, with very little micronutrient fortification. The main conclusion of this work is that consumers' perception that organic food products are healthy is unfounded from a nutritional point of view.

Nutritional Description of Foods with Low- and No-Calorie Sweeteners in Spain: The BADALI Project.

The use of low- and no-calorie sweeteners (LNCS) in foods has increased in recent years in response to the negative effects of free sugar on health. However, the health impact of LNCS is still unclear. Studies of the prevalence of LNCS in foods have been published previously, including in Spain. However, the use of health (HCs) and nutrition claims (NCs) to promote these foods and a full nutritional characterization are largely lacking. For this purpose, we used the BADALI database with 4218 foods present in the Spanish market. Our results show that 9.3% of foods have LNCS (including both intense and polyols). Sucralose and acesulfame K were the intense sweeteners most frequently used (52.4% and 48.2%, respectively), whereas maltitol was the preferred polyol (20.3%). Of all foods with LNCS, 30% also had added sugar. Many more foods with LNCS presented HCs and NCs than those without. Sugar was the nutrient most frequently claimed in NCs for LNCS-containing foods, whereas vitamins were for those without these sweeteners. NCs compliance with regulation was similar in both conditions (60.1% for foods without and 63.9% for foods with LNCS). As expected, foods with LNCS had less total sugar content and energy. Surprisingly, the nutrient profile of yogurts with LNCS changed completely: less total and saturated fat, whereas more proteins and sodium. Biscuits with LNCS contained more fibre. The results of our study reveal that the prevalence of LNCS is becoming high in some food types in Spain and that foods containing LNCS are more frequently promoted with HCs/NCs. In addition, it confirms the general reduction in energy and sugar content expected in foods with LNCS. Furthermore, it suggests a reformulation of products beyond sugar content.

OSDI Questions on Daily Life Activities Allow to Detect Subclinical Dry Eye in Young Contact Lens Users.

Dry eye disease (DED) is difficult to detect in young contact lens (CL) wearers, who usually have no signs, mild symptoms and an ocular surface disease index (OSDI) below the DED diagnosis values (OSDI ≥ 13). We investigate if some of the 12 OSDI questions (OSDI A­ocular symptoms; OSDI B­vision-related functionality; OSDI C­environmental triggers) contribute the most to classify young CL as symptomatic. TBUT and tear volume are also measured. Age, gender and refraction error-matched eye glasses (EG) wearers participated as the control. CL and EG data were compared with t-test and z-test. Confusion matrices and logistic correlation analyses were performed to define the contribution of each OSDI question to classify symptomatic subjects. OSDI classified symptomatic CL better than the tear volume or TBUT values. In CL, only OSDI B and C values were significantly higher in symptomatic vs. asymptomatic subjects (p < 0.001), while values of all twelve OSDI questions were significantly higher in symptomatic vs. asymptomatic EG (p < 0.05−0.001). All OSDI questions contribute equally to identify symptomatic EG, while only OSDI B questions on daily life visual functions are significant to classify symptomatic CL wearers at risk to develop DED or at a subclinical stage. CL wearers scoring ≥ 2 on the OSDI B questions should be considered for preventive treatments, even if their clinical sings are scarce or absent.

Sodium Content of Foods Sold in the Spanish Market. Results from the BADALI Project.

High sodium/salt intake is a risk factor for Non-Communicable Diseases (NCDs). Excess sodium intake has been associated with high coronary heart disease, stroke and high blood pressure. The sodium daily intake is above the recommendations in the world as well as in Spain. Reducing salt content in processed foods and ready meals is one of the main strategies for reducing sodium intake. The aim of the present work is to characterise the presence of sodium in foods sold in the Spanish market. We also study a possible shift in sodium content in products over the last few years. For this purpose, 3897 products included in the BADALI food database were analysed, classified into 16 groups (G). We found that 93.3% of all foods displayed the sodium/salt content in the nutrition declaration. Meat-processed and derivatives (G8) had the highest mean and median values for sodium content, followed by snacks (G15) and sauces (G14). Only 12.7% of foods were sodium-free (≤5 mg/100 g or 100 mL), 32.4% had very low sodium (≤40 mg/100 g or 100 mL) and 48.2% were low in sodium (≤120 mg/100 g or 100 mL). On the contrary, 47.2% were high in sodium according to the Pan American Health Organisation Nutrient Profile Model (PAHO-NPM), while there were 31.9% according to the Chile-NPM. The agreement between the two NPMs was considered 'substantial' (κ = 0.67). When sodium content was compared over the years, no decrease was observed. This analysis was performed in the entire food population, by food group and in matched products. Therefore, more effort should be made by all parties involved in order to decrease the sodium/salt intake in the population.

Persistence of Crystals in Stored Synovial Fluid Samples.

OBJECTIVE: Lack of access to polarized light microscopy is often cited as an argument to justify the clinical diagnosis of crystal-related arthritis. We assessed the influence of time since sampling and preservation methods on crystal identification in synovial fluid (SF) samples under polarized light microscopy. METHODS: This was a prospective, longitudinal, observational factorial study, analyzing 30 SF samples: 12 with monosodium urate (MSU) crystals and 18 with calcium pyrophosphate (CPP) crystals. Each SF sample was divided into 4 subsamples (120 subsamples in total). Two were stored in each type of preserving agent, heparin or ethylenediamine tetraacetic acid (EDTA), at room temperature or at 4°C. Samples were analyzed the following day (T1), at 3 days (T2), and at 7 days (T3) by simple polarized light microscopy, and the presence of crystals was recorded. RESULTS: The identification of crystals in the MSU group was similar between groups, with crystals observed in 11/12 (91.7%) room temperature samples and in 12/12 (100%) refrigerated samples at T3. Identification of CPP crystals tended to decrease in all conditions, especially when preserved with EDTA at room temperature [12/18 (66.7%) at T3], while less reduction was seen in refrigerated heparin-containing tubes. CONCLUSION: Preserving samples with heparin in refrigerated conditions allows delayed microscopic examination for crystals. Avoiding crystal-proven diagnosis because of the immediate unavailability of microscopy no longer appears justified.

Metabolomic analysis of the effects of a commercial complex biostimulant on pepper crops.

Research on plant biostimulants is of interest in their potential benefits for agriculture production and environmental sustainability. These naturally occurring products induce beneficial consequences in plant metabolism and productivity. In most cases their modes of action, and consequences for the whole plant as well as parts, such as the fruit, are well characterized, but the precise mechanisms of action require further attention. This study examined the effects of the commercial biostimulant, Actium®, on Capsicum annuum L. cv Palermo leaves and fruits. The influence of time (characterized by ripening), after 14 and 28 days of treatment, treatment regimen, and their combined impact on the metabolome were studied using HPLC-ESI-QTOF-MS analysis of polar and apolar compounds. The results showed that flavonoids and capsianosides decreased with ripening in leaves, but organic acids, monosaccharides, and carotenoids increased in fruits. The treatment of Capsicum fruits with Actium® increased phenylalanine and total monosaccharides (glucose and fructose) compared to controls, suggesting a further stage in ripening. An increase in carotenoids concomitant with an increase of some digalactosyl diacylglycerols, which are part of the chromoplasts lipid machinery of enzymes involved in the synthesis of carotenoids, was also observed. Our findings suggest that this biostimulant may increase some metabolites related to pepper fruit maturity and coloration in pepper crops.

New Concepts for Production of Scalable Single Layer Oxidized Regions by Local Anodic Oxidation of Graphene.

A deep comprehension of the local anodic oxidation process in 2D materials is achieved thanks to an extensive experimental and theoretical study of this phenomenon in graphene. This requires to arrange a novel instrumental device capable to generate separated regions of monolayer graphene oxide (GO) over graphene, with any desired size, from micrometers to unprecedented mm2 , in minutes, a milestone in GO monolayer production. GO regions are manufactured by overlapping lots of individual oxide spots of thousands µm2 area. The high reproducibility and circular size of the spots allows not only an exhaustive experimental characterization inside, but also establishing an original model for oxide expansion which, from classical first principles, overcomes the traditional paradigm of the water bridge, and is applicable to any 2D-material. This tool predicts the oxidation behavior with voltage and exposure time, as well as the expected electrical current along the process. The hitherto unreported transient current is measured during oxidation, gaining insight on its components, electrochemical and transport. Just combining electrical measurements and optical imaging estimating carrier mobility and degree of oxidation is possible. X-ray photoelectron spectroscopy reveals a graphene oxidation about 30%, somewhat lower to that obtained by Hummers' method.

A Spanish pillbox app for elderly patients taking multiple medications: randomized controlled trial.

BACKGROUND: Nonadherence and medication errors are common among patients with complex drug regimens. Apps for smartphones and tablets are effective for improving adherence, but they have not been tested in elderly patients with complex chronic conditions and who typically have less experience with this type of technology. OBJECTIVE: The objective of this study was to design, implement, and evaluate a medication self-management app (called ALICE) for elderly patients taking multiple medications with the intention of improving adherence and safe medication use. METHODS: A single-blind randomized controlled trial was conducted with a control and an experimental group (N=99) in Spain in 2013. The characteristics of ALICE were specified based on the suggestions of 3 nominal groups with a total of 23 patients and a focus group with 7 professionals. ALICE was designed for Android and iOS to allow for the personalization of prescriptions and medical advice, showing images of each of the medications (the packaging and the medication itself) together with alerts and multiple reminders for each alert. The randomly assigned patients in the control group received oral and written information on the safe use of their medications and the patients in the experimental group used ALICE for 3 months. Pre and post measures included rate of missed doses and medication errors reported by patients, scores from the 4-item Morisky Medication Adherence Scale (MMAS-4), level of independence, self-perceived health status, and biochemical test results. In the experimental group, data were collected on their previous experience with information and communication technologies, their rating of ALICE, and their perception of the level of independence they had achieved. The intergroup intervention effects were calculated by univariate linear models and ANOVA, with the pre to post intervention differences as the dependent variables. RESULTS: Data were obtained from 99 patients (48 and 51 in the control and experimental groups, respectively). Patients in the experimental group obtained better MMAS-4 scores (P<.001) and reported fewer missed doses of medication (P=.02). ALICE only helped to significantly reduce medication errors in patients with an initially higher rate of errors (P<.001). Patients with no experience with information and communication technologies reported better adherence (P<.001), fewer missed doses (P<.001), and fewer medication errors (P=.02). The mean satisfaction score for ALICE was 8.5 out of 10. In all, 45 of 51 patients (88%) felt that ALICE improved their independence in managing their medications. CONCLUSIONS: The ALICE app improves adherence, helps reduce rates of forgetting and of medication errors, and increases perceived independence in managing medication. Elderly patients with no previous experience with information and communication technologies are capable of effectively using an app designed to help them take their medicine more safely. TRIAL REGISTRATION: Clinicaltrials.gov NCT02071498; http://clinicaltrials.gov/ct2/show/NCT02071498.

Corneal sensitivity in diabetic patients subjected to retinal laser photocoagulation.

PURPOSE: To determine the changes in corneal sensitivity to different stimulus modalities in diabetes mellitus (DM)1 and DM2 patients with retinopathy, and to explore whether argon laser photocoagulation exacerbates sensitivity loss in diabetic patients. METHODS: Corneal sensitivity to different modalities of stimulus was determined in one randomized eye in 52 patients with DM1 (n = 35) or DM2 (n = 17), and in 27 healthy subjects. Medical history was obtained from all the patients, including age, sex, time from DM diagnosis, type of diabetes, time from onset of retinopathy, type of diabetic retinopathy, and type of argon laser treatment. Corneal sensitivity was determined using a gas esthesiometer. Mechanical, chemical, and thermal (heat and cold) stimuli were applied on the central cornea. RESULTS: Sensitivity thresholds to selective mechanical, chemical, and cold stimulation were significantly higher in DM patients compared to controls. Sensitivity threshold to mechanical and chemical stimuli was higher in DM2 than in DM1 patients. In DM1 patients, mechanical threshold increased with time after DM diagnosis. No correlation was found between sensitivity thresholds to chemical or thermal stimulation and the age of the patient, type of retinopathy, or time from its diagnosis. Laser treatment generated a further impairment of corneal sensitivity. CONCLUSIONS: Corneal sensitivity to mechanical, chemical, and thermal stimulation is decreased in DM patients, suggesting that diabetes affects homogeneously the different types of sensory neurons innervating the cornea. Corneal sensitivity appears to be more disturbed in DM2 than in DM1. Laser treatment of DM patients generates a further impairment in corneal sensitivity, probably as the result of physical damage to ciliary nerves.

Weight loss reporting: predicted body mass index after bariatric surgery.

BMI and %EBMIL are the most accurate methods for comparing results of patients after bariatric surgery. %EBMIL is based on BMI 25 as a constant end-point for all patients, but BMI 25 is easily achieved by patients with BMI < 50, whereas it is not so feasible for patients with BMI > 50. We were prompted to obtain by statistical methods a mathematical formula able to calculate the final BMI (FBMI) 3 years after the operation, dependent on the initial or preoperative BMI (IBMI) of a multicenter group of morbid obese patients operated with different bariatric techniques. We also obtained a specific formula for each bariatric procedure of this group of patients. We propose the name Predicted BMI for the value obtained with these formulas and its application in the %EBMIL instead of the constant value of BMI 25. We have analyzed the IBMI and FBMI of a multicenter group of 7,410 patients, subjected to different bariatric procedures with a minimum follow-up of 36 months. Statistical methods with a linear regression model have been used to obtain the two types (global and specific) of Predicted BMI. We first obtained a general formula of PBMI = IBMI x 0.4 + 11.75 for the total population of patients, and a second specific formula for each bariatric technique: PBMI = IBMI x 0.43 + 13.25 + technique_correction_adjustment. Predicted BMI and its application to the %EBMIL may result in a more rational comparison of results of bariatric patients, bariatric techniques, and groups of bariatric surgeons. Predicted BMI may advance the BMI that each patient would probably achieve after surgery.

Respuesta de los autores: Sobre el índice de masa corporal esperable o deseable / Authors’ reply: About the expected or desirable body mass index

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Índice de masa corporal esperable tras cirugía bariátrica / Expected body mass index after bariatric surgery

El índice de masa corporal (IMC) es el método más práctico para medir y comparar la obesidad entre diferentes individuos. El porcentaje perdido del exceso de IMC (PPEIMC) se utiliza para presentar los resultados de los pacientes operados y se basa en la premisa de que un IMC de 25 es el objetivo final, al ser el límite superior de individuos normales. Alcanzar un IMC de 25 es posible en pacientes obesos mórbidos con IMC inicial bajo (<50), pero es poco frecuente en pacientes superobesos con IMC superior a 50. El IMC esperable (IMCE) sería aquel que deberían alcanzar todos los individuos de acuerdo con su IMC inicial. Objetivo El objetivo de este trabajo es buscar por métodos estadísticos una fórmula, basada en hechos clínicos, que identifique el IMCE de acuerdo con el IMC inicial. Pacientes y método Sé ha analizado el IMC inicial y final de un grupo de 135 pacientes operados de obesidad mórbida con la técnica del cruce duodenal con un seguimiento superior a 3 años. Se ha utilizado un método estadístico de regresión lineal para obtener una fórmula que calcule el IMCE de cada paciente operado. Resultado Se ha obtenido un algoritmo en el que el IMCE=IMC inicial×0,33+14. Si se aplicaba el IMCE individualizado en vez de la constante del IMC de 25, el PPEIMC mediano era de 99,48 (rango: 76,75 a 110,46). Conclusión Este resultado evidencia que la aplicación individual del IMCE estima con mayor fiabilidad el éxito o fracaso de las operaciones bariátricas (AU)

Introduction The body mass index (BMI) is the most practical method to measure and compare obesity between individuals. The Percentage of Excess BMI Loss (PEBMIL) is used to present results in operated patients and is based on the premise that a BMI-25 is the final aim, on being the upper limit in normal subjects. It is possible to achieve a BMI-25 in morbid obese (MO) patients with initial low BMIs (<50) but it is rare in overweight (OW) patients with a BMI >50. Expected BMI (EBMI) would be that which should be reached by all subjects depending on their initial BMI. Objective The objective of this study is to search for, using statistical methods, a formula based on clinical evidence that can identify the EBMI depending on the initial BMI. Patients and method We analysed the initial and final BMI in a group of 135 MO patients, operated on using the duodenal switch procedure and with a follow up of over 3 years. A linear regression method has been used to obtain a formula that could calculate the EBMI of each patient operated on. Results We obtained an algorithm in which EBMI=Initial BMI×0.33+14. If we apply the individualised EBMI instead of the BMI-25, the median PEBMIL was 99.48 (range: 76.75–110.46).Conclusion This result suggests that the application of an individual EBMI is a more reliable estimate of the success or failure of bariatric operations (AU)

[Expected body mass index after bariatric surgery]. / Indice de masa corporal esperable tras cirugía bariátrica.

INTRODUCTION: The body mass index (BMI) is the most practical method to measure and compare obesity between individuals. The Percentage of Excess BMI Loss (PEBMIL) is used to present results in operated patients and is based on the premise that a BMI-25 is the final aim, on being the upper limit in normal subjects. It is possible to achieve a BMI-25 in morbid obese (MO) patients with initial low BMIs (<50) but it is rare in overweight (OW) patients with a BMI>50. Expected BMI (EBMI) would be that which should be reached by all subjects depending on their initial BMI. OBJECTIVE: The objective of this study is to search for, using statistical methods, a formula based on clinical evidence that can identify the EBMI depending on the initial BMI. PATIENTS AND METHOD: We analysed the initial and final BMI in a group of 135 MO patients, operated on using the duodenal switch procedure and with a follow up of over 3 years. A linear regression method has been used to obtain a formula that could calculate the EBMI of each patient operated on. RESULTS: We obtained an algorithm in which EBMI=Initial BMIx0.33+14. If we apply the individualised EBMI instead of the BMI-25, the median PEBMIL was 99.48 (range: 76.75-110.46). CONCLUSION: This result suggests that the application of an individual EBMI is a more reliable estimate of the success or failure of bariatric operations.

Outcomes of ZB5M angle-supported anterior chamber phakic intraocular lenses at 12 years.

PURPOSE: To evaluate the visual and refractive stability and the potential long-term risks associated with ZB5M phakic intraocular lens (PIOL) implantation. METHODS: A retrospective, non-randomized, cumulative clinical study was performed over 12 years in a consecutive group of 225 eyes implanted with the ZB5M PIOL. The main analyzed variables were visual and refractive outcomes (best spectacle-corrected visual acuity [BSCVA], uncorrected visual acuity [UCVA], and spherical equivalent), endothelial cell density, and postoperative complications. RESULTS: Mean preoperative spherical equivalent refraction was -17.23 +/- 7.69 diopters (D) and 12 years postoperatively it was -1.80 +/- 0.80 D. Mean BSCVA at 1- and 12-year follow-up was 0.38 +/- 0.19 and 0.57 +/- 0.18, respectively (Wilcoxon test, P < .001). At 12 years postoperatively, 3.5% of eyes lost > or = 2 lines of BSCVA. An initial 10.6% reduction in endothelial cell density was noted in the first year, followed by a mean annual rate of decrease of 1.78%. The cumulative incidence of pupil ovalization was 34.7% (78 eyes), and there was no statistical correlation with endothelial cell impairment. Bilateral hypertensive uveitis was diagnosed in 3 (1.33%) eyes. CONCLUSIONS: The ZB5M PIOL offers good refractive outcomes and stability in the long-term; however, endothelial cell loss increases over 12 years, requiring annual endothelial cell counts.

Influence of age, gender and iris color on mechanical and chemical sensitivity of the cornea and conjunctiva.

The purpose of this study was to establish the influence of age, gender and iris color on the mechanical and chemical sensitivity of the cornea and the conjunctiva. In 57 healthy subjects (27 males, 30 females; ages between 23 and 71 years), sensory thresholds to mechanical and chemical stimulation were measured in the central cornea and the temporal conjunctiva using a Belmonte's gas esthesiometer. Mechanical stimulation consisted of warmed air pulses of 3s duration at different flow rates (40-200 ml/min). For chemical (acidic) stimulation, 3-s warmed gas pulses containing 10% to 80% CO(2) in air were applied, at a flow below mechanical threshold flow. Corneal and conjunctival thresholds to mechanical and chemical stimuli increased with age. Premenopausal women were more sensitive to corneal stimulation than men of similar ages but overall differences in mechanical and chemical threshold between men and women were not significant. Individuals with blue eyes had significantly lower corneal chemical thresholds than those with brown or green eyes. Multiple linear regression analysis evidenced that corneal mechanical threshold depends on age and iris color according to the equation 58.2 ml/min+1.3.(Age-23 years)-9.7 if blue eyes. For chemical threshold, the equation was 28.6%CO(2)+05.(Age-23 years)-12.5 if blue eyes. In the case of the conjunctiva, only age determined mechanical and chemical thresholds according to the equations: 78.2 ml/min+1.4.(Age-23 years) and 41.6%CO(2)+0.8.(Age-23 years), respectively. Therefore, normal values of mechanical and chemical thresholds of the cornea and conjunctiva measured with the Belmonte gas esthesiometer can be predicted according to age and iris color. Variations of sensitivity with age, iris color and gender may reflect differences in innervation density and neural responsiveness associated with the hormonal status.

Decreased corneal sensitivity in patients with dry eye.

PURPOSE: To explore changes in corneal sensitivity that develop in patients with dry eye and the relationship between sensibility and severity of the dry eye disease. METHODS: Experiments were performed in 44 patients with dry eye and 42 healthy individuals. Corneal sensitivity was measured with the Belmonte noncontact gas esthesiometer. Mechanical (air jets at flow rates from 0 to 200 mL/min, reaching the corneal surface at 34 degrees C), thermal (cold or warm air at subthreshold flow rates changing corneal basal temperature +/-1 degrees C), and chemical stimuli (air containing 0% to 50% CO2 at subthreshold flow rate and temperature at the cornea of 34 degrees C) were applied to the center of the cornea to determine the sensitivity threshold for each stimulus modality. The clinical state of the ocular surface was also explored, measuring the fluorescein tear break-up time, the degree of corneal staining with fluorescein and Lissamine green, and tear production with the Schirmer test. RESULTS: Both in control subjects and patients with dry eye, the corneal thresholds for mechanical, chemical, and thermal stimulation increased with age. Moreover, the thresholds for the three modalities of stimuli were significantly higher in patients with dry eye than in control subjects. In both groups, individual mechanical, chemical, and thermal thresholds correlated significantly. Also, high thresholds in patients with dry eye correlated with the intensity of fluorescein and Lissamine green corneal staining but not with the results of the Schirmer test. CONCLUSIONS: Patients with dry eye exhibit corneal hypoesthesia after mechanical, thermal, and chemical stimulation that appears to be related to damage to the corneal sensory innervation.