Abstract
Abstract: :
Purpose: To evaluate the effect of Chlorpromazine-UV-B exposure on cornea and crystalline lens. Methods: An experimental rabbit T-1 (n=1) received a single dose of 0.5 ml 32S-Chlorpromazine per iv, sacrificed 1 hr later, eyes excised, tissues harvested and frozen for histochemical analyses showed that chlorpromazine crossed the blood-aqueous barrier to reach the cornea within 1 hr. Twelve pigmented rabbits (2-3 kg, body weight) were used in this study. Each eye of experimental rabbits was examined with the slit lamp biomicroscope for ocular health certification, and any animal with corneal and/or lenticular opacities, was excluded from the experiment. Control group C-1 (n=2) were not subjected to drug or radiation treatments. The animals were monitored for tissue changes for the entire period of the experiments. Experimental group E-1A (n=5) had one eye irradiated with 0.04 Joules/cm2 UV-B (295-320 nm). Experimental group E-1B (n=5) received a single dose (25 mg/kg, per i.v) of chlorpromazine and in addition one eye of each rabbit was irradiated with 0.04 Joules/cm2 of UV-295-320 nm bandpass. Experimental group E-2A (n=5) received a single dose of chlorpromazine and 0.75 Joules per cm2 UV-295-320 nm irradiation in one eye. The non-irradiated rabbit eyes in each experiment groups E-1A, E-1B, E-2A served as internal system control. The cornea, iris, anterior chamber, and lens were examined every hr for 6 hrs, and pachymetry performed at each interval. Experimental treatment animals were monitored the remainder of 7 days at 4-6 hourly intervals. Group E-1A and E-1B animals were sacrificed by overdose injection of pentobarbital sodium after 7 days. Group E-2A rabbits were monitored for 2-3 weeks post-irradiation. Results: Group E-2A rabbits showed acute inflammatory responses (lid erythema/edema and cornea edema/keratic precipitate, cells and flares), increase (40-78%) in corneal stromal thickness, corneal infiltrates, epithelial exfoliation were observed. Corneal thickness changes peaked at between 12 and 20 hrs post-irradiation. Tissue recovery was slow with onset time of 38-60 hours post-irradiation. Crystalline lens showed increased prominence of the zones of discontinuity, mild anterior subcapsular and posterior cortical opacities, seen only after 6 days post-treatment observation. Conclusion: Chlorpromazine may be a predisposing risk factor to corneal edema, keratitis, and early onset cataract in patients further exposed to suprathreshold UV-B level of exposure experienced by snow skiers. Commercial Affiliation (N)
Keywords: 374 cornea: stroma and keratocytes • 378 crystallins • 537 radiation damage: light/UV