Ms. N.N is a 25-year-old woman with no previous medical history, or any known family history of keratoconus. She first consulted us for a refractive surgery suitability evaluation . Her myopia has been stable for many years.
Her Refraction was : RE 20/20 -5,50 (-0,5 x 10 °) and LE 20/20 -4,75 (-0.75 x 150 °).
Clinical examination with the slit lamp revealed dry eye (break up time < 4 seconds) with bilateral inferior superficial punctate keratopathy . The rest of the examination is normal.
Systematic corneal topography revealed bilateral inferior corneal steepening consistent with forme frustre keratoconus.
When first questioned about eye rubbing, the patient initially denied such a habit. Upon further interrogation, she told us that she rubbed the lower part of her eyes through the lower eyelids with horizontal movements many times a day, very much in a tic-like fashion. She used the pulp of her index fingers to do the rubbing. To her, this was not « eye rubbing ». She is right-handed and has no particular favorite sleeping position. There are no known allergies.
We advised her to stop this eye rubbing habit and treated her dry eye with lubricants
This case strongly demonstrated that a focal (localized) deformation of the cornea can be induced by localized rubbing.
This patient does not have keratoconus, but has instead forme frustre keratoconus (FFKC). Nevertheless if she continues to rub her eyes, there is a risk of her condition evolving into a frank keratoconus. It is crucial therefore, for such patient to stop rubbing their eyes.
She presents a with a dry eye syndrome, with superficial punctate keratopathy inferiorly, which results in itch and discomfort, especially in the inferior part of the eyes. This triggers the need to rub. Rubbing provides symptomatic relief, but when repeated many times a day, causes a localized deformation on the lower part of the cornea. (The inspection of the topography raw images revealed a real steepening and not an artifact). Rubbing was performed with the pulp of the fingers, and this generally exerts a moderate pressure, resulting in only a mild deformation.
This same rubbing mechanism may be responsible for ectasia after refractive surgery, when the cornea is thinned, and dry eye more pronounced. It is mandatory to detect this possible habit in preoperative consultations for refractive surgery. If the patient stops rubbing her eyes, and there is no topographic change over one year after discontinuation of the ocular friction, refractive surgery may be considered in her case.
We advised her to consult an ophthalmologist every 2 years and of course to definitively rubbing her eyes