BACKGROUND: To investigate the association between atopic dermatitis (AD) and keratoconus (KC) in atopic dermatitis patients with no prior ophthalmologic diagnosis.

METHODS: Thirty eyes of 30 patients with moderate to severe AD were included in this pilot study and compared to healthy controls (n=20) and patients with forme fruste KC (n=28). In the AD group, diagnosis of KC was based on clinical signs and corneal topography criteria such as inferior steepening (inferior-superior difference>1.45 D) and elevated maximum keratometry values (>47 D). Subclinical KC was defined by the presence of specific sensitive indices from corneal topography, tomography, or biomechanical assessments. Risk factors analyzed for ectasia development were the onset and severity of AD, sensitization to aeroallergens, systemic therapy, concomitant atopic diseases, eyelid eczema, and total IgE.

RESULTS: We identified two manifest KC (6.7%), and six subclinical KC (20%) cases in patients with AD but with no previous diagnosis of KC. No overall differences were found in corneal tomography and biomechanics indices between control and AD patients. However, eye rubbing was not identified as a risk factor for developing ectasia in the AD group.

CONCLUSION: Dermatologists should be aware that patients with moderate or severe AD may have a higher risk for developing corneal ectasia, particularly when eyelid eczema is present. The estimated prevalence of KC in patients with AD appears to be higher than that in the general population but more studies are needed.