Biomedical subjects

Iclal Yücel

Publications and source records attributed to Iclal Yücel.

9 recordsLinked to original sources

PubMed2006

Phacoemulsification with topical anesthesia: Resident experience.

PURPOSE: To compare the intraoperative and postoperative complications and outcomes of phacoemulsification performed by residents using topical and retrobulbar anesthesia. SETTING: Two university ophthalmology departments. METHODS: One hundred fifty phacoemulsification procedures were performed by 3 residents who used retrobulbar anesthesia (retrobulbar group), and 146 phacoemulsification procedures were performed by another 3 residents who used topical anesthesia and who had no experience with retrobulbar or peribulbar anesthesia (topical group). Case notes were prospectively compared. The data analyzed included the ocular history, intraoperative and postoperative complications, and final best spectacle-corrected visual acuity (BSCVA). RESULTS: There were no differences between the 2 groups in complication rates. Anterior capsule tears occurred in 8 eyes (5.3%) in the retrobulbar group and 7 eyes (4.7%) in topical group. Capsulorhexis was continuous but not curvilinear in 14 eyes (9.3%) and 12 eyes (8.2%), respectively. Capsulorhexis tear or posterior capsule rupture that necessitated conversion to extracapsular cataract extraction occurred in 3 eyes (2.0%) in the retrobulbar group and in 1 eye (0.6%) in the topical group. Posterior capsule rupture with vitreous loss occurred in 10 eyes (6.6%) and 9 eyes (6.1%), respectively. Loss of lens fragments in the vitreous cavity occurred in 3 eyes (2.0%) and 4 eyes (2.7%), respectively. The 63 postoperative complications (41 eyes [27.3%], retrobulbar group; 22 eyes [15.0%], topical group) included cystoid macular edema, intraocular lens decentration, endophthalmitis, bullous keratopathy, transient intraocular pressure elevation, temporary corneal edema, and vitreous hemorrhage. Some cases had more than 1 complication. The BSCVA, including in eyes with preexisting ocular pathology, was 20/40 or better in 86.7% in the retrobulbar group and 84.9% in the topical group. CONCLUSION: When supervised and in selected patients, residents who have no retrobulbar or peribulbar anesthesia experience can safely perform phacoemulsification using topical anesthesia.

Adult↗

PubMed2006

Brinzolamide 1% versus apraclonidine 0.5% to prevent intraocular pressure elevation after neodymium:YAG laser posterior capsulotomy.

PURPOSE: To compare the efficacy of brinzolamide 1% with that of apraclonidine 0.5% in preventing intraocular pressure (IOP) rise after neodymium:YAG (Nd:YAG) laser posterior capsulotomy. SETTING: Department of Ophthalmology, Akdeniz University, Antalya, Turkey. METHODS: One hundred fifteen patients who had Nd:YAG laser posterior capsulotomy for posterior capsule opacification were prospectively randomized to receive brinzolamide 1% (57 patients) or apraclonidine 0.5% (58 patients) approximately 1 hour before laser surgery. A masked observer measured IOP by Goldmann applanation tonometry before treatment and after treatment at 1, 2, and 3 hours and 7 days. RESULTS: The mean IOP changes from baseline were not statistically different between the study groups at 1, 2, and 3 hours and 7 days (P =.109, P = .764, P =.275, and P =.879, respectively). The incidence of IOP elevation of 5 mm Hg or higher was 12.2% (7 of 57 eyes) in the brinzolamide group and 10.3% (6 of 58 eyes) in the apraclonidine group (P = .743); IOP elevations of 10 mm Hg and greater occurred in 3.5% (2 of 57 eyes) and 1.7% (1 of 58 eyes) (P = .618), respectively. There were no IOP elevations greater than 20 mm Hg in either group. CONCLUSION: Brinzolamide 1% and apraclonidine 0.5% given prophylactically before Nd:YAG laser capsulotomy were effective in preventing IOP spikes after treatment.

Adrenergic alpha-Agonists↗

PubMed2006

Outbreak of toxic anterior segment syndrome associated with glutaraldehyde after cataract surgery.

PURPOSE: To present clinical findings of a cluster of cases of toxic anterior segment syndrome (TASS) after uneventful phacoemulsification cataract surgery. SETTING: Department of Ophthalmology, Akdeniz University, Antalya, Turkey. METHODS: Six eyes of 6 patients developed TASS after uneventful phacoemulsification cataract surgery with implantation of a 3-piece acrylic IOL performed by 2 ophthalmologists on the same day. Clinical findings included corneal edema, Descemet's membrane folds, anterior chamber reaction, fibrin formation, and irregular, dilated, and unreactive pupils. RESULTS: Glutaraldehyde 2% solution was used inadvertently by the operating room staff who cleaned and sterilized reusable ocular instruments before autoclaving. None of the affected corneas improved. Additional surgical procedures were required and included penetrating keratoplasty, trabeculectomy, and glaucoma tube implantation. CONCLUSIONS: Glutaraldehyde in concentrations generally used for cold sterilization is highly toxic to the corneal endothelium. The operating room staff involved in sterilizing instruments should be well educated about and careful to follow the protocols to properly clean and sterilize reusable ocular instruments.

Aged↗

PubMed2006

Transmission electron microscopy and autofluorescence findings in the cornea of diabetic rats treated with aminoguanidine.

BACKGROUND: The accumulation of advanced glycation end products (AGEs) has been implicated in the pathogenesis of diabetic keratopathy. The present study was aimed to understand if aminoguanidine (AG), an AGE inhibitor, was protective against the development of corneal complications in a diabetic rat model. METHODS: Wistar rats were divided into three experimental groups: control, diabetic, and AG-treated diabetic. Diabetes was induced in rats via a single intraperitoneal injection (60 mg/kg) of streptozocin (STZ) and AG was administered in drinking water at a dose of 1 g/L. All animals were sacrificed at the end of 10 weeks and corneas from diabetic and nondiabetic rats were analyzed via transmission electron microscopy (TEM). Corneal autofluorescence measurements were also performed in all experimental groups. RESULTS: Electron microscopic evaluation revealed that aminoguanidine treatment in diabetic rats prevented the formation of intracellular spaces between neighbouring cells in the superficial corneal epithelium. Hyperglycemia-induced degeneration of intracellular organelles and formation of cytoplasmic vacuoles in the corneal stroma was also prevented with the treatment of AG. Corneal autofluorescence detected in the diabetic group (5.98 +/- 2.17 Fi/mg protein) was found to be significantly greater than the control (3.92 +/- 0.56 Fi/mg protein) and the AG-treated diabetic group (4.18 +/- 0.59 Fi/mg protein) (p < 0.05). INTERPRETATION: The presented data provide evidence that AG is preventive against corneal alterations in experimental diabetes.

Animals↗

PubMed2006

Nitrotyrosine formation and apoptosis in rat models of ocular injury.

This study was performed to examine inducible nitric oxide synthase (NOS-2) expression, nitrotyrosine formation and apoptosis in rats with elevated intraocular pressure (IOP) and/or ocular inflammation. Ocular inflammation was induced via injection of intra-vitreal lipopolysaccharide (LPS) while IOP was elevated by episcleral vessel cauterization. Animals were randomized to one of the following conditions: elevated IOP, LPS, elevated IOP+LPS, and control. Immunohistochemical staining and western blot analysis of retinal lysates revealed NOS-2 and nitrotyrosine immunoreactivity in all disease groups. NOS-2 expression and protein nitration was significantly greater in rats with elevated IOP+LPS compared to elevated IOP, LPS, and control groups. Nitrite levels in the retina affirmed significantly increased levels of nitric oxide generation in LPS-treated rats with elevated IOP (346+/-23.8 microM) vs LPS-treated, elevated IOP and control groups (195.6+/-12.6, 130+/-2.5 and 76.6+/-15.6 microM, respectively). Retinal TUNEL staining showed apoptosis in all diseased groups. Percent of apoptotic cells was significantly greater in the elevated IOP+LPS group compared to LPS-treated or elevated IOP groups. Presented data illustrates that both elevated IOP and ocular inflammation augment NOS-2 expression, retinal protein nitration and apoptosis in rats.

Animals↗

PubMed2006

Comparison of the inferior oblique weakening by disinsertion or disinsertion-resection and tucking in the patient with infantile esotropia.

The effectiveness of disinsertion vs disinsertion-resection and tucking procedure of the inferior oblique muscle for infantile esotropia was studied. Preoperative muscle overaction scores were +3.2 +/- 0.6 and +3.3 +/- 0.48 for the two groups, respectively. Postoperatively, there was + 0.52 average score in five Group I cases, whereas there were none in Group 2. We conclude that the disinsertion-resection and tucking procedure is more effective than simple disinsertion.

Child, Preschool↗

PubMed2005

Plasma homocysteine levels in noninsulin-dependent diabetes mellitus with retinopathy and neovascular glaucoma.

AIM: This study was designed to evaluate plasma homocysteine levels in noninsulin-dependent diabetes mellitus patients (NIDDM) with preproliferative retinopathy and neovascular glaucoma. The experimental goal was to determine the relationship between plasma homocysteine content and the development of microvascular lesions. METHODS: Plasma homocysteine levels were assessed in three experimental groups consisting of healthy controls (n = 30), NIDDM patients with preproliferative retinopathy (n = 20) and NIDDM patients with neovascular glaucoma (n = 20). Homocysteine levels were determined via a fluorescence polarization immunoassay method by an Abbot IMX instrument. RESULTS: Plasma homocysteine levels in NIDDM patients with preproliferative retinopathy and neovascular glaucoma (n = 40) were found to be significantly higher than those of controls (n = 30) (p < 0.01). When statistical analysis was performed separately among the three experimental groups, no significant difference in plasma homocysteine levels were found in patients with preproliferative retinopathy compared to controls. However, homocysteine levels in patients with neovascular glaucoma were found to be significantly higher than the control group (p < 0.001). No significant difference in plasma homocysteine levels could be detected between patients with preproliferative retinopathy and neovascular glaucoma. CONCLUSIONS: Hyperhomocysteinemia is a risk factor for the development of microvascular lesions in patients with NIDDM but cannot be used as a marker to assess the progression of lesions observed in neovascular glaucoma.

Case-Control Studies↗

PubMed2004

Effect of hypercholesterolemia on inducible nitric oxide synthase expression in a rat model of elevated intraocular pressure.

PURPOSE: This study was performed to examine the effect of hypercholesterolemia on inducible nitric oxide synthase (NOS-2) expression and oxidative tissue injury in an experimental rat model of elevated IOP. METHODS: Wistar rats were maintained on either regular chow or a high-cholesterol diet for 24 weeks. Intraocular pressure (IOP) was elevated in hypercholesterolemic rats by unilaterally cauterizing three episcleral vessels. Rats were divided into four experimental groups as follows; hypercholesterolemia, hypercholesterolemia+elevated IOP, elevated IOP and control. NOS-2 distribution, lipid peroxidation and retinal nerve fiber layer (RNFL) thickness was evaluated in all experimental groups at the end of 24 weeks. RESULTS: Light microscopic evaluation of retinas in hypercholesterolemic rats revealed breaks and discontinuation in focal areas in the outer nuclear layer (ONL). NOS-2 positive staining was observed throughout the outer plexiform layer (OPL), inner plexiform layer (IPL) and ganglion cell layer (GCL) in rats with elevated IOP and/or hypercholesterolemia. Calculated values of RNFL thickness in hypercholesterolemic rats were significantly higher than those in the control and elevated IOP group. Vitreous malondialdehyde (MDA) levels detected in elevated IOP (3.51+/-0.31 nmol/mg protein) and hypercholesterolemia+elevated IOP (5.14+/-1.28 nmol/mg protein) groups were significantly higher than those detected in hypercholesterolemic (1.92+/-1.43 nmol/mg protein) and control (1.89+/-0.24 nmol/mg protein) groups. CONCLUSION: The presented data confirms hypercholesterolemia as a risk factor in the development of glaucomatous optic neuropathy (GON) and suggests that increased circulating cholesterol may exacerbate disease progression by inducing NOS-2 expression and elevating oxidant tissue injury.

Animals↗

PubMed2003

Levels of zinc and magnesium in senile and diabetic senile cataractous lenses.

Zinc and magnesium in serum, hair, and lens were determined in diabetic and nondiabetic patients who have been operated because of senile cataract. Both trace elements were measured by atomic absorption spectrometry, after acidic digestion of the lens and hair samples. Although there was no difference in serum, lens, and hair levels of magnesium between the two groups, the lens levels of zinc in diabetic patients (0.56+/-0.05 micromol/g dry weight) were significantly higher as compared with nondiabetic group (0.42+/-0.03 micromol/g dry weight). There was no statistically significant difference in serum and hair levels of zinc between the groups. The increased concentration of zinc in the lens of diabetic patients suggests that zinc might play a role in developmental mechanism of the diabetic senile cataract.

Blood Glucose↗