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.
Aqueous Humor ; Intravitreal Injections* ; Sodium

PURPOSE: Although the process by which intravitreal perfluorocarbon gas is absorbed is incompletely understood, it is known that considerable absorption of intravitreal perfluorocarbon gas occurs through the aqueous humor. The aim of the study was to evaluate experimentally the effect of topical aqueous humor suppressants on the intravitreal perfluorocarbon gas bubble duration. METHODS: After sulfur hexafluoride and perfluoropropane were injected intravitreally in ten rabbits, we measured the time of gas bubble disappearance in eyes treated with topical aqueous humor suppressants and in those not treated. RESULTS: The mean time(+/-SD) to disappearance of 0.4 cc of sulfur hexafluoride was 6.0+/-0.71 days, which was prolonged to 8.0+/-0.71 days with topical aqueous humor suppressants. The mean time(+/-SD) to disappearance of 0.2 cc perfluoropropane was 14.8+/-0.84 days, while it was prolonged to 22.0+/-1.58 days with topical aqueous humor suppressants. CONCLUSIONS: Sulfur hexafluoride and perfluoropropane intravitreal gas bubbles last longer in rabbit eyes treated with aqueous humor suppressants than in fellow control eyes.
Absorption ; Aqueous Humor* ; Rabbits* ; Sulfur Hexafluoride

PURPOSE: We evaluated ocular penetration and drug level in tear after topical ofloxacin instillation in rabbit eye with amniotic membrane transplantation(AMT). METHODS: In the first set of experiment, 24 rabbits(24 eyes) were divided into 4 groups according to the epithelial removal or AMT. Topical ofloxacin was instilled 4 times every 15 minutes and then, 1 hour after the last eyedrop, the samples of amniotic membrane(AM), cornea and aqueous humor were collected. In the second set of experiment, 24 rabbits(24 eyes) were divided into 6 groups according to the freshness of AM or its attached time. Topical ofloxacin was applied to eyes and then, tear samples were collected at 30 minutes, 1, 2, 4, and 6 hours. Ofloxacin concentration in the samples of two experiments were evaluated using high performance liquid chromatography. RESULTS: Mean ofloxacin concentrations in cornea and aqueous humor were statistically higher in deepithelized corneas regardless of AMT(P<0.05). And mean tear levels of ofloxacin in AMT groups were statistically higher than those in non-AMT groups(P<0.05). CONCLUSIONS: AMT seems to interfere with the ocular penetration of topical ofloxacin in normal rabbit cornea, but rather enhances ofloxacin penetration in the cornea with epithelial defect. And also the ofloxacin level in tear was higher in eyes with AMT up to 1 hour after topical ofloxacin use. Therefore it seems that AM has potential to act as an effective drug delivery system.
Amnion* ; Aqueous Humor ; Chromatography, Liquid ; Cornea ; Drug Delivery Systems ; Ofloxacin*

Cyclodialysis and ciliochoroidal detachment was performed in one eye of three rabbits and in one eye of another three rabbits respectively. 0.1 ml of 10% sodium fluorescein was injected intracamerally after aspiration of aqueous humor and the eyeball was enucleated between 30 minutes and one hour after sodium fluorescein injection and prepared for fluorescence microscopy. Sodium fluorescein concentration in supraciliary space was much greater in group with cyclodialysis or ciliochoroidal detachment than in normal control group. These results suggest that in the eye with cyclodialysis, aqueous humor may gain access freely to supraciliary space through the cleft between anterior chamber and supraciliary space and then is removed rapidly and in the eye with ciliochoroidal detachment, aqueous humor may pass through uveoscleral outflow pathway.
Anterior Chamber ; Aqueous Humor* ; Fluorescein ; Microscopy, Fluorescence ; Rabbits

The fibrovascular tissues surrounding a glaucoma implant have been found to play a major role for the orbital absorption of aqueous humor following a glaucoma implant surgery. An ultrasonographic study was performed to investigate the ultrasonographic, characteristics of the tissues and its relationship with the postoperative intraocular pressure(IOP) control. Twenty-three eyes of 23 patients had undergone the e-PTFE membrane-silicone tube implantation and had been followed up for at least 6-month(mean +/- SD, 17 +/- 8.8 months). An ultrasonographic study for these eyes included such paramneters as presence of an aqueous reservoir surrounding the implant, size(height) of the aqueous reservoir and echoreHectivity from the reservoir wall tissues. The aqueous reservoir was identified in 22(96%) of 23 eyes and had a height varying from 1.0 mm to 5.5 mm. In eyes with an aqueons reservoir. 3 mm high or more, the IOPs were all 21 mmHg or less without further glaucoma medications(p=0.040, chi-square). In one eye with an obliterated reservoir on ultrasonography, the opening of the silicone tube was found to be occluded toward the extrascleral portion of the implant when reoperation was performed. The echo reflections from reservoir wall tissues were denser and higher comparing with those from the sclera of the respective eye in 7 eyes with a complete failure of postoperative lOP control(>or=30 mmHg on maximum medical theraph). These eyes also had and irregular echoreflections within the aqueous reservoir, which reflect an invasion of proliferating tissues into the reservoir.
Absorption ; Aqueous Humor ; Glaucoma* ; Humans ; Orbit ; Reoperation ; Sclera ; Silicones ; Ultrasonography

The purpose of this paper is to investigate the difference in concentration of 0.53% betamethasone in aqueour humor after betamethasone subconjunctival injection on upper and lower fornix after cataract extraction. A total of 8 rabbits were used. Cataract extractions were performed with the cryoprobe. After 6 hours, 0.53% betamethasone was subconjunctivally in upper fornix of the left eye and injected in lower fornix of the right eye. The control group of 3 rabbits underwent with the same procedures but the without lens delivery. the concentration of 0.53% betamethasone in aqueous humor was measured with HPLC(High Performance Liquid Chromatograph) after fine needle aspiration of aqueous humor. The results obtained were as follows. 1. In 5 eyes of the control group in 3 rabbits, 0.53%betamethasone was injected subconjunctivally on the lower fornix. The mean concentration of 0.53% betamethasone in aqueous humor was 0.544 +/- 0.0818 microgram/ml. 2. After 0.53% betamethasone subconjunctival injection on upper fornix after lens extraction, the mean concentration of 0.53% betamethasone in aqueous humor was 0.318 +/- 0.0117 microgram/ml. 3. After 0.53% betamethasone subconjunctival injection on lower fornix agter lens extraction, the mean concentration of 0.53%betamethasone in aqueous humor was 0.702 +/- 0.0332 microgram/ml. 4. The mean concentration of the betamethasone in aqueous humor after 0.53% betamethasone subconjunctival injection on lower fornix after lens extraction was significantly higher than on upper fornix(p<0.05).
Aqueous Humor* ; Betamethasone* ; Biopsy, Fine-Needle ; Cataract Extraction ; Rabbits

To evaluate the effects of mitomycin C(MMC) on the fibrous capsule of the anterior chamber tube shunt to a surgical membrane(ACTSSM) surgery, 0.04% MMC solution was applied on the episclera for 5 minutes before ACTSSM surgery(group A, 9 rabbits). At postoperative 2, 4 and 8 weeks, 6 eyes of the 3 rabbits from each group were enucleated and light microscopic examinations of the fibrous capsules were done. In group A, fibrous capsules had many microcystic spaces and fibrous tissues between twofold surgical membranes were scanty. But in control group(group B, 9 rabbits), fibrous capsules showed higher density of fibroblast and less microcystic spaces than group A, suggesting low permeability of the fibrous capsule to aqueous humor. These results suggest that MMC may increase the success rate of the ACTSSM surgery.
Anterior Chamber* ; Aqueous Humor ; Capsules ; Fibroblasts ; Membranes* ; Mitomycin* ; Permeability ; Rabbits*

The effect of 0.25% and 0.5% Timolol on intraocular pressure and concentration in aqueous humor was studied after topical instillation in the white rabbit. The intraocular pressure was measured with pneuma tonometer and the Timolol concentration in aqueous humor was measured with High Preformance Liquid Chromatograph after fine needle aspiration of aqueous humor at various time intervals. The results were as follows; 1. The percentage reduction of intraocular pressure increased with time and reached a peak after 3 hours. 2. The concentration of Timolol in aqueous humor increased with time and reached a peak after 3 hours. 3. There was close correlation between intraocular pressure and Timolol concentration in aqueous humor.
Aqueous Humor* ; Biopsy, Fine-Needle ; Intraocular Pressure* ; Timolol*

The Beta-adrenergic blocker(timolol maleate) decreases intraocular pressure by reducing the production of aqueous humor. Twenty patients scheduled to undergo cataract extraction were induced in study. After timolol maleate administration, we found the increase in the total protein concentration. By double-masked controlled study, 0.5% timolol maleate solution and normal saline were applied topically, and aqueous humor was aspirated during surgery. Total protein concentrations were determined by HPGFC. The total protein concentration as well as the concentration of high, medium and low molecular weight protein were elevated in the timololadministrated group. The relation of the levels of the three different molecular weight classes did not differ significantly between the timolol maleate group and the normal group.
Aqueous Humor* ; Cataract Extraction ; Humans ; Intraocular Pressure ; Molecular Weight ; Timolol*

Aqueous flare, the scattering of light by the Tyndall phenomenon, have been applied for the assessment of aqueous protein by the ophthalmologists. Since the intensity of flare ultimately reflects the severity of ocular inflammation. Laser flare-cell meter was developed to determine protein concentration and number of cells in the aqueous with non-invasive technique. The principle of evaluation was similar to that of slit-lamp examination in the viewpoint of scattering of light. The significant linear correlation was observed between the values of concentration for protein and photon counts, in the range from 5mg/100ml to 2,500ml/100ml in boine serum albumin (BSA) and from 5mg/100ml to 1,000mg/100ml in human gamma globulin (HGG), the valuses of HGG was three times higher than those of BSA in the same concentration. In experiments for WBC, RBC and latex particles with diameter of 2.95 micrometer, although somewhat differences was observed according to the sort of cells, significant linear correlation was shown between the number of detected peaks and that of cells.
Aqueous Humor ; gamma-Globulins ; Humans ; Inflammation ; Microspheres ; Serum Albumin