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Purpose: To assess the change in the amount of astigmatism caused by frown, straight, and smile incision in patients with pre?existing against?the?rule (ATR) astigmatism of more than and equal to 1 diopter Methods: This is a prospective, comparative study conducted over 18 months on 60 patients. Twenty patients were allocated to each incision using simple random sampling. Demographic details, best?corrected visual acuity (BCVA), intraocular pressure (IOP), anterior and posterior segment evaluation, and A?scan were done. An average of three measurements of K horizontal (Khavg), K vertical (Kvavg), and difference between the two (Khavg ? Kvavg) were taken using manual keratometry. All surgeries were performed by a single surgeon. All the data analyses were performed by using IBM Statistical Package for the Social Sciences (SPSS) version 20 software. Frequency distribution and cross tabulation were performed to prepare the tables. Results: In frown incision, Khavg ? Kvavg was significantly decreased on day 45 from the preoperative value (P < 0.001), followed by straight incision (P < 0.001), and smile incision (P < 0.001). Maximum decrease was observed in frown incision (49.15%) followed by straight (37.75%) and smile (28.57%) incisions. Conclusion: Our results are consistent with reduction of pre?existing ATR astigmatism with temporal incisions, and frown incision seems to be the best approach.
RESUMO
Objetivo: Determinar el astigmatismo inducido por la técnica de facoemulsificación según el lugar de la incisión en los pacientes operados de catarata en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" de enero a diciembre de 2010. Métodos: Se realizó un estudio descriptivo, longitudinal y retrospectivo en 2 510 pacientes operados de catarata mediante la técnica de faco chop por diferentes zonas de abordaje de la incisión principal (superior, oblicua, temporal) y extracción extracapsular del cristalino por incisiones tunelizadas. Se analizó la mejor agudeza visual corregida y sin corregir, la dureza del cristalino, el lugar de la incisión, el equivalente esférico, la queratometría y el astigmatismo inducido. Resultados: La media del astigmatismo queratométrico inducido fue de 0,45 dioptrías por facoemulsificación y 1,30 dioptrías por vía tunelizada. Al relacionarlo con la dureza del cristalino fue de 0,44 dioptrías en los núcleos de 2 cruces de dureza. Se indujo 0,03 dioptrías de astigmatismo con incisión temporal menor o igual a 3 mm. La mejor agudeza visual promedio sin corregir antes de la cirugía fue de 0,12 y después de 0,31; mientras que la corregida fue de 0,50 antes, a 0,77 después de la cirugía. Estos valores fueron mejores en la incisión temporal con cuatro líneas de ganancia de visión sin corregir y cinco líneas con corrección. El mejor equivalente esférico se obtuvo en la incisión temporal con 0,73 dioptrías. Conclusiones: La facoemulsificación con incisión por el lado temporal induce un menor astigmatismo. Esto logra una ganancia visual mejor y satisfactoria para el paciente.
Objective: To determine the astigmatism induced by the phacoemulsification technique, according to the surgical site in the patients operated on from cataract in "Ramón Pando Ferrer" Cuban Institute of Ophthalmology in the period of January to December 2010. Methods: A retrospective, longitudinal and descriptive study was conducted to evaluate the behaviour of post surgery astigmatism in 2510 patients operated on from cataract by means of phacoemulsification technique (Phaco Chop) for different approach areas of main incision (upper, oblique, temporal) and extracapsulary cataract extraction with tunnelized incisions. Variables such as best corrected and non-corrected visual acuity, hardness of the crystalline lens, site of incision, spheral equivalent, keratometry, and induced astigmatism were all analyzed. Results: The mean induced astigmatism in phacoemulsification was 0.45 D, and for the extracapsulary cataract extraction technique was 1.30 D. When relating to the crystalline hardness, the induced astigmatism was 0, 44 D in the nuclei of 2 hardness crossings. The induced astigmatism was 0.03 D with temporal incisions or smaller than or similar to 3mm. The best non-corrected average visual acuity before surgery was 0.12 and after surgery was 0.31, whereas the preoperative corrected acuity was 0.50 and the postoperative value was 0.77. These values were better in temporal incisions with four lines of visual gain without correction and five lines with correction. The best spheral equivalent was 0.73 D in the temporal incision. Conclusion: The phacoemulsification on the temporary side induces smaller postoperative astigmatism with better satisfactory visual gain for the patient.
RESUMO
We analyzed postoperative astigmatic changes according to the location of incision in 129 eyes that sutureless cataract surgeries were performed. We followed up the astigmatic changes until six months postoperatively, and compared the results of two groups of which the one is the preoperative against-the-rule astigmatic cases with superior incisions and temporal incisions, the other is the preoperative oblique astigmatic cases with superior incisions and superotemporal incisions. In the preoperative against-the-rule astigmatic cases, postoperative astigmatic changes were shifted toward against-the-rule astigmatism(0.23 diopters) in superior incisions and toward with-the-rule astigmatism(0.20 diopters) in temporal incisions until 6 months following surgery(p0.05). Surgically induced astigmatisms were less in superotemporal incisions than superior incisions (p<0.01) and corneal astigmatisms were stabilized after one month postoperatively in both groups(p<0.05). These results demonstrated that surgically induced astigmatisms were decreased by the incision at steep axis, and in the cases of preoperative againstthe rule astigmatism, the preexisting astigmatisms were decreased by the temporal incisions.