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Purpose: To determine the energy expenditure in phacoemulsification surgery expressed as cumulative dissipated energy (CDE) among the divide and conquer, ultrachopper-assisted divide and conquer, and phaco-chop techniques for dense cataract removal. Patients and Methods: The clinical data were obtained from the medical charts of dense cataracts patients undergoing routine phacoemulsification employing any of three phaco-fragmentation techniques, including divide and conquer using the Kelman 0.9 mm tip, the ultrachopper tip, and the phaco-chop technique using the Kelman 0.9 mm tip. Cumulated dissipated energy (CDE), longitudinal ultrasound time (UST), and endothelial cell loss were compared among groups at the one-month postoperative. Results: Surgeries from 90 eyes were analyzed, among whom the conventional divide-and-conquer technique group included 30 patients, 32 in the ultrachopper group, and 28 in the phaco-chop technique group. The average CDE in the conventional divide and conquer group was 44.52 ± 23.00, the ultrachopper technique was 43.27 ± 23.18, and 20.11 ± 11.06 in the phaco-chop group. Phaco-fragmentation chop demonstrated significantly lower CDE than the other techniques (p= <0.0001). The phaco-chop technique showed statistically significantly lower CDE when compared to the other two groups (p=<0.0001) with 93.96 ± 39.71 seconds. There were no statistically significant differences in postoperative endothelial cell density between groups (p=0.4916). Conclusion: The use of the phaco-chop technique in hard cataract phacoemulsification represents a lower energy expenditure than divide and conquer and ultrachopper techniques; nevertheless, no differences regarding endothelial density loss were evidenced.
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OBJETIVOS: Describir los resultados morfofuncionales alcanzados con la técnica stop and chop en la cirugía de catarata por facoemulsificación (faco), en el Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología Ramón Pando Ferrer entre Junio de 2006 y Marzo de 2009. MÉTODOS: Se realizó un estudio descriptivo, transversal en el cual el universo y la muestra del trabajo lo constituyeron todos los pacientes con diagnóstico de catarata presenil y senil, quienes cumplían con los criterios de selección y aceptaron someterse a la técnica quirúrgica señalada, lo cual correspondió a 201 ojos operados. Estos datos se analizaron a través de tablas de contingencia con frecuencias absolutas y relativas; además se emplearon medias con el uso del programa de procesamiento de datos SPSS versión 11.1, donde se aplicó la prueba t de student para su comparación. RESULTADOS: Se encontró que la catarata predominó en mayores de 70 años en el 33,4 por ciento de los pacientes. La mejor agudeza visual con corrección obtenida se incrementó hasta siete líneas en la escala de Snellen en el 93,0 por ciento de los casos; el cilindro refractivo apenas se modificó en 0,15 dioptrías; la pérdida de células endoteliales fue de 8,2 por ciento y las complicaciones operatorias fueron de 1,5 por ciento. CONCLUSIONES: La edad de los pacientes sometidos a cirugía de catarata por la técnica de stop and chop fue en su mayoría de más de 70 años. La MAVC posoperatoria ganó hasta siete líneas en la escala de Snellen; el astigmatismo que se indujo en la cirugía fue menor de media dioptría; la pérdida celular y las complicaciones posoperatorias no fueron significativas
OBJECTIVES: To describe the morphofunctional results of the stop and chop technique in cataract surgery in phacoemulsification at the Eye Microsurgery Center of Ramón Pando Ferrer Cuban Institute of Ophthalmology from June 2006 to March 2009. METHODS: A cross-sectional descriptive study was conducted. The universe and sample of the study were all the patients diagnosed with presenile and senile cataract, who met the selection criteria and accepted to undergo the surgical technique in question, that is, 201 operated eyes. These data were analyzed through the contingency tables with relative and absolute frequencies; additionally means were used in the SPSS data processing software, version 11.1, in which Student´s t test served for their comparison. RESULTS: It was found that cataract prevailed in over 70 years-old and in 33,4 percent of patients. The best visual acuity with correction increased to reach seven lines in Snellen´s chart in 93 percent of cases. The refractive cylinder barely changed in 0,15 dioptres and the loss of endothelial cells occurred in 8,2 percent of patients and the operative complications were 1,5 percent. CONCLUSIONS: The age of the patients undergoing the cataract surgery through stop and chop technique was mostly over 70 years. The postoperative better corrected visual acuity increased 7 lines in Snellen´s chart; induced astigmatism was lower than 0,5 dioptres; cell loss and the postoperative complications were not significant