ABSTRACT
PURPOSE: To evaluate the accuracy of 12 intraocular lens (IOL) power formulas; Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hill-Radial Basis Function (RBF), Hoffer Q, Holladay I, Kane, Ladas Super Formula, Olsen Lenstar, Panacea, Pearl-DGS, Sanders-Retzlaff-Kraff/theoretical (SRK/T). In addition, an analysis of the efficacy as a function of the axial length was performed. METHODS: About 171 from 93 patients: 68 male eyes and 103 female eyes. Twelve IOL power formula calculations were studied with one IOL platform (trifocal hydrophilic IOL, FineVision Micro F), one biometer (Lenstar LS 900), one topographer (CSO Sirius Topographer), one surgeon, and one optometrist. Optimization were determined to be zeroed mean refractive prediction error. Mean error (ME), mean absolute error (MAE), median absolute error (MedAE) and refractive accuracy within ±1.00 D was calculated. Axial length was split in short and medium eyes. RESULTS: One hundred and seventy eyes were included. Formulas were ranked by percentage within ±0.50 diopters and MAE (D). Among all eyes, Olsen 86.55% (0.273 D) and Barrett Universal II 86.55% (0.285D). For short eyes (<22.5 mm), Olsen 90.70% (0.273 D) and Kane 90.70% (0.225 D). For medium eyes, Barrett 89.34% (0.237 D) and Pearl 86.89% (0.263 D). CONCLUSION: Olsen and Barrett formula obtained excellent accuracy for overall eyes. Kane and Olsen formula obtained the best results in short eyes. For medium axial length Barrett formula achieved the best accuracy results.
Subject(s)
Lenses, Intraocular , Phacoemulsification , Axial Length, Eye , Biometry , Female , Humans , Lens Implantation, Intraocular , Male , Optics and Photonics , Refraction, Ocular , Retrospective StudiesABSTRACT
PURPOSE: To determine if there are any differences between eye parameters measured by the IOLMaster (Carl Zeiss Meditec AG, Jena, Germany) biometer before and after dilating the pupil. The effect of those changes on intraocular lens (IOL) power calculation is also analyzed. METHODS: A prospective observational study was carried out including 107 right eyes of 107 patients with cataract and no other ocular morbidity. An IOLMaster baseline measurement included axial length (AL), mean keratometry (K), and anterior chamber depth (ACD) (corneal epithelium to lens). A second measurement was taken 45 minutes after instillation of topical tropicamide and phenylephrine. Biometric variation was analyzed and prediction for IOL power based on the Haigis and the Sanders/Retzlaff/Kraff Theoretical (SRK/T) formulas was calculated for both measurements. RESULTS: The ACD increased significantly after dilation (+0.12 ± 0.12 mm; p<0.01). The AL and K variation was not significant: +0.00 ± 0.02 mm (p = 0.62) and +0.01 ± 0.22 D (p = 0.57), respectively. Pupil dilation did not affect IOL power calculation based on SRK/T formula either targeting emmetropia (-0.02 ± 0.26, p = 0.30) or the lowest myopic residual refraction (-0.03 ± 0.34, p = 0.30). However, using the Haigis formula significantly changed calculations for emmetropia (0.07 ± 0.34, p = 0.03) and for the lowest myopic refraction (0.10 ± 0.40, p = 0.01). CONCLUSIONS: Pupil pharmacologic dilation produces a significant increase in ACD when measured by the IOLMaster. This change results in a different IOL power prediction according to the Haigis formula, which calculates the effective lens position taking into account the ACD.
Subject(s)
Anterior Chamber/pathology , Interferometry/methods , Lenses, Intraocular , Mydriatics/administration & dosage , Optics and Photonics , Pupil/drug effects , Aged , Aged, 80 and over , Algorithms , Axial Length, Eye , Biometry/methods , Corneal Pachymetry , Drug Combinations , Female , Humans , Lens Implantation, Intraocular , Light , Male , Middle Aged , Phenylephrine/administration & dosage , Prospective Studies , Tropicamide/administration & dosageABSTRACT
BACKGROUND: The purpose of this study is to evaluate the retinal and choroidal thickness of the macular region in patients with unilateral relentless placoid chorioretinitis (RPC) and macular involvement. Patients diagnosed with RPC affecting only one eye underwent a comprehensive ophthalmologic examination including best-corrected visual acuity (BCVA), axial length (AL) measurement, slit-lamp examination, and color fundus and autofluorescence photography. The macular region was scanned by swept-source optical coherence tomography in the 1,050-nm wavelength. Automated segmentations of the retina and the choroid were used to obtain the corresponding thickness values. RESULTS: A total number of three patients (two men and one woman; age range 17 to 62 years) were included. Eyes with clinically evident RPC had a mean AL of 24.62 ± 0.11 mm, whereas in the clinically healthy fellow eyes, the mean AL was 24.65 ± 0.03 (p = 0.70). The mean BCVA was 0.93 ± 0.16 in eyes with RPC, and 1.0 in all the fellow eyes (p = 0.70). Slit-lamp examination did not reveal any sign of vitreous inflammation in any cases. The mean macular retinal thickness was 288.10 ± 10.22 µm in eyes with RPC, and 300.30 ± 7.17 µm in the healthy fellow eyes (p = 0.20). The mean central choroidal thickness was 260.70 ± 140.60 µm in eyes with RPC, and 262.30 ± 123.10 µm in the fellow eyes (p = 0.99). The mean macular choroidal thickness was 248.60 ± 128.40 and 255.10 ± 123.60 µm, respectively (p = 0.99). CONCLUSIONS: The pathogenesis of RPC remains unknown. No changes in the retinal and choroidal thickness were observed in the macular area of eyes diagnosed with RPC with macular involvement compared with the asymptomatic healthy fellow eyes. Further prospective studies are warranted in order to investigate the role of the choroid in cases of RPC.
