Patient right profile
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
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.
Other cases :
- Date 14 janvier 2018
- Tags Allergy, Asymmetric, Ectasia, Eye rubbing, Intacs Corneal Implants, Male, Pillow hugging, Sleep position