白内障对眼压影响.pdf

EXPERIMENTAL AND THERAPEUTIC MEDICINE 5:507-510,2013Abstract.The aim of this study was to investigate the effects of phacoemulsification with intraocular lens(IOL)implanta-tion on intraocular pressure(IOP)and anterior chamber depth(ACD)in patients with cataract or cataract associated with primary angle closure(PAC).A total of 361 patients(481 affected eyes)with senile cataract(cataract group)and 44 patients(52 affected eyes)with cataract associated with PAC(cataract with PAC group)underwent phacoemulsifica-tion with IOL implantation from July 2005 to May 2007 and were followed up for 3 to 25 months.There was a significant difference between pre-operative and post-operative IOPs(t=9.270,P0.01)in the cataract group and in the cataract with PAC group(t=3.29,P0.05)and the IOP three months after surgery(t=2.154,P0.05)between the two groups.There was a significant difference between the pre-operative and post-operative ACDs(t=7.781,P0.01)in the cataract group and in the cataract with PAC group(t=4.528,P0.01).A significant difference in ACD between the two groups(t=8.325,P0.05).Phacoemulsification with IOL implantation has IOP-lowering effects on cataract and cataract with PAC patients.The International Society of Geography and Epidemiology of Ophthalmology classification method for angle closure glaucoma was adopted in our study.Furhter studies are required to prove the safety and mechanism of lowering IOP impact of phacoemulsifation towards PAC glau-coma(PACG).IntroductionThe incidence of cataract and glaucoma,including primary angle closure(PAC),gradually increases with age.Some patients suffer from both cataract and glaucoma.In the treat-ment of PAC,phacoemulsification and intraocular lens(IOL)implantation have been used.The occurrence and development of disease risk factors,the anterior chamber angle of PAC and the degree of intraocular pressure(IOP)are reported to be significantly improved by phacoemulsification(1-8).According to the clinical situation,cataract and glaucoma may be treated by a simple cataract surgery,surgical staging(where cataract surgery is carried out before glaucoma surgery or vice versa)or combined surgery(9).The general risk factors for PAC glaucoma(PACG)include:family history of angle closure(10,11),age(12,13),gender(12-14)and Asian or Inuit descent(15-19).Other risk factors include eye hyperopia(20-22),the perimeter of the shallow anterior chamber(20,22,23),the perimeter of the central shallow anterior chamber(22,24),the steepness of the corneal curvature(25),the thickness of the lens(22,26)and the axial length(22,26,27).The lens element has been gaining widespread attention.A study has shown that the lens weighs 205 mg in 20-year-old individuals and up to 285 mg in 80-year-olds,a growth of 30%.The thickness of the lens at the age of 20 is 4 mm and at the age of 65,it may reach 4.8 mm,a 20%increase(28).Therefore,in PAC with cataract,cataract removal by surgery is expected to provide new options on anterior segment structure and its function improvement.We analyzed 481 eyes among 361 patients with cataract and 52 eyes among 44 cataract patients with PAC to observe the effect of phacoemulsification cataract surgery on IOP and central anterior chamber depth(ACD).Patients and methodsGeneral information.From July 2005 to May 2007,481 eyes in 361 patients(cataract group)undergoing senile cataract phacoemulsification and IOL implantation were investigated.A total of 144 males(193 affected eyes)and 217 females(288 affected eyes)were included.There were 44 patients(52 eyes)who had cataract with PAC(cataract group),including 18 males(21 eyes)and 26 females(31 eyes)aged 47-94 years old.The mean age was 70.5 years.Eight patients(8 eyes)of cataract patients presented acute Effects of phacoemulsification on intraocular pressure and anterior chamber depthXIN-QUAN LIU,HUA-YING ZHU,JING SU and XIAO-JUN HAOAffiliated Longhua Hospital,Shanghai University of Traditional Chinese Medicine,Shanghai 200032,P.R.ChinaReceived August 25,2012;Accepted November 1,2012DOI:10.3892/etm.2012.835Correspondence to:Professor Xin-Quan Liu,Affiliated Longhua Hospital,Shanghai University of Traditional Chinese Medicine,No.725 South Wanping Road,Shanghai 200032,P.R.ChinaE-mail:Key words:cataract,intraocular pressure,glaucoma,lenses,intraocularLIU et al:PHACOEMULSIFICATION EFFECT ON INTRAOCULAR PRESSURE508attack with an initial IOP45 mmHg(1 mmHg=0.133 kPa),corneal edema,shallow anterior chamber,dilated and fixed pupil,opaque lens and an anterior chamber angle revealed by gonioscopy to have closed by more than half.These patients were given 20%mannitol,acetazolamide and-blocker therapy and when the corneal transparency was restored,the IOP returned to normal.Phacoemulsification and IOL implan-tation was performed after one week.A total of 36 cases(44 eyes)of cataract associated with chronic angle closure were identified,with an initial IOP higher than normal.They also exhibited a transparent cornea,shallow anterior chamber,normal pupil size,opaque lens and ocular pressure of 21.8-34 mmHg.Gonioscopy revealed that the anterior chamber angle had closed by more than half.Following treatment with acetazolamide and/or-blocker,the IOP dropped to normal,at which point the patients underwent phacoemulsification and IOL implantation.Follow-up was performed 3-25 months post-surgery,with an average of 13.4 months.This study was conducted in accordance with the Declaration of Helsinki.This study was conducted with approval from the Ethics Committee of the Affiliated Longhua Hospital of Shanghai TCM University.Written informed consent was obtained from all participants.Pre-operative examination.In addition to conventional visual function,the IOPs of all patients were measured using a Canon TX-10 tonometer prior to surgery.The results were as follows:6.50-21.00 mmHg in the cataract group,with an average of 14.863.79 mmHg,and 16.20-21.30 mmHg in the cataract with PAC group,with an average of 19.923.76 mmHg.The ACD was measured with an Alcon ultrascan A/B ultrasound.The ACD was 1.97-3.25 mm in the cataract group,with an average of 2.380.32 mm.The central ACD was 1.29-2.78 mm in the cataract and glaucoma group,with an average of 1.690.35 mm.Gonioscopy was used for static checks and pressure checks for both eyes.Surgical methods.All surgeries were performed by the same surgeon.Following ocular anesthesia,an incision was made 3.2 mm above the transparent cornea.The anterior chamber was injected with a viscoelastic agent.Following ocular anes-thesia,a 3.2mm clear corneal incision was made.The anterior chamber was injected with a viscoelastic agent.Approximately 5 to 5.5 mm diameter continuous curvilinear capsulorhexis was performed.After the lens nucleus was water-separated,phacoemulsification was performed in the capsular bag.The lens cortex was sucked clean using an automatic irriga-tion/aspiration system.Before and after capsule polishing,the viscoelastic agent was injected into the capsular bag and an artificial lens was implanted into it.The viscoelastic agents were then sucked clean to restore the anterior chamber.All surgeries were successful and no complications occurred.Post-operative check.The post-operative check included the slit-lamp examination of anterior segment,keratometry,uncorrected vision acuity and best-corrected vision acuity.The follow-up was conducted at 1 day,1 week,1 month and 3 months after surgery to measure the IOP.In the final visit,the anterior chamber angle and depth of both eyes were checked for all cases.Statistical analysis.Analysis was carried out using SPSS 11.5 software(SPSS Inc.,Chicago,IL,USA).Data were compared between different groups using a t-test.Different time periods were compared using analysis of variance(ANOVA).P3 months after surgery.The IOP pre-surgery was not statistically different from that 1 day after surgery(t=-3.82,P0.05).The differ-ence between the IOP pre-surgery and 1 week after surgery was statistically significant(F=6.259,P3 months,16.523.15 mmHg.The IOP of 8 acute PAC cases on the first post-operative day was more than 40 mmHg,with fibrin-like exudate in anterior chamber,unclear iris texture and corneal edema.After actively reducing the IOP,the inflammation was controlled,the IOP decreased to normal levels and the inflammation subsided.No IOP spike was observed and no IOP lowering therapy was required for the remaining cases in the two groups.The pre-operative and the first day post-operative IOP in each group showed no statiscally significant difference(t=0.514,P0.05).No significant differences were observed between the two groups in pre-operative IOP(t=-2.437,P0.05)or IOP from the last visit(t=2.154,P0.05).However,a significant difference was observed in each group when comparing pre-operative IOP to post-operative IOP 1 week(F=3.290,P0.01).ACD.The ACD axis was found to be 3.040.39 mm when a return visit was conducted 3 months after surgery in the cata-ract group.The difference in the ACD before and after surgery was significant(t=7.781,P0.01).The anterior chamber shaft depth in the cataract with PAC group 3 months after surgery was 2.820.41 mm and the difference between the anterior chamber shaft depths before and after surgery was significant(t=4.528,P0.01).The ACD axes of the two groups prior to surgery were statistically significantly different(t=8.325,P0.05).DiscussionGlaucoma of the eye has become the second most prevalent cause of blindness and the primary cause of irreversible blind-ness(29).Previous studies have confirmed that the damaging effects of PACG occur more rapidly and are more severe than those of primary open-angle glaucoma(POAG)(30,31).In China,PACG is estimated to cause unilateral blindness(visual acuity 2.5 mm and 98.9%of the angles was greater than 200,with no possibility of angle-closure glaucoma(40).Filtering surgery had been recommended for eyes with peripheral anterir synechia of more than 180.However,for the present study group cases,we considered that cataract plays an important role in the development of angle closure.Phacoemulsification and IOL implantation remove the trig-gers of lens expansion,deepen the anterior chamber following surgery,open the angle,normalize the functionality of the damaged trabecular and decrease IOP(40).Patients who use drugs for the effective control of IOP may use this method as a safe and effective surgical choice.The current study focused on patients with clinically significant cataracts.In PAC or PACG patients,it remains unknown whether the transparent lens should be removed to curb or control IOP PAC progress due to the lack of evidence to support large-scale controlled studies.In the absence of reli-able evidence,it appears that PAC for cataract patients is not associated with lens-derived risk factors;thus,its treatment with phacoemulsification cataract extraction surgery should be carefully considered.References 1.Euswas A and Warrasak S:Intraocular 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