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Biomedical subjects

Y Totan

Publications and source records attributed to Y Totan.

At least 19 recordsLinked to original sources
PubMed2001

Incidence of keratoconus in subjects with vernal keratoconjunctivitis: a videokeratographic study.

PURPOSE: To detect the incidence of keratoconus by videography in patients with vernal keratoconjunctivitis (VKC) and to evaluate the clinical characteristics of VKC associated with keratoconus. DESIGN: a prospective, cross-sectional (prevalence) study. PARTICIPANTS: Eighty-two consecutive subjects with the diagnosis of VKC. METHODS: Both eyes of VKC subjects were investigated by videokeratography in comparison with slit-lamp biomicroscopy and keratometry. To detect keratoconus, corneal topography maps were examined with modified Robinowitz-McDonnell test. MAIN OUTCOME MEASURES: In this test, maps with central corneal power greater than 47.2 diopters and/or the inferosuperior asymmetry value greater than 1.4 were considered to have a keratoconus pattern. The findings of VKC were also recorded, RESULTS: The distribution of clinical forms of VKC were as follows: 46.34% mixed, 43.90% palpebral, and 9.76% limbal types. Twenty-six (31.7%) of 82 subjects had complications with keratopathy such as pseudo-genontoxon, punctate keratitis, and shield ulcer. Forty-four eyes (26.8%) were detected as keratoconus by quantitative evaluation of videokeratography maps. 14 eyes (8.5%) by biomicroscopy, and 30 eyes (18.3%) by keratometry. The increased incidence of keratoconus was associated with male gender, long-standing disease, mixed and palpebral forms, and advanced corneal lesions. CONCLUSIONS: The higher incidence of keratoconus in our study compared with the previous reports may result from early detection of mild keratoconus by interpretation of color-coded videokeratographic maps with a sensitive quantitative method.

Adolescent↗
PubMed2001

Comparison of subretinal fluid levels of two 0.3% ciprofloxacin-containing eye drops.

PURPOSE: Two ophthalmic solutions of 0.3% ciprofloxacin eye drops are available in Turkey: Ciloxan and Siprogut. A previous study by the same authors was the first to report vitreous penetration of ciprofloxacin-containing eye drops. The aim of the present study was to compare the levels of drug found in the subretinal fluid by the two products following local administration. METHODS: Forty-three patients undergoing conventional retinal detachment surgery received either Ciloxan (22 patients) or Siprogut (21 patients). Beginning 6 h before surgery, two drops of solution were instilled onto the operative eye every 30 min for the first 3 h and then hourly for the next 3 h. Subretinal fluid samples were collected 30 min after administration of the last dose and were assayed for ciprofloxacin levels using a method involving high-performance liquid chromatography with fluorometric detection. RESULTS: The minimum and maximum subretinal fluid concentrations measured were 0.11 microg/mL and 0.65 microg/mL, respectively, with Ciloxan, and 0.08 microg/mL and 0.62 microg/mL, respectively wth Siprogut. There was no statistical difference between the subretinal fluid ciprofloxacin levels of the two products. The subretinal fluid drug evels attained by both products were below the minimum inhibitory concentrations of common ocular pathogens. CONCLUSIONS: Ciloxan and Siprogut can penetrate subretinal fluid. The ocular bioavailability of ciprofloxacin after local administration is equivalent for both pharmaceutical products.

Absorption↗
PubMed2001

Effect of caffeic acid phenethyl ester on corneal neovascularization in rats.

PURPOSE: Caffeic acid phenethyl ester (CAPE), a biologically active component of propolis from honeybee hives, has potent antiinflammatory and antioxidant properties. We aimed to evaluate the ability of topically applied CAPE in comparison with known steroidal (dexamethasone sodium phosphate) and nonsteroidal (indomethacin) topical agents to reduce corneal neovascularization (CNV) induced by silver nitrate cauterization in rats. METHODS: Following silver nitrate cauterization on both eyes, male rats were randomly assigned to the study and control groups, each consisting of ten rats. The inhibitory effects of the test drugs against a placebo (isotonic saline) on CNV were tested and compared to each other using a previously described method in which extent of neovascularization and burn stimulus intensity were scored by a masked examiner. Briefly, burn stimulus intensity was scored from 0 to +3 according to the height of blister from corneal surface, and extent of neovascularization was recorded from 0 to +6 according to the distance from limbus to the end point of CNV toward the central corneal burn. Results. The mean burn stimulus score were not different among the groups (P = 0.807). Percent inhibition of CNV compared to the placebo control and its significance were 31.5 %, P = 0.011 for indomethacin; 56 %, P < 0.001 for dexamethasone; and 52 %, P < 0.001 for CAPE. Dexamethasone was significantly (P < 0.05) more effective than indomethacin in inhibition of neovascular growth. CAPE was found to be superior (P < 0.05) to indomethacin and almost as effective as (P > 0.05) dexamethasone in reducing CNV. Conclusion. Topically applied CAPE was demonstrated to have an inhibitory effect, comparable to that of topical dexamethasone, on CNV in this rat model. Antiinflammatory and antioxidant properties of CAPE may contribute to its suppression on CNV.

Administration, Topical↗
PubMed2001

Plasma malondialdehyde and nitric oxide levels in age related macular degeneration.

AIMS: To evaluate alteration of plasma malondialdehyde (MDA) and nitric oxide (NO) levels in patients with exudative age related macular degeneration (ARMD). METHODS: Plasma nitrite plus nitrate concentrations as an index of plasma NO levels and plasma MDA level as a marker of lipid peroxidation were measured in patients with exudative ARMD and age and sex matched healthy subjects. RESULTS: Significantly higher MDA and lower NO levels were detected in plasma of patients with ARMD compared with their controls (p=0.01, p=0.001, respectively). CONCLUSION: The results may support involvement of oxidative damage and vascular theory in the pathogenesis of ARMD as part of the ageing process.

Aged↗
PubMed2001

The efficacy of acetazolamide on visual functions in a patient with choroid metastasis of breast carcinoma.

Breast carcinoma is the most frequent cancer in women and is the second leading cause of death. Choroid metastasis of breast carcinoma can be found either at presentation or in remission. It is frequently encountered in disseminated breast cancer with multiple organ metastasis. It has been proposed that the oedema-reducing effect of acetazolamide is due to stimulated ion and fluid removal from the retina to the choroid. A 40-year-old female patient on adjuvant chemotherapy for breast cancer was found to have an isolated choroid metastasis. Clinical and radiological remission was achieved after orbital radiotherapy, chemotherapy and acetazolamide treatment. In this case report, we emphasise the possible beneficial effect of acetazolamide in patients with choroid metastasis.

Acetazolamide↗
PubMed2000

Bilateral cataract surgery in adult and pediatric patients in a single session.

PURPOSE: To evaluate the results of bilateral simultaneous cataract surgery in adult and pediatric patients under local or general anesthesia. SETTING: Department of Ophthalmology, Inönü University, Turgut Ozal Medical Center, Malatya,Turkey. METHODS: Eighty-two eyes of 41 patients were included in the study. Twelve of 17 pediatric patients with congenital cataract had bilateral simultaneous lensectomy, posterior capsulotomy, and anterior vitrectomy; 5 patients, aged 10 to 19 years, had bilateral extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PC IOL) implantation. Forty-eight eyes of 24 adult patients had bilateral simultaneous ECCE with primary (43 eyes) or secondary (5 eyes) PC IOL implantation. Local anesthesia was administered to 20 adult patients by retrobulbar injection; the other cases were performed using general anesthesia. The procedures were treated as 2 separate surgeries in the same session; care was taken to ensure surgical asepsis. RESULTS: No serious intraoperative complications occurred such as posterior capsule rupture, vitreous loss, endophthalmitis, and anesthesia-related problems. Of patients tested, 84.4% achieved a final best corrected visual acuity of 6/12 or better and 31.0%, of 6/6 or better. CONCLUSIONS: Simultaneous bilateral cataract surgery was not associated with an increased rate of complications, and visual results were good. If strict rules of surgical asepsis are followed, this may be a useful option in a variety of bilateral cases using general or local anesthesia.

Adolescent↗
PubMed2000

Combined phacoemulsification, vitrectomy, foreign-body extraction, and intraocular lens implantation.

PURPOSE: To assess the outcome of simultaneous phacoemulsification, pars plana vitrectomy, intraocular foreign-body extraction, and intraocular lens (IOL) implantation. SETTING: SSK Ankara Eye Hospital, Department of Vitreoretinal Surgery, Ankara, Turkey. METHODS: Seventeen patients with corneal perforation, intraocular foreign body, vitreous hemorrhage, and lens opacity had simultaneous clear corneal phacoemulsification, pars plana vitrectomy, intraocular foreign-body extraction, and IOL implantation. RESULTS: Postoperative complications included massive retinal fibrosis in 2 patients, retinal detachment in 1, and cilioretinal artery occlusion in 1. At a mean follow-up of 15.2 months, best corrected visual acuity improved in the remaining 13 eyes (76%). The IOL was stable in all cases. CONCLUSION: Combined phacoemulsification with IOL implantation and vitreoretinal surgery was safe in selected cases of penetrating ocular trauma resulting from an intraocular foreign body.

Adolescent↗
PubMed2000

Small incision extracapsular cataract surgery with manual phacotrisection.

PURPOSE: To evaluate the safety and efficacy of small incision extracapsular cataract extraction (ECCE) using the manual phacotrisection technique. SETTING: Department of Ophthalmology, Turgut Ozal Medical Center, InönüUniversity, Malatya, Turkey. METHODS: Fifty-nine eyes of 54 patients had small incision ECCE by the manual phacotrisection technique. Mean follow-up was 10 months. After capsulorhexis and hydrodissection were performed, the endonucleus was prolapsed into the anterior chamber and trisected using an anteriorly positioned triangular trisector and posteriorly placed solid vectis. Pieces were extracted with a forceps through a small incision. RESULTS: Postoperatively, best spectacle-corrected visual acuity of 20/40 or better was achieved in 48 eyes (83%) and of 20/25 or better in 28 eyes (47%). The most frequent intraoperative complication was posterior capsule rupture (n = 5). Of eyes that developed posterior capsule rupture, 3 had vitreous loss and 2 had implantation of an anterior chamber intraocular lens (IOL). In 44 eyes, the IOL was implanted in the bag and in 12 eyes, in the ciliary sulcus. The most significant postoperative complication was transient corneal edema, which developed in 32 eyes (54%). No permanent complications (e.g., corneal endothelial decompensation) occurred in any case. CONCLUSIONS: Manual phacotrisection has several advantages such as nucleus safety, less dependence on assistant personnel, the elimination of the phaco machine, and cost effectiveness.

Adult↗
PubMed1999

The effect of verapamil in the prevention of radiation-induced cataract.

PURPOSE: Cataract is an unavoidable complication when radiation therapy includes the lens, even in small doses. Alterations in the ion content of the lens were considered to play an essential role in cataract formation. In this experimental study, the effect of verapamil on ion concentrations within the irradiated lenses was investigated in rats. METHODS AND MATERIALS: Forty female Wistar albino rats, each weighing 180-250 g, were divided into three groups: (a) radiation treated (n = 10); (b) no treatment (n = 10); (c) or a combination of radiation and verapamil (n = 20). Both the radiation group and verapamil-treated group received 5 Gy radiation to the cranium in a single fraction, including the eyes, within the irradiation volume. All animals were sacrificed by bleeding, 7.5 weeks posttreatment. Calcium, sodium, and potassium levels were measured in blood and in lens homogenates. However, for technical reasons, magnesium levels could only be studied in lens homogenates. RESULTS: Potassium and sodium concentrations in lens homogenates did not differ in the control and radiation groups, but both were significantly lower in the verapamil-treated group (p = 0.001, p = 0.009, respectively). Calcium levels were higher in the radiation group and lower in the verapamil-treated group compared to the controls (p < 0.0001); magnesium levels did not differ (p = 0.37). CONCLUSION: Verapamil effectively decreased the lens calcium concentration, which is accepted as the key element in radiation cataractogenesis. It is therefore concluded that verapamil may reduce the risk of radiation-induced cataract formation.

Animals↗
PubMed1999

Manual tunnel incision extracapsular cataract extraction using the sandwich technique.

Small incision extracapsular cataract extraction (ECCE) using the sandwich technique is described. After capsulorhexis, hydrodissection, and hydrodelineation, the endonucleus is moved into the anterior chamber and extracted by sandwiching it between the irrigating vectis and iris spatula. In a series of 37 eyes, most achieved a best corrected visual acuity of 5/10 or better postoperatively. Complications were posterior capsule rupture, vitreous loss, and transient corneal edema. Small incision ECCE using the sandwich technique is safe, easy, and does not require expensive instrumentation.

Adult↗
PubMed1999

Management of traumatic retinal detachment with vitreon in children.

PURPOSE: To report the use of perfluoroperhydrophenanthrene (vitreon) for traumatic retinal detachment in children. METHODS: Vitreon was used as an intraoperative adjunct in 34 children with complicated retinal detachment secondary to penetrating and perforating trauma. The characteristics of the injuries, the final visual acuities, the postoperative complications and the rate of anatomic success were evaluated in a retrospective study. RESULTS: Patients were followed-up an average of 20 months. Eighteen retinas (53%) were reattached, and the postoperative visual acuity was counting fingers or better in 9 cases (26%), and only 4 eyes saw better than 10/200 at last follow-up. Hypotony developed in 7 (21%) of 34 eyes. CONCLUSION: Management of traumatic retinal detachment in children is difficult. Vitreon, as other perfluorocarbons, may be an effective intraoperative tool for vitreoretinal surgery in pediatric eyes that suffer trauma.

Adolescent↗
PubMed1999

Aqueous humour levels of topically applied ciprofloxacin and ofloxacin in the same subjects.

PURPOSE: To evaluate aqueous humour levels of topical 0.3% ciprofloxacin and 0.3% ofloxacin in the same subjects. METHODS: Thirty-two bilateral cataractous patients received topical 0.3% ciprofloxacin in one eye and 0.3% ofloxacin in the other eye before each cataract extraction. Eyedrops were repetitively instilled for 6 h. Aqueous humour samples were collected and assayed for drug concentrations by a method described originally by us using high-performance liquid chromatography. RESULTS: Mean aqueous ciprofloxacin and ofloxacin levels were 0.33 +/- 0.04 microgram/ml (mean +/- SEM) and 1.34 +/- 0.14 micrograms/ml respectively (p < 0.0001). CONCLUSION: Ofloxacin level in the aqueous humour is 4 times higher than that of ciprofloxacin in the same subjects.

Administration, Topical↗
PubMed1999

Penetration of topical, oral, and combined administered ofloxacin into the subretinal fluid.

AIMS: To assess the subretinal fluid (SRF) levels of ofloxacin following topical, oral or combined administration. METHODS: 31 patients undergoing conventional retinal reattachment surgery were randomly assigned to three groups. Nine patients received topical ofloxacin, 11 patients received oral ofloxacin, and the other 11 patients received combined administration. Collected SRF samples were analysed for drug level by using high performance liquid chromatography. RESULTS: SRF drug levels after oral and combined administration were significantly higher than that after topical administration (p=0.0002 and p=0.0002, respectively) while there was no significant difference between oral and combined administration (p=0.0844). CONCLUSIONS: Ocular bioavailability of ofloxacin in SRF after oral and combined administration is equivalent. The addition of oral ofloxacin to topical therapy increased drug SRF penetration sixfold.

Administration, Oral↗
PubMed1999

Nickel, chromium, manganese, iron and aluminum levels in human cataractous and normal lenses.

Atomic absorption spectrophotometry was used to detect lenticular nickel, chromium, manganese, iron and aluminum levels in 37 senile cataractous and 9 normal human lenses. The nuclear parts of the lenses were used for the study in both groups. It was found that the concentrations of nickel and iron were significantly higher, and those of chromium, manganese and aluminum were significantly lower in human cataractous lenses than those in normal human lenses. None of the elements showed a significant difference according to sex in both groups. As remarkable differences in chromium, manganese, iron, aluminum and nickel levels exist in cataractous lenses, all the five elements may play some roles in cataractogenesis.

Aged↗
PubMed1999

Superoxide dismutase, catalase, glutathione peroxidase and xanthine oxidase in diabetic rat lenses.

The activities of the protective enzymes, superoxide dismutase, catalase, glutathione peroxidase and of xanthine oxidase, an enzyme acting as a source of O(-)(2), were measured in the lenses of alloxan-induced diabetic and control rats. Superoxide dismutase and glutathione peroxidase activities were found to be significantly decreased, while catalase and xanthine oxidase activities were increased. This means that the ratio of the oxidant/antioxidant enzymes increases in the diabetic rat lens, suggesting an increased oxidative stress. This imbalance is possibly an important contributing factor in the pathogenesis of diabetic cataract.

Animals↗
PubMed1999

Penetration of ofloxacin and ciprofloxacin in aqueous humor after topical administration.

BACKGROUND AND OBJECTIVE: To compare the aqueous humor levels of 0.3% ofloxacin and 0.3% ciprofloxacin containing eyedrops in patients with healthy cornea. PATIENTS AND METHODS: Fifty patients with cataract were randomly assigned to have 0.3% ofloxacin containing eyedrop (25 patients) or 0.3% ciprofloxacin containing eyedrop (25 patients). Both drugs were repetitively instilled to each patient for 6 hours before the surgery. Aqueous samples were collected after penetrating the anterior chamber during cataract extraction and assayed by high-performance liquid chromatography method. RESULTS: The aqueous humor level of ofloxacin (1.43 +/- 0.26 microg/ml, mean +/- SEM) was significantly higher than that of ciprofloxacin (0.35 +/- 0.07 microg/ml) following the topical application (P < .0002). CONCLUSION: Aqueous humor penetration of topical ofloxacin is about 4 times higher than that of topical ciprofloxacin when the drugs are applied as described above.

Administration, Topical↗