Effect of Some Drugs on Intraocular Pressure in Normal and Induced Ocular Hypertensive Rabbits

number: 
1448
إنجليزية
department: 
Degree: 
Imprint: 
Medicine
Author: 
Bahaa Ameen Abdul-Hussein
Supervisor: 
Dr. Adeeb Ahmed Al-Zubaidy
year: 
2006

Abstract:

Glaucoma is a multifactorial disease involving progressive optic neuropathy and altered intraocular hemodynamics; furthermore, glaucoma can cause blindness if it is left untreated. Glaucoma is a very misunderstood disease. Often, people don’t realize the severity or who is affected. Aim of the study
To explore effects of topical carvedilol, diltiazem and nifedipine on IOP of normal rabbits' eye. To evaluate the possible beneficial effects of topically applied various doses of carvedilol, diltiazem and nifedipine on IOP values of experimentally induced ocular hypertension in rabbits. To explore the possible local adverse effects of the tested drugs . Materials and methods A group of 108 males of the rabbits were included in the present study. Induction of ocular hypertension was achieved by injection of (0.4 ml) of (2% w/v) hydroxy propyl methylcellulose in the anterior chamber of rabbits right eye. In addition to distilled water (as negative control), each of timolol (as positive control) and carvedilol, diltiazem and nifedipine (the tested drugs) (0.5%) eye drops were instilled 3 times daily to right eye prophylactically for 4 days and therapeutically for further 10 days (part Ι). Part ΙΙ of the present study involved evaluation of the same drugs in two concentrations (0.5% and 0.25%) 3 times daily but only after the disease being induced (i.e. therapeutically). The parameters which had been frequently detected in both left and right eyes were: intra ocular pressure, pupil diameter, light reflex, corneal reflex and conjunctival redness. Results Part Ι: Carvedilol (0.5%) caused highly significant (P < 0.01) reduction in intraocular pressure of right eye on 4th day prior the induction of the disease and 10th day after its induction. Both diltiazem and nifedipine (0.5%) simulated that of carvedilol (0.5%) at 4th day prior the induction of ocular hypertension; at 10th day post induction, each of them caused a significant reduction (0.01

significantly (P> 0.05) the mean pupil diameter, and couldn't induce any significant adverse effect (P > 0.05) (i.e., regarding light reflex, corneal reflex and conjunctival redness) during trial period. Conclusions Each of carvedilol, diltiazem and nifedipine exerted a detectable ocular hypotensive effect on the normal eye of rabbits when applied at concentration (0.5%) or (0.25%) 3 times daily. Each of these topical tested agents at concentration (0.5%) 3 times daily for 4 days could prevent the development of ocular hypertension in
spite of administration of the inducing agent (hydroxypropyl methylcellulose) and maintained IOP normal if their administration continued for further 10 days. Each of these topical tested agents at concentration (0.5%) or (0.25%) 3 times daily for 10 days had a beneficial ocular hypotensive effect on hydroxy propyl methyl cellulose-induced ocular hypertension in rabbits.