Classification of ocular atopic/allergic disorders and conditions: An unsolved problem

Purpose: To review the different classifications of ocular allergic diseases and to define the most suitable one according to the current understanding of the pathophysiology and clinical course of these disorders. Methods: Review of the major published ocular allergy classifications. Results: Based on past and present classifications, the author proposes the following classification: 1. allergic conjunctivitis (acute and chronic); 2. giant papillary conjunctivitis; 3, vernal keratoconjunctivitis; and 4, atopic keratoconjunctivitis, In addition, use of the term "allergic conjunctivitis" as a synonym for all ocular allergic disease is discouraged. Conclusion: The proposed classification for ocular allergic disorders intends to unify the present criteria and to serve as an initial forum of discussion. This should enhance a common understanding among and between ophthalmologists and other allergy specialists. Constructive criticism of this classification system is required for further improvement.