Ocular surface - a complex and vulnerable adoptive environment for topical glaucoma treatment.

Ocular surface is a complex functional unit in which tissues so different as structure and function harmonize to produce a very short life (15-45 sec) film - tear film essential for the quality of the vision. With age, the ocular surface undergoes a physiological decline, often with a limitation of its functionality. Administration of topical glaucoma treatment itself constitutes a solicitation of the ocular surface and the nature of "accessories" included in this "drop glaucoma treatment", that might be the last straw which breaks the fragile balance or aggravates a previously nonexistent suffering subclinical symptomatology by opening and inducing reactions to treatment. Topical treatment in glaucoma could have the complex aspect of an adoption. Every adoption is a delicate and unpredictable phenomenon. Success does mean harmony and coexistence. For the adoption to succeed, one needs to know well the adoptive environment, the adopted element and the science and art to harmonize them together.