Original Article Evaluation of the difference between intended and measured ablation and its impact on refractive outcomes of the wavefront optimize profile and the S001 Wellington nomogram in myopic spherocylindrical corrections Georgios Labiris MD PhD, 1,2 Haris Sideroudi PhD, 2 Athanassios Giarmoukakis MD, 1 Stavrenia Koukoula MD, 1 Georgios Pagonis MD 2 and Vassilios P Kozobolis MD PhD 1,2 1 Department of Ophthalmology, University Hospital of Alexandroupolis, and 2 Eye Institute of Thrace, Alexandroupolis, Greece ABSTRACT Background: To evaluate the level of agreement between intended and measured ablation of the wavefront optimize profile corrected by the Welling- ton nomogram in myopic spherocylindrical correc- tions and assess its impact on refractive outcomes. Design: Prospective, university–institute setting. Participants: Eighty-six participants (86 eyes for pho- torefractive keratectomy group) and 86 participants (86 eyes for laser in situ keratomileusis group) recruited in a consecutive-if –eligible basis. Methods: Differences between intended and mea- sured ablation were evaluated with Scheimpflug camera. Refractive outcomes were evaluated by means of postoperative spherical equivalent, post- operative defocus equivalent, contrast sensitivity, correction index, difference vector and index of success. Main Outcome Measures: Correlation of visual out- comes with intended ablation. Results: Both groups demonstrated significant over- ablations (16.7  8.5, P < 0.001 & 11.8  18.5, P < 0.001, respectively). Intended ablation was the pri- mary determinant of the measured difference (r-square 0.769 & 0.765, respectively). Photorefrac- tive keratectomy corrections over 100 m had signifi- cant impact on postoperative spherical equivalent, postoperative defocus equivalent, correction index, difference vector and index of success (P = 0.044, P = 0.05, P = 0.019, P = 0.016, P = 0.006, respec- tively), but laser in situ keratomileusis corrections over 100 m had significant impact only on postopera- tive defocus equivalent, difference vector and index of success (P = 0.04, P = 0.05). Conclusions: The results suggest that the wavefront optimize profile seems to over-ablate corneal tissue both in photorefractive keratectomy and laser in situ keratomileusis. Over-ablation exerts significant impact on refractive outcomes only in high sphero- cylindrical corrections. Key words: LASIK, PRK, refractive surgery, wavefront optimize, Wellington nomogram.  Correspondence: Dr Georgios Labiris, Department of Ophthalmology, University Hospital of Alexandroupolis, Dragana, 68100 Alexandroupolis, Greece. Email: labiris@usa.net Received 26 October 2010; accepted 5 June 2011. Conflict/competing interest: No stated conflict of interest. Funding sources: No specific funding. Congress presentation: The results of the study were presented at the 24th International Congress of HSIOIRS (4–7 February 2010) in Athens, Greece. Clinical and Experimental Ophthalmology 2012; 40: 127–133 doi: 10.1111/j.1442-9071.2011.02633.x © 2011 The Authors Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists