Erdinc Aydin

Serum homocysteine, vitamin B 12 and folic acid levels in different types of glaucoma

BackgroundThis study was performed to compare levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with primary open-angle glaucoma (POAG), pseudoexfoliative glaucoma (PEXG), normotensive glaucoma (NTG) and healthy controls.MethodsTwentyfive patients with POAG, 24 with PEXG, and 18 with NTG, along with 19 control healthy subjects were included this prospective study. Levels of serum Hcy were measured using immunoassay, and those of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay.ResultsThe mean Hcy concentration in the PEXG group was significantly higher (P < 0.001) as compared to the other groups. There were no significant differences with respect to the mean Hcy concentrations among other groups (P > 0.05). There were no statistical differences in serum vitamin B12 levels among POAG, PEXG, NTG and control subjects (P > 0.05).The mean serum folic acid level was significantly lower in the subjects with PEXG (P < 0.009). However, the mean folic acid concentrations among the other groups did not differ significantly (P > 0.05).ConclusionElevated levels of Hcy in PEXG may explain the role of endothelial dysfunction among patients with PEXG.

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

PURPOSEnTo evaluate the results of bilateral simultaneous cataract surgery in adult and pediatric patients under local or general anesthesia.nnnSETTINGnDepartment of Ophthalmology, Inönü University, Turgut Ozal Medical Center, Malatya,Turkey.nnnMETHODSnEighty-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.nnnRESULTSnNo 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.nnnCONCLUSIONSnSimultaneous 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.

Prevention of corneal neovascularization: evaluation of various commercially available compounds in an experimental rat model.

Purpose: To evaluate the effect of topically administered agents doxycycline, triamcinolone, low molecular weight heparin (LMWH), and flurbiprofen on experimental corneal neovascularization in rats. Methods: Chemical cauterization of cornea was performed in 36 eyes of 36 rats by using silver nitrate/potassium nitrate sticks. Topical instillation of doxycycline, triamcinolone, LMWH, flurbiprofen, and normal saline solution was continued for 7 days. Percent areas of cornea covered by neovascularization and covered by scar in each group were calculated by use of computer software on digital photographs. Groups were compared for any significant (P < 0.05) differences among them. Results: The means of percent area of corneal neovascularization in triamcinolone, doxycycline, flurbiprofen, LMWH, and control groups were 13.3%, 35.5%, 50.6%, 66.7%, and 74.9%, respectively. The triamcinolone and doxycycline groups were different from control group (P < 0.05). There was no significant difference in the percent area of neovascularization between the LMWH and flurbiprofen groups compared with the controls. Although the effects of LMWH and flurbiprofen were not significant, there seemed to be a trend, and the lack of significance may be related to small sample size. Because the mechanisms of action of these agents are not identical to each other, performing other studies using combinations of them seems to be reasonable. There were no significant differences in percent area of corneal scar among groups. Conclusion: Topical instillation of commercially available triamcinolone and doxycycline seems to diminish corneal neovascularization caused by chemical cauterization of cornea in rats.

Inhibition of experimental angiogenesis of cornea by various doses of doxycycline and combination of triamcinolone acetonide with low-molecular-weight heparin and doxycycline.

Purpose: To evaluate the effect of topically administered doxycycline in various doses; the combination of triamcinolone acetonide and low-molecular-weight heparin (LMWH); and the combination of triamcinolone acetonide and doxycycline on experimental corneal neovascularization in rats. Methods: This project is the combination of 2 separate studies. First, the chemical cauterization of corneas in 36 eyes of 36 Long Evans male rats was performed by using silver nitrate/potassium nitrate sticks. Topical instillation of doxycycline at 0.05% (pH = 3.3), 0.1% (pH = 3.1), 1% (pH = 2.3), 2% (pH = 2.1), 2% (pH neutralized to 7.4), and normal saline continued for 7 days. Second, the chemical cauterization of the corneas in 24 eyes of 24 rats was achieved by application of silver nitrate/potassium nitrate sticks. Topical instillation of triamcinolone acetonide (10 μg/mL) and either LMWH (10 mg/mL) or doxycycline (10 mg/mL) was compared with normal saline treatment of 7 days. For both studies, the percent area of the cornea covered by neovascularization and scar in each group was calculated separately by using computer software on digital photographs. All corneas were evaluated histopathologically in study and control groups. Results: The mean percent area of corneal neovascularization determined in the eyes given doxycycline 0.05%, 0.1%, 1%, 2%, and 2% (pH neutralized) study groups and control groups was 69.8% ± 18.0%, 64.5% ± 14.0%, 56.4% ± 20.8%, 54.8% ± 6.0%, 36.2% ± 4.3%, and 69.4% ± 5.7%, respectively. The mean of percent area of neovascularization in the 2% doxycycline (pH neutralized) doxycycline group was significantly less than that of the control group and the <1% doxycycline concentrations (P < 0.05). The percent corneal neovascularization in the 2% (pH neutralized) doxycycline group was not significantly different from that of the 1% and 2% doxycycline groups (P < 0.05). There was no significant difference in percent area of corneal scar between control and study groups (P > 0.05). The mean percent area of corneal neovascularization in triamcinolone acetonide and LMWH, triamcinolone acetonide and doxycycline, and control groups was 2.35% ± 4.42%, 9.42% ± 6.8%, and 64.7% ± 10.0%, respectively. The mean percent area of neovascularization in the triamcinolone acetonide plus LMWH or triamcinolone acetonide plus doxycycline groups was significantly different from that of the control group (P = 0.001 for both). There was no significant difference between study groups with regard to percent area of neovascularization or percent area of corneal scar between the control and study groups. Conclusions: Topically administered combinations of triamcinolone acetonide plus LMWH or triamcinolone acetonide plus doxycycline had effects that contributed to efficient suppression of corneal neovascularization; these drugs were ineffective at similar concentrations used alone. Topically administered 2% (pH neutralized) doxycycline has antiangiogenic effects, which contributed to significant suppression on corneal neovascularization. This drug may be therapeutically beneficial in treatment of corneal neovascularization in clinical trials.

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.

Association of Plasma Homocysteine and Macular Edema in Type 2 Diabetes Mellitus

Purpose The aim of this study was to assess the association of macular edema (ME) with plasma homocysteine, vitamin B6, vitamin B12, and folic acid levels in patients with Type 2 diabetes. Methods Sixty-five diabetic subjects with no retinopathy and nonproliferative diabetic retinopathy (NPDR) (no DR, without ME, with ME: 16, 25, 24, respectively), 28 with proliferative diabetic retinopathy (PDR) (with and without ME: 14, 14, respectively), and 19 healthy subjects as control were recruited in this cross-sectional study Plasma homocysteine, vitamin B12, vitamin B6, and folate levels were determined after 8-hour of fasting for all subjects. The levels of serum homocysteine and vitamin B6 were measured using high performance liquid chromatography (HPLC) with fluorescence detection, and the levels of serum vitamin B12 and folic acid were measured by electrochemiluminescence immunoassay. Results When diabetic groups with ME were compared with diabetic groups without ME for homocysteine, vitamin B12, vitamin B6, and folic acid, the only significant difference was detected in homocysteine levels (p=0.001). There was no significant difference between NPDR with ME group compared with NPDR without ME group and no DR group for plasma homocysteine, vitamin B12, vitamin B6, and folic acid (p=0.200, p=0.660; p=0.999, p=0.678; p=1.0, p=0.248; p=1.0, p=0.982, respectively). On the other hand, when PDR with ME group was compared with PDR without ME group, there was only significant difference in homocysteine levels (p=0.023). Conclusions Mild to moderate elevation of homocysteine may explain the role of vascular dysregulation and endothelial dysfunction in patients with DR. The present study suggests hyperhomocysteinemia may be one of the crucial risk factors for development of ME.

Comparison of Serum Nitric Oxide, Malondialdehyde Levels, and Antioxidant Enzyme Activities in Behçet’s Disease with and without Ocular Disease

Objective: The pathogenesis of Behçet’s disease (BD) may be related to excessive production of reactive oxygen species, activated neutrophils, and T lymphocytes. The goal of this prospective study was to investigate whether there is any relationship among the oxidant/antioxidant system and nitric oxide (NO) and malondialdehyde (MDA) levels in patients with BD and its subtypes: complete Behçet’s disease (CBD) and incomplete Behçet’s disease (ICBD), with or without ocular disease. Methods: Thirty-two patients and 26 age- and sex-matched healthy control subjects were evaluated for NO and MDA levels and antioxidant enzyme activities. The patients with BD were divided into two subgroups: those with and without ocular disease. Twelve patients with CBD and 4 patients with ICBD had ocular disease. The serum NO level was determined by Griess reaction. The MDA level was detected by thiobarbituric acid reaction. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum were analyzed with spectrophotometric methods. Results: Increased MDA levels but decreased GSH-Px activities in plasma were observed in BD patients with all subtypes, as compared with controls. Concerning the presence of ocular disease and the subtype (CBD or ICBD) compared with each other, there were no significant differences in MDA or NO serum levels and SOD or GSH-Px enzyme activities. Conclusions: Serum NO levels and SOD enzyme activities were not significantly changed in patients with BD and its subtypes; however, a remarkable decrease of GSH-Px enzyme activity and increase of MDA levels were found.

Levels of Iron, Zinc, and Copper in Aqueous Humor, Lens, and Serum in Nondiabetic and Diabetic Patients Their Relation to Cataract

The purpose of this study was to investigate iron (Fe), zinc (Zn), and copper (Cu) levels of aqueous humor, lens, and serum in nondiabetics and diabetics and to determine the effects of diabetes on Fe, Zn, and Cu contents in the lens. Fe, Zn, and Cu contents of aqueous humor, lens, and serum samples of 19 patients (9 nondiabetic patients with a mean age of 62.3±5.4 yr, and 10 diabetic patients with a mean age of 59.5±5.9 yr) were analyzed by atomic absorption spectrometry using a prospective study design. The lens levels of Cu in diabetic patients were significantly higher compared with nondiabetic patients (p=0.02); however; there was no difference in the other elements (Zn, Fe; p=0.28, p=0.74, respectively). The levels of Fe, Zn, and Cu in the aqueous humor and serum of diabetic patients were not found to be statistically significant when compared to nondiabetics (p=0.46, p=0.11, p=0.18, and p=0.22, p=0.43, p=0.72, respectively). These results demonstrate that increased Cu content of the lens presumably has a greater association with the development of lens opacification in diabetics than Zn and Fe content.

Intravitreal Toxicity of Levofloxacin and Gatifloxacin

To determine whether prone postoperative near visual acuity following macular hole surgery can be used as a reliable indicator of successful hole closure, data from 21 patients undergoing macular hole surgery were collected. Seventeen of the 18 patients with hole closure and all 3 patients with persistent macular holes had a Rosenbaum acuity better than preoperative visual acuity, yielding 94% sensitivity, 0% specificity, 85% positive predictive value, and 0% negative predictive value. Fourteen of the 18 patients with macular hole closure and all 3 patients with persistent macular holes had a Rosenbaum acuity better than 20/40, yielding 78% sensitivity, 0% specificity, 82% positive predictive value, and 0% negative predictive value. Although postoperative near visual acuity can predict macular hole closure with 94% sensitivity, the test is not clinically useful to predict hole closure because of the high surgical success rate of macular hole surgery. The test could be useful in encouraging patients to maintain head prone positioning and alleviate patient anxiety.

The role of axial length in central and branch retinal vein occlusion.

BACKGROUND AND OBJECTIVEnTo assess whether the axial length is a local risk factor in central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).nnnPATIENTS AND METHODSnThe axial lengths of affected and fellow eyes of 19 patients with CRVO and 27 with BRVO and of their controls were measured with A-scan ultrasonography. The control group consisted of 17 individuals for CRVO and 25 for BRVO matched in age, sex and the prevalence of hypertension and diabetes in patient groups. The results of measurements in affected, unaffected and control eyes were compared.nnnRESULTSnThe mean axial length was different among the affected and unaffected eyes in patients with CRVO and their controls (P < .05). The affected eyes had significantly shorter axial length compared to the fellow and control eyes (P < .01 and P < .01, respectively). In the BRVO group, the mean axial length did not differ among affected, unaffected and control eyes (P > .05).nnnCONCLUSIONSnOur study demonstrates a significantly shorter axial length in eyes with CRVO and not significantly shorter axial length in those with BRVO. The shorter axial length could be an additional risk factor in the pathogenesis of CRVO.