ESCRS - CC02.12 - Bilateral Post Pkr Ectasia

Bilateral Post Pkr Ectasia

Published 2024 - 42nd Congress of the ESCRS

Reference: CC02.12 | Type: Case Report | DOI: 10.82333/k329-fb51

Authors: Doha Hamidallah* 1 , ITTAH IAN 1

1PARIS,hopital 15/20,PARS,France

Purpose

highlight the importance of researching ectasia risk factors and contraindications before performing refractive surgery, 

Setting

Induced corneal ectasia (or iatrogenic keratoconus) is a rare complication of PKR surgery  that affects visual function.
The main risk factor for ectasia is the presence of an undetected form of subclinical keratoconus beginning at the operated cornea.
As with keratoconus, the notion of repeated ocular friction is also a risk factor, this friction having led to the reduction of corneal resistance
before the intervention, and after it if the friction was continued.

Report of case

this is the case of a 29 years old caucasian male , who underwent a PKR  in  2019  for a mild myopie of -2 according to the patient as he had lost all of his documents and previous exams .he had an atopic dermatitis and had a clear notion of rubbing eyes even after the surgery .

the patient returns for progressive loss of vision in both eyes on examination we return a collapsed acuity lower than 2/20 with 
on clinical examination a visible lower bulge and punctuated keratitis in the center of the cone
at the topography bulging lower with a minimum pachymetry at 400 
the oct anterior segment we see the bulging cornea
. is it a frustrated keratoconus which went unnoticed pre-operatively or a post-surgical decompensation due to regular friction ?
in this case we have two risk factors

Eye rubbing

Eye rubbing witch has been implicated as an important factor in the development of keratoconus. One study reported a statistical difference between the normal and keratoconus subjects who rubbed eyes, 89% of the patients with keratoconus rubbed eyes versus 39% of the control subjects [Rubbing eyes, could therefore be, one of the contributing factors towards the development of keratoconus, owing to the biomechanical, mechanical and biochemical changes that could result from rubbing.

Young age

 young age is significant risk factor for the development of iatrogenic corneal ectasia. A study reported 33% of the patients younger than 30 years in their study of keratoconus cases. .

 

Conclusion/Take home message


Two presumed mechanisms are mentioned This is either the presence of keratoconus or a insufficient posterior stromal bed. However, cases of ectasia have 
been described when the topography was normal and the posterior bed greater than 300 microns thereby suggesting that other, unknown factors were in question.
Some reported clinical facts suggest that PKR could have a stabilizing effect. 
However, post-PKR ectasias have been published their number being significantly lower than that of ectasias post-lasik, without being able to identify the cause. He maybe the technique is safer, but also that a bias statistic is induced by the fact that the PKR is less practiced as lasik.