The role of advanced oxidation protein products and total thiols in diabetic retinopathy.

PURPOSE: This study aimed to investigate the role of protein peroxidation by detecting the serum levels of advanced oxidation protein products (AOPP), a novel marker for the degree of oxidative damage to proteins, and total thiol as a marker of antioxidant status in diabetic patients with or without diabetic retinopathy (DR) and to compare the results with those of control subjects. METHODS: The study groups consisted of two separate subgroups: 1) 37 patients (14 male, 23 female) with noninsulin-dependent diabetes mellitus (NIDDM) showing diabetic retinopathy (DR) and 2) 20 patients with NIDDM and without any signs of DR (9 male, 11 female); 26 healthy non-diabetic control subjects (15 male, 11 female) were selected from the patients attending our department for refractive disorders. Venous blood samples of all participants were collected in the morning after an overnight fast, and serum samples storedat -70 degrees C until assay for AOPP, and total thiol. RESULTS: AOPP levels were significantly higher in diabetic patients with (210.9+/-73.0 micronmol/L) or without DR (222.7+/-94.4 micronmol/L) when compared to those of controls (152.4+/-72.04 micronmol/L) (p=0.004). Even though the difference was not statistically significant (p=0.095), total thiol levels in cases with DR (278.7+/-139.1 micronmol/L) were lower than those without DR (334.0+/-129.4 micronmol/L) and controls (353.2+/-145.6 micronmol/L). Correlation tests did not reveal any association between these parameters and age, sex, or duration of DM. CONCLUSIONS: The present study suggests that increased protein oxidation may contribute to the pathogenesis of DR.

Serum paraoxonase activity is decreased in the active stage of Behçet's disease.

AIMS: To evaluate paraoxonase1 (PON1) activities and malondialdehyde (MDA) levels, one of the end products of lipid peroxidation induced by reactive oxygen species in patients with Behçet's disease (BD) in the active stage. METHODS: Serum MDA levels and PON1 levels were measured spectrophotometrically in 16 patients with BD in the active stage of the disease and in 15 healthy subjects who constituted the control group. RESULTS: In the BD group, median (range) serum PON1 and MDA levels were 149.64 U/l (88.02-281.68) and 1.21 nmol/ml (0.90-3.42), respectively. In the control group, median (range) serum PON1 and MDA levels were 206.86 U/l (114.43-422.52) and 0.72 nmol/ml (0.50-1.12), respectively. There was a statistically significant decrease in serum PON1 levels (p = 0.02) and an increase in serum MDA levels (p<0.001) in patients with BD in the active stage when compared to controls. CONCLUSION: Endothelial damage and increased polymorph nuclear leucocyte activity in the active stage of BD could result in a pro-oxidation environment which, in turn, results in decreased antioxidant PON activity and increased lipid peroxidation as evidenced by increased MDA levels.

Tear nitrite and nitrate levels as nitric oxide end products in patients with Behçet's disease and non-Behçet's uveitis.

To evaluate the role of nitric oxide (NO) in ocular inflammation, tear nitrite and nitrates (NN) as NO end products were determined in 11 patients with Behçet's disease (BD) and in 11 with non-Behçet's uveitis (NBU) during the active and remission stages and in 12 healthy controls. Median (with the range) NN levels were 82.29 (59. 60-98.25) micromol/l in the active and 98.25 (52.88-246.92) micromol/l in the remission stage of BD; 88.17 (25.99-116.73) micromol/l in the active and 83.00 (31.04-250.28) micromol/l in the remission stage of NBU and 109.17 (88.17-158.74) micromol/l in the controls. The NN levels in the active stage of BD and NBU were significantly decreased when compared to the controls (p < 0.05; Kruskal-Wallis test). Decreased NN levels at the activation stage may be caused by the rapid transformation of the NO to peroxynitrites, which are highly oxidizing and cytotoxic substances.

Intravitreal trovafloxacin against experimental Staphylococcus epidermidis endophthalmitis.

This study was designed to test the effects of intravitreal trovafloxacin on an experimental rabbit model of Staphylococcus epidermidis endophthalmitis. Out of 26 rabbits, 22 were given intravitreal S. epidermidis (100,000 CFU). At 24 h, group 1 (8 rabbits) and, at 48 h, group 2 (8 rabbits) received 100 microg intravitreal trovafloxacin. Group 3 (6 rabbits) was used as inoculated but untreated controls. Four rabbits (group 4) were used as uninfected controls. Clinical scores were calculated at 24, 48 and 72 h. Microbiological and histopathological scorings were made. Microbiological analysis showed that trovafloxacin administered at 24 or 48 h significantly reduced the number of bacteria compared to the untreated group. We conclude that trovafloxacin applied at 24 or 48 h is effective against S. epidermidis endophthalmitis in this experimental rabbit model.

Comparison of the effects of 0.5% timolol maleate, 2% carteolol hydrochloride, and 0.3% metipranolol on intraocular pressure and perimetry findings and evaluation of their ocular and systemic effects.

PURPOSE: To compare the effects of 0.5% timolol maleate, 2% carteolol, and 0.3% metipranolol on intraocular pressure (IOP) in 45 patients with primary open-angle glaucoma (POAG) and ocular hypertension. A secondary goal of this study was to evaluate the ocular and systemic side effects of these medications. METHODS: Measurements of IOP were taken at baseline (pretreatment) and 2, 6, and 12 hours after instillation on treatment days 15, 30, 60, and 90. Mean sensitivity (MS) and mean defect (MD) values of perimetry before and after treatment and the effects of the three beta blockers on serum lipid profiles were determined. Ocular and systemic side effects were recorded. RESULTS: The most prominent IOP lowering effect was noted with metipranolol at 2 and 6 hours on day 15, and with timolol maleate at 12 hours on day 15 and at all hours of the subsequent days on which measurements were taken. Timolol maleate produced a significant decrease in IOP at 12 hours on day 15 compared with carteolol. There was not a statistically significant difference between the MS and MD values on perimetry before and after treatment for any treatment. There was a statistically significant decrease in levels of total cholesterol and high-density lipoprotein (HDL) cholesterol and a significant increase in triglyceride levels; these changes were observed for all treatments. CONCLUSION: The effects of the three medications were not statistically different from each other in terms of IOP reduction and visual field changes. Careful monitoring of blood lipid levels is necessary with long-term treatment with beta blockers, because these agents reduced serum levels of HDL and total cholesterol while increasing triglycerides. Such changes in lipid levels could lead to increased incidence of complications, particularly in patients with atherosclerosis or coronary heart disease.

Ophthalmological effects of high altitude.

High altitude has various effects on human beings. Altitude-related illnesses are a frequent cause of morbidity and occasional mortality in travelers to high altitudes throughout the world. The mountaineers all around the world are familiar with this condition, which is called acute mountain sickness (AMS). The primary altitude illnesses are AMS, high-altitude pulmonary edema and high-altitude cerebral edema. Altitude has potential undesired ophthalmological effects. The pathogenesis of these syndromes remains unclear despite considerable research in this field. Most of these problems are primarily preventable with an adequate level of information before and during travel. Further studies are needed to reveal the exact relationship between high altitude and ophthalmological findings. In this article, ophthalmological effects of high altitude, likely to be encountered by mountaineers as well as other enthusiasts of high altitude sports are reviewed. Emphasis on aviation and aerospace medicine is briefly given under related SUB_TITLEs.

Selenium concentrations in serum, lens and aqueous humour of patients with senile cataract.

Selenium (Sc) is a trace element which incorporates into the selenoenzyme glutathion peroxidase. Cataractogenesis may be caused either by the excess or deficiency of this trace element. More recently, its potential of becoming a possible environmental pollutant has been emphasized. In an attempt to reveal the relationship of this element with cataractogenesis, we detected its level in 48 serum, 36 lens and 9 aqueous humour samples of 48 patients with senile cataract, comparing the results with appropriate controls. Selenium levels (mean +/- SD) of cataractous patients were found to be 0.28 +/- 0.04 microgram/ml (CI: 0.27 to 0.29 microgram/ml) in sera (controls: 0.32 +/- 0.04 microgram/ml; CI: 0.30 to 0.34 microgram/ml, p < 0.0001), 5.43 +/- 3.07 microgram/g dry weight (CI: 4.43 to 6.43 microgram/g dry weight) in lens (controls: 4.43 +/-2.53 microgram/g dry weight; CI: 2.78 to 6.08 microgram/g dry weight; p=0.374) and 0.19 +/- 0.06 microgram/ml (CI:0.15 to 0.23 microgram/ml) in aqueous humour samples (controls: 0.31 +/-0.12 microgram/ml; CI: 0.24 to 0.38 microgram/ml, p = 0.02). When patient subgroups were analyzed, serum Se levels were found to be 0.28 +/- 0.05 microgram/ml (CI: 0.26 to 0.30 microgram/ml in the nuclear cataract and 0.28 +/- 0.02 microgram/ml (CI: 0.27 to 0.30 microgram/ml) in the cortical cataract. Lens Se levels, on the other hand, were detected as 5.91 +/- 3.56 microgram/g dry weight (CI:4.49 to 7.33 microgram/g dry weight) in the nuclear cataract and 4.47 +/- 1.40 microgram/g dry weight (CI: 3.68 to 5.26 microgram/g dry weight) in the cortical cataract. It is anticipated that decreased Se in aqueous humour and sera of patients with senile cataract may reflect defective antioxidative defense systems which may lead to the formation of cataract.

Filtering surgery with mitomycin-C in uncomplicated (primary open angle) glaucoma.

Mitomycin is an antibiotic with antineoplastic activity which inhibits fibroblast proliferation in the operative field in glaucoma filtering surgery. The authors retrospectively evaluated the effectiveness of trabeculectomy with mitomycin-C as an initial surgical procedure in uncomplicated (primary open angle) glaucoma in 17 eyes of 17 patients; 12 eyes of 12 patients that received standard trabeculectomy constituted the control group. Mitomycin was applied at a concentration of 0.5 mg/ml for 3 min to the episclera and 2 min under the scleral flap. Median values for preoperative intraocular pressure was 43 mmHg (range 26-65) in the control group and 40 mmHg (range 30-60) in the mitomycin group (p > 0.05, Mann-Whitney U-test). After an average follow-up of 17 months, median postoperative IOP was 10 mmHg (range 3-18) in the control group and 4 mmHg (range 1.1-20) in the mitomycin group (p < 0.05, Mann-Whitney U-test). Percentage IOP drop was 75.6% in the control group (range 30.8-93.5%) and 89.6% (range 54.2-98%) in the mitomycin group (p < 0.05, Mann-Whitney U-test). The postoperative visual acuities of the two groups did not differ significantly (p > 0.05, Fisher exact test). Although there was not a statistically significant difference between complications, such as elevated intraocular pressure, wound leakage or bleb ulceration in both groups (p > 0.05, Fisher exact test), the number of hypotonous eyes (having an average IOP < or = 5 mmHg) was significantly higher in the mitomycin-C group compared to the controls (p < 0.05, Fisher exact test). Mitomycin established a well formed bleb and reduced the IOP more effectively than did the standard filtering procedure (p < 0.05, Mann-Whitney U-test); however, further work is necessary to evaluate the long-term complications of mitomycin-C surgery such as hypotony. This would help clear any doubts about the safety of this procedure on long-term.

Postoperative endophthalmitis caused by an Enterobacter species.

Six patients (aged 8 to 75 years) who were operated upon during the same day developed bacterial endophthalmitis on the following day; seven eyes were affected. Two patients had intracapsular cataract extraction, one extracapsular lens extraction, two extracapsular cataract extraction with intraocular lens implantation and one repair of bilateral scleral or corneoscleral perforations. Vitreous cultures taken from six eyes were positive for an Enterobacter sp. Despite antibiotic treatment systemically, subconjunctivally and intravitreally, four eyes had to be eviscerated, while two eyes showed evidence of shrinkage (phthisis); only one eye retained useful vision (9/10). Cotton swabs used during surgery, prepared manually from cotton wool moistened with saline, were identified as the source of infection; the batch had not been subjected to the prescribed autoclaving process. The importance of proper sterile procedures in association with surgery is emphasized.

Congenital nasolacrimal duct obstruction in Kayseri, Turkey.

Congenital nasolacrimal duct obstruction was diagnosed in 170 patients between 1982 and 1991 in Kayseri, Turkey, and 111 patients were treated with massage plus topical antibiotics (MBC), pressure irrigation (PI), probing (PRB) or infracturing of the inferior turbinate (INF). The ages of the patients ranged from one week to 15 years. The obstruction was bilateral in 38 patients. Among the 149 obstructed lacrimal drainage systems of 111 patients, 101 were cleared by MBC (67.8%), 30 by PI (20.1%), eight by PRB (5.3%) and two by INF (1.3%). Eight cases were unsuccessful (5.3%), and the overall success rate was 94.6%. The efficacy of four interventions was correlated to the patients' ages and to the presenting pathology. MBC carried out at the serofibrinous stage and at 7-13 months was more effective than other interventions, with a statistical significance (p < 0.01). The effectiveness of four interventions is discussed, with an emphasis on the importance of early MBC. The importance of fluoroscopy during PI or PRB is also emphasized.

Diagnosis and management of a biorbital pencil injury.

A 9-year-old girl was wounded by a pencil which entered the right orbit and passed towards the left. The broken part remained inside. The diagnosis was delayed for 9 months since the history and the symptoms were misleading. The pencil, which could not be detected with plain X-rays, was demonstrated with computerized tomography (CT) and removed from the orbit successfully. The case is presented to emphasize the contribution of CT to the perforating injuries of the orbit with wooden particles. Importance of orbital foreign bodies in the differential diagnosis of proptosis in the pediatric age group is also discussed.

Unilateral naso-orbital meningocele and bilateral congenital fistulae of the lacrimal passages.

Orbital meningocele is the protrusion of a sac containing cerebrospinal fluid into the orbit, through a defect called cranium bifidum. Although the occipital and frontal basis of the cranial cavity constitute the two most frequent localizations, this pathology may rarely be located in the naso-orbital region. Other developmental anomalies of the eyes may accompany the anomalies of the bony orbit. The case described in the present paper had a right naso-orbital meningocele associated with bilateral fistulae of the lacrimal passages which represents a very rare condition.