Case #79

Case #79

The patient

Patient right profile

Unilateral Asymmetric Post-LASIK Corneal Ectasia induced by eye rubbing

Identity : Ms C.D
First visit : 03/16/2017
Last Visit : 03/09/2018

37
Age (years)
12
Follow-up (months)
EYE RUBBING : WHEN AND WHY ?

Ms C.D is a 37-year-old female with no previous medical history or any known family history of keratoconus. She had bilateral LASIK performed in December 2006 at another institution. Pre-operatively, she had myopia of about -4.5 D in both eyes. There were no known surgical complications during the procedure.

She complained of a progressive decrease in visual acuity one year after the surgery (2007), greater in the right eye than the left one.

Her refraction at the first visit at the Rothschild Foundation (on 03/16th/2017) was : Right Eye (RE) 20/20 with -1.50 (-0.5 x 155 °) and Left Eye (LE) 20/20 with -0.75 (-0.5 x 155 °).

Clinical examination with the slit lamp suggested a right thin and irregular cornea. Both eyes were dry with tear film BUT (Break Up Time) < 8 secs. 

Corneal topography performed at our institution showed the presence of a unilateral corneal ectasia in the right eye.

The retrospective analysis of the examinations performed before the LASIK revealed no topographic abnormalities in both eyes.

We investigated the risk factors for ectasia at her first visit. When asked about the possibility of frequent eye rubbing, the patient admitted to rubbing her eyes before and after LASIK. After the surgery in particular, she would rub her eyes vigorously at night after eye makeup removal because she enjoyed it. As she was right-handed, she would rub her right eye especially and more vigorously than the left eye.

With regards to her sleeping position, she sleeps on her right side, with the head buried in the pillow (pillow hugging). 

At the subsequent visits, she admitted to rubbing her eyes in the mornings as well, and that she was rubbing her eyes more frequently and vigorously than she had initially thought.

We explained to the patient how vigorous eye rubbing could have induced weakening of her corneas, which were further compromised by the LASIK procedure. The corneas were subsequently further weakened by eye rubbing after LASIK, culminating in corneal ectasia in both eyes. 

We therefore strongly advised this patient to stop rubbing her eyes  and to change her unhealthy sleeping position. She was also prescribed an eye shield to be worn during sleep to prevent ocular compression and rubbing during bedtime. 

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

photo right eye post LASIk ectasia.PATIENT RIGHT PROFILE. The central flattening and inferior steepening is perceptible.
defeat keratoconus left eye profileLEFT EYE PROFILE. The left eye profile is unremarkable.
sleeping position, pillow hugging, right eye, post LASIK ectasiaPATIENT SHOWING HER SLEEP POSITION (right side with the eye buried in the pillow)
eye rubbing of the left eye, post LASIK ectasiaPATIENT RUBBING HE RIGHT EYE. She rubs frequently and vigorously, exerting a strong pressure on the corneal dome.
blur disk seen by a patient with post LASIK ectasiaA white disc on a dark background is shown to the patient, who is then asked to observe it monocularly with the right and then the left eye. She is then asked to draw the image seen, detailing any blurring.
drawing of a visual blurThe patient perceives ghost images of the white discs. These are caused by the corneal deformation as a consequence of the ectasia. The light rays are deflected more by the inferior steepened zone. This irregular astigmatism can be quantified by aberrometric examinations.

Here are the pre-LASIK Orbscan quadmaps performed at another institution in 2006

RIGHT EYE PRE-OPERATIVE ORBSCAN. As you can see, the examination is strictly normal with no signs of keratoconus or ectasia susceptibility, with reassuring keratometry, pachymetry and posterior curvature.
LEFT EYE PRE-OPERATIVE ORBSCAN. As you can see, the examination is strictly normal with no signs of keratoconus or ectasia susceptibility, with reassuring keratometry, pachymetry and posterior curvature.

Here are the Orbscan quadmaps and OPD scan results of the first visit at our institution.

post lasik ectasia corneal topographyRIGHT EYE ORBSCAN (1st VISIT). The post LASIK ectasia pattern is characterized by the asymmetry (inferior steepening on the axial map, bottom left). It’s an ectasia at an early stage given the minor inferior deformation.
post LASIK topography profile corneaLEFT EYE ORBSCAN (1st VISIT). The cornea is thin, and flatter centrally. This topographic pattern corresponds to a normal post-myopic LASIK profile.
wavefront sensing corneal topography OPSscan III post LASIK ectasiaRIGHT EYE OPD. The irregularity and vertical asymmetry of the corneal surface results in the induction of coma and other higher order aberrations. These aberrations account for the visual symptoms in the right eye (ghost images).
LEFT EYE OPD. The wavefront analysis reveals the increase in some coma-like higher order aberrations.

Difference maps were performed at each subsequent visit. No evolution was observed between the first and last visits. The corneal ectasia is stable, more than 12 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 ORBSCAN (3rd VISIT). Stable since first visit.
LEFT EYE ORBSCAN (3rd VISIT). Stable since first visit.
difference map orbscan post lasik ectasiaRIGHT EYE ORBSCAN DIFFERENTIAL MAPS. The difference map demonstrates the absence of aggravation of the LASIK ectasia.
orbscan difference mapLEFT EYE ORBSCAN DIFFERENTIAL MAPS. The difference map demonstrates the absence of topographic changes in the non-ectatic eye.

Induced corneal ectasia (or iatrogenic keratoconus) is a rare but devastating complication of  LASIK.

The role of eye rubbing in post LASIK ectasia is probably underestimated. It should be suspected for every case of ectasia, especially in late-onset cases.

The unilateral corneal ectasia development in this case is related to the sleeping position (right- sided) and the habit of preferentially rubbing the right eye.

In our experience, the cessation of eye rubbing is the most important parameter in the control of progression of the corneal deformation. Cross linking was not necessary to stop the progression of the ectasia in this case. In our opinion, corneal ectasia post refractive surgery, similar to keratoconus, is not an inherited disease, but the consequence of repeated mechanical trauma, especially in cases which were determined to be of low ectasia risk pre-operatively. Logically, the cessation of inflicted trauma leads to the eradication of the inciting cause of deformation and the cessation of eye rubbing thus arrests the evolution of the corneal ectasia. This website provides many other encouraging examples of this.

The monocular diplopia (double vision) in this case is an interesting point and is the consequence of the corneal asymmetry and irregularity induced by the ectasia. The visual symptoms of ghost images are frequently observed not just in post-LASIK ectasia but in the early course of keratoconus as well.

  • Date 10 mars 2018
  • Tags Asymmetric, Cleansing eye rubbing, Dry eyes, Ectasia, Eye rubbing, Female, Lasik, Nails rubbing, Pillow hugging, Sleep position, Stabilization