OPTIC NERVE COLOBOMA

Course overview

THE TERM COLOBOMA DERIVES FROM THE GREEK WORD KOLOBOMA, ORIGINALLY USED TO INDICATE A PART THAT WAS REMOVED BY MUTILATION, MISSING OR CUT SHORT. COLOBOMAS ARE CONGENITAL OCULAR DEFECTS THAT CAN AFFECT THE IRIS, THE LENS, THE CHOROID, THE RETINA, AND THE OPTIC NERVE. OPTIC NERVE COLOBOMAS HAVE BEEN ASSOCIATED WITH MICROPHTHALMOS, IRIS COLOBOMA, CILIARY COLOBOMA, LENS NOTCHING, RETINAL DETACHMENT, NEOVASCULAR MEMBRANES, AND MACULAR HOLES. OPTIC NERVE COLOBOMAS HAVE BEEN ASSOCIATED WITH MICROPHTHALMOS, IRIS COLOBOMA, CILIARY COLOBOMA, LENS NOTCHING, RETINAL DETACHMENT, NEOVASCULAR MEMBRANES, AND MACULAR HOLES. ON A TYPICAL FUNDUSCOPIC EXAM, CLINICIANS SEE LARGE OPTIC NERVE EXCAVATIONS USUALLY INFERIORLY. DEFECTS OCCUR BOTH UNILATERALLY AND BILATERALLY AT EQUAL RATES. PATIENTS MAY HAVE MICROPHTHALMIA OR OPTIC NERVE CYSTS THAT COMMUNICATE WITH THE SUBARACHNOID SPACE. CYSTS RARELY EXPAND TO CAUSE COMPRESSIVE OPTIC NEUROPATHY. OPTIC NERVE HYPOPLASIA IS A MORE COMMON CAUSE OF VISUAL IMPAIRMENT IN CHILDREN THAN OPTIC NERVE COLOBOMA. BILATERAL DISEASE IS MORE COMMON THAN UNILATERAL DISEASE. THE FORMER PRESENTS WITH NYSTAGMUS, WHEREAS THE LATTER PRESENTS WITH STRABISMUS. VISUAL ACUITY CAN RANGE FROM 20/20 TO NLP. ON EXAMINATION THE OPTIC NERVE IS SMALL.IRIS COLOBOMAS MAY CAUSE PHOTOPHOBIA, VISUAL DISTORTION AND DOUBLE VISION. THEY MAY ALSO BE COSMETICALLY UNACCEPTABLE. COSMETIC CONTACT LENSES WITH AN ARTIFICIAL PUPIL MAY BE USED. SURGICAL REPAIR OF THE DEFECT WITH SUTURES MAY BE POSSIBLE. ARTIFICIAL IRIS PROSTHETIC DEVICES ARE BEING EXPLORED IN THE PRESENCE OF PSEUDOPHAKIA. IRIS-PAINTED INTRAOCULAR LENSES MAY BE IMPLANTED AFTER REMOVAL OF THE CATARACT. FOLDABLE ARTIFICIAL IRISES MAY ALSO BE INSERTED THROUGH A SMALL INCISION. THIS ACTIVITY REVIEWS THE EVALUATION AND TREATMENT OF OPTIC NERVE COLOBOMA AND THE ROLE OF THE INTERPROFESSIONAL TEAM IN MANAGING THIS CONDITION.