Background: A colobomatous cyst has a neuroectodermal origin and results from an incomplete closure of the optic nerve fissure during eye development. It is typically accompanied by microphthalmia and can occasionally cause distention of the lower eyelid. It is relatively commonly detected during childhood.
Case presentation: A 59-year-old female patient had poor left visual acuity during childhood; however, she had not undergone any detailed testing. Left corneal opacity and ocular pain had appeared approximately 1 year ago. She was referred to our department after diagnostic imaging, performed by her local physician, revealed a left orbital tumor. At the initial examination, her visual acuity was 1.2 in the right eye, whereas her left eye could not perceive light. No findings of note were observed in the right eye except for a mild cataract. Anterior chamber and ocular fundus transparency were poor in the left eye due to corneal opacity. Contrast-enhanced magnetic resonance imaging revealed a diverticular structure connected to the vitreous cavity behind the left eye. The optic nerve was connected to the cyst. Diagnostic imaging suggested that it was a colobomatous cyst. Because the ocular pain worsened, enucleation of the left eye was performed. The ocular pain disappeared postoperatively. Histopathological testing revealed that the cyst comprised an inner layer of retinal tissue and an outer layer of collagenous fibers connected to the sclera. Therefore, it was diagnosed as a colobomatous cyst. Because there were findings suggestive of rubeosis iridis and persistent hyperplastic primary vitreous in the eye, the cyst appeared to be the cause of corneal opacity and vitreous body hemorrhage, whereas an increased ocular pressure due to secondary glaucoma appeared to be the cause of the ocular pain.
Conclusions: We treated a patient with a colobomatous cyst that remained undiagnosed over a long term and was eventually detected due to unilateral corneal opacity and ocular pain. Our findings suggested that when a colobomatous cyst is not treated on time, it eventually causes corneal opacity and ocular pain.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 123: 39-44, 2019.