25
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The Comparative Study of Refractive Index Variations between Haigis, Srk/T and Hoffer-Q Formulas Used for Preoperative Biometry Calculation in Patients with the Axial Length >25 mm

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background:

          To compare refractive index variation between Hoffer-Q, Haigis and SRK/T formulas used for preoperative biometry calculation in patients with axial length >25 mm, undergoing cataract surgery.

          Materials and Methods:

          This is a randomized clinical trial study was performed on 54 eyes of 54 patients with ages of 40–70 years old and axial length >25 mm classified into three groups that their IOL POWER were calculated by Haigis, SRK/T and Hoffer-Q formulas before undergoing cataract surgery. Their refractive index variations were calculated from the difference between predicted refractive error formula and actual post-operative refractive error formula. The collected data was entered in SPSS software and was analyzed by ANOVA and Chi-square statistical test.

          Results:

          With comparison sphere, astigmatism and spherical equivalent indexes before and after of cataract surgery between Haigis, SRK/T, and Hoffer-Q formulas, statistically significant differences were found between the mean of sphere and SE indexes in patients with use of Haigis and SRK/T formulas that have been more favorable post-operative refraction.

          Conclusions:

          Haigis formula and then, with slight difference, SRK/T formula have better and more acceptable post-operative refraction results than Hoffer-Q formula in patients with high axial myopia. Therefore, it is recommended using Haigis and SRK/T formulas for IOL power calculation in patients with high axial myopia undergoing cataract surgery.

          Related collections

          Most cited references16

          • Record: found
          • Abstract: found
          • Article: not found

          Intraocular lens power calculation using the IOLMaster and various formulas in eyes with long axial length.

          To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster (Carl Zeiss) and different IOL power calculation formulas in eyes with a long axial length (AL). Department of Ophthalmology, Far Eastern Memorial Hospital, Taipei, Taiwan. This study included 68 eyes with an AL longer than 25.0 mm that had phacoemulsification with IOL implantation. Preoperative AL and keratometric index measurements were obtained with the IOLMaster (Group 1) or, respectively, with applanation ultrasound and automatic keratometry (Group 2). The power of the implanted IOL was used to calculate the predicted postoperative spherical equivalence (SE) by various formulas: SRK/T, SRK II, and Holladay 1 (Groups 1 and 2) and Haigis (Group 1). The predictive accuracy of the formula was analyzed by comparing the mean difference between the actual and predicted postoperative SE; that is, the mean absolute error (MAE). The mean AL was significantly longer in Group 1 than in Group 2 (P = .03). The MAEs calculated by the SRK/T, SRK II, and Holladay 1 formulas were comparable between the 2 groups (P>.05). The lowest MAE was obtained using the IOLMaster data in the Haigis formula (P<.05). Although AL measured by the IOLMaster was longer than that measured by ultrasound, use of optical or ultrasound biometry data in the SRK/T, SRK II, and Holladay 1 formulas resulted in similar accuracy of IOL power prediction in eyes with higher myopia. The IOL power calculated using the Haigis formula predicted the best refractive outcome in long eyes.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Accuracy of intraocular lens calculations using the IOLMaster in eyes with long axial length and a comparison of various formulas.

            To evaluate the relationship between eyes with long axial length (AL) and postoperative refractive errors as predicted by various commonly used intraocular lens (IOL) formulas using the Zeiss IOLMaster (Carl Zeiss Meditec, Jena, Germany).
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              IOLMaster biometry: refractive results of 100 consecutive cases.

              To study the refractive outcome of cataract surgery employing IOLMaster biometry data and to compare it with that of applanation ultrasonography in a prospective study of 100 eyes that underwent phacoemulsification with intraocular lens implantation. The Holladay formula using IOLMaster data was employed for the prediction of implanted intraocular lenses (IOLs). One month after cataract surgery the refractive outcome was determined. Preoperative applanation ultrasonography data were used retrospectively to calculate the IOL prediction error. The two different biometry methods are compared. 100 patients, 75.42 (SD 7.58) years of age, underwent phacoemulsification with IOL implantation. The optical axial length obtained by the IOLMaster was significantly longer (p<0.001, Student's t test) than the axial length by applanation ultrasound, 23.36 (SD 0.85) mm v 22.89 (0.83) mm. The mean postoperative spherical equivalent was 0.00 (0.40) D and the mean prediction error -0.15 (0.38) D. The mean absolute prediction error was 0.29 (0.27) D. 96% of the eyes were within 1 D from the intended refraction and 93% achieved unaided visual acuity of 6/9 or better. The Holladay formula performed better than the SRK/T, SRK II, and Hoffer Q formulas. Applanation ultrasonography after optimisation of the surgeon factor yielded a greater absolute prediction error than the optimised IOLMaster biometry, 0.41 (0.38) D v 0.25 (0.27) D, with 93% of the eyes within 1 D from the predicted refraction. IOLMaster optical biometry improves the refractive results of selected cataract surgery patients and is more accurate than applanation ultrasound biometry.
                Bookmark

                Author and article information

                Journal
                Adv Biomed Res
                Adv Biomed Res
                ABR
                Advanced Biomedical Research
                Medknow Publications & Media Pvt Ltd (India )
                2277-9175
                2017
                14 July 2017
                : 6
                : 78
                Affiliations
                [1] From the Department of Ophthalmology, Isfahan University of Medical sciences, Isfahan, Iran
                Author notes
                Address for correspondence: Dr. Neda Kargar, Department of Ophthalmology, Feiz Hospital, Isfahan University of Medical sciences, Isfahan, Iran. E-mail: drnkargar@ 123456gmail.com
                Article
                ABR-6-78
                10.4103/2277-9175.210657
                5539664
                06e652a4-3bf3-4c06-b6d7-1516bea77ceb
                Copyright: © 2017 Advanced Biomedical Research

                This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.

                History
                : May 2014
                : August 2014
                Categories
                Original Article

                Molecular medicine
                cataract surgery,high myopia,iol power calculation formula
                Molecular medicine
                cataract surgery, high myopia, iol power calculation formula

                Comments

                Comment on this article