Tadpole Pupil: A Very Rare Entity
Fig. 2: Normal Shape of Left Pupil after an Episode.
in both eyes with normal pupillary reactions in light
and dark. Color vision, contrast, visual fields by
confrontation, extraocular movements were all normal.
Ophthalmic and neurologic examination was also
unremarkable.
pupil. Since its not known whether the tadpole pupil or
Horner syndrome precedes, the importance is to
diagnose such a rare case and exclude its associations
like Horner that can be life threatening. It points to the
significance of this case. As our patient had no
associations till now, we counseled her for the benign
nature with reinforcement of the regular follow-up.
10% Phenylephrine did not show any change in
pupil size. A diagnosis of left tadpole pupil was made
and patient was reassured about the benign nature of
her condition that was not associated with Horner’s
syndrome.
CONCLUSION
Since tadpole pupil itself is a benign condition but all
patients should be checked for Horner syndrome
because of its high association with it. This can save
the patient from life threatening condition associated
with Horner’s syndrome.
DISCUSSION
Most of the data available by Thompson, who
described 26 cases, reveals that tadpole pupil is usually
a spontaneous unilateral condition and the side and the
peaked iris segment of the pupil involvement can be
different at different times of episodes. Although most
cases have been found in young females for few
minutes and mostly without any systemic association
but Aggarwal et al described 2 year old girl with
tadpole pupil associated with congenital Horner
syndrome5. Similarly, Weir et al described 2 year old
boy with this pupillary abnormality during
uncomplicated strabismus surgery6. Hansen et al.
presented atypical case of a 12 year old girl who
developed tadpole pupil after physical exercise7.
Vijayaraghavan et al presented a case of 19-year old
boy who had bilateral tadpole pupil with reference to
seizures associated with hyponatremia8. The reason of
the tadpole pupil is not known but these atypical cases
suggest the presence of different pathophysiology.
Since tadpole pupil is frequently seen with Horner
syndrome3 as compared to the general population, it
may be because of denervation hypersensitivity of iris
dilator muscle. Lee et al9 excluded it by doing Horner
Syndrome by using phenylephrine test. We did the
same in our patient. Tadpole pupil is also found to be
associated with migraine and Adies pupil but that was
not the case with our patient. The iris dilator muscle is
the muscle that shows segmental spasm10 in tadpole
Conflict of Interest
Authors declared no conflict of interest.
Author’s Designation and Contribution
Royala Zaka; Ophthalmologist: Study design,
manuscript writing, literature review, critical review.
Muhammad Moez Uddin; Ophthalmologist: Study
design, literature review, critical review.
Zaki Uddin Ahmed Sabri; Ophthalmologist: Study
design, literature review, critical review.
Zunair Aziz; Ophthalmologist: Study design, literature
review, critical review.
REFERENCES
1. Erlenmeyer A. Beschreibung von periodischem
Auftreten einer wandernden Pupille. Berlin Klin Wschr.
1912; 49: 539-42.
2. Udry M, Kardon R, Sadun F, Kawasaki A. The
Tadpole Pupil: Case Series with Review of the
Literature and New Considerations. Front Neurol. 2019;
10: 846. Doi. Org/10.3389/Fneur.2019.00846.
3. Thompson HS, Zackon DH, Czarnecki JSC.
Tadpole-shaped pupils caused by segmental spasm of
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