Power vector analysis as an aid to correct a rotated Artiflex toric phakic intraocular lens

We describe the use of power vector analysis in quantifying the amount of lens rotation and assesing the subsequent correction in a case of rotated Artiflex toric phakic intraocular lens (pIOL) (Ophtec BV, Netherlands). A 33 year old patient was corrected by bilateral implantation of Artiflex toric pIOLs for high myopia and astigmatism. Two months after the surgery the patient reported worse vision with her left eye, with residual refractive error of +1.25 –2.00 x 135° yielding a corrected visual acuity of 1.0. Pre-operative and post-operative refractions in vectorial notation were subtracted and the result changed back into clinical notation, the resulting refraction being –8.98 –4.03 x 15°, which was the same amount as attempted but rotated 15 degrees counterclockwise. A second procedure to rotate the position of the lens clockwise by this amount resulted in a residual error of +0.50 –0.75 x 105° and uncorrected visual acuity of 1.0–.