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.

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.

Effects of topically applied prostaglandin F2 alpha tromethamine salt on glaucomatous human eyes.

Prostaglandin F2 alpha (PGF2 alpha) as its tromethamine salt was topically applied, and hypotensive and other ocular effects were studied, in glaucomatous human eyes. After baseline intraocular pressure (IOP) measurements, 100 micrograms PGF2 alpha tromethamine salt dissolved in 50 milligrams saline was applied to 23 glaucomatous eyes of 20 patients. The pretreatment diurnal IOP values of the same eye served as control group. It was found that in comparison with baseline values, PGF2 alpha caused significant but transient elevation in IOP in the first half-hour (mean 1.95 mm Hg, p < 0.01), but it decreased below baseline values at the first hour. A significant decrease in IOP from baseline was observed at the 2nd hour (p < 0.05), which became more prominent between the 4th and 24th hours (p < 0.001). PGF2 alpha produced a maximal IOP reduction of 10.21 mm Hg at the 12th hour (p < 0.001). The IOP differences between PGF2 alpha-treated and control groups were significant between the 4th and 24th hours (p < 0.001), with the maximal IOP difference of 9.21 mm Hg at the 12th hour (p < 0.001). PGF2 alpha caused marked conjunctival hyperaemia in all eyes. Aqueous flare and cellular response were not seen in any of the eyes. Half of the patients experienced ocular smarting or a foreign-body sensation, periocular pain and headache. PGF2 alpha reduced IOP effectively in glaucomatous human eyes.

Effects of topically applied prostaglandin F2 alpha on normotensive human eyes.

The ocular effects of topical prostaglandin F2 alpha (PGF2 alpha) were studied in normotensive human eyes. PGF2 alpha as tromethamine salt, 100 micrograms, was applied to one eye of 23 normotensive subjects, intraocular pressure (IOP) and pupil size were measured, objective and subjective findings recorded during the first 24 h. Tonography was performed in 10 subjects. As compared with the baseline, PGF2 alpha caused a significant IOP reduction between 1 and 24 h (p < 0.001), being maximal (4.9 +/- 0.5 mm Hg, mean +/- SEM, p < 0.001) between 4 and 8 h. As compared with the contralateral control eyes, which received 50 microliters of saline, treated eyes exhibited significant IOP reduction between 1 and 24 h (p < 0.001), being maximal (4.2 +/- 0.4 mm Hg, mean +/- SEM, p < 0.001) at 4 h. PGF2 alpha caused marked conjunctival hyperemia in all eyes. Pupillary diameter was not altered. Aqueous flare and cellular response were not seen. Half of the subjects complained of ocular smarting, mild ocular pain or headache. Total outflow facility did not change (p > 0.05).

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.

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.