How do you apply eye drops to a rat? - briefly
Restrain the animal gently, hold the eyelid open with a sterile forceps or fingertip, and place a calibrated drop of the solution onto the corneal surface, avoiding contact with the eye or fur; release the eyelid and allow the rat to blink naturally to distribute the medication.
How do you apply eye drops to a rat? - in detail
Administering ocular medication to a laboratory rat requires preparation, restraint, and precise delivery to ensure the dose reaches the corneal surface without causing injury.
First, gather all materials: sterile eye‑dropper or micropipette calibrated to the required volume (typically 1–2 µL per eye), the specific ophthalmic solution, sterile gauze, disposable gloves, and an appropriate restraining device such as a transparent tube or a soft cloth wrap. Verify that the solution is at room temperature to avoid corneal shock.
Second, acclimate the animal to the handling environment for several minutes. Place the rat on a clean, non‑slippery surface and allow it to settle. Apply gentle pressure with a thumb and forefinger on the dorsal neck to immobilize the head while keeping the body supported. Some researchers prefer a brief isoflurane induction (<2 minutes) to reduce movement; if used, maintain a light plane of anesthesia and monitor respiration.
Third, position the eye. Using a fine forceps or a gloved finger, pull the upper eyelid gently upward and the lower eyelid downward to create a small pocket. Avoid excessive force that could damage the eyelid margin or cornea.
Fourth, deliver the drop. Hold the calibrated pipette or dropper just above the ocular surface, allowing the droplet to fall into the conjunctival sac. Do not touch the tip to the eye or surrounding fur to prevent contamination. After the drop is placed, release the eyelids and keep the rat’s head steady for 10–15 seconds to permit absorption and to prevent immediate blinking or tearing.
Fifth, repeat the procedure for the opposite eye if required, using a fresh portion of the solution to maintain sterility. Dispose of used gauze and gloves according to biosafety protocols, and record the administered volume, time, and any observable reactions (e.g., lacrimation, redness).
Finally, observe the animal for at least five minutes post‑administration. Look for signs of distress, excessive tearing, or ocular irritation. If adverse effects appear, consult veterinary staff immediately. Proper documentation and adherence to institutional animal‑care guidelines ensure reproducibility and welfare throughout the experiment.