| BackgroundCataracts are the leading cause of blindness in the world. However, in the vast majority of cases, vision loss is reversible. New cataract surgery techniques have made cataract surgery one of the most successful procedures available in restoring patients' quality of life. Technological advances in recent years have made cataract surgery faster, safer, more comfortable and ultimately more effective. But, The high frequency vibrat energy and the heat it generates, emulsion Particles associated with Phacoemulsification will inevitably result in damage to the intraocular tissues such as corneal, iris, Posterior capsule. So, studies about the efficiency and consumption energy never stopped.In the conventional US mode, the ultrasonic tip make a forward and backward motion at a frequency of 40-45kHz on longitudinal axis. The high frequency may lead to a high energy, except some of which was taken away by the irrigation and aspiration, others was absorbed by the intraocular tissures, then result in damage to them. Among these damages, changes to structure, physiological function and number of comeal endothelial cells are most common, which can lead to comeal edema, decrease of endothelial cells, transparency drop, and other Postoperative complications that will affect the surgical results.In January 2006, Alcon Surgical incorporated OZiL torsional into the Infiniti Vision System. The OZiL torsional portion is a hardware and software upgrade of the machine and includes a dedicated handpiece that produces rotary oscillations of the phacoemulsification tip with a frequency of 32 Kz. This upgrade was required to use the OZiL torsional technology Torsional US uses a torsional handpiece that produces side-to-side rotary oscillations at a frequency of 32kHz. Many studies have proved that torsional mode is more effective and less energy consumption than conventional mode. Theoretically, this side-to-side movement cuts nuclear material in both directions at the tip (shearing effect), which, unlike longitudinal phacoemulsification, does not result in repulsion of lenticular material from the phaco tip. However, it is likely that the torsional motion of the bent tip reduces friction at the incision in the transparent cornea, decreasing the risk for corneal thermal damageBut with torsional, the lens material is not pulverized into little pieces. Now that surgeons are moving toward smaller incisions and smaller instrumentation. So, there is a tendency for the phaco needle to clog when we're working with dense cataracts only using torsional.In September 2009, Alcon Surgical incorporated OZiL IP into the Infiniti Vision System on the base of OZIL torsional. The OZiL IP is a software addition of the infiniti, It is an Intelligent Phaco and When the vacuum level approaches or reaches the preset maximum, short (10ms) pulses of longitudinal phaco are added every 100 ms until the vacuum drops. We designed this study to compare the intraoperative and short-term outcomes of phacoemulsification using these three different technologies.The most important thing which make a visual defect is myopia. The incidence has racial difference.22%～25% in the United States, Western Europe, Australia have myopia, while 47.5% in Japan. Large epidemiological data show that China is a country with one of the highest rates of myopia, there are more than 3 billion mypioa,and the figure is increasing year by year, in which high myopia accounted for about 27%-33%.PIOL implantation become one of the preferred treatment in high myopia because of its good predictability, visual quality, retained adjust ability and reversiblility. Posterior chamber PIOL may cause more cataract and pupil block, while the angle-supportted PIOL will damage the corneal endothelial and anterior chamber.The iris-fixed PIOL has a special advantages.High myopic patients requires not only good visual acuity but also good visual quality. So the calculation of the SI A has the important practical significance.Part 1 The impact of Different ultrasound oscillation mode for cataract extraction on ocular tissuesObjectiveTo discuss the impact of different ultrasound oscillation mode include Longitudinal mode, Torsional mode and Ozil IP mode,for cataract extraction on ocular tissues.MethodsPatients who were diagnosed as cataract from Dec.2009 in our department were divided into 4 blocks according to LOCSⅢ, then the patients in each block were randomly assigned to Longitudinal group(L), Torsional group(T) and Ozil IP(IP) group. The intraoperative data of Total Time(TT),Cumulative Dissipated Energy(CDE), Total Equivalent Power in Position 3(TEPP3),and the consumption of perfusate were measured and compared. One day Postoperative outcome measures the degree of corneal edema, the thickness of corneal incision, corneal volume, and endothelial cell count 3months after surgery.Results193 eyes were enrolled in this study, include 84 males and 109 females, the age range from 36-91 y(mean 70.43±9.10 y).50 eyes in the second degree group,composed of 13 Longitudinal,20 Torsional and 17 Ozil IP.62 eyes in the third degree group,composed of 20 Longitudinal,23 Torsional and 19 Ozil IP.52 eyes in the forth degree group,composed of 14 Longitudinal,17 Torsional and 21 Ozil IP.29 eyes in the fifth degree group,composed of 9 Longitudinal,8 Torsional and 12 Ozil IP.178 eys were followed more than 3 months.OP. INDEX:1 UST:Second degree group:mean UST in the Longitude,Torsional,OZiL IP group is:37.16±18.84s,24.88±11.06s,27.53±15.78s,Third degree group: 40.28±20.23s,29.81±10.66s,35.88±18.11s,Forth degree group:48.22±12.81s,35.84±9.74s,38.41±7.24s,Fifth degree group:92.97±46.89s,57.88±16.03s. 55.60±17.60s. In the forth and fifth degree,mean UST were significantly higher in Longitude group than the other two group.2 TEPP3:Second degree group:mean TEPP3 in the Longitude,Torsional,OZiL IP group is:34.68±10.90%,34.86±12.37%,30.81±4.82%,Third degree group: 40.28±20.23s,29.81±10.66s.35.88±18.11s,Forth degree group:48.89±3.73%,33.21±2.91%,35.10±3.18%,Fifth degree group:42.31±7.71%,35.00±1.82%. 37.21±27.17%. In the third, forth and fifth degree,mean TEPP3 were significantly higher in Longitude group than the other two group.3 CDE:Second degree group:mean CDE in the Longitude,Torsional,OZiL IP group is:13.78±8.34s,10.11±6.88s,9.51±4.63s,Third degree group:18.50±7.16s,9.08±3.07s,9.64±2.84s,Forth degree group:28.41±4.01s,14.65±3.58s,16.32±3.17s,Fifth degree group:81.44±42.15s,57.38±15.42s,65.10±23.88s. In the third, forth and fifth degree,mean CDE were significantly higher in Longitude group than the other two group.4 consumption of perfusate:Second degree group:mean consumption of perfusate in the Longitude,Torsional,OZiL IP group is:59.30±17.53ml,35.24±12.03ml,49.19±20.56ml,Third degree group:58.75±14.35ml,45.39±14.14ml,39.32±10.71ml,Forth degree group:48.43±10.73ml,43.44±13.85ml 48.14±20.95ml,Fifth degree group:82.56±7.72ml,56.12±8.77ml,57.92±12.12ml. In the second degree, mean consumption of perfusate were significantly lower in Torsional group than the other two groups, and in the third and fifth degree higher in Longitude group than the other two group.5 No complications were found during the operation. Blocks were happened in 9 eyes,2 in Longitude and 7 in Torsional, none in IP group.PostOP. INDEX:1 Corneal edema:(1)The thickness of the corneal were measured by Pentacam, then calculate the ICTR, CCTR, TCTR and COVR, and there were no significant difference between those groups. (2) The edema were also divided into four degrees by slitlap, in Longitude group,13 eyes in 0 degree,26 eyes in 1 degree,14 eyes in 2 degree,3 eyes in 3 degree. In Torsional group,13 eyes in 0 degree,41 eyes in 1 degree,17 eyes in 2 degree,3 eyes in 3 degree. In IP group,14 eyes in 0 degree,34 eyes in 1 degree,14 eyes in 2 degree,2 eyes in 3 degree. There were no significant difference between three groups. 2 ECD:ECD were measured before and 3 months after surgery, then calculate the ECDR, Third degree group:ECDR were significantly higher in Longitude group than in Torsional group. Forth degree group:ECDR were significantly higher in Longitude group than the other two group,Fifth degree group:ECDR were significantly higher in Longitude group than in IP group.Conclusion1 The Torsional mode and Ozil IP mode is safer, less consumption energy, and shorter TT than longitudinal mode, especially in dense cataract.2 Coreal edema in the three different ultrasound oscillation mode for cataract extraction on ocular tissues are the same, show that phaco power is no longer the most important thing.3 There are more damages in ECD in Longitude mode especially in dense cataract.Part 2 Surgical induced astigmatism in the implantation of an Artisan phakic intraocular lens through a 5.5mm superior scleral tunnel incisionObjectiveTo evaluate the surgical induced astigmatism in the implantation of an Artisan phakic intraocular lens through a superior scleral tunnel incision of 5.5mm..MethodsThis was a case observational study. The clinical data of 202 eyes of 111 patients with Artisan IOL implantation for high myopia from October 2004 through October 2008 was collected. The patients were followed-up for 12 months. The uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), spherical equivalent (SE), cylinder equivalent (CE) and cylinder axis were examined before surgery and postoperative 1,3,6,12 months, The patients were divided into with rule group and against rule group according to the cylinder axis. Surgery induced astigmatism value was calculated using Holladay vector analysis formula. This clinical trial was approved by the Ethics Committee of Guangdong General Hospital. Written informed consent was obtained from each patient prior to the surgery.ResultsThe UCVA of 195 eyes (94.1%) was 0.5 or better in postoperative 12 months, and that of 172 eyes (85.1%) showed the improvement of BCVA during the follow-up duration. The mean CE values were reduced in 1,3,6,12 months after surgery in comparison with before surgery (t=-4.30, P=0.00; t=-2.27, P=0.01; t=-2.04, P=0.04, t=-2.79, P=0.01). Vector analysis of total surgically induced Astigmatism revealed that the mean incision-induced astigmatism value was+1.94 D,+2.26 D,+2.29 D,+2.25D at 171°,170°,181°,175°in 1,3,6,12 months after surgery. The surgery-induced astigmatism was (+1.97±1.84)D, (+2.25±1.75)D, (+2.27±1.76)D, (+2.24±1.75)D in with rule group at postoperative 1,3,6,12 months respectively; while those in against rule group was (+1.75±1.88)D, (+2.35±1.74)D, (+2.38±1.76)D, (+2.34±1.74)D respectively. No significant differences were found Between the two groups (t=0.54,-0.29,-0.27,-0.29; P=0.59,0.78,0.79,0.78). Conclusion Implantation of Artisan IOL is an effective approach to correction of high myopia. A 5.5 mm superior scleral tunnel incision in operation induces a+2.25 D astigmatism at 175°meridian.ConclusionImplantation of Artisan IOL is an effective approach to correction of high myopia. A 5.5 mm superior scleral tunnel incision in operation induces a+2.25 D astigmatism at 175°meridian. |
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