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Show ' oumal of C1illical NClIro- ol'hthalmology 11( 3): 217- 219, 1991. Letters to the Editor Tonic Pupil and Czarnecki's Sign Following Third Nerve Palsy To the Editor: I was glad to see my case report in the Journal of Clinical Neuro- Ophthalmology ( 1991; 11( 2): 55- 6), but I was surprised to see the " Editorial Comment" that accompanied my article. I had no idea that this Comment was going to be published; none of the points in the Comment were raised in the editorial review of my paper; and I did not see or hear about the Comment before it appeared. It might have been more appropriate to publish Dr. Miller's comments as a letter to the editor, with a simultaneous reply from me addressing the points raised. If I had known about Dr. Miller's concerns about my paper, I could have added a sentence or two to the discussion to clarify some points in the case. For example, I might have pointed out that the pupillary measurements in the Table provide strong evidence for a tonic pupil. The response to near was actually better in the involved eye than in the normal eye. Like slow redilatation, this type of response is probably a manifestation of supersensitivity to endogenous acetylcholine ( 1,2). After instillation of weak pilocarpine, the involved pupil was smaller than the normal pupil; this response indicates a true pharmacologic supersensitivity of the pupillary sphincter. Therefore this patient had a defective light response, rewiring of the pupil by accommodative fibers, and supersensitivity to endogenous and exogenous acetylcholine. Dr. Miller ignored the above points and chose to concentrate on my statement that there was no noticeable tonicity of redilatation. I agree that tonic pupils should show tonic redilatation when the near response is present, particularly wh~ n mo~ e than a small portion of the pupillary sphmcter IS paretic, and I strongly believe that the data in my 217 ( i) 1991 Raven Press, Ltd., New York paper demonstrates that my patient had a tonic pupil. Using pupillography, Loewenfeld and Thompson ( 1) found that the delay in onset of redilatation after near effort was 0.3 seconds or less in 6 of 29 cases ( 20.7%); this interval would require ideal conditions in order to be seen clinically. They also found that the speed of redilatation varied considerably and was often in the normal range. Why didn't I see tonic redilatation? Because both pupils dilated slowly and the patient blinked a lot, and because I honestly could not say that the rate of redilatation was slower in the involved eye. I didn't say this in the paper because I wasn't asked. I did not intend to imply that clinicians should make a habit of diagnosing tonic pupils when there is no tonic redilatation, but when extenuating circumstances complicate the clinical evaluation of dynamic pupillary responses, the diagnosis of a tonic pupil can still be accomplished by looking for light- near dissociation associated with a segmental pupillary response to light, a response to near that is better in the involved than the normal eye ( in the absence of pupillary constriction on adduction), and true pharmacologic supersensitivity. I should add that the paper referred to in the Comment was published after my paper was submitted ( 3). Terry A. Cox, M. D. Department of Ophthalmology University of Utah Health Sciences Center Salt Lake City, Utah REFERENCES 1. Loewenfeld IE, Thompson HS. The tonic pupil: a reevaluation. Am I Ophthalmol 1967; 63: 46- 87. 2. Thompson HS, Hurwitz j, Czarnecki jSc. Aberrant regeneration and the tonic pupil. In: Glaser jS, ed. Neuroophthalmology, vol to. SI. Louis: CV Mosby, 1980, 100- 6. 3. Hawke SHB, Mullie MA, Hoyt WF, Hallinan jM, Halmagyi GM. Painful oculomotor nerve palsy due to dural- cavernous sinus shunt. Arch Neurol 1989; 46: 1252- 5. |