The patient
Patient right profile
Unilateral Keratoconus induced by eye rubbing with forme fruste keratoconus in the contralateral eye
Identity : Ms T.E
First visit : 02/21/2017
Last Visit : 03/13/2018
Ms. T.E is a 22-year-old female medical student with no previous medical history, or any known history of keratoconus in her family of 6 siblings. She has no known allergies.
She complained of a progressive decrease in visual acuity in the right eye over a year.
Her refraction was : RE 20/40 with -1 (-5 x 15 °) and LE 20/20 with -3.50 (-0.5 x 10 °).
Clinical examination with the slit lamp revealed a discrete Fleischer ring and a thin slightly bulging cornea in the right eye. Examination of the left eye was unremarkable.
Corneal topography revealed unilateral keratoconus in the right eye. The left eye showed fruste forme keratoconus.
When asked about a possible eye rubbing habit, the patient was initially hesitant. However, her father, who was present during the consultation informed us that she often rubbed her eyes, especially the right one! She eventually admitted to rubbing her right eye at work and after taking a shower.
This patient is right-handed and she prefers sleeping on the right side.
We explained that unilateral (or predominant) right eye rubbing had caused the cornea to be warped and deformed, and that it was crucial for her to stop rubbing that eye. The fact that she was almost constantly sleeping on the right side may have caused chronic local irritation, itch and may explain the preferential rubbing on that side. We advised her to change her sleeping position, and to pay attention to possible right eye rubbing episodes in the mornings and after showering.
We fitted her with rigid gas permeable contact lenses and she wears swimming goggles in the shower to avoid contact irritation with water and therefore the need to rub her eyes.
The patient demonstrates how she rubs her right eye. The repeated contact of the hard part of the fingers (knuckles) has probably caused permanent warpage of the right cornea. The left eye, spared by this rubbing habit, is not warped.
Here, the patient shows us how she positions her head when she sleeps. She acknowledges that her right orbit is compressed on the hand or pillow.
Here, the patient's father demonstrates how his daughter rubs the right eye.Here are the Orbscan quadmaps, Pentacams maps, OPDScan results and the Ocular Response Analyzer (ORA) results at the first visit
ORBSCAN Right Eye. The cornea is thinned and the deformation is obvious on the axial curvature map (bottom left) with an "asymmetric bow-tie" and "SRAX - Skewed Radial Axes" patterns. 
ORBSCAN Left Eye. The cornea is thin, but no deformation evocative of keratoconus is perceptible. This indicates a possible frustre forme keratoconus.
PENTACAM RIGHT EYE (1st VISIT)
PENTACAM LEFT EYE (1st VISIT)
OPD RIGHT EYE (1st VISIT)
OPD LEFT EYE (1st VISIT)
ORA RIGHT EYE : The biomechanical evaluation with the Ocular Repsonse Analyzer of the right eye reveals low applanation peaks and reduced hysteresis.
ORA LEFT EYE : The left eye biomechanical evaluation shows slightly higher peaks, and a reduced hysteresis value (due to the corneal thinning in this eye).
RIGHT EYE OCT EPITHELIAL MAP
LEFT EYE OCT EPITHELIAL MAPDifference maps were performed at each subsequent visit. No evolution has been observed between the first and last visits. The keratoconus is stable for over 7 months.
RIGHT EYE ORBSCAN (2nd VISIT)
PENTACAM DIFFERENTIAL MAPS : RIGHT EYE (between 1st and 2nd visits). There is no keratoconus progression.
RIGHT EYE ORBSCAN (3rd VISIT)
PENTACAM DIFFERENTIAL MAPS : RIGHT EYE (between 1st and 3rd visits). There is no keratoconus progression.
LEFT EYE ORBSCAN (2nd VISIT)
PENTACAM DIFFERENTIAL MAPS : LEFT EYE (between 1st and 2nd visits. There is no keratoconus progression.
LEFT EYE ORBSCAN (3rd VISIT)
PENTACAM DIFFERENTIAL MAPS : LEFT EYE (between 1st and 3rd visits). There is no keratoconus progression.
RIGHT EYE ORBSCAN (4th VISIT)
RIGHT EYE PENTACAM (4th VISIT)
RIGHT EYE PENTACAM (4th VISIT)
LEFT EYE PENTACAM (4th VISIT)
PENTACAM DIFFERENTIAL MAPS : RIGHT EYE
PENTACAM DIFFERENTIAL MAPS : LEFT EYEThis case represents another striking example of a unilateral keratoconus associated with unilateral eye rubbing with forme fruste keratoconus in the contralateral eye. This reinforces the hypothesis that eye rubbing, which precedes the onset of keratoconus, is the root cause of it.
This predominant rubbing of the right eye is probably linked to the sleeping habit (preferential sleeping on the right side, causing contact irritation of the right eye with allergens from the pillow and bed linen).
It should be noted that the ORA charts are almost identical in both eyes despite the unilateral keratoconus, which imply that both corneas have similar biomechanics. This suggests that, despite a similar corneal fragility, the asymmetry is mainly explained by her habits of ocular friction and sleeping side.
