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http://www.ncbi.nlm.nih.gov/pubmed/23378734
Clin Ophthalmol. 2013;7:157-65. doi: 10.2147/OPTH.S38732. Epub 2013 Jan 20.
Exacerbation of signs and symptoms of allergic conjunctivitis by a controlled adverse environment challenge in subjects with a history of dry eye and ocular allergy.
Gomes PJ, Ousler GW, Welch DL, Smith LM, Coderre J, Abelson MB.
Source
Ora Inc, Andover, MA.
Abstract
BACKGROUND:
The goal of this study was to assess the effect of a controlled adverse environment (CAE) challenge on subjects with both allergic conjunctivitis and dry eye.
METHODS:
Thirty-three subjects were screened and 17 completed this institutional review board-approved study. Subjects underwent baseline ocular assessments and conjunctival allergen challenge (CAC) on days 0 and 3. Those who met the ocular redness and itching criteria were randomized to receive either the controlled adverse environment (CAE) challenge (group A, n = 9) or no challenge (group B, n = 8) at day 6. Thirty minutes after CAE/no-CAE, subjects were challenged with allergen and their signs and symptoms graded. Exploratory confocal microscopy was carried out in a subset of subjects at hourly intervals for 5 hours post-CAC on days 3 and 6.
RESULTS:
Seven minutes post-CAC, subjects exposed to the CAE had significantly greater itching (difference between groups, 0.55 ± 0.25, P = 0.028), conjunctival redness (0.59 ± 0.19, P = 0.002), episcleral redness (0.56 ± 0.19, P = 0.003) and mean overall redness (mean of conjunctival, episcleral, and ciliary redness, 0.59 ± 0.14, P < 0.001). The mean score at 7, 15, and 20 minutes post-CAC for conjunctival redness (0.43 ± 0.17, P = 0.012), episcleral redness (0.49 ± 0.15, P = 0.001), mean overall redness in all regions (0.43 ± 0.15, P = 0.005), and mean chemosis (0.20 ± 0.08, P = 0.017) were also all significantly greater in CAE-treated subjects. Confocal microscopic images of conjunctival vessels after CAC showed more inflammation in CAE-treated subjects.
CONCLUSION:
In subjects with both dry eye and allergic conjunctivitis, exposure to adverse environmental conditions causes anocular surface perturbation that can intensify allergic reactions.
PMID: 23378734
[PubMed]
PMCID: PMC3553653
Free full text http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553653/
From the full article:
Clin Ophthalmol. 2013;7:157-65. doi: 10.2147/OPTH.S38732. Epub 2013 Jan 20.
Exacerbation of signs and symptoms of allergic conjunctivitis by a controlled adverse environment challenge in subjects with a history of dry eye and ocular allergy.
Gomes PJ, Ousler GW, Welch DL, Smith LM, Coderre J, Abelson MB.
Source
Ora Inc, Andover, MA.
Abstract
BACKGROUND:
The goal of this study was to assess the effect of a controlled adverse environment (CAE) challenge on subjects with both allergic conjunctivitis and dry eye.
METHODS:
Thirty-three subjects were screened and 17 completed this institutional review board-approved study. Subjects underwent baseline ocular assessments and conjunctival allergen challenge (CAC) on days 0 and 3. Those who met the ocular redness and itching criteria were randomized to receive either the controlled adverse environment (CAE) challenge (group A, n = 9) or no challenge (group B, n = 8) at day 6. Thirty minutes after CAE/no-CAE, subjects were challenged with allergen and their signs and symptoms graded. Exploratory confocal microscopy was carried out in a subset of subjects at hourly intervals for 5 hours post-CAC on days 3 and 6.
RESULTS:
Seven minutes post-CAC, subjects exposed to the CAE had significantly greater itching (difference between groups, 0.55 ± 0.25, P = 0.028), conjunctival redness (0.59 ± 0.19, P = 0.002), episcleral redness (0.56 ± 0.19, P = 0.003) and mean overall redness (mean of conjunctival, episcleral, and ciliary redness, 0.59 ± 0.14, P < 0.001). The mean score at 7, 15, and 20 minutes post-CAC for conjunctival redness (0.43 ± 0.17, P = 0.012), episcleral redness (0.49 ± 0.15, P = 0.001), mean overall redness in all regions (0.43 ± 0.15, P = 0.005), and mean chemosis (0.20 ± 0.08, P = 0.017) were also all significantly greater in CAE-treated subjects. Confocal microscopic images of conjunctival vessels after CAC showed more inflammation in CAE-treated subjects.
CONCLUSION:
In subjects with both dry eye and allergic conjunctivitis, exposure to adverse environmental conditions causes anocular surface perturbation that can intensify allergic reactions.
PMID: 23378734
[PubMed]
PMCID: PMC3553653
Free full text http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553653/
From the full article:
The results of this study demonstrate that in subjects with a history of both dry eye and ocular allergy, a break in the ocular surface has a direct effect on clinical reactions to allergens. When the corneal epithelium was compromised by a CAE challenge, subjects reacted not only with more severe itching, conjunctival and episcleral redness, and chemosis, but also with a more rapid response, showing peak redness and swelling at 7 minutes following CAC instead of the usual peak at 20 minutes. This rapid dilation might reflect a more vulnerable conjunctival blood vessel, a pathological state brought on by the coexistence of allergy and dry eye, and the many inter-related and cumulative events at the origin of both diseases.
In conclusion, in patients with both ocular allergy and dry eye, exposure to an adverse ocular environment prior to allergen challenge exacerbated the clinical response of itching, redness, and chemosis. This finding might have relevance to both the treatment and diagnosis of patients with these two diseases. It is not known if the exacerbation was due to a breakdown in the tear film barrier leading to higher allergen load of mast cells. Future studies are planned to identify the comorbidity of allergic conjunctivitis and dry eye in our study populations, to delineate further the conjunctival vessel changes after CAC through confocal microscopy, to identify if an adverse environment challenge would exacerbate ocular allergic signs and symptoms in normal subjects without dry eye, and to modulate endpoints of this dual challenge model with potential treatments for ocular allergy and/or dry eye.