ABSTRACT
PURPOSE: To compare the accuracy of 11 intraocular lens (IOL) power calculation formulas (SRK-T, Hoffer Q, Holladay I, Haigis, Holladay II, Olsen, Barrett Universal II, Hill-RBF, Ladas Super formula, EVO and Kane). SETTING: Private university hospital (QuironSalud, Madrid, Spain). DESIGN: Retrospective case series. METHODS: Data were compiled from 481 eyes of 481 patients who had undergone uneventful cataract surgery with IOL insertion. Preoperative biometric measurements were made using an IOL Master® 700. Respective ULIB IOL constants (http://ocusoft.de/ulib/c1.htm) for each of 4 IOL models implanted were used to calculate the predictive refractive outcome for each formula. This was compared with the actual refractive outcome determined 3 months postoperatively. The primary outcome was mean absolute prediction error (MAE). The study sample was divided according to axial length (AL) into three groups of eyes: short (⩽22.00 mm), normal (22.00-25.00 mm) and long (⩾25.00 mm). RESULTS: The Barrett Universal II and Haigis formulas yielded the lowest MAEs over the entire AL range (p < .01, except EVO) as well as in the long (p < .01, all formulas) and normal (p < .01, except Haigis, Holladay II, Olsen and LSF) eyes. In the short eyes, the lower MAEs were provided by Haigis and EVO (p < .01 except Hoffer Q, SRK/T and Holladay I). CONCLUSIONS: Barrett Universal II was the most accurate for IOL power calculation in the normal and long eyes. For short eyes, the formulas Haigis and EVO seem best at predicting refractive outcomes.
Subject(s)
Lenses, Intraocular , Phacoemulsification , Axial Length, Eye , Biometry , Humans , Lens Implantation, Intraocular , Optics and Photonics , Refraction, Ocular , Retrospective StudiesABSTRACT
PURPOSE: To evaluate the refractive and functional outcomes of the trifocal 1stQ AddOn® (Medicontur) supplementary intraocular lenses (IOLs) designed for implantation into the ciliary sulcus. PATIENTS AND METHODS: The study included 18 eyes of 11 pseudophakic patients with uncomplicated previous implantation of monofocal capsular bag IOLs. These patients had a desire for spectacle independence. Distance, intermediate and near visual acuities were measured, and defocus curves were plotted over a period of 6 months following implantation of the add-on IOLs. Intraocular pressure (IOP), endothelial cell density measurements and biomicroscopic evaluation were also performed. RESULTS: In this study, 83.3% of eyes had spherical refractions within ±0.5 D from emetropia and 100% of eyes had spherical equivalent refractions that were within ±1.0 D of the target refraction. Visual acuities and defocus curves clearly confirmed trifocal optical performance (UDVA=0.03 ±0.05; UIVA=0.21 ±0.04; UNVA=0.12 ±0.04 logMAR; expressed as mean ±SD). Depth of focus showed identical results (DOF=0.486 D) compared to a trifocal capsular bag IOL, while the defocus curve was found to be superior in the intermediate and near ranges when compared to a trifocal capsular bag IOL. All patients achieved spectacle independence at all distances. All add-on IOLs were well positioned in the ciliary sulcus. No negative changes were noted in connection with endothelial cell counts, IOPs, the angle structure during surgery and during the follow-up period. CONCLUSION: The supplementary trifocal add-on IOL seems to be a safe, efficient and stable solution for achieving spectacle independence in pseudophakic patients with monofocal primary IOLs.
ABSTRACT
PURPOSE: To evaluate the refractive predictability obtained with an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis, confirming which intraocular lens power formula provides the most accurate calculation. METHODS: The study enrolled 71 eyes with previous successful myopic laser in situ keratomileusis surgery of 43 patients undergoing cataract surgery with implantation of the extended range of vision intraocular lens TECNIS Symfony (Johnson and Johnson Vision). Intraocular lens power was calculated using all American Society of Cataract and Refractive Surgeons formulas, and their average value was selected for implantation. Refractive outcomes were evaluated at 3 months postoperatively. RESULTS: Postoperative spherical equivalent within ±0.50 and ±1.00 D was found in 61.6% and 86.3% of eyes, respectively. In eyes with pre-laser in situ keratomileusis data available, no significant correlation was found between pre-laser in situ keratomileusis spherical equivalent and post-cataract surgery spherical equivalent (r = 0.237, p = 0.114). A postoperative spherical equivalent within ±0.50 D was found in 65.2% and 55.6% of eyes in the subgroups with and without pre-laser in situ keratomileusis data available, respectively (p = 0.480). Statistically significantly higher differences between the intraocular lens power implanted and the calculation provided by the Potvin-Hill (p = 0.028) and Barrett True K No History formulas (p = 0.022) were found in those eyes with postoperative spherical equivalent > 0.50 D. CONCLUSION: The extended range of vision intraocular lens evaluated can provide a predictable refractive correction in eyes with previous laser in situ keratomileusis surgery. The Potvin-Hill and Barrett True K No History are the most adequate formulas to perform intraocular lens power calculations in these cases.
