NOTES, CASES, INSTRUMENTS T H E USE OF NAPHTHOCAINE

AS A LOCAL ANESTHETIC IN OPHTHALMOLOGY

ROY ALLEN STEWART, M.D.* Baltimore

Naphthocaine1'2 is the mono-hydrochlo-ride of beta-diethylaminoethyl ester of 4-amino-1-naphthoic acid. Its structural formula is as follows:

O /

QH6

—C—OCH2CH2N—HC1

CjH6

-NH,

It is a yellowish crystalline material soluble up to 2 percent in distilled water, making a clear pale-yellow solution with a pH of about 4.4. The solutions used for this clinical study contained sodium bi­sulfite, chloretone, and adrenalin 1:50,000; the naphthocaine* was 0.2-per­cent, 0.3-percent, and 1.0-percent. The 0.3-percent and 1.0-percent solutions were superior in their anesthetic properties to the 0.2-percent solution, but even the 0.2-percent solution was superior to pro-

* From the Baltimore Eye, Ear, and Throat Hospital.

t The naphthocaine was supplied by courtesy of Parke, Davis, and Co.

caine. I could not discern any difference in the anesthetic properties between 0.3-percent naphthocaine and 1.0-percent naphthocaine.

When 4-percent cocaine instillations and 5.0 c.c. of 2-percent procaine injec­tions are used as a local anesthetic in intraocular surgery there appear to be definite disadvantages. When the su-perior-rectus suture is placed the patient usually has a definite pain. Likewise there is pain when an iridectomy is performed. Akinesia is often faulty. Postoperatively, the patient often has pain in the eye that has been operated on within a few hours or less time.

When 4-percent cocaine instillations and 5.0 c.c. of 0.3-percent naphthocaine injections are used in intraocular surgery there is usually no pain when the superior-rectus suture is placed, and no pain when an iridectomy is done. Akinesia is really excellent. The average length of time be­fore postoperative pain begins is 8 to 10 hours.

At the Baltimore Eye, Ear, and Throat Hospital we have made a clinical study of naphthocaine as a local anesthetic in oph­thalmology. The following list of opera­tions under this anesthetic have been per­formed :

Number of Cases

Amount Injected Instillations

Intracapsular cataract extraction Iridectomy Iridencleisis Lagrange anterior sclerectomy Posterior sclerotomy Walker operation for retinal detachment Enucleation Suture of lacerated lids Lacrimal probing Reese resection and Jameson recession Curretment of chalazia Conjunctival plastic for symblepharon Kuhnt-Szymanowski operation for ectropion

20 1 3

IS

c.c. 5.0 5.0 5.0 5.0 1.0 8.0 8.0 5.0 1.0 5.0 0.5 2.0

13.0

4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 4% cocaine 0.5% pontocaine 0.5% pontocaine 0.5% pontocaine

178

NOTES, CASES, INSTRUMENTS 179

The striking features of local anesthesia with naphthocaine are its immediate anes­thetic effect after injection, the excellent akinesia, the real anesthesia during the operation, and the long duration of the anesthesia. The Walker operation is a real test of a local anesthetic. In the two cases reported the patients complained of no pain during the operation and required only codeine 0.5 gr. and 10 gr. of acetyl-salicylic acid 10 hours postoperatively. When this procedure was carried out with procaine the patient was rather uncom­fortable and the postoperative pain some­what severe.

Although naphthocaine works best when injected it has a good anesthetic ef­fect upon instillation, and corneal foreign

NOMINAL DUCTION AND TRUE DUCTION POWER

JOSEPH I. PASCAL, M.D. New York

One of the striking points in Abraham's article on "Near horizontal phoria and duction tests" in the March, 1943, issue of the American Journal of Ophthalmology is the wide discrepancy in the adduction-abduction ratio at near in the normal group as found by him and as found by Berens et al. in their investigation. The latter found a ratio of practically 2:1 of' adduction to abduction, while Abraham found a ratio of practically 1:1. However, these results may not be so far apart as

bodies can be removed, tonometry and other minor procedures can be effected without pain to the patient. When naph­thocaine is injected into the lacrimal sac by way of the canaliculus, lacrimal prob­ing can be done with very little discom­fort to the patient. In the cases reported no patient developed toxic symptoms,3"5

nor any appreciable change in pulse, res­piration, or blood pressure. The Nose and Throat Department has used 30.0 c.c. of naphthocaine for injection many times and there has been no reaction to the drug.

From this small experience with naph­thocaine it would seem to be the best drug for obtaining local anesthesia in ophthal­mology.

5802 Edmondson Avenue.

they seem if we take into consideration the difference between nominal ductions and true ductions. Nominal ductions refer to the amount of prism power, base out or base in, overcome without reference to an existing phoria; true ductions refer to the amount of prism power, base out or base in, overcome but with reference to an existing phoria. True duction power measures what has been called breadth of fusion and refers to a forced movement of the eyes inward or outward in order to maintain or regain single binocular vision.

To take case 1, table 1, as an instance. This patient had 6 delta of exophoria (I prefer the short term delta to the clumsy term prism-diopter). The nominal abduc-

REFERENCES 1 Blicke, F. F., and Parke, H. C. Alkylaminoalkyl esters of aminonaphthoic acids as local an­

esthetics. Jour. Amer. Chem. Soc, 1939, v. 61, p. 1200. Jour. Amer. Chem. Soc, 1940, v. 62, Dec, p. 3316

2 Rowe. L. W. Local anesthetic action of some aminonaphthoic acid esters. Jour. Amer. Pharm. Assoc, 1940, v. 29, June, p. 241.

3 Haury, V. G., Gruber, C. M., and Drake, M. E. The toxicity, anesthetic potency, and some pharmacological actions of a new local anesthetic beta-diethylaminoethyl ester of 4-amino-l-naphthoic acid (naphthocaine). Jour. Pharm. Exp. Therap., 1940, v. 70, Nov., p. 315.

* Rose. Anesth. and Analg., 1931, v. 10, p. 1S9. 5 Mclntyre and Sievers. Jour. Pharm. Exp. Therap., 1937, v. 61, p. 107.