Abstract
Background
Ocular allergy is one of the most common ophthalmologic conditions. The prevalence of these disorders has increased in recent years due to environmental factors such as air pollution and allergens. The interaction between allergies and lacrimal gland dysfunction may contribute to the development of dry eye, which exacerbates symptoms in these patients. This study aims to evaluate the prevalence of ocular allergy (OA), dry eye and the association of symptoms with levels of environmental pollutants and atmospheric conditions.
Methods
Skin tests were performed to determine sensitization to environmental and food allergens. In addition, a complete ophthalmologic examination was conducted. The research results were analyzed using descriptive statistics, including the prevalence of various ophthalmologic and allergic conditions. Average levels of environmental pollutants and atmospheric conditions were correlated with dry eye disease as well as mean scores from the EAPIQ, which was completed weekly for 17 weeks by each participant.
Results
The study evaluated 44 patients with symptoms of ocular allergy. Dermatophagoides spp. were the most prevalent environmental allergens, with a rate of 68.1%. The prevalence of sensitization to food allergens was 11.3% for salmon. Perennial allergic conjunctivitis was the most frequent condition (63.6%), followed by seasonal allergic conjunctivitis (29.5%). Dry eye was confirmed in 59% of subjects. The correlation analysis between environmental pollutants and ocular symptoms showed a moderate and significant correlation between ozone (O3) levels and the mean EAPIQ score (r = 0.500, p = 0.041). Symptoms of swollen eyes and eyelids showed a significant correlation with ozone (r = 0.538, p = 0.026) and temperature (r = 0.568, p = 0.017). Ocular itching was significantly correlated with temperature (r = 0.651, p = 0.005) and wind speed (r = 0.615, p = 0.009). Likewise, dry eye symptoms showed significant correlations with temperature (r = 0.675, p = 0.003) and wind speed (r = 0.723, p = 0.001). No statistically significant correlations were observed between ocular symptoms and the levels of NO2, SO2, PM10, or PM2.5 in this study.
Conclusions
This study provides a comprehensive overview of the prevalence of ocular allergy and dry eye, highlighting sensitization to environmental allergens such as Dermatophagoides spp., Quercus spp., and Canis familiaris as the main triggers of ocular symptoms. This study highlights the importance of environmental allergens and atmospheric factors such as O3, temperature, and wind speed in the management and prevention of ocular allergy. The results accentuate the need to implement environmental control strategies and public policies to reduce exposure to these factors, particularly in urban areas with high atmospheric pollution.
Keywords: Allergic, conjunctivitis; Corneal diseases; Pollutants; Climatic factors; Dry eye disease
Introduction
Ocular allergy (OA) comprises a group of diseases characterized by conjunctival inflammation. It affects approximately 10% of the global population, with the highest prevalence observed in individuals with other allergic conditions, in whom the frequency of ocular symptoms may reach up to 60%.1
In the pathophysiology of the disease, inflammation has been described as a well-known disruptor of the epithelial barrier.2 In addition to serving as a mechanical barrier, conjunctival epithelial cells actively participate in OA by contributing to the amplification of allergic inflammation through the expression and production of cytokines, chemokines, adhesion molecules, and other factors that sustain local inflammation and lead to tissue remodeling.2 The symptomatology of OA is dominated by 4 cardinal signs: epiphora, ocular pruritus, hyperemia, and edema.3 These symptoms result from the disruption of the function and organization of tight junctions, as well as the abnormal expression of junctional proteins in the ocular epithelial barrier, which may be altered by triggers such as allergens and pollutants.2,3
Several studies have reported positive skin prick test reactivity in patients diagnosed with allergic conjunctivitis. In 2018, Machado et al. described that 70.6% of 92 patients aged 3–74 years had at least 1 positive skin prick test to allergens.4 A 2015 review identified pollen as the most common trigger. However, exposure to non-specific environmental conditions, pollutants, and cigarette smoke has also been reported.5
Pollution is the leading environmental cause of disease and premature death globally. Pollution-related diseases have been attributed to approximately 9 million deaths over the past 5 years, accounting for 16% of all deaths worldwide.6 The adverse effects of air pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), and ozone (O3) on the human eye primarily include irritation and inflammation, with conjunctivitis being a common issue.7 An increasing number of studies have indicated an association between air pollutants—particularly PM2.5—and allergic conjunctivitis. An extensive review confirmed the negative impact on the ocular surface, OA, and dry eye caused by environmental factors such as climate factors (temperature, humidity, and windspeed), air pollutants, and allergens. In 2016, Hong et al. found that higher levels of nitrogen dioxide (NO2), ozone (O3), and ambient temperature were associated with increased outpatient visits for allergic conjunctivitis. They concluded that ambient air pollution and climatic changes may contribute to the exacerbation of allergic conjunctivitis.8,9
Despite these reported associations, few studies have investigated the interactions between pollutant levels, OA symptoms, and sensitization to outdoor and food allergens. This study aims to explore the relationship between the exacerbation of OA symptoms, dry eye and environmental pollution, along with climatic factors.
Methods
A longitudinal, observational, prospective, and descriptive study was conducted in the Allergy and Ophthalmology Departments of a tertiary care hospital in Monterrey, Nuevo León, from April to August 2024. The research protocol was approved by the Ethics Committee of the Faculty of Medicine at the Universidad Autónoma de Nuevo León under approval number AL24-00002.
Patients over 18 years of age living in the metropolitan area of Monterrey with a clinical diagnosis of OA confirmed by ophthalmologic evaluation and positive skin prick tests to food and/or environmental allergens were recruited in the allergy department and if accepted were included. New or follow-up patients with a presumptive diagnosis of ocular allergy, based on ocular signs and symptoms (pruritus, redness, photophobia, tearing, eyelid edema, eyelid dermatitis, folliculitis, papillae, and keratitis) at the time of allergy department consultation or a prior history of such symptoms, were invited to participate in the study. The study objectives, procedures, and duration were explained, and those who agreed were referred to the Ophthalmology Department for a complete ophthalmologic examination to confirm or rule out the diagnosis of ocular allergy.
Two visits were scheduled: the first one on the day of recruitment, during which skin prick testing was performed and patients were referred to the Ophthalmology Department for an ophthalmic assessment. The ophthalmic evaluations included visual acuity measurement, intraocular pressure measurement, ocular surface staining (OSS), cornea fluoresceine staining (CFS), fluorescein tear film breakup time (FBUT), eyelid margin evaluation, fornix and tarsal fornix evaluation, and evaluation of the anterior segment, ocular surface, and posterior segment, conjunctival hyperemia or injection, chemosis, tearing, tarsal papillae and their size, Horner's sign, limbal disorders, fornix shortening, corneal erosions, corneal ulcers and scars, among others. Additionally, a questionnaire on dry eye symptoms, ocular surface index questionnaire (OSDI) was administered.10 Specifically, the presence of dry eye disease (DED), meibomian gland dysfunction, non-allergic conjunctivitis, blepharitis, and other conditions was sought. They all underwent corneal topography with a Pentacam. The second visit took place in the allergy department 4 weeks after recruitment, the follow-up consultation included questions regarding ocular symptomatology and the use of rescue medications for ocular symptoms. Patients were informed about the study participation format, and informed consent was obtained via a digital questionnaire. Participants received a Google Forms access link to the EAPIQ19 (Eye Allergy Patient Impact Questionnaire),11 which they completed weekly (over 17 weeks) according to their ocular symptomatology.
The EAPIQ questionnaire consists of 35 items addressing 4 main areas: the onset of ocular allergy symptoms, measures taken to manage these symptoms, the impact of symptoms on daily activities and emotions, and satisfaction with symptom treatment. Allergen sensitization was confirmed by performing skin prick tests on the inner side of the right forearm using the MultiTest® device (Lincoln Diagnostics), with environmental and food allergen extracts provided by the Mexican supplier Allerquim®. A wheal diameter greater than 3 mm compared to the negative control at 15 min post-application was considered a positive result.
Patients with a confirmed diagnosis of allergic conjunctivitis through both sensitization tests and ophthalmologic examination were classified into 1 of the 6 clinical forms of ocular allergy: intermittent or seasonal allergic conjunctivitis (SAC), persistent or perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), giant papillary conjunctivitis (GPC), and contact blepharoconjunctivitis (CBC).3 Diagnosis of DED was performed with the following diagnostic criteria (TFOS DEWS III): symptoms (OSDI≥13 or DEQ-5≥ 6) + 1 sign (+OSS o FBUT <5 or NIBUT first <10, osmolarity ≥308). OSDI-6 did not exist at the time this studied was performed.10
Pollution levels were monitored weekly and obtained from the Nuevo Leon Environmental Monitoring System (SIMA), including sulfur dioxide (SO2), NO2, particulate matter <2.5 μm (PM2.5), particulate matter <10 μm (PM10), CO, and O3. Meteorological conditions were also monitored weekly, and average weekly values of temperature, atmospheric pressure, wind speed, and humidity were calculated using data from SIMA. These values were then correlated with the scores obtained from the EAPIQ questionnaires completed weekly by participants over the 17-week study period.
A sample of 44 subjects was calculated. The simple correlation formula was used based on the study objectives: to evaluate the correlation between increased air pollution and the occurrence of allergic conjunctivitis. In the formula, “K” is the value assigned based on the required significance and power; in this case, a two-tailed significance of 0.05 and a power of 95%. The expected correlation coefficient (ECC) is a value that reflects the strength of the correlation between 2 phenomena. In this case, the ECC value of 0.54 was obtained through a review of international literature and based on the reported correlation between increases in NO2 and the incidence of allergic conjunctivitis.12
Statistical analysis was performed using SPSS version 25.0 (SPSS, Inc., Armonk, NY). Descriptive analyses were conducted, stratified by pollution level and atmospheric conditions, and correlated with the EAPIQ scores. Pearson's correlation coefficient was used to assess linear dependence between quantitative random variables.
Results
A total of 44 patients were included, of whom 61.3% were female and 38.6% were male. The mean ± SD age of the participants was 30.6 ± 9.7 years, ranging from 20 to 62 years old. Most patients lived in the municipality of Monterrey (70.5%), followed by San Nicolás de los Garza (9.1%) and other municipalities with lower prevalence such as Escobedo, Guadalupe, Santa Catarina, among others. The majority of patients reported spending most of the day in Monterrey (88.6%), with fewer in San Nicolás de los Garza (6.8%) and some in less represented municipalities.
Regarding the results of the skin tests, Dermatophagoides spp. were the most prevalent environmental allergens, with 68.1%. Other environmental allergens included Quercus spp. (40.9%) and Canis familiaris (40.9%). Sensitization to Felis domesticus was reported in 38.6% of patients. The most frequent food allergen was fish (salmon) with 11.3%, followed by soy (9%), peanut (6.8%), and milk, egg white, egg yolk, wheat, shrimp, and walnut, all with a prevalence of 2.2% (Table 1).
Table 1.
Sensitization to environmental and food allergens
| Allergen | Frequency N = 44 (%) |
|---|---|
| Enviromental allergen | |
| Dermatophagoides spp. | 29 (68.1) |
| Quercus spp. | 18 (40.9) |
| Canis familiaris | 17 (40.1) |
| Felis domesticus | 16 (38.6) |
| Fraxinus spp. | 15 (34.0) |
| Junglans rupestris | 11 (25.0) |
| Phleum pratense | 11 (25.0) |
| Lolium perenne | 8 (18.1) |
| Atriplex bracteosa | 8 (18.1) |
| Salsola pestifer | 8 (18.1) |
| Bromus carinatus | 7 (15.9) |
| Cynodon dactylon | 7 (15.9) |
| Juniperus spp | 7 (15.9) |
| Alternaria alternata | 6 (13.6) |
| Prosopis spp. | 6 (13.6) |
| Amaranthus palmeri | 5 (11.3) |
| Ambrosia eliator | 5 (11.3) |
| Sorghum halapense | 5 (11.3) |
| Chenopodium ambrosioides | 4 (9.0) |
| Aspergillus fumigatus | 4 (9.0) |
| Cupressus spp. | 3 (6.8) |
| Populus spp. | 2 (4.5) |
| Artemisia ludoviciana | 2 (4.5) |
| Helianthus spp. | 1 (2.2) |
| Ligustrum spp. | 1 (2.2) |
| Hormodendrum cladosporioides | 0 (0) |
| Food allergen | |
| Fish (salmon) | 5 (11.3) |
| Soy | 4 (9.0) |
| Peanut | 3 (6.8) |
| Milk | 1 (2.2) |
| Egg white | 1 (2.2) |
| Egg yolk | 1 (2.2) |
| Wheat | 1 (2.2) |
| Shrimp | 1 (2.2) |
| Walnut | 1 (2.2) |
| Almond | 0 (0) |
Types of ocular allergy and associated ophthalmic conditions
According to the classification of ocular allergy, perennial allergic conjunctivitis was the most frequent (63.6%), followed by seasonal allergic conjunctivitis (29.5%). Vernal keratoconjunctivitis and atopic keratoconjunctivitis, severe forms of ocular allergy, were less frequent (4.5% and 22.7%, respectively).
Regarding ophthalmological conditions associated with ocular allergy, DED was observed in 65.9% of cases, followed by Meibomian gland dysfunction (52.2%). Mixed blepharitis was present in 15.9%, while anterior and posterior blepharitis were less common (4.5% each). In addition, keratoconus was diagnosed in 1 patient. According to OSDI, 28 subjects (61.3%) presented a diagnosis of symptomatic DED while a total of 26 (59%) were confirmed with DED based diagnostic criteria (Table 2).
Table 2.
Types of ocular allergy, associated ophthalmic conditions and dry eye disease.
| Type of ocular allergy | Frequency n = 44 (%) |
|---|---|
| Perennial allergic conjunctivitis | 28 (63.6) |
| Seasonal allergic conjunctivitis | 13 (29.5) |
| Atopic keratoconjunctivitis | 10 (22.7) |
| Vernal keratoconjunctivitis | 2 (4.5) |
| Associated ophthalmic conditions | |
| Symptomatic dry eye disease (OSDI) | 29 (65.9) |
| Dry eye disease (DEWS criteria) | 26 (59) |
| Meibomian gland dysfunction | 23 (52.2) |
| Mixed blepharitis | 7 (15.9) |
| Anterior blepharitis | 2 (4.5) |
| Posterior blepharitis | 2 (4.5) |
| Keratoconus | 1 (2.2) |
| Horner Trantas dots | 0 (0) |
| Presence of papillae | 44 (100) |
| Small | 37 (84) |
| Medium | 5 (11.3) |
| Giant | 2 (4.5) |
| OSDI results | |
| Symptomatic dry eye (OSDI>12) | 28 (63.6) |
| Mild (13–22 points) | 20 (45.4) |
| Moderate (23–32 points) | 8 (18.1) |
| Severe (33–100 points) | 0 (0) |
| Dry eye tests | Mean (SD) |
| FBUT | 5.62 (2.8) |
| Schirmer without anesthesia | 22.5 (12.1) |
| CFS CLEK (0-15) | 0.63 (0.95) |
| OSS SICCA (0-12) | 1.15 (1.2) |
CFS: cornea fluorescent staining; FBUT: fluorescein break-up time; OSDI: ocular surface index questionnaire; OSS: ocular surface staining
Relationship between ocular allergy symptoms (mean EAPIQ) and pollutants and environmental variables during total follow-up weeks
The significant correlations between mean EAPIQ and environmental conditions and pollutants were: temperature with r = 0.651 and p = 0.005; wind speed with r = 0.493 and p = 0.044, CO with r = 0.573 and p = 0.016; O3 with r = 0.551 and p = 0.022; SO2 with r = 0.482 and p = 0.050. There was a negative correlation between EAPIQ and precipitation with r = −0.545 and p = 0.024.
Regarding correlation between eyelid edema and pollutants as well as environmental factors: CO with r = 0.645 and p = 0.005; O3 with r = 0.548 and p = 0.023; SO2 with r = 0.512 and p = 0.036; temperature with r = 0.495 and p = 0.044.
The correlations involving tearing and pollutants along with environmental factors was: CO with r = 0.616 and p = 0.008; O3 with r = 0.590 and p = 0.013; temperature with r = 0.586 and p = 0.013; PM10 with r = 0.530 and p = 0.028; PM2.5 with r = 0.511 and p = 0.036. A negative correlation was observed with PRS having r = −0.580 and p = 0.015. Regarding redness symptoms, a positive correlation was seen between temperature with r = 0.671 and p = 0.003; O3 with r = 0.606 p = 0.010; wind speed with r = 0.562 and p = 0.019. A significant negative correlation was observed between PRS with r = −0.620 and p = 0.008 as well as humidity with r = −0.534 and p = 0.027.
A negative correlation was observed analyzing pruritus and PRS with r = −0.499 and p = 0.041 and a positive correlation regarding temperature r = 0.595 and p = 0.012.
Temperature and wind speed both showed a positive correlation with eye dryness having r = 0.613, p = 0.009 and r = 0.680 and p = 0.003 respectively. All the correlations are shown in Table 3.
Table 3.
Statistical analysis by environmental pollutant and its relationship with ocular symptoms. Weeks 1–17.
| CO | NO2 | O3 | SO2 | PM2.5 | PM10 | PRS | Humidity | Temperature | Wind speed | |
|---|---|---|---|---|---|---|---|---|---|---|
| EAPIQ | 0.573 (0.016) | −0.120 (0.646) | 0.551 (0.022) | 0.482 (0.050) | 0.307 (0.230) | 0.344 (0.177) | −0.545 (0.024) | −0.449 (0.070) | 0.651 (0.005) | 0.493 (0.044) |
| Eyelid edema | 0.645 (0.005) | −0.142 (0.588) | 0.548 (0.023) | 0.512 (0.036) | 0.174 (0.503) | 0.227 (0.381) | −0.477 (0.053) | −0.446 (0.073) | 0.495 (0.044) | 0.433 (0.083) |
| Tearing | 0.616 (0.008) | −0.019 (0.943) | 0.590 (0.013) | 0.457 (0.065) | 0.511 (0.036) | 0.530 (0.028) | −0.580 (0.015) | −0.314 (0.219) | 0.586 (0.013) | 0.252 (0.330) |
| Redness | 0.462 (0.062) | −0.193 (0.457) | 0.606 (0.010) | 0.353 (0.164) | 0.333 (0.192) | 0.310 (0.226) | −0.620 (0.008) | −0.534 (0.027) | 0.671 (0.003) | 0.562 (0.019) |
| Pruritus | 0.464 (0.061) | −0.016 (0.951) | 0.458 (0.065) | 0.392 (0.120) | 0.287 (0.265) | 0.349 0.169) | −0.499 (0.041) | −0.407 (0.105) | 0.595 (0.012) | 0.420 (0.093) |
| Eye dryness | 0.394 (0.118) | −0.279 (0.278) | 0.321 (0.209) | 0.466 (0.059) | 0.004 (0.988) | 0.036 (0.891) | −0.298 (0.245) | −0.414 (0.099) | 0.613 (0.009) | 0.680 (0.003) |
Pearson correlation, r value (p value) was used. CO: Carbon monoxide; NO2: nitrogen dioxide; O3: ozone; SO2: sulfur dioxide; PM2.5: particulate matter that are 2.5 μm in diameter or less, PM10 particulate matter that are 10 μm in diameter or less; PRS: precipitation
Discussion
Our results show that PAC was the most frequent among participants. This high incidence aligns with other recent studies in various geographic locations. The high prevalence of these perennial allergies, which are present year-round—including house dust mites and animal epithelia as previously mentioned—has been associated with constant exposure to these allergens in the home and urban environments. In our study, sensitization to Dermatophagoides spp. was observed in most of our patients. The presence of PAC and dermatophagoides as the most frequent makes sense since this allergen is present all year round and it is expected to have allergic conjunctivitis in a permanent way.13 The house dust mite is typically considered the main causative allergen in perennial allergic conjunctivitis. In a recent German retrospective study found in subjects monosensitized to house dust mites, the prevalence of itching and red eye was 23% and 5%, respectively. These percentages raised to 45% and 9%, respectively, in polysensitized patients.13 Christiansen et al. reported that transient early-life sensitization to house dust mites has been associated with a significantly increased risk of rhino-conjunctivitis in 14-year-old subjects (OR 3.33 95% CI 1.29–8.66).14 Studies from South America showed that, although not typical of tropical areas, sensitization to cats and/or dogs were frequent in patients with allergic conjunctivitis, which correlated with disease severity in children affected by vernal keratoconjunctivitis.15 In our study, sensitization to cats or dogs was found in 38.6% and 40.1% respectively, representing a common allergen for perennial symptoms.
Regarding ophthalmological diagnoses, dry eye disease was the most common disorder, which is a concerning finding. The presence of dry eye in patients with ocular allergy is associated with the interaction between allergic responses and chronic ocular inflammation. This inflammation affects both the lacrimal glands and Meibomian glands, which are essential for tear film production and stability. Patients with ocular allergies have a higher risk of developing dry eye due to Meibomian gland dysfunction, contributing to excessive evaporation of the tear film and alteration of its composition. Recent studies have indicated that inflammation of the Meibomian glands is common in patients with both perennial and seasonal allergy, contributing to decreased tear film quality and increased tear evaporation.15
Regarding the influence of environmental factors, concentrations of O3 and temperature showed a moderate and significant positive correlation with ocular symptoms, particularly with ocular and eyelid inflammation and dry eye sensation. Similarly, O3 exposure has been associated with increased severity of allergic symptoms and exacerbation of ocular conditions in sensitive individuals according to Eguiluz et al.16 Increased ozone levels of 0.003 ppm were significantly associated with symptoms and diagnosis of dry eye disease (symptoms: OR 1.17 95%CI 1.02–1.34. and diagnosis: OR 1.27 95%CI 1.09–1.48). Importantly, NO2, not PM10, was associated with dry eye disease.17 In a meteorological data from a cohort of patients with allergic conjunctivitis in the United States, the odds of a health care visit for allergic conjunctivitis were statistically significantly associated with temperature (OR 1.028, p < 0.001), as well as temperature-variations (OR 1.054, p < 0.01), and temperature-humidity interaction (OR 1.0003, p < 0.01).18 The impact of these environmental factors on ocular allergy is an area of growing interest.7 According to Patel et al, the risk of allergic conjunctivitis was negatively associated with relative humidity (OR 0.998, p < 0.001), and was positively associated with increased temperature (OR 1.028, p < 0.001), SD of temperature (OR 1.054, p < 0.01), and temperature-relative humidity interaction (OR 1.0003, p < 0.01). The association between allergic conjunctivitis and the environment relies on the fact that these conditions make possible air particulate and aeroallergen dispersion along with tear film instability.18
Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, as observed in our study with a positive correlation with eyelid edema, tearing, redness, pruritus and eye dryness.7 Humidity has been found to be negatively associated with dry eye disease.19 There is little data on wind speed, a retrospective observational study investigated the incidence of ocular diseases and correlations with weather data, reporting a positive correlation between the weekly total patient number, the incidence of corneal foreign bodies and conjunctivitis and the meteorological data.20 The positive correlations were statistically significant for the weekly sunshine duration and the weekly average temperature, but no correlation was found for the weekly average of any disease with wind speed in that study.21 Pollutants such as NO2 and soil pollution (from chromium) has been associated with dry eye disease,22,23 however, we did not find a significant relation regarding pollutants and eye dryness in our study.
Extreme heat has also been identified as an aggravating factor of ocular symptoms in patients predisposed to allergies.24,25 A temperature near 40 °C can change the properties of meibomian gland lipids and disrupt the tear film. In a South Korean population, diagnosis of dry eye disease was positively associated with outdoor temperature [(1 °C increase in temperature was associated with an odds ratio (OR) of 1.076; 95% confidence interval (CI) 1.009–1.148)].26 The association of dry eye with environmental factors such as temperature, humidity and air speed has already been reported, and this is confirmed and coincides with our study of patients with ocular allergies and DED.
The study has some limitations. First, the sample size was relatively small, limiting the generalizability of the results to larger populations. Additionally, the absence of a control group (without ocular allergy symptoms) prevents direct comparisons with non-allergic subjects.
Conclusions
This study provides a comprehensive overview of the prevalence of ocular allergy, highlighting sensitization to environmental allergens such as Dermatophagoides spp., Quercus spp., and Canis familiaris as the main triggers of ocular symptoms. Although food allergens are also present, their impact on ocular sensitization was considerably lower. Furthermore, a significant prevalence of different types of ocular allergy was found, with perennial allergic conjunctivitis being the most common, followed by seasonal allergic conjunctivitis. Regarding associated conditions, the presence of symptoms such as dry eye, ocular itching, and swollen eyes was notably high in the studied population.
This study highlights the importance of environmental allergens and atmospheric factors such as O3, temperature, and wind speed in the management and prevention of ocular allergy. The results highlight the need to implement environmental control strategies and public policies to reduce exposure to these factors, particularly in urban areas with high atmospheric pollution. Additionally, the importance of awareness and appropriate treatment for patients sensitized to both environmental and food allergens is suggested.
Abbreviations
AKC: atopic keratoconjunctivitis; CBC: contact blepharoconjunctivitis; CFS: cornea fluorescent staining; CO: Carbon monoxide; DED: dry eye disease; DEWS: dry eye workshop; EAPIQ: eye allergy patient impact questionnaire; ECC: expected correlation coefficient; FBUT: Fluorescein break up time; GPC: giant papillary conjunctivitis; NIBUT: Non-Invasive Break-Up Time; NOx: nitrogen oxides; NO2, nitrogen dioxide; OA: ocular allergy; O3, ozone; OSDI: ocular surface index questionnaire; OSS: ocular surface staining; PAC: perennial allergic conjunctivitis; PM, particulate matter; PM2.5: particulate matter that are 2.5 μm in diameter or less; PM10: particulate matter that are 10 μm in diameter or less; PRS: precipitation; SAC: seasonal allergic conjunctivitis; SIMA: Environmental Monitoring System; SO2: sulfur dioxide; TFOS: Tear film ocular surface society; VKC: vernal keratoconjunctivitis.
Data availability statement
Any additional data is available upon request to the authors.
Author contributions
Sandra Nora Gonzalez-Diaz: Design of the study, manuscript elaboration, and revision. Brenda María Curiel-Velázquez contributed to design of the study, data collection, interpretation of the results, and manuscript writing. Karim Mohamed-Noriega, Jesus Mohamed-Hamsho and Fernando Morales-Wong contributed to design of study, data collection and manuscript writing. Jesús Marcelo Alanís-Alvarez and Valeria Muñoz-Silva contributed to data collection, analysis and manuscript writing. Natalhie Acuña-Ortega, Carlos Macouzet-Sánchez, Ana Karen Chávez-Ruiz, Alejandra Macias-Weinmann, Rosa Ivett Guzmán-Avilán, María del Carmen Zarate-Hernandez, contributed to manuscript writing. Cindy Elizabeth de Lira-Quezada contributed to design of the study, interpretation of the results, manuscript writing and revision.
All authors give consent for publication.
Statement of ethics
The study was submitted and approved by the Ethics Committee of the Faculty of Medicine of the Autonomous University of Nuevo Leon, with registration number AL24-00002. Upon verbal informed consent obtained by subjects or parents/legal guardians (previously authorized by Faculty of Medicine Ethics Committee), subjects above 18 years old who lived in the metropolitan area of Monterrey with diagnosis of ocular allergy were included.
Use of generative artificial intelligence (AI) and AI-assisted technologies
Nothing to disclose.
Funding sources
Funding was provided by the authors.
Conflict of Interest Statement
The authors have no conflicts of interest to declare.
Footnotes
Full list of author information is available at the end of the article
References
- 1.Navarrete-Rodríguez E., Sienra-Monge J.J.L., Ureña-Ortiza R. Ocular allergy. Rev Fac Med. 2018;61(3):7–16. [Google Scholar]
- 2.Singh N., Diebold Y., Sahu S.K., et al. Epithelial barrier dysfunction in ocular allergy. Allergy. 2022;77(5):1360–1372. doi: 10.1111/all.15174. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Fauquert J.L. Diagnosing and managing allergic conjunctivitis in childhood: the allergist's perspective. Pediatr Allergy Immunol. 2019;30(4):405–414. doi: 10.1111/pai.13035. [DOI] [PubMed] [Google Scholar]
- 4.Miranda-Machado P.A., De la Cruz-Hoyos Sánchez B. Cutaneous reactivity in allergic conjunctivitis. Rev Alerg Méx. 2018;65(3):208–216. doi: 10.29262/ram.v65i3.351. [DOI] [PubMed] [Google Scholar]
- 5.Leonardi A., Castegnaro A., Valerio A.L.G., et al. Epidemiology of allergic conjunctivitis: clinical appearance and treatment patterns in a population-based study. Curr Opin Allergy Clin Immunol. 2015;15(5):482–488. doi: 10.1097/ACI.0000000000000204. [DOI] [PubMed] [Google Scholar]
- 6.González-Díaz S.N., Lira-Quezada C.E.D., Villarreal-González R.V., et al. Environmental pollution and allergy. Rev Alerg Méx. 2022;69:24–30. doi: 10.29262/ram.v69iSupl1.1010. [DOI] [PubMed] [Google Scholar]
- 7.Lin C.-C., Chiu C.-C., Lee P.-Y., et al. The adverse effects of air pollution on the eye: a review. Int J Environ Res Public Health. 2022;19:1186. doi: 10.3390/ijerph19031186. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Hong J., Zhong T., Li H., et al. Ambient air pollution, weather changes and outpatient visits for allergic conjunctivitis: a retrospective registry study. Sci Rep. 2016;6 doi: 10.1038/srep23858. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Prince A., Norris M.R., Bielory L. Seasonal ocular allergy and pollen counts. Curr Opin Allergy Clin Immunol. 2018;18(5):387–392. doi: 10.1097/ACI.0000000000000475. [DOI] [PubMed] [Google Scholar]
- 10.Wolffsohn J.S., Benítez-Del-Castillo J., Loya-Garcia D., et al. TFOS DEWS III diagnostic methodology. Am J Ophthalmol. 2025 Nov;279:387–450. doi: 10.1016/j.ajo.2025.05.033. [DOI] [PubMed] [Google Scholar]
- 11.Alexander M., Berger W., Buchholz P., et al. The reliability, validity, and preliminary responsiveness of the Eye Allergy Patient Impact Questionnaire (EAPIQ) Health Qual Life Outcomes. 2005 Oct 31;3:67. doi: 10.1186/1477-7525-3-67. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Lu C.W., Fu J., Liu X.F., et al. Air pollution and meteorological conditions significantly contribute to the worsening of allergic conjunctivitis: a regional 20-city, 5-year study in Northeast China. Light Sci Appl. 2021; Sep 17;10(1):190. doi: 10.1038/s41377-021-00630-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Englhard A.S., Holzer M., Eder K., et al. How reliable is anamnestic data in predicting the clinical relevance of house dust mite sensitization? Eur Arch Otorhinolaryngol. 2022;279:801–810. doi: 10.1007/s00405-021-06862-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Christiansen E.S., Kjaer H.F., Eller E., et al. Early-life sensitization to hen's egg predicts asthma and rhinoconjunctivitis at 14 years of age. Pediatr Allergy Immunol. 2017;28:776–783. doi: 10.1111/pai.12815. [DOI] [PubMed] [Google Scholar]
- 15.Hemmer W., Sestak-Greinecker G., Braunsteiner T., et al. Molecular sensitization patterns in animal allergy: relationship with clinical relevance and pet ownership. Allergy. 2021;76:3687–3696. doi: 10.1111/all.14885. [DOI] [PubMed] [Google Scholar]
- 16.Eguiluz-Gracia I., Mathioudakis A.G., Bartel S., et al. The need for clean air: the way air pollution and climate change affect allergic rhinitis and asthma. Allergy. 2020 Sep;75(9):2170–2184. doi: 10.1111/all.14177. Epub 2020 Jan 30. PMID: 31916265. [DOI] [PubMed] [Google Scholar]
- 17.Hwang S.H., Choi Y.H., Paik H.J., Wee W.R., Kim M.K., Kim D.H. Potential importance of ozone in the association between outdoor air pollution and dry eye disease in South Korea. JAMA Ophthalmol. 2016;134:503–510. doi: 10.1001/jamaophthalmol.2016.0139. [DOI] [PubMed] [Google Scholar]
- 18.Patel S., Kaplan C., Galor A., Kumar N. The role of temperature change, ambient temperature, and relative humidity in allergic conjunctivitis in a US veteran population. Am J Ophthalmol. 2021;230:243–255. doi: 10.1016/j.ajo.2021.04.035. [DOI] [PubMed] [Google Scholar]
- 19.Song M.S., Lee Y., Paik H.J., et al. A comprehensive analysis of the influence of temperature and humidity on dry eye disease. Korean J Ophthalmol. 2023 Dec;37(6):501–509. doi: 10.3341/kjo.2023.0077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Landrigan P., Fuller R., Acosta N., et al. Comission on pollution and health. Lancet. 2018;3:391–10119. doi: 10.1016/S0140-6736(17)32345-0. [DOI] [PubMed] [Google Scholar]
- 21.Peng C.C., Cerretani C., Braun R.J., et al. Evaporation-driven instability of the precorneal tear film. Adv Colloid Interface Sci. 2014;206:250–264. doi: 10.1016/j.cis.2013.06.001. [DOI] [PubMed] [Google Scholar]
- 22.Kern C., Kortum K., Muller M., et al. Correlation between weather and incidence of selected ophthalmological diagnoses: a database analysis. Clin Ophthalmol. 2016;10:1587–1592. doi: 10.2147/OPTH.S107656. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Alves M., Asbell P., Dogru M., et al. TFOS lifestyle report: impact of environmental conditions on the ocular surface. Ocul Surf. 2023 Jul;29:1–52. doi: 10.1016/j.jtos.2023.04.007. [DOI] [PubMed] [Google Scholar]
- 24.Saxena R., Srivastava S., Trivedi D., et al. Impact of environmental pollution on the eye. Acta Ophthalmol Scand. 2003;81(5):491–494. doi: 10.1034/j.1600-0420.2003.00119.x. [DOI] [PubMed] [Google Scholar]
- 25.Hong J., Zhong T., Li H., et al. Ambient air pollution, weather changes and outpatient visits for allergic conjunctivitis: a retrospective registry study. Sci Rep. 2016;6(1) doi: 10.1038/srep23858. 6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Um S.B., Kim N.H., Lee H.K., Song J.S., Kim H.C. Spatial epidemiology of dry eye disease: findings from South Korea. Int J Health Geogr. 2014;13:31. doi: 10.1186/1476-072X-13-31. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Any additional data is available upon request to the authors.