Clinical Comparison of Three Viscoealsitcs: Healon, healon GV, Provisc

Viscoelastics which are used in intraocular surgery sell many kinds as to its unique properties. We intended to valuate the clinical usefulness of three viscoelastics, Healon, Healon GV and Provisc. We performed phacoemulsificatioin and posterior chamber intraocular lens implantation in 26, 28, 29 eyes with each viscoelastics and measured the corneal thickness at preoperatively, postoperative 1 day, 1 week, 1 month, 2 months, 5 months and endothelial cell count at preoperatively, postoperative 2 months. We also analysed the anterior chamber maintenance and easiness of injection and removal during operation, In Healon used group, Preoperative corneal thickness was 549.7+/-24.3micrometer, in Healon GV group, 550.1+/-28.7micrometer, in Provisc group, 543.1+/-39.0micrometer and which were changed into 552.1+/-39.0micrometer, 533.1+/-21.1micrometer, 522.2+/-32.0micrometer at postoperative 5 months respectively, but there was no statistically significant difference between preoperative and postoperative status in all three groups. There was a tendency of slight reduction of endothelial cell count at postoperative 2 month in three groups, but it wasn`t statistically significant, too. Healon GV and Provisc were better in anterior chamber maintenance but injection into anterior chamber and removal by irrigation and aspiration were more easy in Healon used group. So, we suggest all three viscoelastics has hood endothelial protective effect and can be used freely as to their unique properties and the operative situation.

The changes of Corneal Endothelial Morphology after Phacoemulsification by using Healon GV of Viscoat

Corneal endothelial cell damage from phacoemulsification has been attributed to mechanical injury caused by surgical manipulation and oxygen free radicals produced by ultrasound. We evaluated role of protective effect in Healon GV and Viscoat on corneal endothelial cell damage during phacoemulsificatin Seventy five eyes underwent phacoemulsigication hrough scleral tunnel incision with posterior chamber lens implantation.: Healon GV, 32 eyes and Viscoat, 43 eyes. We analyzed the corneal endothelial morphology using non-contact specualr microscope and analysis program.The percent loss of corneal endothelial density at 3 months postoperative period was greater in Viscoat(5.87%) than in Healon GV(2.47%),although it was not statistically significant(p>0.1). Coefficient of variation in cell size and hexagonality of the corneal endothelial cells also showed no significant difference between the two groups(p>0.1). In conclusion, Healon GV and Viscoat have similar protective effect on the corneal endothelial cell damage induced by ultrasound during phacoemulsification.

Comparative Animal Study of Healon and Hyal 2000

We compared Healon which is widely used as a viscoelastic with Hyal 2000, recently produced in Korea. We evaluated anterior chamber reaction, intraocular pressure, and specular microscopy after injection of 0.2ml Healon and Hyal 2000, respectively, into anterior chamber of 20 cats, and performed light microscopy and scanning electron microscopy 8 weeks later. We calculated the corneal swelling rate after 0.2ml Healon and Hyal 2000 were coated on the corneal endothelium of 10 rabbits and GBR solution with 0.5mM H2O2 was perfused. Anterior chamber reaction disappeared after 2 days of injections, and intraocular pressure(IOP) increased after 6 hours of infection but normalized after 24 hours in both 2 groups. Corneal endothelial cell count was 4956cells/mm2 in the Healon group and 5021cell.mm2 in the Hyal 2000 group on the first post-injection day. and 4827cells/mm2 and 4810cell/mm2, 1 week later, without a statistical difference. The histologic abnormality was not detectable in light microscopy or scanning electron microscopy in both groups. The corneal swelling rate with Healon was 15.85micrometer/hr and 12.72micrometer/hr with Hyal 2000, while it increased to 69.29micrometer/hr and 67.51micrometer/hr in controls(p<0.05), respectively. The clinical findings showed no difference and histologic findings appeared normal in both the Healon and the Hyal 2000 groups. The inhibitory effect on the corneal swelling was similar during in vitro perfusion in both groups.

Evaluation of New Viscoelatics in Rabbit: Healon, Healon GV, Provisc

Viscoelastic substance which is one of the most important thing in anterior segment surgery sells many kinds as to its unique properties. The complications during its use are acute postoperative intraocular pressure elevation, corneal edema, severe ocular pain, blurred vision. The extent of elevation, peak time and normalized time of intraocular pressure can be varied by operative technique, amount of residual viscoelastics in anterior chamber, kinds of viscoelastics. To compare the safety of Healon GV and Provisc with Healon, we injected the same amount of those three viscoelastics into anterior chamber of 27 rabbits divided by three groups and examined the degree and change of intraocular pressure elevation, corneal edema, intraocular inflammation, maintenance of anterior chamber. Healon GV showed the persistent intraocular pressure elevation immediately after injection and normalized at 24 hours. Healon and Provisc showed elevated pressure at 7 and 5 hour but normalized within 12 hour. Corneal thickness increased significantly at 1 to 7 hour in Healon and Healon GV group and continued to 24 hour in Healon GV group and there was no significant pressure change in Provisc group compared with preinjection status. There were no significant differences in intraocular inflammation, amintenance of anterior chamber between three viscoelastics. Healon GV shoed more frequent, higher intraocular pressure elevation as compared to the other two viscoelastics, but pressure was normalized within 24 hour. From the above results, it is concluded that Healon GV can be used well with caution and Provisc can be used widespreadly due to its minor complication, too.

Comparison of The Effects of Healon(R) and BioLon(R) on Rabbit Eyeballs after Intracameral and Intravitreal Injections

We conducted a study to compare the effects of Healon(R) and BioLon(R), which are sodium hyaluronates made by different raw materials, on rabbit eyeballs after intracameral and intravitreal injections. In the intracameral-injection group, aqueous humor was replaced with 0.2 ml of Healon(R) or BioLon(R), and in the intravitreal-injection group. 0.4 ml of Healon(R) or BioLon(R) was injected after the removal of the same amount of vitreous. Slitlamp and indirect ophthalmoscopic examination, measurement of IOP, and measurement of corneal thickness were performed preoperatively and at 2hours, 24 hours, 3 days, and 7 days postoperatively. Histopathologic examinaion was done at 7 days postoperatively. No group had significant differences in all tests(p>0.05) and the findings were normalized within 7 days. These results indicated that there were no significant differences between the Healon(R) and BioLon(R) groups in the effects on rabbit eyeballs after intracameral and intravitreal injections.

The Effects of Ascorbic Acid on Intraocular Pressure Elevation by Viscoelastic Substance

We evaluated intraocular pressure(IOP), remained radioactivity of 51Cr tagged Healon(R) in the anterior chamber following lens aspiration in rabbit eyes, and ultrastructual changes of trabecular meshwork were observed after intravenous injection of ascorbic acid. The average lOPs returned to preoperative lOP level on the postoperative seventh day in control group. While, those in experimental group returned on the postoperative third day. Healon(R) was completely outflowed in control group on the postoperative seventh day and in experimental group, on the postoperative third day. There is a significant correlation between lOP and remained radioactivity rate of Healon(R) in control and experimental group. Under scanning electron microscope examination, the control group showed the most of Healon(R) debris outflowed on the postoperative seventh day. On the other hand, the experimental group showed no Healon(R) debris was observed on the postoperative third day. In conclusion, our experiment showed ascorbic acid is effective in lowering intraocular pressure and preventing chance of intraocular pressure elevation.

The Effect of Healon(R) and Metrol(R) on Cornea and Intraocular Pressure in Extracapsular Cataract Extraction with Posterior Chamber Lens Implantation

The aim of this study is to evaluate the effect of viscoelastic substance on corneal thickness, corneal endothelium and intraocular pressure by measuring corneal thickness, corneal endothelial cell density and intraocular pressure in extracapsular cataract extraction with posterior chamber lens implantation. The study comprised of 50 patients, divided into two groups: extracapsular cataract extraction with posterior chamber lens implantation using Healon(R) or 2% methylcellulose(Metrol(R)). The txtracapsular cataract extraction was done by irrigation and aspiration technique and the posterior chamber lens was implanted into posterior chamber. The corneal thickness and endothelial cell density were measured preoperatively and at 6 weeks of postoperative period: intraocular pressure was measured preoperatively and at 24 hours of postoperative preiod. The results were as follows: 1. The preoperative corneal thickness, endothelial cell density and intraocular pressure were 499 +/- 34 micrometer, 2523 +/- 388 cells/mm2 and 15.9 +/- 2.4mmHg in average respectively. 2. The postoperative corneal thickness with Healon(R) was 501 +/- 42 micrometer, and with Metrol(R) was 491 +/- 28 micrometer. There was no significant difference between Healon(R) used and Metrol(R) used group(p<0.05). 3. The loss of endothelial cell with Healon(R) was 10.7%, and with Metrol(R) was 17.1%. The endothelial cell loss was lower in Healon(R) used group than that of Metrol(R) group. 4. The intraocular pressure with Healon(R) was 14.6 +/- 3.9mmHg, and with Metrol(R) was 12.3 +/- 4.4mmHg. There was no significant difference between Healon(R)-used and Metrol(R)-used group(p<0.05).

Clinical evaluation of AMVISC(R) as a Vicodlastic Substance in Extracapsular Cataract Extraction with Intracoular lens Implantation

The effects of AMVISC(R) and Healon(R) in patients undergoing extracapsular cataract extraction with intraocular lens implantation were compared to the operative efficiency and postoperative reactions namely, inflammation, intraocular pressure, corneal endothelial damage, and corneal thickness. During the course of the cataract operations, twenty eyes received AMVISC(R) and twenty eyes received Healon(R). The AMVISC(R) and Healon(R) were all aspirated from anterior and posterior cha mbers by means of the irrigation and aspiration system at the end of the procedure. There were no significant difference in operative efficacy and postoperative reactions between AMVISC(R) group and Healon(R) group.