K R Liu

Louisiana State University, Baton Rouge, Louisiana, United States

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Publications (15)16.94 Total impact

  • K R Liu · G A Peyman · M S Chen · K B Chang
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    ABSTRACT: We successfully used high-density vitreous substitutes to remove four dislocated crystalline lenses and three dislocated intraocular lenses (IOLs) from the vitreous cavity. Fluorosilicone oil (300 cs) was used to remove the four lenses and one of the IOLs. Perfluorophenanthrene (Vitreon) was used to remove the other two dislocated IOLs. The dislocated lenses or IOLs were floated by the high-density vitreous substitutes and removed safely without damaging the retina; there were no intraoperative complications. Postoperative residual fluorosilicone oil droplets were found in one case.
    No preview · Article · Oct 1991 · Ophthalmic surgery

  • No preview · Article · Jan 1991
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    ABSTRACT: We evaluated the use of a heavier-than-water fluorinated silicone oil in the treatment of 30 selected cases of complicated retinal detachment from January 1988 to July 1989. Proliferative vitreoretinopathy grade C-2 or greater accounted for 19 cases, proliferative diabetic retinopathy with traction detachment for two cases, giant retinal tears five, ruptured globe with retinal detachment two, massive choroidal effusion with retinal detachment one, and acute retinal necrosis with retinal detachment one. Initial retinal reattachment was achieved in all cases. Complications included redetachment seven (23%), cataract six (75% of phakic patients), raised intraocular pressure four (13%), hypotony four (13%), keratopathy three (10%), uveitis-synechia formation three (10%), phthisis two (3%), choroidal haemorrhage one (3%), and vitreous haemorrhage one (3%). Postoperative visual acuities with at least six months' follow-up range from no light perception to 20/50, with seven patients (23%) 20/400 or better.
    Preview · Article · Dec 1990 · British Journal of Ophthalmology
  • K R Liu · G A Peyman · M V Miceli
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    ABSTRACT: Fluorosilicone oil, a high specific gravity fluorinated silicone oil, has been recently reevaluated for temporary use in surgery to repair complicated retinal detachments. We evaluated the toxicity of a low-viscosity (300 centistokes) fluorosilicone oil as a vitreous substitute in vitrectomized eyes of albino rabbits. No toxicities could be demonstrated by histopathologic and electroretinographic examinations 6 weeks following surgery. In vitro experiments also showed no toxic effects on cultured retinoblastoma cells. When fluorosilicone oil was injected into the anterior chamber, endothelial cell damage could be seen 2 weeks following injection. Low-viscosity fluorosilicone oil appears to be a safe vitreous substitute for temporary use; it is easily injected and removed, and it maintains adequate surface tension for intraocular tamponade. Because of its relative low viscosity, 300-cst fluorosilicone oil (FS) may be a better vitreous substitute than perfluorocarbon liquids for both intraoperative manipulation of the retina and short-term intraocular tamponade for complicated retinal detachments.
    No preview · Article · Nov 1989 · Ophthalmic surgery
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    K R Liu · G A Peyman · B Khoobehi
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    ABSTRACT: The efficacy of intravitreally administered amphotericin B was evaluated. Experimental fungal infections were produced by inoculation of Candida albicans organisms into the vitreous cavities of 46 rabbit eyes. After 72 hr, eight eyes received intravitreal injections of 10 micrograms of free amphotericin B; and ten eyes each received 10 micrograms, 20 micrograms, and 40 micrograms of liposome-bound amphotericin B. The remaining eight eyes served as controls: four eyes received dextrose solution and four eyes received empty liposomes. Histopathologic examination 8 weeks after inoculation showed clear vitreous without retinal damage in groups treated with either 10 micrograms free amphotericin B or 20 micrograms of liposome-bound drug. All eyes in the control group and six eyes (60%) in the group treated with 10 micrograms of liposome-bound amphotericin B developed vitreous abscesses with evidence of fungal infection. In eyes treated with 40 micrograms of liposome-bound amphotericin B, fungal infection was successfully eradicated, but retinal damage was detected in all eyes by light microscopy. It is proposed that a reduced toxicity of intravitreally injected liposome-bound drugs is accompanied by reduced efficacy. In the treatment of fungal endophthalmitis, an increased dosage of liposome-bound amphotericin B (above that dosage of free drug which would be required) is suggested.
    Preview · Article · Aug 1989 · Investigative Ophthalmology & Visual Science
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    ABSTRACT: A 68-year-old white male had a pigmented choroidal tumor associated with progressive loss of vision. Clinical studies with fluorescein angiography and magnetic resonance imaging suggested a diagnosis of choroidal melanoma. Specimens obtained by internal eye wall resection revealed a choroidal nevus.
    No preview · Article · Aug 1989 · International Ophthalmology
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    ABSTRACT: Cytarabine has been demonstrated to be a more potent inhibitor of fibroblast proliferation than fluorouracil. It is, however, more toxic to the retina. We evaluated the ocular toxicity of liposome-encapsulated cytarabine in vitrectomized and nonvitrectomized rabbit eyes by ophthalmic and histopathologic examination. In the vitrectomized group, doses of up to 26 micrograms were nontoxic to the retina. In nonvitrectomized eyes, doses of up to 55 micrograms were nontoxic. Doses of 85 micrograms resulted in loss of ganglion cells and disorganization of photoreceptor cells. The results obtained in this study demonstrated a substantial reduction in ocular toxicity of liposome-encapsulated cytarabine, as compared with a previous study which employed free drug. By virtue of its reduced toxicity, cytarabine in a liposomal vehicle may be of value in the treatment of ocular proliferative disorders.
    No preview · Article · Jun 1989 · Ophthalmic surgery
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    ABSTRACT: Perfluorophenanthrene, a liquid fluorocarbon with a specific gravity approximately twice that of water, potentially offers certain advantages as a vitreous substitute in vitreoretinal surgery. To determine its efficacy and safety we first purified it by chemical methods used in the preparation of experimental blood substitutes to a level at which it was not at all or only minimally toxic to culture-grown retinoblastoma cells. Nineteen of 22 vitrectomized eyes of white New Zealand rabbits injected with this purified perfluorophenanthrene showed satisfactory clinical tolerance. Light and electron microscopy showed minimal or no toxic effects in the 19 eyes, although uptake of perfluorophenanthrene by some preretinal cells was observed 28 days after implantation. Postoperative light-adapted electroretinography recordings of eight of the injected eyes showed no significant change. Perfluorophenanthrene injected into the anterior chamber of the rabbit eyes had toxic effects on the cornea. If further experimentations confirm our findings, perfluorophenanthrene may be a suitable transparent high-density liquid for temporary use in surgery to repair retinal detachments.
    No preview · Article · May 1989 · Ophthalmic surgery
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    ABSTRACT: Gore-Tex (polytetrafluoroethylene) grafts have been used in a variety of surgical procedures, particularly vascular, plastic, and reconstructive surgery. As suggested by previous animal studies, Gore-Tex soft tissue patches (expanded polytetrafluoroethylene) may have application in ocular surgery for scleral buckling and support procedures. We buckled the scleras of 14 rabbit eyes using strips of polytetrafluoroethylene soft tissue patches and monitored ocular tissue reaction and histologic changes in response to this material.
    No preview · Article · Apr 1989 · Ophthalmic surgery
  • K R Liu · G A Peyman · J D Myers · S A Hamlin · N Katoh
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    ABSTRACT: Two pulsed neodimium yittrium aluminum garnet (Nd:YAG) laser systems were evaluated for contact surgery through a fiberoptic system with a sapphire tip. Pulsed Nd:YAG laser at 1060 nm was as effective as continuous-wave Nd:YAG laser in producing tissue incisions. A combination of 1060-nm and 530-nm wavelengths achieved smooth cutting at lower energy levels. Corneal endothelial cell damage occurred at the high power level (7 watts) required for smooth underwater incisions with both continuous wave and pulsed lasers.
    No preview · Article · Feb 1989 · Japanese Journal of Ophthalmology
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    ABSTRACT: The concentration of cyclosporine in the aqueous and vitreous humors of albino rabbits was measured, using HPLC at intervals of 24, 48, 96, and 192 hours after subconjunctival injections of 2.5 mg of free or liposome-bound cyclosporine. The aqueous concentration was reasonably high in both groups until day 4: 1050 nanograms per milliliter in the group receiving free cyclosporine, and 1438 nanograms per milliliter in the group receiving liposome-bound cyclosporine. The vitreous concentration was very low in both groups.
    No preview · Article · Feb 1988 · International Ophthalmology
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    ABSTRACT: The effect of both regular silicone and fluorosilicone in preventing retinal detachment caused by experimental proliferative vitreoretinopathy was studied in rabbit eyes which received 250,000 fibroblasts after vitrectomy and lensectomy. In the control group, 14 out of 20 eyes which received fibroblasts had retinal detachments with disorganization of internal structures. In eyes receiving fibroblast and regular silicone, 4 out of 20 eyes had shallow retinal detachment. In the eyes receiving fibroblasts and fluorosilicone, 5 of 28 eyes had shallow retinal detachment. Our findings indicate that both regular silicone and fluorosilicone were effective in preventing retinal detachments caused by experimental proliferative vitreoretinopathy. There was no statistical difference between the two silicone oils.
    No preview · Article · Feb 1988 · International Ophthalmology
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    ABSTRACT: Intravitreal liposome-encapsulated antibiotics and antiviral drugs were used in patients with acute toxoplasmosis retinochoroiditis, presumed propionibacterium acne endophthalmitis after cataract surgery, and presumed cytomegalovirus retinitis associated with AIDS. A single intravitreal dose was effective in the treatment of all the conditions. Intravitreal liposomes may prove to be an advantageous drug delivery system for the treatment of chronic intraocular inflammatory disorders.
    No preview · Article · Feb 1988 · International Ophthalmology
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    ABSTRACT: The concentration of cyclosporine in the vitreous after intravitreal injection of 100 micrograms of either free or liposome-bound cyclosporine was studied in albino rabbits. We found that the half-life of free cyclosporine was about 6 hours and that of liposome-bound cyclosporine was about 3 days. The finding indicates that liposome-bound cyclosporine prolongs the availability of the drug.
    No preview · Article · Feb 1988 · International Ophthalmology
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    ABSTRACT: Two groups of albino rabbits received an intravitreal injection of liposome-encapsulated trifluorothymidine. One group underwent a clearance study using high-performance liquid chromatography. The results of this study demonstrated a prolonged vitreal drug level within the range of ID50 for many strains of herpesvirus and human cytomegalovirus (CMV) at 28 days after injection. The eyes of another group were evaluated with preoperative and postoperative indirect ophthalmoscopy, electroretinography, and histologic examination. No retinal toxicity was found.
    No preview · Article · Oct 1987 · Ophthalmology

Publication Stats

334 Citations
16.94 Total Impact Points

Institutions

  • 1988-1990
    • Louisiana State University
      Baton Rouge, Louisiana, United States
    • Louisiana State University Health Sciences Center New Orleans
      • Eye Center
      New Orleans, Louisiana, United States
  • 1987
    • University of Illinois at Chicago
      Chicago, Illinois, United States