Comparative evaluation of possible ocular photochemical toxicity of fluoroquinolones meant for ocular use in experimental models.

Fluoroquinolones (FQs) are extensively used in bacterial keratitis and other intraocular infections. Since eye is constantly exposed to light, incidence of ocular phototoxicity due to commonly used FQs is of great interest for their safe use. Phototoxicity of commonly used FQs (ciprofloxacin, lomefloxacin, pefloxacin, ofloxacin, sparfloxacin and gatifloxacin), has been evaluated by using HET-CAM-UV model (Photo Hen Egg Test-C Chorioallantoic Membrane model). This study was further extended by adding lomefloxacin dissolved in bovine vitreous (0.5 ml) on the chorioallantoic membrane (CAM). Using a standard scale, the phototoxic damage was assessed at different time intervals. Respective controls were kept in dark to distinguish the toxicity of the drugs per se. The results showed that the phototoxicity induced by lomefloxacin was very high followed by gatifloxacin and sparfloxacin and least for other drugs studied. Interestingly, lomefloxacin along with vitreous showed significantly low phototoxicity. This could be due to the antioxidant property of ascorbic acid present in the vitreous.

Protection from ultraviolet radiation by spectacle lenses available in India: a comparative study.

BACKGROUND: Exposure to ultraviolet radiation (UVR) can result in several ocular ailments. We studied the UV absorption (UV-A and -B bands) in 20 lenses (11 hard resin and 9 glass) commonly available in India as uncut lenses for the purpose of prescription as well as non-prescription wear. METHODS: Using a UV-visible spectrophotometer (Thermo-Spectronic, UV-1 model, Thermo Electron Corporation, USA), the percentage transmittance was scanned between 190 and 400 nm, from which the results at 280, 320, 340, 360, 380 and 400 nm were analysed. RESULTS: At 360 nm (UV-A), 75% of the lenses studied failed to offer 95% protection as recommended by the United States Food and Drug Administration (US FDA). At 280 nm (UV-B), 35% of the lenses failed to offer 99% protection against UV-B. Hard resin lenses showed a higher degree of variation in protection from UV-A. CONCLUSONS: Most of the lenses studied failed to meet the US FDA recommendations in terms of protection from UV-A. Glass lenses afforded better protection up to 320 nm compared with hard resin lenses. As the claims of lens manufacturers regarding UVR protection fall short of international standards, certification of UVR protection for different lenses should be introduced in India.

Effect of vitamin E on the severity of myocardial infarction induced by isoproterenol.

The effect of vitamin E administration on the severity of myocardial infarction induced by isoproterenol on rats was studied. Judging from serum enzyme activity (CPK 714 micromoles; GOT 291.7 micromoles; and GPT 155.5 micromoles), mortality rate (60 to 65% survived) and histopathological observation, vitamin E has been observed to offer very little protection to the myocardium during experimental myocardial infarction when compared to control animals given isoproterenol alone (CPK 775.8 micromoles; GOT 336.2 micromoles; and GPT 168 micromoles), mortality rate (60 to 65% survived) and histopathological observation (more or less similar). The level of lipid peroxides namely hydroperoxides (control 3.15; vitamin E + iso. 14.8); conjugated diene (4.45 and 6.85) and malondialdehyde (1.22 and 2.55) in the heart were higher in the vitamin E treated animals given isoproterenol when compared to control animals given vitamin E alone. The level of cholesterol and phospholipid was more or less similar in the control animals given vitamin E alone (183.6 and 3.12) and vitamin E treated animals given isoproterenol (170.25 and 2.49), but the ratio of cholesterol to phospholipid was higher in the vitamin E treated animals given isoproterenol when compared to control animals given vitamin E alone.