Macrophthalmos



Macrophthalmos


Bernadette L. Koch, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Staphyloma


  • Neurofibromatosis Type 1


Less Common



  • Acquired Glaucoma


  • Congenital Glaucoma


Rare but Important



  • Congenital Myopia


  • Sturge-Weber Syndrome


  • Congenital Cystic Eye


  • Coloboma with Macrophthalmia


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Elongated globe in anteroposterior (AP) dimension may be secondary to myopia, staphyloma, or coloboma


  • Diffuse enlargement of globe in AP and transverse dimension = buphthalmos (“ox eye” or “cow eye”)



    • Buphthalmos may be present in congenital glaucoma, neurofibromatosis type 1 (NF1), Sturge-Weber, acquired glaucoma


Helpful Clues for Common Diagnoses



  • Staphyloma



    • Key facts



      • Thinning and stretching of scleral-uveal layers of globe


      • Progressive myopia (nearsightedness) results in posterior staphyloma


      • Posterior staphyloma may also occur in glaucoma, connective tissue disorders, scleritis, necrotizing infection, or trauma


      • Anterior staphyloma may occur if infection or inflammation image corneal thinning


    • Imaging



      • Elongated globe, thinning of posterior wall, unilateral or bilateral


  • Neurofibromatosis Type 1



    • Key facts



      • Congenital neurocutaneous syndrome


      • Mutation of gene on chromosome 17


      • Orbitofacial abnormalities in NF1 typically unilateral


      • Plexiform neurofibroma (PNF) diagnostic


      • Up to 50% with facial and eyelid involvement have ipsilateral glaucoma


    • Imaging



      • Buphthalmos


      • Thickening of uveal and scleral layer; anterior rim enlargement


      • PNF orbit and skull base + sphenoid bony dysplasia image enlargement of orbital foramina and middle cranial fossa image herniation of intracranial contents into orbit image pulsatile exophthalmos


      • ± enlargement, tortuosity, and enhancement of optic nerve glioma


Helpful Clues for Less Common Diagnoses



  • Acquired Glaucoma



    • Key facts



      • Leading cause of blindness in African-Americans and 2nd leading cause of blindness worldwide


      • > 4,000,000 Americans have glaucoma; only 1/2 know they have it


      • Risk factors: African-American, > 60 years, family member with glaucoma, Hispanic, Asian, high myopia, diabetes mellitus, hypertension, trauma


      • Primary open angle > > angle closure


      • Diagnosis by tonometry (measures intraocular pressure), ophthalmoscopy (may show evidence of optic nerve atrophy), visual field tests (lose peripheral vision 1st), or gonioscopy (measure angle between iris and cornea)


    • Imaging



      • Less plasticity in globe of adults; therefore buphthalmos and deep anterior chamber uncommon


  • Congenital Glaucoma



    • Key facts



      • Incidence 1:5,000-1:10,000 live births; boys > > girls; bilateral in majority


      • Present at birth; usually diagnosed within 1st year of life


      • Clinical: Large eyes, excessive tearing, cloudy cornea, and light sensitivity


      • Obstruction to flow of aqueous humor from anterior chamber image elevated intraocular pressure, enlargement of globe and deep anterior chamber


      • Normal mean anterior chamber depth: 3 mm; in congenital glaucoma, mean anterior chamber depth: 6.3 mm



      • Complications: Subluxated lens, optic nerve atrophy


    • Imaging



      • Enlarged AP dimension of globe


      • Deep anterior chamber


Helpful Clues for Rare Diagnoses

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Aug 10, 2016 | Posted by in PEDIATRICS | Comments Off on Macrophthalmos

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