Mr. B.K is a 48-year-old male policeman with no previous history of atopy or keratoconus in the family. He complained of a progressive decrease in visual acuity in the left eye for the past year.
His Refraction was : RE 20/20 +0,5 (-0,75 x 105 °) and LE 20/25 -1,50 (-2,25 x 40 °).
When asked about eye rubbing, he admitted rubbing his eyes regularly at work, especially the left eye with his knuckles.
Clinical examination with the slit lamp revealed an irregular corneal bulge in the left eye with a Fleischer ring. The right eye examination was essentially normal .
We advised him to stop eye rubbing.
Unfortunately we do not have pictures of this patient.
This case, like many others on this site, reveals that the asymmetric or unilateral character of keratoconus is mainly related to the way the patient rubs his eyes. By preferentially rubbing one eye, the patient selectively induces keratoconus on the same side. The dominant hand is usually stronger, rubs harder, and as it is used more often (« dominant » hand), is more likely to harbour germs and irritants, and thus transfer more allergens to the ocular surface. This alone can explain in part, the asymmetric affliction of keratoconus in many patients.
It is essential to seek a history of eye rubbing in all patients with keratoconus, especially in unilateral or asymmetric cases.