The Clinical Efficacy of the Haigis Formula Using A-Scan Contact Ultrasound Biometry

PURPOSE: To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry. METHODS: This study was performed on 94 patients (114 eyes) who underwent cataract surgery in our hospital. Axial length (AXL) and anterior chamber depth (ACD) were measured using both A-scan and intraocular lens (IOL) Master(R). Patients were divided into three groups based on AXL; Group I (AXL or = 25.5 mm). Before cataract surgery, predicted refraction was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas using both A-scan and IOL Master(R) measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas. RESULTS: Using contact ultrasound biometry, in Group I, MAE of Haigis was 0.80 +/- 0.67 D and was significantly lower than that using SRK/T. In Group II, the Haigis MAE was 0.72 +/- 0.55 D and was significantly lower than the results of all other formulas. In Group III, the Haigis MAE was 0.76 +/- 1.13 D and not significantly different from the results of other formulas. Comparing MAE of A-scan to IOL Master(R), the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range. CONCLUSIONS: Using contact ultrasound biometry, the Haigis formula provided the best predictability of postoperative refractive outcome compared to other formulas in eyes with normal axial length.

The Clinical Efficacy of the Haigis Formula Using A-Scan Contact Ultrasound Biometry

PURPOSE: To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry. METHODS: This study was performed on 94 patients (114 eyes) who underwent cataract surgery in our hospital. Axial length (AXL) and anterior chamber depth (ACD) were measured using both A-scan and intraocular lens (IOL) Master(R). Patients were divided into three groups based on AXL; Group I (AXL or = 25.5 mm). Before cataract surgery, predicted refraction was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas using both A-scan and IOL Master(R) measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas. RESULTS: Using contact ultrasound biometry, in Group I, MAE of Haigis was 0.80 +/- 0.67 D and was significantly lower than that using SRK/T. In Group II, the Haigis MAE was 0.72 +/- 0.55 D and was significantly lower than the results of all other formulas. In Group III, the Haigis MAE was 0.76 +/- 1.13 D and not significantly different from the results of other formulas. Comparing MAE of A-scan to IOL Master(R), the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range. CONCLUSIONS: Using contact ultrasound biometry, the Haigis formula provided the best predictability of postoperative refractive outcome compared to other formulas in eyes with normal axial length.

Cirugía de catarata en pacientes vitrectomizados con aceite de silicona / Results of the cataract surgery in patients undergoing vitrectomy with silicone oil

Objetivo: Describir los resultados de la cirugía de catarata en pacientes vitrectomizados con aceite de silicona. Métodos: Se realizó un estudio descriptivo y prospectivo en 50 ojos de 49 pacientes vitrectomizados con aceite de silicona que necesitaron cirugía de catarata, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" de septiembre de 2008 a noviembre de 2009. Se analizó el componente esférico esperado y obtenido (con aceite de silicona y sin este), las diferencias queratométricas, el astigmatismo resultante, los cambios morfológicos y morfométricos del endotelio corneal, la mejor agudeza visual sin corrección y corregida y las complicaciones intraoperatorias y posoperatorias. Los resultados se expresaron en frecuencias absolutas y relativas, media aritmética y desviación estándar. Resultados: Predominó el sexo masculino entre 51 y 60 años de edad. El aceite de silicona produjo una hipercorrección en el componente esférico obtenido promedio de 4,08 dioptrías que disminuyó hasta rangos de emetropía esperada cuando se extrajo. No hubo diferencias queratométricas posoperatorias significativas y el astigmatismo resultante fue mínimo (0,31 dioptrías). La mejor agudeza visual sin corrección y con esta, mejoró después de la cirugía. Hubo una pérdida mínima de células endoteliales (6,4 %) y la variabilidad del pleomorfismo y polimegatismo estuvo dentro de los rangos clasificados en el preoperatorio. La opacidad de la cápsula posterior (62 %) fue la complicación más frecuente. Conclusiones: La biometría óptica coherente y las fórmulas de cuarta generación permiten obtener una buena predictibilidad en el cálculo del lente intraocular en casos especiales como los vitrectomizados con aceite de silicona.

Objective: To describe the results of cataract surgery results in patients who had undergone vitrectomy with silicone oil. Methods: A prospective and descriptive study was performed in 50 eyes from 49 patients who had previously undergone vitrectomy with silicone oil, and later had required cataract surgery at “Ramón Pando Ferrer”, Cuban Institute of Ophthalmology from September 2008 to November 2009. Several variables were analyzed such as the expected and obtained spherical component with and without silicone oil, the keratometric differences and the resulting astigmatism, the morphological and morphometric changes in the corneal endothelium, the best uncorrected and corrected visual acuity and transoperative and postoperative complications. The results were provided in absolute and relative frequencies, arithmetic means and standard deviation. Results: : The male group predominated as well as the 51 - 60y age group. The silicone oil caused hypercorrection in average spherical component of 4.08 D, which was reduced to the expected emmetropia ranges when the silicone oil was removed. There were no significant postoperative differences in keratometry and the resultant astigmatism was minimal (O.31 D). All the patients improved their best uncorrected and corrected visual acuity after surgery. There was minimal loss of endothelial cells (6.4 %) and the variability of pleomorphism and polymegatism remained within the preoperative classified range. The posterior capsule opacity was the most common complication (62 %). Conclusion: Optical coherence biometry and fourth-generation formulas allow obtaining good predictability in the calculation of intraocular lens in special cases such as the ones that undergo vitrectomy with silicon oil.

Accuracy of the Haigis Formula Based on Axial Length and Anterior Chamber Depth

PURPOSE: To evaluate the effect of axial length (AXL) and anterior chamber depth (ACD) on the accuracy of the Haigis formula in comparison to its effect on other 3rd generation IOL power calculations. The possibility of measurement error in ACD using either method was also investigated. METHODS: A study was performed on 137 eyes of 98 patients who underwent cataract surgery in our hospital. AXL and ACD were measured using IOL Master, and IOL power was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas. ACD was also measured using Pentacam. Patients were divided into 3 groups based on ACD and AXL. Mean numeric error and mean absolute error were analyzed 1 month after surgery. RESULTS: Five formulae showed no significant difference in refractive error in the 3 groups based on AXL. In contrast, the Haigis formula showed statistically significant differences in the group with shallow ACD, in which hyperopic shift was also demonstrated. The difference in ACD between using IOL Master and using Pentacam was significant in the shallow ACD group, with IOL Master showing more shallow measurement. However, the other groups based on ACD showed no significant difference in the refractive error from the Haigis formula, and in the difference in ACD between measurements. CONCLUSIONS: Errors in ACD measurement should be taken into consideration for discrepancy between the Haigis formula measurement and other formula measurements. The authors of the present study suggest that ACD-driven refractive error should be considered in determination of IOL.