Late-Phase Reaction in Ocular Allergy
Late-Phase Reaction in Ocular Allergy
Purpose of Review: To determine if the late-phase reaction, which commonly occurs in allergic rhinitis and asthma, is also found in ocular allergy.
Recent Findings: Using PubMed, 542 articles were found; 18 articles in the allergy and ophthalmology literature were specifically related to late-phase reaction. Ocular late-phase reaction is clinically seen in 50-100% of allergic rhinoconjunctivitis patients, is associated with progression to systemic atopic disorders that is allergic rhinoconjunctivitis and occurs in several forms including biphasic, multiphasic and a prolonged response.
Summary: The existing literature demonstrates that an ocular late-phase reaction also exists and has implications in the development severity of disease, change of reactivity and progression of the atopic disease state from a localized target organ, such as the nose or eye, to a more systemic atopic disorder. The existence of the clinically relevant allergic late-phase response is not only limited to the nose, skin and lungs but also includes the eyes. The appreciation that the late-phase response may be clinically very important as there is a continuum of ocular mast-cell activation during the waking hours of the day, a better understanding of its clinical impact may be a more appropriate focus in the development of future treatments.
Although late-phase reaction (LPR) is frequently seen in allergic nasal, respiratory and skin disease, the clinical impact of LPR in ocular allergy has been questioned. Allergic responses in tissues may vary, partially because of the heterogeneity of mast cells from different tissues. Among the different tissues, the eye's anterior surface is easily observed with highly magnifying instrumentation (i.e. slit-lamp microscope or other digital equipment). In addition, mediator release and cellular infiltration can be measured in the immunological fluid that bathes the eye's surface (i.e. tears) and through direct examination of the biopsied conjunctiva, which is easily accessible.
While using the conjunctival provocation test (CPT), which was initially employed to study the early-phase response (EPR), researchers discovered that the conjunctiva also exhibited a dose-dependent LPR. As LPR is garnering more attention due to its influence on morbidity and its association with the development of more chronic and systemic forms of atopic disorders, it is becoming important to research the role of LPR in ocular allergy. The CPT is an excellent tool that mimics ocular allergic responses, allowing for the measurement of symptoms, inflammatory mediators, cells and pharmacologic modulation with the use of the contralateral eye for control purposes. The CPT is extremely allergen specific and sensitive and has proven to be safe and effective in confirming a diagnosis of allergy, even in cases in which the patient's history and skin testing were doubtful as demonstrated in cases of serologic negativity [negative radioallergosorbent test (RAST)], but with the presence of a positive ocular provocation (positive CPT).
Abstract and Introduction
Abstract
Purpose of Review: To determine if the late-phase reaction, which commonly occurs in allergic rhinitis and asthma, is also found in ocular allergy.
Recent Findings: Using PubMed, 542 articles were found; 18 articles in the allergy and ophthalmology literature were specifically related to late-phase reaction. Ocular late-phase reaction is clinically seen in 50-100% of allergic rhinoconjunctivitis patients, is associated with progression to systemic atopic disorders that is allergic rhinoconjunctivitis and occurs in several forms including biphasic, multiphasic and a prolonged response.
Summary: The existing literature demonstrates that an ocular late-phase reaction also exists and has implications in the development severity of disease, change of reactivity and progression of the atopic disease state from a localized target organ, such as the nose or eye, to a more systemic atopic disorder. The existence of the clinically relevant allergic late-phase response is not only limited to the nose, skin and lungs but also includes the eyes. The appreciation that the late-phase response may be clinically very important as there is a continuum of ocular mast-cell activation during the waking hours of the day, a better understanding of its clinical impact may be a more appropriate focus in the development of future treatments.
Introduction
Although late-phase reaction (LPR) is frequently seen in allergic nasal, respiratory and skin disease, the clinical impact of LPR in ocular allergy has been questioned. Allergic responses in tissues may vary, partially because of the heterogeneity of mast cells from different tissues. Among the different tissues, the eye's anterior surface is easily observed with highly magnifying instrumentation (i.e. slit-lamp microscope or other digital equipment). In addition, mediator release and cellular infiltration can be measured in the immunological fluid that bathes the eye's surface (i.e. tears) and through direct examination of the biopsied conjunctiva, which is easily accessible.
While using the conjunctival provocation test (CPT), which was initially employed to study the early-phase response (EPR), researchers discovered that the conjunctiva also exhibited a dose-dependent LPR. As LPR is garnering more attention due to its influence on morbidity and its association with the development of more chronic and systemic forms of atopic disorders, it is becoming important to research the role of LPR in ocular allergy. The CPT is an excellent tool that mimics ocular allergic responses, allowing for the measurement of symptoms, inflammatory mediators, cells and pharmacologic modulation with the use of the contralateral eye for control purposes. The CPT is extremely allergen specific and sensitive and has proven to be safe and effective in confirming a diagnosis of allergy, even in cases in which the patient's history and skin testing were doubtful as demonstrated in cases of serologic negativity [negative radioallergosorbent test (RAST)], but with the presence of a positive ocular provocation (positive CPT).