Mr. T.N, is a 24-year-old male student with no previous medical history or any known keratoconus in his family. He first came to us for a refractive surgery suitability assessment. The patient complained of a progressive decrease in visual acuity in the right eye. He also noted the perception of vertical ghosting with the right eye, which persists despite the wear of corrective spectacles for mild myopia (RE :-2.75 D, LE : -3.00D).
His refraction at the first visit (12/10th/2015) was: Right Eye (RE) 20/20 with -1.75 (-1 x 90 °) and Left Eye (LE) 20/20 with -3.25 (-0.25 x 125 °).
Clinical examination with the slit lamp revealed Vogt’s striae (fine whitish lines in the posterior stroma) and Fleischer ring (Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin), in the right eye.
Systematic corneal topography, performed for every refractive surgery candidate, revealed unilateral keratoconus in the right eye. The left eye topography showed only mild irregularity on the curvature map.
The patient is right-handed and sleeps on his right side with head in the pillow (« pillow hugging »).
When asked about possible rubbing habits, the patient denied eye rubbing at the first visit. His mother, however, who was with him during the consultation, claimed that she witnessed her son rubbing his eyes very often, for many years. We informed the patient that he must pay attention to the possibility of unconscious rubbing at waking up, during the day while working on the computer, at night, etc.
At the second visit, the patient confessed to becoming more aware of rubbing his eyes several times a day, especially in the mornings with his right hand, using predominantly the index pulp and knuckles. He felt an irritation on the right eye on awaking. The RE refraction was 20/20 with -2.75 (-1.00 x 100°), and the vertical ghosting persisted.
The patient’s mother took a photo of her son sleeping to demonstrate his sleeping posture, and this was presented to us.
We explained to the patient that since vigorous rubbing had preceded the drop in visual acuity and quality on the right eye, this habit may have caused the cornea to deform in his case. We strongly advised this patient to stop rubbing his eyes and to change his unhealthy sleeping position and try to sleep on the back without any ocular or orbit nocturnal compression.
Here are pictures of the patient rubbing his eyes and his sleeping posture
PATIENT RUBBING HIS RIGHT EYE : Note the use of the knuckles to rub.
PATIENT SLEEP POSITION : Note the head buried deeply in the pillow (pillow hugging) and the direct contact of the pillow with the right eye (compression + heating responsible for local inflammation and irritation).
Here is a video of the patient rubbing his right eye
Here is another video of the patient showing how he used to rub his right eye (last visit)
Difference maps were performed at each subsequent visit. No evolution was observed between the first and last visits. The keratoconus is stable, more than 3 years after the patient definitively stopped rubbing his eyes .
At the first visit, the patient denied any excessive eye rubbing. After he received proper information, the patient acknowledged that he had come to realize his eye rubbing habit, and the preferential rubbing of the right eye. He informed us that the rubbing was so intense that it generated a « little noise », and admitted that kicking the habit was difficult to do. This stresses the importance of delivering exhaustive information to the patient and help him to realize unconscious rubbing episodes. As this cases and other demonstrate, the cessation of eye rubbing is the key factor for keratoconus stabilization.
It is interesting to note the concordance between unilateral rubbing of the right eye and the unilateral (right) location of the keratoconus. The patient has also been sleeping on his right side since childhood. Unilateral chronic eye irritation related to the extended compression of the right eye on the pillow induces the patient to rub his right eye during the day. At night, the right eye is exposed to local heating and contamination by irritants (allergens from laundry products, dust mites, etc.). Local heating could up regulate the activity of collagenases and related enzymes. These combined factors have facilitated the effect of repeated frictions, which eventually cause the deformation (severing of the stromal collagen lamellae) and thinning (by redistribution of the ground substance of the cornea) typically seen in keratoconus.
The deformation of the corneal dome explains the apparition of the visual disturbances (vertical ghosting of the right eye).
While he denied eye rubbing at the first visit, his mother, fortunately accompanying him, could alert him to the habit which he was not aware of. Many patients, like Mr S.M, are not conscious of their eye rubbing, or aware of its deleterious effects, and believe it to be a banal and harmless maneuver. It is important therefore, in all patients with keratoconus, to elucidate the history of eye rubbing, and then counsel the patients accordingly to change their habits.
As this case and others strongly suggest, « unilateral » keratoconus does exist: it occurs in patients who rub excessively one eye only. This is however seldom, as allergies and other factors favoring eye rubbing usually affect both eyes. In this case, the sleep position on the right side, resulting in chronic compression and heating of the cornea, along with the irritation of the eyelids and conjunctiva on the same side (promoting itch and subsequent rubbing) have synergistically contributed to the apparition of the permanent corneal thinning and warpage, which are the hallmarks of keratoconus.
In this case, like the many other cases in this website, the keratoconus ceased to evolve after the patient definitively stopped rubbing his right eye. The absence of excessive rubbing on the left eye prevented keratoconus to occur. This and other observations gathered on this website strongly suggest that keratoconus progression can be stopped and that its incidence can be suppressed, all by very simple recommendations and hygiene.