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Biomedical subjects

O Cekic

Publications and source records attributed to O Cekic.

At least 19 recordsLinked to original sources
PubMed2001

Effect of Ca(2+)-free and Mg(2+)-free BSS Plus solution on the retinal pigment epithelium and retina in rabbits.

PURPOSE: To determine whether intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus (Alcon Laboratory, Fort Worth, Texas) solution alters the adhesiveness between the retinal pigment epithelium and the retina of rabbits. METHODS: Thirty-four eyes of 34 Dutch pigmented rabbits underwent lensectomy and vitrectomy. Subsequently, the vitreous cavity of 24 eyes was irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 10 or 20 minutes. The other 10 eyes were irrigated with BSS Plus solution for 20 minutes as controls. To determine the adhesiveness between the retinal pigment epithelium and retina, a retinal detachment was produced in 12 of the 34 eyes. The apical surface of the retinal pigment epithelium and the photoreceptor outer segments were examined by scanning electron microscopy. Retinal physiology was assessed by electroretinography and retinal morphology by light microscopy. RESULTS: After retinal detachment was produced, the number of cone sheaths on the apical surface of the retinal pigment epithelium after irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes (33 +/- 15, mean +/- SD) was significantly less than the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after irrigation with BSS Plus solution for 20 minutes (120 +/- 50) or the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after 10 minutes of irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution (115 +/- 49; P =.02). The b-wave amplitudes in the eyes irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes were depressed compared with the b-waves in eyes irrigated with BSS Plus solution for 20 minutes on the first postoperative day (P =.03). After the third postoperative day, there was no significant difference in the b-waves (P >.06). Light microscopy demonstrated no morphologic abnormalities after the use of both solutions. CONCLUSIONS: Intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes altered the adhesion between the retinal pigment epithelium microvilli and retinal outer segments and made the creation of retinal detachment less traumatic. These results suggest that Ca(2+)-free and Mg(2+)-free BSS Plus solution may be of clinical value for the creation of an intentional retinal detachment for foveal translocation surgery.

Animals↗
PubMed2000

Intraocular gas tamponades.

Intraocular gas tamponades are an important part of vitreoretinal surgery and have become a standard of care. The use of intraocular gas began in 1911. Modem use of intraocular gases as a surgical adjunct is continuously broadening. Today, sulfur hexafluoride and perfluoropropane are increasingly being used as intraocular gas tamponades for a wide range of complicated vitreoretinal diseases. This article reviews the types and function of commonly used gases, their indications and efficacy in certain types of vitreoretinal diseases, and their complications.

Air↗
PubMed1998

Penetration of ofloxacin in human aqueous and vitreous humors following oral and topical administration.

PURPOSE: To determine aqueous and vitreous humor ofloxacin levels following oral and topical application of ofloxacin in patients with noninflamed cornea and intact crystalline lens, and to compare the drug levels provided by each route. MATERIALS AND METHODS: Twenty-six patients undergoing pars plana vitrectomy for various ocular pathologies were divided into two groups. Fourteen patients received two drops of 0.3% ophthalmic solution of ofloxacin every 30 minutes for 3 hours and every 60 minutes for the next 3 hours, and 12 patients received a single oral dose of 400 mg ofloxacin 8 hours before surgery. The aqueous and vitreous humor samples were simultaneously collected after oral or topical administration during pars plana vitrectomy to assess penetration of the drug. Samples were assayed for ofloxacin concentrations by a previously described method using high-performance liquid chromatography. RESULTS: The aqueous and vitreous humor levels of ofloxacin were 1.54 +/- 0.27 microg/mL (mean +/- standard error) and 1.77 +/- 0.24 microg/mL after oral and 1.44 +/- 0.24 microg/mL and 0.37 +/- 0.05 microg/mL after topical ofloxacin administration, respectively. Aqueous humor levels were not statistically different following oral or topical administration (P > 0.8). However, vitreous level of the drug after oral administration was significantly higher than that after topical administration (P < 0.001). CONCLUSION: Ocular bioavailability of ofloxacin in aqueous humor after oral and topical administration is similar when the drug is applied as described. Penetration of ofloxacin into vitreous humor is less than that into aqueous humor following topical application. The aqueous humor levels of ofloxacin via both routes and the vitreous level of the drug after oral route exceed the minimum inhibitory concentrations for certain bacterial species that frequently cause intraocular infection.

Administration, Oral↗
PubMed1998

Effect of cigarette smoking on copper, lead, and cadmium accumulation in human lens.

AIM: To identify cigarette smoking as a risk factor for development of cataract, to determine the importance of copper, lead, and cadmium in cataractogenesis, and to learn about any relation between those elements. METHODS: Copper, lead, and cadmium concentrations were measured by atomic absorption spectrophotometry in 37 cataractous and nine normal human lenses. RESULTS: All three element accumulations in lenses with cataract were statistically meaningful. Lenticular copper, lead, and cadmium were increased significantly with cigarette smoking. Cadmium had a positive correlation both with lead and copper in cataractous lenses. CONCLUSION: The accumulation of copper, lead, and cadmium occurs in cataract. The probable source of cadmium in humans is cigarettes. Lenticular cadmium accumulation also increases copper and lead precipitation in the lens. Cigarette smoking might be cataractogenic.

Aged↗
PubMed1998

Copper, lead, cadmium and calcium in cataractous lenses.

Lenticular copper, lead, cadmium and calcium levels were measured using atomic absorption spectrophotometry in 9 normal and 37 cataractous human lenses. The nuclear parts of the lenses were used for the study in both groups. The lenticular deposition of these four elements in cataract was statistically significantly. In the cataractous group, males had higher levels of cadmium compared to females. No lead was detected in normal lenses. The calcium content was significantly higher in cortical cataract whereas the other elements were not correlated with the types of cataract.

Cadmium↗
PubMed1998

Lenticular calcium, magnesium, and iron levels in diabetic rats and verapamil effect.

Lenticular calcium (Ca), magnesium (Mg), and iron (Fe) changes in diabetic rats and the effects of the Ca antagonist drug verapamil on this electrolyte imbalance were studied. Verapamil administration had no effect on the blood glucose values. Compared to the control group, a significant increase was observed in the lenticular Ca, Mg, and Fe content of the diabetic rats. Eight weeks of verapamil administration to the diabetic animals significantly reduced lenticular Ca, Mg, Fe values. Therefore it is suggested that verapamil might be a useful drug to prevent diabetic cataract formation.

Animals↗
PubMed1998

Effects of the long-term use of perfluoroperhydrophenanthrene on the retina.

Perfluorocarbon liquids have gained wide acceptance as intraoperative tools that can simplify vitreoretinal surgical maneuvers. These low-viscosity liquids facilitate injection into the eye and removal from the eye during surgery. Tolerance to perfluoroperhydrophenanthrene and the development of proliferative vitreoretinopathy with its extended use are not clear. The authors present the clinical and histologic findings of a patient, previously lost to follow-up, who was examined after several weeks of intraocular tamponade with perfluoroperhydrophenanthrene. Damage to the retina was seen in response to the long-term postoperative use of perfluoroperhydrophenanthrene.

Adult↗
PubMed1998

Changes in anterior chamber depth and intraocular pressure after phacoemulsification and posterior chamber intraocular lens implantation.

BACKGROUND AND OBJECTIVE: To determine anterior chamber depth (ACD) and intraocular pressure (IOP) following uncomplicated cataract extraction with phacoemulsification and posterior chamber intraocular lens (IOL) implantation. PATIENTS AND METHODS: The ACDs and IOPs of 56 patients were prospectively evaluated after phacoemulsification and IOL implantation. Measurements of ACD were performed using ultrasonography and measurements of IOP were performed using a Goldmann applanation tonometer preoperatively and at 1 week and 1, 3, 6, and 9 months postoperatively. RESULTS: The mean IOP had decreased and the mean ACD had increased significantly by 1 month postoperatively (P < .03 and P < .01, respectively). Between 1 and 3 months, a significant increase in ACD (P < .05) and decrease in IOP (P < .01) was also observed. The ACD peaked (3.51 +/- 0.45 mm) and the IOP reached its lowest value (10.05 +/- 2.23 mm Hg) at 3 months postoperatively. The reduction in IOP and increase in ACD remained significant during the follow-up period, compared with the preoperative values. CONCLUSION: These results suggest that increases in ACD and decreases in IOP occur in selected patients after uncomplicated cataract extraction by phacoemulsification with IOL implantation.

Adult↗
PubMed1998

The use of perfluorodecalin in retinal detachments with retinoschisis.

BACKGROUND AND OBJECTIVE: To evaluate the effect of perfluorodecalin on the repair of retinal detachments with retinoschisis. PATIENTS AND METHODS: Twenty-two eyes of 20 patients with degenerative and X-linked retinoschisis underwent pars plana vitrectomy, perfluorodecalin injection, internal fluid drainage, and fluid-air exchange. RESULTS: The retina was reattached intraoperatively in 21 (95.4%) of the 22 eyes. In 4 eyes, retinal detachment recurred within 2 months postoperatively. All of the recurrent cases underwent reoperation with perfluoropropane gas and the retina was reattached at the end of 2 operations. As a result, visual acuity increased in 18 (81.8%) of the 22 eyes. CONCLUSION: Perfluorodecalin makes flattening of the retina and evacuation of subretinal fluid easier in the management of rhegmatogenous retinal detachments associated with degenerative and X-linked retinoschisis.

Adolescent↗