Vision Loss after Lasik
Renu Shelar (name changed) a 30 year old dentist underwent LASIK in 2009. She was fine for some time and then started developing decreased vision again in both her eyes. When she presented to us she did not have preoperative topographies (investigation reports done before her surgery) and surgical records.
Dr Vandana Jain evaluated her in detail and she was found to have myopia (near sightedness) and high astigmatism (cylinder power) and vision with glasses was less than normal due to irregular cornea (the outer dome shaped portion of the eye) with a little bulge. Renu’s corneal topography(a test for 3D mapping of the cornea surface) and pachymetry (to test thickness of cornea) was performed. Corneal topography revealed an irregular cornea with an area of steeping in the lower half. Her corneal thickness on pachymetry was also on the lower side.
Renu was diagnosed with post-LASIK Ectasia- a condition in which a weak cornea bulges out. She was advised to consider specialised lenses called Scleral contact lens for a better vision and to follow up for monitoring future progression. If a progression is documented then to stabilize her disease she will need to undergo a procedure called collagen cross linking.
Ectasia is a very serious complication of refractive surgery. A pre-LASIK detailed evaluation is really mandatory to ascertain if someone is at risk of developing this complication later. Some of the known risk factors for this complication are-
Abnormal corneal topography
Lesser corneal thickness
Younger patients (who may be predisposed to Keratoconus or forme fruste keratoconus but have not yet had time to develop them)
Enhancements - repeat LASIK if the first time correction is not enough
High Myopia where more ablation of cornea is needed
Take Home Message:
Though Lasik is a good option to get rid of the hassles of glasses and contact lenses, one has to make sure that one is a right candidate for Lasik. After all, it is our most prized sense- sense of SIGHT.
Someone may not be a candidate for Lasik if:
Age is less than 18 years
Spectacle numbers are fluctuating or eyesight is progressively getting worse.
Suffer from persistent Dry Eyes (especially for Conventional Lasik)
Have severe near sightedness
Have systemic diseases like diabetes or arthritis
Eye problems, like glaucoma, cataract or any corneal dystrophy
Are on medications that affects healing of the cornea.
Treatment during pregnancy and while breastfeeding is not recommended