Case #68

Case #68

The patient

Patient right profile

Bilateral Asymmetric Corneal Ectasia induced by eye rubbing

Identity : Mr H.B
First visit : 07/22/2014
Last Visit : 12/12/2017

42
Age (years)
53
Follow-up (months)
Ectasia or permanent corneal warpage?

Mr. H.B is a 42-year-old male with an allergy to dust mites and pollen in childhood. He has no known family history of keratoconus. He complained of a progressive decrease in visual acuity greater in the left eye than the right.

He had bilateral LASIK performed in 2008 at another institution. Pre-operatively, he had myopia of about -3 D in both eyes. 2 years after the initial refractive surgery, he developed astigmatism which required glasses, and as astigmatism progressively increased, his ophthalmologist diagnosed post-LASIK ectasia. In order to improve his vision, his ophthalmologist inserted INTACS in his left eye in 2012.  Unfortunately, his ectasia continued to evolve and he was proposed corneal collagen cross-linking. He then consulted us for a second opinion.

His refraction at the first visit at the Rothschild Foundation (on 07/22th/2014) was : Right Eye (RE) 20/25 with+0.25 (-2.5 x 70 °) and Left Eye (LE) 20/40 with -0.5 (-6.75 x 115 °).

Clinical examination with the slit lamp suggested a thin and irregular cornea in the left eye, with a discrete Fleischer ring. (Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin). Both eyes were dry with tear film BUT (Break Up Time) < 8 secs

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

At the first visit, when asked about the possibility of frequent eye rubbing, the patient admitted to rubbing his eyes especially when he awoke in the mornings. He used to rub very frequently and intensely during his childhood because of allergy. His left eye was always itchier than the right one. 

The patient is right handed and rubs his right eye with his right hand. He sleeps on his left side, with the head buried in the pillow (pillow hugging). 

The retrospective analysis of the examinations performed before the LASIK revealed that both eyes presented topographic and aberrometric abnormalities, which were more pronounced in the left eye. We believe that these irregularities were caused by chronic eye rubbing which began in childhood (see below).

We explained to the patient how vigorous eye rubbing could have induced weakening of his corneas, which were further compromised by the LASIK procedure. Subsequent eye rubbing after the surgery incurred further weakening, culminating in corneal ectasia in both eyes. 

We strongly advised this patient to stop rubbing his eyes and to change his unhealthy sleeping position, in order to prevent further aggravation of the post LASIK ectasia.

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

Corneal ectasia on right eyePATIENT RIGHT PROFILE. This profile is unremarkable: the central flattening (caused by the corneal remodeling during LASIK) is perceptible.
Left eye profile with intacsPATIENT LEFT PROFILE. The central flattening zone is perceptible, along with the reflection of the corneal intra stromal segment (INTACS).
left eye rubbing with index finger pulpPATIENT RUBBING HIS EYES WITH HIS FINGER PULP.
patient showing his sleeping positionPATIENT DEMONSTRATING HIS FAVORITE SLEEPING POSITION (LEFT SIDE). He buries the left side of his face in the pillow

BEFORE LASIK

Here are the examinations before bilateral LASIK (performed in another institution).

Orbscan map of an eye that developed LASIK ectasia (preoperative)RIGHT EYE PRE-OPERATIVE ORBSCAN. This examination reveals the presence of a slight inferior steepening (axial map, bottom left).
Orbscan map, preopertiveLEFT EYE PRE-OPERATIVE ORBSCAN. The inferior steepening is partly masked by a wide scale (bottom left, axial map). Note the asymmetry on the anterior and posterior elevation maps. The pachymetry map suggests the presence of a central thinned zone.
Zywave wavefront analysisRIGHT EYE PRE OP OPERATIVE WAVEFRONT ANALYSIS (Zywave). Note the elevated amount of higher order aberrations, which are induced by the corneal irregularities.
Zywave wavefront analysisLEFT EYE PRE OP OPERATIVE WAVEFRONT ANALYSIS. There is a slight increase in higher order aberration of coma and trefoil type. These aberration are induced by the corneal irregularities.
Tomey corneal topographyRIGHT EYE PRE OP OPERATIVE TOMEY. Despite some irregularities in the topographic pattern of the anterior corneal surface, all the detection indices are negative for keratoconus preoperatively.
Preoperative topography mapLEFT EYE PRE OP OPERATIVE TOMEY SPECULAR TOPOGRAPHY EXAMINATION. This examination was performed before the LASIK surgery. It reveals minor irregularities (abnormal CSI index= center vs surround curvature). However, these were insufficient to raise the suspicion of keratoconus with the automated indices (Klyce Maeda and Rabinowitz)

AFTER LASIK

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

orbscan map of a post LASIK ectasia eyeRIGHT EYE ORBSCAN (1st VISIT). The axial curvature map (bottom left) reveals a "claw pattern", which corresponds to local irregularity (corneal deformation). The posterior surface is highly prolate (top right). The thickness map (bottom right) reveals localized central thinning.
Orbscan map post LASIK ectasiaLEFT EYE ORBSCAN (1st VISIT). The topographic pattern is similar to that of the right eye, but more pronounced.
post LASIK ectasia, Pentacam mapRIGHT EYE PENTACAM (1st VISIT). The ectatic pattern is underlined by the marked asymmetry of the curvature map (inferior steepening).
Pentacam map, corneal ectasia after LASIK.LEFT EYE PENTACAM (1st VISIT). The marked asymmetry (inferior steepening) is the consequence of the biomechanical decompensation of the corneal wall.
OPDscan III topography and aberrometry map of an eye with post LASIK ectasiaRIGHT EYE OPDscan III examination (corneal topography and aberrometry). The irregularity of the corneal surface results in the induction of coma and other higher order aberrations. This explains the loss of visual quality, which cannot be corrected with spectacles.
OPDscan III examinationLEFT EYE OPDscan III maps (combined topography and aberrometry). The irregularity of the corneal surface results in the induction of coma and other higher order aberration, more pronounced in the left eye. These aberrations result in a reduction of the visual quality which cannot be corrected with spectacles.
Ocular response analyzer map of an eye with post LASIK ectasiaRIGHT EYE ORA (Ocular Response Analyzer) (1st visit). The biomechanical examination reveals low applanation peaks, indicating a "locally more deformable" cornea.
ocular response analyzer (ORA) waveform map in an eye with post LASIK ectasiaLEFT EYE ORA (Ocular Response Analyzer) (1st visit). As for the right eye, the biomechanical examination reveals low applanation peaks, indicating a "locally more deformable" cornea.

Difference maps were performed at each subsequent visit. No evolution was observed between the first and last visits. The post LASIK ectasia is still stable in both eyes, more than 53 months after the patient definitely stopped rubbing his eyes.

orbscan map post LASIK ectasiaRIGHT EYE ORBSCAN (2nd VISIT).
Post LASIK ectasia topographic pattern (Orbscan)LEFT EYE ORBSCAN (2nd VISIT).
RIGHT EYE PENTACAM (2nd VISIT).
LEFT EYE PENTACAM (2nd VISIT).
RIGHT EYE ORBSCAN (3rd VISIT)
LEFT EYE ORBSCAN (3rd VISIT)
RIGHT EYE PENTACAM (3rd VISIT)
LEFT EYE PENTACAM (3rd VISIT)
RIGHT EYE ORBSCAN (4th VISIT)
LEFT EYE ORBSCAN (4th VISIT)
RIGHT EYE PENTACAM (4th VISIT)
LEFT EYE PENTACAM (4th VISIT)
RIGHT EYE ORBSCAN (5th VISIT)
LEFT EYE ORBSCAN (5th VISIT)
RIGHT EYE PENTACAM (5th VISIT)
LEFT EYE PENTACAM (5th VISIT)
RIGHT EYE PENTACAM DIFFERENTIAL MAPS
LEFT EYE PENTACAM (6th VISIT)
difference map corneal ectasiaRIGHT EYE PENTACAM DIFFERENCE MAPS. This difference map reveals the absence of progression of the ectasia.
difference map pentacam stability of post LASIK ectasiaLEFT EYE PENTACAM DIFFERENCE MAPS. This difference map shows the absence of progression of the corneal deformation. There is no progression of the corneal ectasia.
post LASIK ectasia difference map: stabilityRIGHT EYE PENTACAM DIFFERENTIAL MAPS. The difference map (third column) reveals the absence of significant change between the two examinations. The post LASIK ectasia is stable.
difference map post LASIK ectasiaLEFT EYE PENTACAM DIFFERENTIAL MAPS 2. Analysis of the difference map reveals the absence of progression of the corneal ectasia.

The induced corneal ectasia (or iatrogenic keratoconus) is a rare complication of LASIK that compromises vision. It corresponds to a biomechanical decompensation of the cornea, which loses its regularity and whose central curvature increases. Consequently, ectasia results in the reappearance of evolutionary myopia and astigmatism.

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 post-LASIK ectasia. This case is very informative about the risks of eye rubbing before and after LASIK surgery.  The pre-LASIK topographies showed irregularities, with inferior steepening seen on the anterior curvature maps. This could possibly be a consequence of chronic intensive eye rubbing during childhood (due to allergy). Following excimer laser ablation in LASIK, the cornea is thinned. The repeated and sustained friction on this thinned cornea afforded by eye rubbing can be particularly detrimental to the biomechanical integrity of the corneal wall and the compressive effect makes it thinner and more irregular. It is interesting to note that the topographic irregularities detected were all more pronounced in the left eye, which was the eye buried in the pillow at night, and the eye that was rubbed more.

This case nicely demonstrates that although the main risk factor for post LASIK ectasia is the presence of preoperative topographic abnormalities (e.g. « keratoconus form fruste »), eye rubbing should not be neglected as an important risk factor for reasons mentioned above. Our experience shows that eye rubbing is at the core of the mechanism of post LASIK ectasia, as it is for keratoconus. The habit usually precedes the surgery, and may be more incessant after the surgery because of the discomfort induced by dry eye. It is therefore mandatory to alert every LASIK candidate to the dangers of pursuing or initiating vigorous and repeated eye rubbing after the surgery.

In our experience, the cessation of eye rubbing is the most important parameter in the control of the progression of the corneal deformation. We believe that corneal ectasia post-refractive surgery, similar to keratoconus, is not an inherited disease, but the consequence of repeated mechanical trauma. Logically, the cessation of inflicted trauma leads to the eradication of the cause of deformation and thus like the many other cases described in this site, the cessation of eye rubbing arrests the evolution of the corneal ectasia. This website provides many other encouraging examples of this.

  • Date 14 janvier 2018
  • Tags Allergy, Asymmetric, Ectasia, Eye rubbing, Intacs Corneal Implants, Male, Pillow hugging, Sleep position