We evaluated histopathologically the effect of the viscoelastic substance on surgery of the extraocular muscle in the 26 rabbits with 1. 6-2. 5kg of weight. The viscoelastic substances were 1% sodium hyaluronate(Healon) and 2% hydroxypropyl methylcellulose(Methocel), which were introduced between the extraocular muscle and its adjacent tissue on surgery. The rabbits were categorized by group 1(the rabbits with Healon), group 2(with Methocel), and group 3(with normal saline as control). These rabbits were enuclated at 3rd, 7th, 14th, 28th and 56th day following operations, and the eyes were fixed in 2.5% glutaraldehyde solution. The tissue was stained with hematoxylin-eosin and Masson's trichrome, and examined under a light microscope. The results were as follows: 1. In the first group(Healon), the tissue adhesion and degeneration of the muscle were milder than those of control(saline) group. 2. The changes in second group(Methocel) was milder than in the first group and more severe than in control group. 3. It is concluded that 2% Methocel can be used clinically in the surgery of the extraocular muscle.
Glutaral ; Methylcellulose ; Muscles* ; Rabbits ; Sodium ; Tissue Adhesions ; Viscoelastic Substances

Several different viscoelastic substances are widely used in many ophthalmologic fields. In our study, the efficacy and safety of the different kinds of viscoelastics -Healon(R), Provisc(R), Viscorenal(R), Hyal-2000(R), Viscoat(R) and Biolon(R)-was evaluated in undergoing phacoemulsification and posterior intraocular lens implantation, corneal transplantation and ocular trauma surgery. We evaluated and the facility of the injection the foreign materials during injection of viscoelastics through the microscopy. We measured the changes of intraocular pressure at the postoperative 1 day and corneal endothelial cell count at the postoperative 2 month. The mean endothelial cell loss after phacoemulsification and posterior intraocular lens implantation was 13.71% at postoperative 1 day and there was no significantly different among groups. The incidence of the foreign materials including air bubles in viscoelastics in the operating microscope was Provisc(R), Hyal 2000 Viscorneal(R), Biolon(R), Healon(R) in order. The mean incidence of the intraocular pressure above 25 mmHg after cataract surgery at postoperative 1 day was 3.94%and was Hyal 2000(R), Biolon(R), Viscorneal(R), Healon(R), Provisc(R) in order. The incidence of the additional use of the antiglaucoma drugs in keratoplasty patients was 76%in Healon(R) group, 26.7%in Viscoat(R) group, 69.2%in Provisc(R) group respectively. From the results of this report, we conclude that it is desirable to use the proper viscoelastics according to the chemical and physical properties in special situations, but there is no significant difference in the same viscoelastic substance.
Cataract ; Corneal Transplantation ; Endothelial Cells ; Humans ; Incidence ; Intraocular Pressure ; Lens Implantation, Intraocular ; Microscopy ; Phacoemulsification ; Viscoelastic Substances

When the corneal endothelium is injured by intraocular surgery, corneal edema occurs above the threshold level. Preoperative examination of corneal endothelium is valuable in prediction the degree of transparency of the cornea. We conducted this study to elucidate what factors affect corneal endothelial cells in performing the cataract extraction and IOL insertion and what is necessary to minimize the corneal endothelial damage. We performed pacoemulsification and IOL insertion in guttata patients, and preoperative and postoperative endothelial examination was done by using specuar microscope and pachymeter. Although the mean of endothelial cell density was diminished from 1498.7cells/mm2 to 1301cells/mm2 after operation. visible edema was not detected by slit lamp examination and visual acuity was improved from 0.15 to 0.48. The older the patient`s age, the longer the time of phaceemulsification; as the ages of the patients are increased, postoperative corneal thicknesses were increased and postoperative endothelial cell densities were decreased. The endothelial cells were relatively well preserved after cataract operation in patients of preoperative diminished endothelial cells. We suggest that when performing the cataract operation in patients of decreased endothelial function, one must use appropriate large amount of viscoelastic substances, and minimize phacoemulsification power and time in as short operation time as possible by accurate surgical technique. We also believe that periodic postoperative endothelial examination is necessary in patients with decreased endothelial function.
Cataract Extraction* ; Cataract* ; Cornea ; Corneal Edema ; Edema ; Endothelial Cells* ; Endothelium, Corneal ; Humans ; Phacoemulsification ; Viscoelastic Substances ; Visual Acuity

PURPOSE: To determine whether viscoelastic materials are effective to protect the corneal endothelium from air bubble damage. METHODS: Human eye bank (n=12) and rabbit (n=22) eyes underwent a standardized phacoemulsification procedure with or without viscoelastic material [1% sodium hyaluronate (Healon(R)), 1.4% sodium hyaluronate (Healon GV(R)), 3% sodium hyaluronate with 4% chondroitin sulfate (Viscoat(R))]. The integrity of the endothelium was examined after the procedure with F-actin staining and scanning electron microscopy (SEM). RESULTS: In the phacoemulsification experiment without viscoelastic material, with Healon, and with Healon GV, the endothelium of both human and rabbit corneas had many areas of cell loss in a pattern consistent with air bubble damage. But with Viscoat, endothelial cells remained intact. CONCLUSIONS: We found that Viscoat was effective to protect the endothelium from air bubble damage. Viscoat seems to protect the endothelium by acting as a physical barrier.
Actins ; Chondroitin Sulfates ; Cornea ; Endothelial Cells ; Endothelium ; Endothelium, Corneal ; Eye Banks ; Humans ; Hyaluronic Acid ; Microscopy, Electron, Scanning ; Phacoemulsification* ; Viscoelastic Substances*