Atopic Keratoconus Cases Appear to Have Thicker Choroids

Patients with atopic keratoconus (KC) have thicker choroids than those with nonatopic KC, which might suggest that atopy plays a role in the choroidal profile of KC, according to a study published in Clinical Ophthalmology.

“This constitutes a completely new sight in this field of research that needs further investigation,” according to the study.

The analytical cross-sectional study looked at how, even though KC has been typically classified as a noninflammatory condition, evidence for an inflammatory basis is growing. Recent research has shown that KC has increased choroidal thickness (CT). 

“Among inflammatory disorders, atopy has been associated with KC development; therefore, the aim of this study was to evaluate if the increased CT in patients with KC is related to atopy,” researchers explain.

The study included 80 patients, of which 51 were atopic and 29 were nonatopic. Patients were classified as atopic or nonatopic by their atopy history (allergic rhinoconjunctivitis (AR), asthma (AA) or atopic dermatitis (AD)) and their eye rubbing habits. Choroidal profiles were evaluated using optical coherence tomography (OCT) with enhanced depth imaging (EDI) mode, and the CT was measured and compared between groups at the center of the fovea and at 500 μm intervals along a horizontal section. Researchers conducted a multivariable analysis to assess atopy’s influence in CT, adjusted for sex, age, spherical equivalent, history of medication and atopy. 

While the differences were not statistically different, researchers did find that atopic patients had a thicker choroid in every measured location than the nonatopic patients (mean subfoveal CT 391.53 μm vs 351.17 μm, respectively). 

“The multivariable analysis revealed that being atopic makes the choroid statistically thicker, on average,” the report says. It found the atopic patients had an average choroidal thickness 55.14 μm thicker than nonatopic patients (P =.043). Furthermore, patients who are frequent eye rubbers had significantly thicker choroids than those who are not eye rubbers (P =.004), the report says.

The study had limitations, including its cross-sectional design, which might impact the “determination of a causal relationship between atopy, altered choroid profile, and KC development.” The study’s low participation, and the fact that they were all from the same medical tertiary center, was also a limitation.

Reference

Moleiro AF, Aires AF, Alves H, et al. The role of atopy in the choroidal profile of keratoconus patients. Clin Ophthalmol. 2021;15(4):1799-1807. doi:10.2147/OPTH.S301330.