A rare case of congenital pupillary abnormality: a case report

Congenital anomalies of the pupil are quite varied, including abnormal size, shape, color, response to stimulus, and function. We are here reporting an unusual case presented with the absence of pupillary opening with folds of iris tissue at the center. Only an extremely small pupil (diameter < 0.5 mm) could be observed during the operation.

A 15-year-old male patient visited our outpatient clinic due to vision difficulty in his right eye for more than ten years. The best-corrected visual acuity was 2.0 logMAR and 0 logMAR for the right and left eye, respectively. There were amblyopia, astigmatism and constant exotropia in his right eye. Ophthalmic examination of the right eye showed flat iris root, minimal iris pigmentation, and the pupil area was entirely covered by iris tissue. Lens status and fundus evaluation could not be commented. The left eye was found to be within normal limit. Based on ophthalmic examination, the admission diagnosis was given as acorea. Pupilloplasty was performed on the right eye due to the situation that the iris tissue blocked the visual axis, which led to visual impairment and stimulus deprivation amblyopia. However, an extremely small pupil at the center of his pupillary area was observed during the operation. The postoperative course was favorable, and a normal pupil was secured. Hospital discharge diagnosis was given as microcoria, and amblyopia treatment was followed.

We report a rare case of congenital pupillary abnormality. The further diagnosis was given as microcoria, which should be differentiated from acorea. For this kind of pupil disorder which blocks the visual axis, early diagnosis and treatment can help prevent the development of stimulus deprivation amblyopia.