Future shock: the long term consequences of refractive surgery

As anyone who has invested in the futures market, read The Time Machine by H G Wells, or implanted a closed looped anterior chamber lens can attest, accurately predicting the future can be a difficult and challenging task. With any new surgical technique or procedure there are implicit unknown long and short term risks and consequences. There is no exception in the rapidly changing technology, patient and doctor driven field of refractive surgery, the youngest subspecialty of ophthalmology and a discipline that is evolving at an astonishing pace. There has been appropriate discussion about the effects of refractive surgery on qualitative aspects of vision such as optical aberration and impaired night vision.1 The majority of refractive surgery procedures are performed on individuals currently between the ages of 30 and 50. As this population ages, there is also likely to be a significant impact on several other important aspects of ophthalmology that may not be as readily obvious, yet are worthy of careful thought and consideration. It is the goal of this commentary to focus on these areas. Refractive surgery techniques induce changes in the curvature, thickness, shape, structural, and biochemical composition of the cornea. Screening potential donor tissue by slit-lamp biomicroscopy alone may not detect prior laser intrastromal keratomileusis (LASIK), photorefractive keratectomy (PRK), or automated lamellar keratoplasty (ALK) procedures. The use of such donor tissue, and the likely decentration of the flattened or, in the case of hyperopia, steepened optical zone in relation to the entrance pupil, may have profound effects on the refractive outcome of the corneal transplant recipient. Even if well centred over the entrance pupil, unexpected central corneal flattening or steepening may result in significant ametropia and anisometropia following penetrating keratoplasty or triple procedures using preoperated donor tissue. We have recently reported on the efficiency of …