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Dilution of Proparacaine in Balanced Salt Solution Reduces Pain of Anesthetic Instillation in the Eye

Author: Brady MD; Hustead RR; RobinsonRH; Becker KE Jr, Department of Anesthesiology, University of Kansas School of Medicine-Wichita 67214

Publication: Reg Anesth 1994 May-Jun;19(3):196-8

BACKGROUND AND OBJECTIVES: Proparacine (P), 0.5%, is often applied topically to the eye to diminish the pain of injection of anesthetic for eye surgery; however, application of 0.5% P itself can cause some degree of discomfort. This study evaluated the use of balanced salt solution to dilute P before instillation in the eye to prevent discomfort.

METHODS: In a double-blinded manner, 42 consenting adults about to undergo cataract surgery were given 0.5% P in one eye and 0.03% P in the other eye. One minute later the same solutions were instilled into each eye. Ten minutes later, 0.5% P was instilled into both eyes. After each instillation the patients were asked to describe the pain in each eye on a 0 to 10 scale.

RESULTS: Those receiving 0.5% as the first drop had a mean score of 1.28, which was greater than the score of 0.09 for the 0.03% P group (P<.01). No one reported pain after the second drop was applied 1 minute later. After receiving 0.5% P 10 minutes later, the group that received 0.5% P reported a mean pain score of 0.09 while those who had received 0.03% P reported a score of 0.76, which was significantly greater than that reported by the 0.5% P group after the 10 minute instillation (P<.01) but significantly lower than the score reported after the first instillation of 0.5% P (P<.05). CONCLUSIONS: Dilution of P in balanced salt solution to a concentration of 0.03% produces a solution that is significantly less painful than 0.5% P and reduces the discomfort of the instillation of 0.5% P.

While beginning to wear contact lenses, I had an experience which the use of the Morgan Lens saved the day.


I was just finishing a sixteen-hour shift as manager and staff nurse of the ED when I was notified that they had received a bomb threat.  Disaster situation were part of my duties, so I went into action.  By 4:00 AM, I realized I still had my contacts in.  So I got a container and soaked them in an eye solution from our eye tray.  I arrived home with enough time to take a quick nap before returning to work for another sixteen-hour shift.  When I put my contacts in, I felt like someone had placed a hot poker into my eyes.  I took the contacts out, but my eyes continued to burn and were also fire engine red.  I did report to work at 7:00 AM but my eyes continued to burn.  I then decided the best thing I could do was to irrigate, so I placed a Morgan lens into both eyes and irrigated with 1000 cc of lactated Ringer's.  Laying down during the irrigation process was relaxing and I felt no discomfort while my eyes were irrigated.  After the process, the burning was relieved and I was able to complete my shift without further discomfort.

Registered Nurse (South Carolina)

MorTan Inc.

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Why Use The Morgan Lens?

The Morgan Lens is used in 90% of hospital emergency departments in the USA and can be inserted in less than 20 seconds. There simply is no other "hands-free" method of eye irrigation. Nothing else frees medical personnel to treat other injuries or to transport the patient while irrigation is underway. Nothing is more effective at treating ocular chemical, thermal, and actinic burns or removing non-embedded foreign bodies, even when the patient's eyes are closed tightly. Its design makes it simple and straightforward to use so minimal training is required.