STUDY OF EFFECT OF ADRENALINE ON RABBIT EYES

Learn (pharmacology practical experiment)

THEORY:-

1.Adrenergic receptor activation:-

Adrenaline binds to adrenergic receptors (α1, α2, β1, β2) in the eye, specifically in the iris dilator muscle, ciliary muscle, and conjunctiva.

2.Intraocular Pressure (IOP):-

The pressure inside the eye measured in millimeters of mercury (mmHg).

3.Increased IOP:-

An elevation of IOP above the normal range, which can be caused by various factors such as glaucoma, uveitis, or eye trauma.

4.Ocular Tension:-

The pressure inside the eye often used interchangeably with IOP.

Causes of Increased IOP:

1.Glaucoma:-

The most common cause of increased IOP.

2.Uveitis:- 

Inflammation of the uvea which can increase IOP.

3.Eye Trauma:-

 Trauma to the eye can increase IOP.

4.Steroid-Induced Glaucoma:-

Prolonged use of steroids can increase IOP.

5.Other Medical Conditions:-

Certain medical conditions such as diabetes, hypertension, and thyroid disorders can increase IOP.

Symptoms of Increased IOP:

1.Vision Loss:-

Gradual or sudden vision loss.

2.Eye Pain:-

Pain or discomfort in the eye.

3.Redness:-

Redness or inflammation of the eye.

4.Blurred Vision:-

Blurred or distorted vision.

4.Vasoconstriction:-

 Adrenaline causes vasoconstriction of the blood vessels in the eye, leading to decreased blood flow.

ONSET OF ACTION:-

                              * Very rapid 

DURATION OF ACTION:-

                                  * 5-10 minutes

Effects on Rabbit Eyes:-

When applied topically to the eyes of rabbits, adrenaline produces the following effects:

1.Mydriasis:-

 Adrenaline causes rapid dilation of the pupil.

2.Cycloplegia:-

Adrenaline relaxes the ciliary muscle leading to a loss of accommodation.

3.Increased IOP:-

Adrenaline can increase IOP which can be a concern in rabbits with pre-existing glaucoma.

Materials:-

- Rabbits (healthy, adult)

- Adrenaline solution (1:1000 or 1:10,000)

- Topical anesthetic 

- Eye drops or ointment

- Observational equipment

Preparation:-

1.Acclimatization:-

 Acclimatize the rabbits to the experimental environment for at least 30 minutes before the start of the experiment.

2.Baseline measurements:-

Measure the baseline pupil diameter, intraocular pressure (IOP), and other relevant parameters before administering adrenaline.

Procedure:-

4.Adrenaline administration:- 

Administer a single drop of adrenaline solution (1:1000 or 1:10,000) to one eye of each rabbit.

5.Observations:-

 Observe the rabbits for the following parameters:

    - Pupil diameter 

    - IOP 

    - Conjunctival vasculature 

    - Behavioral changes 

6.Time course:-

Record the observations at regular time intervals (e.g., 5, 15, 30, 60 minutes) after adrenaline administration.

7.Data analysis:-

Analyze the data to determine the effects of adrenaline on the eye.

CLINICAL IMPORTANCE:-

                                                                         Understanding the effects of adrenaline on rabbit eyes has important implications for human ophthalmology.

EYE INJURY:-

                                    Adrenaline can be used to reduce bleeding and inflammation in the eye after an injury.

SURGICAL METHOD:-

                                                             Adrenaline can be used to constrict blood vessels and reduce bleeding during eye surgery.                                       

PRECAUTIONS:-

Animal Welfare:-

1. Ensure proper anesthesia and pain management.

2. Monitor rabbits for signs of stress or discomfort.

Drug Administration:-

1. Use sterile adrenaline solution to avoid contamination.

2. Administer adrenaline in a well-ventilated area.

3. Avoid touching the eye or surrounding area to prevent contamination.

Measurement Precautions:-

1. Calibrate tonometers and other measurement devices regularly.

2. Use proper techniques for measuring IOP pupil diameter and aqueous humor outflow.

3. Avoid touching the cornea or conjunctiva during measurements.

Adrenaline-Specific Precautions:-

1. Wear protective gloves and eyewear when handling adrenaline as it can cause skin and eye irritation.

2. Avoid accidental exposure to adrenaline as it can cause systemic adrenergic effects.

3. Ensure proper disposal of adrenaline-containing waste materials.

General Precautions:-

1. Follow institutional guidelines for animal research.

2. Ensure proper ventilation in the laboratory to prevent accumulation of adrenaline fumes.

3. Keep adrenaline solutions away from children and pets.

                        * Use healthy rabbit and handle carefully

USES:-

1.Mydriasis induction:-

Adrenaline can induce mydriasis (pupil dilation) which is useful for ophthalmic examinations and research studies.

2. Intraocular pressure reduction:-

 Adrenaline can decrease intraocular pressure (IOP) making it a potential treatment for glaucoma.

3.Ocular pharmacology research:-

Adrenaline is used as a tool to study the pharmacology of the eye and develop new ophthalmic drugs.

4.Glaucoma research:-

Adrenaline is used to study the pathophysiology of glaucoma and develop new treatments for the disease.

5.Ophthalmic surgery:-

Adrenaline can be used to induce mydriasis during ophthalmic surgery, improving visualization of the surgical site.

6.Diagnostic testing:- 

Adrenaline can be used as a diagnostic tool to assess the function of the autonomic nervous system in the eye.

7.Treatment of ocular emergencies:-

 Adrenaline can be used to treat ocular emergencies such as acute angle closure glaucoma.

             * Adrenaline is used in emergency to treat serious allergic reactions

             * 2% solution of adrenaline used topically to reduce intra ocular pressure.

RESULTS:-

                  * Relaxation of pupil occur after applying this drug

                  * light and corneal reflex present after applying it