British Journal of Ophthalmology Editorials

Femtosecond laser-assisted corneal transplantation

Baradaran-Rafii, A., Eslani, M. — 2013-05-18T00:11:55-07:00

Introduction

The femtosecond laser (FSL) is a focusable infrared laser that delivers ultrashort pulses in the femtosecond duration range. Contiguous pulses are placed at a definite depth within the cornea, thus resecting only targeted tissue. This surgical device allows cutting of corneal tissue in a number of reproducible, customised transplant designs, and allows the use of sagittal plane trephination profiles, such as zigzag, top-hat, Christmas tree and mushroom shapes to improve wound stability and, probably, postoperative astigmatism.1–5 The unique capability of the FS laser to photo-disrupt tissue with minimal collateral damage has made it a promising tool for increasing accuracy and predictability in corneal surgery.6 It has mainly been used in refractive surgery, for example, for flap preparation in Laser in Situ Keratomileusis (LASIK), for intrastromal corneal ring segments (ICRS) implantation in keratoconus patients7...

The potential for and challenges of spherical and chromatic aberration correction with new IOL designs

Lopez-Gil, N., Bradley, A. — 2013-05-18T00:11:55-07:00

When describing the human eye, celebrated scientist Hermann von Helmholtz once wrote1 ‘Now it is not too much to say that if an optician wanted to sell me an instrument which had all these defects, I should think myself quite justified in blaming his carelessness in the strongest terms, and giving him back his instrument’.

Helmholtz's assertion about the optics of the eye was quantified about a century later by Smirnov2 in Russia and the Howland brothers in the US, who found that normal human eyes exhibit significant levels of high-order aberrations, which can be much higher in eyes with corneal pathology, for instance, keratoconus.3 Laboratory studies and modern clinical aberrometers have allowed a large number of eyes to be measured in the last decade showing that aberrations of the unaccommodated eye are dominated by low-order (spherocylindrical refractive errors), third-order (coma and trefoil)...