Case #60

Case #60

The patient

Patient right profile

Bilateral Asymmetric Keratoconus induced by eye rubbing

Identity : Ms C.T
First visit : 03/22/2016
Last Visit : 10/31/2017

Age (years)
Follow-up (months)

Ms. C.T  is a 27-year-old female with no known family history of keratoconus. She complained of a progressive decrease in visual acuity greater in the left eye than the right over the past 2 years. She has a history of allergies from the age of 18, with the development of asthma at age 20.

Keratoconus was diagnosed in another institution in 2015, where she was offered a rigid gas permeable contact lens correction for the right eye and a corneal collagen cross-linking for the left eye. 

Her refraction at the first visit at the Rothschild Foundation (on 03/22th/2016) was : Right Eye (RE) 20/25 with -1 (-1 x 170 °) and Left Eye (LE) 20/32 with -1.5 (-1.75 x 165 °).

Clinical examination with the slit lamp suggested thin and irregular corneas with Fleischer rings. (Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin). Dry eye was noted with pathological tear break up time of < 8 secs.

Corneal topography performed at our institution showed the presence of bilateral keratoconus, more pronounced in the left eye.

At the first visit, when asked about the possibility of frequent eye rubbing, the patient admitted to enjoying rubbing her eyes when she awoke in the mornings or when working in front of the computer. She complained of dry eye symptoms especially at night. While in front of the computer screen, she would use her left hand to rub her left eye, as the right hand would be on the computer mouse and thus unavailable for rubbing.  

She sleeps on her stomach or with the head on her left arm.

At the subsequent visits, she verbalized remembering that her vision started deteriorating 3 years prior, coincident with the time when she began to prepare for her doctorate and thus had to work for long hours at the computer.

We explained to the patient that since vigorous eye 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 her case.

We strongly advised this patient to stop rubbing her eyes and to change her unhealthy sleeping position.

Here are pictures of the patient rubbing her eyes and her profiles

eye rubbing with the knucklesPATIENT RUBBING HER EYES WITH HER KNUCKLES. This habit is particularly detrimental to the corneas.
patient showing how she is sleeping, with the head pressed on the left armPATIENT DEMONSTRATING HER SLEEPING POSITION (HEAD ON LEFT ARM)

Patient rubbing her eyes

Here are the Orbscan quadmaps, Pentacam maps, OPD scans and Ocular Response Analyzer (ORA) results of the first visit.

orbscan map of an early keratoconusRIGHT EYE ORBSCAN (1st VISIT). As for the left eye, the cornea is thin and irregular, with high levels of astigmatism (toricity). the inferior steepening is obvious on the axial curvature map (bottom left). The corneal is thinned centrally (topography map, bottom left).
orbscan map of a patient with keratoconus (left eye)LEFT EYE ORBSCAN (1st VISIT). The cornea is thin, with increased toricity (astigmatism), vertical asymmetry and prolateness. This corresponds to a mild form of keratoconus.
Pentacam topography map, right eye, keratoconusRIGHT EYE PENTACAM (1st VISIT). The corneal topography features presented here mirror that of the Orbscan.
Pentacam map of an advanced form of keratoconusLEFT EYE PENTACAM (1st VISIT). The changes here mirror that of the Orbscan. There is marked vertical asymmetry and central thinning. Many indices are abnormal.
OPD scan III map corneal topgoraphy and aberrometry keratoconusRIGHT EYE OPD. The cornea is irregular and this translates into increased levels of coma and trefoil like aberrations. This aberration cannot be corrected by spectacles and explains some of the loss of visual quality. The corneal navigator neural network raises the possibility of keratoconus (KCS: Keratoconus Suspect).
OPDscan III map of an eye with keratoconusLEFT EYE OPD. The increase in negative spherical aberration is the consequence of the hyperprolate asphericity (corneal deformation with central steepening and peripheral flattening). The coma-like aberrations are induced by the corneal vertical asymmetry in curvature.
Ocular Response Analyzer, ORA map, corneal biomechanics, keratoconusRIGHT EYE Ocular Response Analyzer map (ORA). The height of the peaks is reduced, as in corneas which have been made softer ("tenderized") by repeated eye rubbing.
Ocular Response Analyzer map (ORA)LEFT EYE ORA. As for the right eye, the height of the peaks is slightly reduced.

Difference maps were performed at each subsequent visit. No evolution was observed between the first and last visits. The keratoconus is stable, more than 19 months after the patient definitively stopped rubbing her eyes .

RIGHT EYE ORBSCAN (2nd VISIT). Stable since first visit
LEFT EYE ORBSCAN (2nd VISIT). Stable since first visit
RIGHT EYE PENTACAM (2nd VISIT). Stable since first visit
LEFT EYE PENTACAM (2nd VISIT). Stable since first visit
PENTACAM DIFFERENTIAL MAPS : RIGHT EYE. (between first and second visits). This difference map demonstrates the absence of keratoconus progression, coincident with the time the patient stopped rubbing her eyes).
PENTACAM DIFFERENTIAL MAPS : LEFT EYE. (between first and second visits). This difference map demonstrates the absence of keratoconus progression, coincident with the time the patient stopped rubbing her eyes.

In this case we find many triggers for eye rubbing like extended hours of computer use and an unhealthy sleeping position.  The asymmetric nature of keratoconus development may be related to the sleeping position (left sided) and the habit of preferentially rubbing the left eye. .

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.

This case is very informative and demonstrative of the causal effects of eye rubbing in the pathogenesis of keratoconus. Cross-linking is unnecessary in this case, as stabilisation of the corneal deformation was achieved with the simple act of cessation of eye rubbing.

As demonstrated again in this clinical example, the cessation of eye rubbing and patient education are the best tools in the prevention of the genesis and/or evolution of keratoconus.

  • Date 7 décembre 2017
  • Tags Allergy, Asymmetric, Bilateral keratoconus, Computer screen, Dry eyes, Enjoyed eye rubbing, Eye rubbing, Female, Inferior keratoconus, Knuckles rubbing, Night shift, Rigid lens, Sleep position, Work rubbing