Resultados del cálculo de la lente intraocular con fórmula Holladay 2 y Barret Universal 2 / Results of Intraocular Lens Calculation with Holladay 2 and Barret Universal 2 formula

Objetivo: Determinar los resultados refractivos con las fórmulas Holladay 2 y Barret Universal 2 a partir del cálculo de la lente intraocular en pacientes operados de catarata. Métodos: Se realizó un estudio descriptivo prospectivo y longitudinal con 60 ojos de 50 pacientes operados de catarata mediante la técnica de facoemulsificación. Se empleó para el cálculo de la lente el IOL Master 700 y el Pentacam AXL con la fórmula Holladay 2 y Barret Universal 2, respectivamente. Resultados: Predominó el sexo femenino y el grupo etario mayor de 60 años. Los ojos mayores de 26 mm mostraron la mayor diferencia entre el poder dióptrico de la lente intraocular que se implantó según Holladay y en menores de 22 mm según Barret Universal. Ambos grupos presentaron una disminución del equivalente esférico, siendo superior a 7 y 5 dioptrías en ojos mayores de 26 mm en el posoperatorio de ambas fórmulas. Posterior a la cirugía se observó una mejoría en la agudeza visual sin corrección y corregida de más de 4 líneas en la cartilla de Snellen, independiente de la longitud axial, para ambos grupos en estudio. Sin cambios significativos en el cilindro queratométrico. En el 70,0 por ciento de los casos, el resultado refractivo final estuvo en rango de la emetropía para el grupo Holladay 2 y el 66,7 por ciento para el grupo Barret Universal 2. Conclusiones: Ambas fórmulas resultan útiles para el cálculo de la lente intraocular en todos los rangos de longitud axial(AU)

Objective: To determine refractive outcomes with the Holladay 2 and Barret Universal 2 formulas from intraocular lens calculation in cataract surgery patients. Methods: A prospective and longitudinal descriptive study was performed with 60 eyes of 50 patients who underwent cataract surgery by phacoemulsification. The IOL Master 700 and Pentacam AXL with the Holladay 2 and Barret Universal 2 formula, respectively, were used to calculate the lens. Results: Female gender and age group older than 60 years predominated. Eyes larger than 26 mm showed the greatest difference between the dioptric power of the intraocular lens implanted according to Holladay and those smaller than 22 mm according to Barret Universal. Both groups presented a decrease of the spherical equivalent, being higher than 7 and 5 diopters in eyes larger than 26 mm postoperatively in both formulas. Postoperatively, there was an improvement in uncorrected and corrected visual acuity of more than 4 lines in the Snellen chart, independent of axial length, for both groups under study. No significant changes in keratometric cylinder. In 70.0 percent of the cases, the final refractive result was in the emmetropia range for the Holladay 2 group and 66.7 percent for the Barret Universal 2 group. Conclusions: Both formulas are useful for the calculation of the intraocular lens in all axial length ranges(AU)

Resultados del cálculo de la lente intraocular con la fórmula Holladay 2 en pacientes con catarata / Results of intraocular lens calculation with the Holladay 2 formula in cataract patients

RESUMEN Objetivo: Determinar los resultados refractivos en pacientes operados de catarata, según el cálculo del poder dióptrico de la lente intraocular con la fórmula Holladay 2. Métodos: Se realizó un estudio descriptivo prospectivo y longitudinal en 222 ojos de 173 pacientes operados de catarata mediante la técnica de facoemulsificación. Se empleó para el cálculo de la lente el IOL Master 700 y la fórmula Holladay 2. Resultados: Predominó el sexo femenino y el grupo etario mayor de 60 años. En el posoperatorio se observó una mejoría en la agudeza visual sin corrección y corregida de más de 4 líneas en la cartilla de Snellen, independiente de la longitud axial, sin cambios significativos en el cilindro queratométrico. En 69,0 por ciento de los casos el resultado refractivo final estuvo en el rango de la emetropía. Los ojos mayores de 26 mm presentaron una disminución del equivalente esférico superior a 6 dioptrías en el posoperatorio; los menores de 22 mm mostraron la mayor diferencia entre el poder dióptrico de la lente intraocular que se implantó y el que sugiere la fórmula convencional. Conclusiones: La fórmula Holladay 2 resulta útil para el cálculo de la lente intraocular en todos los rangos de longitud axial(AU)

ABSTRACT Objective: Determine refractive results in patients undergoing cataract surgery based on intraocular lens dioptric power calculation with the Holladay 2 formula. Methods: A prospective longitudinal descriptive study was conducted of 222 eyes of 173 patients undergoing cataract surgery by phacoemulsification technique. IOL Master 700 and the Holladay 2 formula were used for lens calculation. Results: There was a predominance of the female sex and the over-60 years age group. The postoperative period was characterized by improvement in visual acuity without correction and corrected of more than 4 lines on the Snellen chart, regardless of axial length, with no significant changes in the keratometric cylinder. In 69.0 percent of the cases, the final refractive result was within the range of emmetropia. Eyes larger than 26 mm displayed a spherical equivalent reduction above 6 diopters postoperative, whereas eyes smaller than 22 mm showed the greatest difference between the dioptric power of the intraocular lens implanted and the one suggested by the conventional formula. Conclusion: The Holladay 2 formula is useful for intraocular lens calculation in all axial length ranges(AU)

Comparative study of various intra ocular lens formulae by IOL master.

Background: The aim and objective of the study was to calculate intraocular lens power with IOL master in 100 eyes of 100 patients with long axial lengths between 25mm to 32mm.To analyse and compare the results of various formulae by postoperative auto refractometry and corrected distance visual acuity and to know the most accurate formula for highly myopic eyes (Axial length more than 25.00 mm). Methods: Patients coming to Sarojini Devi Eye Hospital from December 2012-September 2014 for cataract surgery were considered in this study. All patients with visually significant cataract having fundus findings within normal limits were included in this study and patients of complicated cataract due to trauma, uveitis, Glaucoma and any corneal pathology were excluded from the study. Results: The Mean AL was 27.25 ± 1.25 mm, the Mean keratometric value was 43.62 ± 1.45 D, and the Mean Absolute Error (MAE) calculated by the Haigis was 0.07 DD. Compared to the MAEs generated by the other formulae, the MAE generated by the Haigis was comparable to that by the SRK/T (0.231 D), and significantly lower than those by the Hoffer Q (0.481 D) and Holladay (0.864 D). Conclusions: The Mean post-operative refractive error (spherical equivalent) was found to be the least with Haigis formula followed by SRK/T for eyes with long axial length. The HAIGIS formula has a better predictability and accuracy. The postoperative hyperopic shift was comparable between HAIGIS and SRK-T formulae the least postoperative hyperopic shift with Haigis formula compared to other formulae.

The Analysis of Refractive Errors of AMO Array(R) Multifocal Intraocular Lens with SRK II Formula

PURPOSE: To evaluate the accuracy of the SRK II formula for the AMO Array(R) multifocal intraocular lens (Array lens) power calculation according to axial length. In case of refractive error more than +/- 1.0 diopter (D), we compared the accuracy of the SRK II with that of other formulas. METHODS: Participants were 178 eyes (142 patients) received the Array lens. These were divided into 3 subgroups based on axial length. Group I had 21 eyes of short axial length (less than 22.0 mm). Group II had 133 eyes of average axial length (more than 22.0mm below 24.5mm). Group III had 24 eyes of long axial length (more than 24.5mm). The difference between preoperative predicted refractive value and postoperative manifest refractive value were calculated. We compared the accuracy of the SRK II and that of SRK/T, Holladay formulas in case of refractive error more than +/- 1.0D. RESULTS: Three eyes (14.2%) in Group I, 14 eyes (10.5%) in group II and 15 eyes (62.5%) in Group III showed refractive errors more than +/- 1.0D. Fifteen eyes (62.5%) in Group III were significantly reduced to 7 eyes (29.1%) with using SRK/T, Holladay formulas. CONCLUSIONS: SRK II formula had better predictive accuracy in axial length less than 24.5mm with Array lens. But it is better to apply SRK/T or Holladay formulas when axial length is more than 24.5mm.

Compartive Accuracy of the SRK II, SRK/T and Holladay Formulas for Intraocular Lens Power Calculation in Severe Myopic Eyes

The predictive accuracy of the SRK II, SRK/T and Holladay formulas was evaluated in 22 eyes with sever myopia who had phacoemulsification and implantaton of posterior chamber IOL without suture. These patients were followed up for at least 6 months postoperatively. Correlation coefficient between the predicted refraction and actual refraction was 0.57(P0.05). The percentage of the eye with hyperopic shift(more hyperopic actual refraction than the predicted refraction) was 77% in the SRK II, 77% in the SRK/T and 86% in the Holladay, but there was no statistically significant difference between each formula(p>0.05). In conclusion, the SRK/T has the better predictive accuracy than the SRK II and Holladay in severe myopia and hyperopic shift tends to occur with the application of all three formulas.

Evaluation for the Accuracy of the SRK/T Formula in PCL Implanted Patients(II): Optimizing, A-Constant

To evaluate the efficacy of optimizing of A-constant, the error in prediction was analyzed in three groups of eyes after posterior chamber lens implantation ; 102 eyes with bag placed, 66 eyes with simple sulcus places, and 25 eyes with sulcus placed with transscleral fixation suture. We compared the predictive accuracy of the SRK/T formula using optimized A-constant (bag-placed, sulcus-placed) derived from the 300 eyes with Holladay and SRK/T using original surgeon factor and A-constant. The SRK/T formula with optimized A-constant has a better mean relative, absolut, and standard error and has a better range of IOL prediction error, which was more accurate than other formulas without optimizing. In this study it is our recommendation that each surgeon use a different optimized A-constants for sulcus or bag placement to enhance the predictability of the postoperative refraction.