Patient right profile
Mr. T.S is a 21-year-old male mechanic with no previous medical history or any known family history of keratoconus (He has two sisters, both of whom have no keratoconus). He complained of a progressive decrease in visual acuity greater in the right eye than the left. He has allergy to dust mites and cat’s fur.
His refraction at the first visit at the Rothschild Foundation (on 10/24th/2017) was : Right Eye (RE) 20/60 with -1.5 (-4.5 x 180 °) and Left Eye (LE) 20/40 with -5 (-2.75 x 105 °).
Clinical examination with the slit lamp suggested thin and irregular corneas with Fleischer rings in both eyes at the base of the cone (Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin).
Corneal topography performed at our institution showed the presence of bilateral keratoconus, more pronounced in the right eye.
At the first visit, when asked about the possibility of eye rubbing, the patient admitted to rubbing his eyes frequently during childhood, especially during spring. He would rub his eyes continuously for up to an hour because it gave him a sense of well being .
The patient is right handed and rubs his right eye with his right hand. He sleeps on his right side, with the head buried in the pillow (pillow hugging).
We explained to the patient that since vigorous rubbing had preceded the drop in visual acuity, this habit may have caused the cornea to deform, leading to the classic clinical presentation of keratoconus in his case.
We strongly advised this patient to stop rubbing his eyes and to change his unhealthy sleeping position. We then prescribed him an eye shield, lubricants and anti-histamine eye drops for both eyes. Fortunately, all these have curbed his desire to rub his eyes.
For visual rehabilation, he was fitted with scleral contact lenses
Here are pictures of the patient rubbing his eyes and his profiles
Here is a video of the patient rubbing his right eye vigorously with the knuckles.
This is a classic example of bilateral keratoconus induced by allergy-triggered eye rubbing. Eye rubbing preceded the onset of the corneal deformation by several years. Cessation of eye rubbing resulted in the stabilization of the deformation (no keratoconus progression).
It is important to explain to patients, especially teenagers with allergies and allergic tendencies, the importance of refraining from eye rubbing, to prevent them from continuing with the habit into adulthood, whereby permanent and severe damage to their corneas would have been inflicted.
Allergy has been described as a classic « risk factor » for keratoconus, but this association might be because allergic patients rub their itchy eyes more frequently and firmly than non-allergic patients. Indeed, children and adolescents who rub their eyes vigorously because of itch and inflammation caused by the phenomena of allergic conjunctivitis have found to have keratoconus. The forces exerted on the corneal dome by the fingers and particularly the bones of the knuckles during eye rubbing are sufficiently intense to cause a rupture of the junctions connecting the collagen fibers of the anterior corneal stroma, causing focal weakening and a cascade of changes culminating in the abnormalities seen in what we call « keratoconus ».
Most medical text books would attribute keratoconus to an unknown genetic factor. Genetics alone would not explain the unilateral occurrence of keraotconus in many cases, while eye rubbing does very well (unilateral rubbing causes unilateral keratoconus). Genetics however, may account for increased ocular sensitivity, atopy, and reduced corneal resistance to repeated trauma.
Other cases :
- Date 10 mars 2018
- Tags Allergy, Asymmetric, Bilateral keratoconus, Central keratoconus, Childhood rubbing, Enjoyed eye rubbing, Eye rubbing, Knuckles rubbing, Male, Palm rubbing, Pillow hugging, Sleep position