The Research Of The Function Of Tear Film After Phacoemulsification By Different Surgery Insicion

Background: Recentely phacoemulsification combined withIOL implantation have already being the clinically classic surgurymethod. Compared with traditionary extracapsular cataractextraction, phacoemulsification has many good qualities, such asshort incision, slight lesion, rapid recovery and fewercomplication. So phacoemulsification has been approved and favoredby clinician.But in clinic we find that there are many patients with thecomplaint of dry eye after surgery step by stap asphacoemulsification has being widely carried out and we have beenknowing the ocular surface disease more and more deeply. The dryeye symptom less or more make patients' linving qualities fall down. Mostof the patients are the olders. It is identified that the density andthe branch number of corneal nerve descend obviously in the olders'cornea compared with that in the youngers' cornea and the contentof goblet cell that excrete mucin in the olders' conjunctivadecrease obviously compared with that in the youngers' conjunctiva.At the sametime clinical analysis manifest the stability of theolders' tear film descends. Under the condition of tempreture21.64±2.80℃ and humidity 58.54±14.70%,the olders'tear breakup time is 4.20±1.46 seconds,of which the symptomless is 5.90±2.23 seconds and the symptomatic is 4.11±1.21.The operation willprecipitate the happening and exacerbation of the dry eyesymptom.So it is significant for clinical practice that wesummarize the regularity of the change of tear film function afterphacoemulsification in the olders.At the present the research about the influence ofphacoemulsification on the tear film is not too many.Almost all thearticles revolve around the influencial factor of tear film.Theeffect of phacoemulsification on tear film comprise five aspects:The first,after surgery the edematization of cornea andconjunctiva,the local eminence of operative incision,the healingof cut and the mechanical injury of operation to the microvillusof corneal epithelium lead to the irregulatity of ocularsurface,which induce decreased stability of tear film.Thesecond , Afte surgery corneal nerve is cut off .Operative procedurecause the transportation disorder of acetylcholine andcholinesterase in the peripheral nerve around the incision nomatter which incision is used, clear corneal incision or sclerotictunnel incision. Then the function of corneal nerve is disorderedand the perception of cornea subsides.Phacoemulsification damagescorneal interstitial nerve and affects the healing of cut,which isdifficult to recover. Not only the ocular suiface shape changes,butalso the damage to cornea affects the feedback system which iscomprised of lacrimal gland,ocular surface,the nerve on the ocularsurface,which causes reduced lacrimal secretion.The third,thetopical anesthetic drug applied preoperatively influences thestability of tear film,which damages the microvillus on the ocularsurface epithelial cell and lead to punctiform denudation ofcorneal epithelium , corneal edema, increased irregularity ofcorneal shape and decreased tear film stability.The forth,thesteriod and non-steriod anti-inflammatory agent appliedpostoperatively impaired tear film function on the ocularsurface.Glucocorticoid eye drop applied for more than 3months willdamage the tear film to some degree and cause decurtated tear filmbreakup time and decreased lacrimal secretion.The fifth,Operationevokes the inflammatory reaction on the ocular surface.Thetransforming growth factor-β1 and nuclear factor-κB in theconjunctival epithelial cells express increasingly afterphacoemulsification.The decreased tear film stability has a closerelationship with the inflammotory level.Now the researches about the influential rule of operativeprocedure on tear film function are almost around laser surgerytreating high myopia. There is few about the research of effect ofphacoemulsification on tear film. It is meaningful for us toinvestigate the influential law of phacoemusification on tear filmand further to approach the machanism of dry eye and find how toguard the ocular surface postoperatively.Objective: Investigating the difference of the influenceddegree and the recovery time of the function of tear film betweenthe two kinds of surgery incision after phacoemulsification. Thusin clinical we would choose the proper incision on the patients withnot too better ocular surface condition.Methods: This clinical trial involved 73 patients(91eyes) withaged related cataract who underwent phacoemulsification and IOLimplantant in our hospital from June 2005 to January 2006 .All thepatients were divided into two groups at random.They were group A(38patients of 48 eyes used sclerotic tunnel incision )and group B (35patients of 43eyes used clear corneal incision ).Tear film break-uptime(BUT),Schirmer's I test without topical anesthesia,cornealfluorescein staining,and the height of tear meniscus were measuredpreoperatively and 1 day and 1 week,1 month,3 monthspostoperativelyResults: The function of tear film of Group A obviously felldown postoperatively: At 1 day,1 week postoperatively, the meantear film break-up time reduced greatly,and returned to thepreoperative value at 1 month postoperatively.Corneal fluoresceinstaining score increased at 1 day and 1 weekpostoperatively ,returned to the preoperative value at 1 monthpostoperatively. The value of Schirmer'I test increased greatlyat 1 day postoperatively,reduced to the preoperative one at 1 weekpostoperatively. and the height of tear meniscus increased greatlyat 1 day,1week postoperatively,reduced to the preoperative one at1 month postoperatively.The function of tear film of Group B(clear corneal incision)also fell down obviously: At 1 day,1 week postoperatively, the meantear film break-up time reduced greatly,and returned to thepreoperative value at 1 month postoperatively.Corneal fluoresceinstaining score increased at 1 day and 1 weekpostoperatively ,returned to the preoperative value at 1 monthpostoperatively. The value of Schirmer'I test increased greatlyat 1 day postoperatively,reduced to the preoperative one at 1 weekpostoperatively. and the height of tear meniscus increased greatlyat 1 day,1week postoperatively,reduced to the preoperative one at1 month postoperatively.There isn't obvious disparity in the recovery of tear filmfunction after phacoemusification between Group A(clear cornealincision) and Group B(sclerotic tunnel incision). Everyindexes(BUT,Schirmer's I test ,fluorescein staining, the heightof tear meniscus) tell no disparity at each time periodpostoperatively(1day,1week,1month,3months).Conclusion: 1.The function of tear film of ocular surfacefalls down obviouslu after phacoemulsification.The functiondecreases obviously at 1day,1week postoperatively and returns tothe preoperative level at 1month postoperatively.2. The damageextent of phacoemulsification on tear film is identical nomatterwhich incision is used,clear corneal incision or sclerotic tunnelincision.