Sir,

I have read with interest the article ‘Relationship between refraction and allergic conjunctivitis’ by Mimura et al1. There are some inconsistencies that need to be addressed.

The authors take the right eye for analysis, ignoring the left eye without any test of correlation between them to validate the use of just one eye as the subject.

In the definition of ‘seasonal allergic conjunctivitis’ (SAC), the authors enumerate the symptoms and cite conjunctival follicle as associated with SAC, which is not true. Papillae are the main biomicroscopic, histological, and anatomical finding associated with SAC.

  • Reference 3 is incorrect. The correct version is Ocul Immunol Inflamm 1994; 2(Suppl 1): S17–S34.

  • In the Results section, Table 1 displays demographic data (number of patients, gender, and age). For methodological reasons, these data pertain to the Materials and methods section, because they are not result of any analysis, only the source/material.

  • The conclusion that the configuration of the corneal surface leads to allergic conjunctivitis is inaccurately interpreted by the authors. What the literature shows is that with the allergic process (commonly in vernal keratoconjunctivitis), a complex process involving biochemical (enzymes and enzymatic inhibitors) and cellular (apoptosis) disturbances, which leads to stromal thinning, increase in the corneal curvature and consequently myopic astigmatism.2, 3, 4 Moreover, in susceptible individuals, long-term allergic disease with a chronic traumatic factor on the corneal epithelium could be related to keratoconus, because, as Kim et al5 pointed out that persistent and chronic corneal trauma on the corneal epithelium (in this particular situation, itching or chronic trauma provoked by giant papillae), induces a ‘silent’ and chronic inflammatory process, leading to progressive loss of stromal mass and consequently to less biomechanical resistance, and thus to anterior corneal steepening, decreasing the optical competence of the anterior corneal surface.

Scientific data support the affirmation that chronic allergic conjunctivitis may be a risk factor for myopic refractive error. In contrast, no consistent data have shown the opposite.