Clinical Image
J Ophthalmol & Vis Sci. 2021; 6(4): 1060.
Keyhole Pupil
Taouri N*, Tagmouti A, Sefrioui M, Amazouzi A, Boutimzin N and Cherkaoui LO
Mohammed V University Souissi, Department A of Ophthalmology, Rabat, Morocco
*Corresponding author: Taouri N, Mohammed V University Souissi, Department A of Ophthalmology, Rabat, Morocco
Received: November 15, 2021; Accepted: December 02, 2021; Published: December 09, 2021
Abstract
Iris coloboma is a cleft caused by defects in the closure of embryonic fissure, typically, it affects the tissue in the inferonasal quadrant of the eye.
We report a case of a 15 years old patient with a typical aspect of “keyhole pupil” which corresponds to inferonasal deficit of the iris tissue.
Keywords: Coloboma; Iris; Keyhole pupil
Clinical Image
We report a case of a 15 years old patient with no significant medical history. The ophthalmological examination with slit lamp examination with diffuse illumination of the pupillary space revealed a typical aspect of “keyhole pupil” which corresponds to inferonasal deficit of the iris tissue (Figure 1). The rest of the ophthalmological examination did not find any involvement of the lens or the posterior pole. There were no ocular or systemic abnormalities or associated family history. The diagnosis was an isolated iris coloboma.
Figure 1: Slit lamp examination of a patient with a typical appearance of iris
coloboma: “keyhole pupil”.
Several authors have reported that iris coloboma is a cleft caused by defects in the closure of embryonic fissure which may occur during the fifth week of gestation; which can be unilateral or bilateral. Typically, it affects the tissue in the inferonasal quadrant of the eye [1,2]. Colobomas in other quadrants are atypical and the embryological basis of these is unclear [2,3].
Previous studies have reported that iris coloboma can be either isolated or associated with colobomas of the lens, the retina, the choroid or the optic nerve, and it can be seen unilaterally or in both eyes. Also microphthalmia, cataract and strabismus can accompany these cases [1,4].
Gregory-Evans, Williams, Halford and al have reported in there review that different degrees of iris coloboma can be found:
A full iris coloboma: involves of the pigment epithelium and the stroma giving to the pupil a typical «keyhole» appearance. Also it can concern only the pupillary margin giving an oval pupil, and sometimes the coloboma affects exclusively the pigment epithelium of the iris and can only be seen by transillumination [5].
References
- Uhumwangho OM, Jalali S. Chorioretinal coloboma in a paediatric population. Eye. 2014; 28: 728-733.
- Jain AM, Ranjan R, Manayath GJ. Atypical superior iris and retinochoroidal coloboma. Indian J Ophthalmol. 2018; 66: 1474-1475.
- Litwin AS, Hakim J. Unusual chorioretinal defects. Eye. 2007; 21: 879-880.
- Chang L, Blain D, Bertuzzi S, Brooks BP. Uveal coloboma: clinical and basic science update. Curr Opin Ophthalmol. 2006; 17: 447-470.
- CY Gregory-Evans, MJ Williams, S Halford, K Gregory-Evans. Ocular coloboma: a reassessment in the age of molecular neuroscience. J Med Genet. 2004; 41: 881-891.
Download PDF