RESUMO
Purpose: To report refractive outcomes following phacoemulsification [PE] and posterior chamber intraocular lens [PCIOL] implantation in eyes with previous corneal refractive surgery
Methods: In this retrospective comparative study, 18 consecutive eyes of 14 patients with previous keratorefractive surgery for myopia including photorefractive keratectomy [PRK, 6 eyes; 33.3%] and laser in situ keratomileusis [LASIK, 12 eyes; 66.7%] underwent PE+PCIOL. Computerized corneal topography was employed to determine the flattest keratometric reading within the 3-mm central zone. This value was inserted into the Sanders-Retzlaff-Kraff/T [SRK/T] formula to calculate IOL power. IOL power selected for implantation was 1 D greater than the calculated value described above
Results: Mean age and follow-up period were 54.1 +/- 11.5 years and 29.9 +/- 26.3 months, respectively. Mean implanted lens power was 18.56 +/- 3.86 D which was not significantly different from mean back-calculated IOL power for target refraction [19.04 +/- 4.16 D] [P=0.28]. There was no significant difference between mean target refraction [-0.94 +/- 0.52 D] and achieved postoperative spherical equivalent refractive error [-0.62 +/- 1.06] at final follow-up [P=0.28]. The achieved spherical equivalent refractive error was within +/- 0.50 D of intended refraction in 8 [44.4%] eyes, within +/- 1.0 D in 11 [61.1%] eyes, and within +/- 2.0 D in 16 [88.9%] eyes. In a subgroup of patients [5 eyes] with complete pre-refractive surgery data, the difference between post-refractive surgery keratometry method and all other methods [P=0.02] and between the current method and the Feiz-Mannis method [P=0.01] was statistically significant
Conclusion: The method suggested herein is simple and independent of pre-refractive surgery data with results comparable to other commonly used methods