Dissertation > Excellent graduate degree dissertation topics show

Investigation of Structure and Function Alterations in Rabbit Eyes after Little Dose Formaldehyde Injection

Author: ChenDongYue
Tutor: LiuZaoXia
School: Jilin University
Course: Ophthalmology
Keywords: formaldehyde rabbit corneal lens retina
CLC: R77
Type: Master's thesis
Year: 2006
Downloads: 30
Quote: 0
Read: Download Dissertation

Abstract

Formaldehyde (HCHO) is a highly reactive chemical material,whichis widely used during the course of various industries and medicaltreatments. Its boiling point is -19.5℃, specific gravity is 1.06g/ L. Its water solution,named formalin, is a kind of achromatistoustransparent liquid and has a rank smell.In hospital, formaldehyde is not only used as tissuepreservative or fixative,but also as common medical sterilizingagent.And if formaldehyde was misconducted ,it would do harm topatients,especially in intraocular operation.Objective :We investigate the side effects of intravitrealinjection of formaldehyde on rabbit eyes and the secure method ofthe use of formaldehyde sterilizing agent.Method:Animals:thirty healthy male rabbits, weighing 2.2–2.5kg, were confirmed to have normal optical media and fundi prior toinitiation of the study.The animals were anaesthetized withintermixture of 50g/l ketamine and 50g/l phenergan. Then, 0.1 ml of1%,0.5%,0.1% or 0.01% formaldehyde was injected through the sclera4 mm from the limbus into the central vitreous cavity of the lefteye . One day, three days, one week, two weeks, and one month afterintravitreal injection, the eyes were inspected and examined bybiomicroscopy and ophthalmoscopy weekly.After two weeks or onemonth ,the eyes were examined by FFA ,VEP, and ERG.In one month, theeyes were enucleated and examined histologically.Result: 1.The rabbit corneas were transparent underophthalmoscope every time.One week after injecton the animals whoreceived 1% and 0.5% formaldehyde showed mild posterior subcapsularcataract and retinal vessel dilation,which was severe after twoweeks.The rabbits who received 0.1% formaldehyde showed mildposterior subcapsular cataract and retinal vessel dilation . The discboundary was blur after three weeks with 1%, 0.5%,0.1% formaldehydeinjection.One month after treatment, the animals who received 0.1%or 1% formaldehyde became mild posterior subcapsular cataract andretinal lesions. The comparitive group E was mild congested.2. Theaverage cell density and the percentage of the hexagonal cell ofendothecium decreased.There was significant correlation betweenformaldehyde dose and morphometric paramerers,i.e. positivecorrelation between formaldehyde dose and the coefficient ofvariation, negative correlation between formaldehyde dose and thecell density of hexagonality. 3. (1)VEP: The delitescence ofexperimental group A ,B prolonged after two or four weeks treatment(P < 0.05).There was positive correlation between the delitescenceand formaldehyde concentration. The amplitude of experimentalgroup A, B, C obviously declined. The amplitude of experimental groupD mildly descended . There was negative correlation between theamplitude and formaldehyde concentration. (2) ERG: The Ab、Lb、Lb were obviously different between experimental group A, B, C,D andcomparative group E after four weeks treatment. The La mildlyprolonged.4.fundi photography and FFA: The experimental groups andthe comparative group did not have abnormal fluorography in rabbitleft eye after twe weeks injection.The experiment group A, B hadfluorescein leakage from capillary vessel on disc or beside it aftertwo weeks injection. 5. Vacuolar degeneration was seen in someendothelial cells with LM ,four weeks later after 1% or 0.5%formaldehyde injection . We found the eyes that received 1% ,0.5%or 0.1% formaldehyde had abnormal retina with SEM. The ganglioncell layer and outer nuclear layer were disorganized in eyes .Markedly disorganized retina was observed in eyes that received 1%or 0.5% formaldehyde . The optic nerve of eyes that received 1% or0.5% formaldehyde showed vacuolizations.The optic nerve of eyes thatreceived 0.01% formaldehyde appeared to be nearly normal.Conclusion : (1) The corneal endothelium is distinctly damagedafter 1% or 0.5% formaldehyde solution intravitreal injection.And the number of corneal endothelium reduces,the shape is mildlyalterated with 0.1%, 0.01% formaldehyde solution intravitrealinjection.(2) Posterior subcapsular cataract was showed after morethan 0.1% formaldehyde solution intravitreal injection.(3) Theinvestigation indicates that intravitreal injection of more than0.01% formaldehyde damages retina and optic nerve.(4) In clinic,instruments and stuffs with formaldehyde solutionbe fumigatingshould be water flushed thoroughly to prevent patients fromdamage.(5) It is the best way not to reuse once stuffs as savingmaterials.

Investigation of Structure and Function Alterations in Rabbit Eyes after Little Dose Formaldehyde Injection

Abstract

Related Dissertations